- test-drb@ccmp.vtda.org - classiccmp.org

by vcf＠siconic.com

http://www.affordablesurplus.com/floppy_drives_main.asp Plus other semi-useful PC/Apple stuff. -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

21 years, 5 months

1
0
0 0

8" drive support on PC's

by dwight.elvey＠amd.com

>From: "Randy McLaughlin" <cctalk at randy482.com> ---snip--- > >Today density select is a general purpose IO pin, originally the 765 used >the direction pin as a dual purpose pin. > >This dual purpose description is now gone but maybe not the action. > >There is no need for TG43 in todays PC's, at least not as far as the >manufacturers are concerned. When the need for a "new" density select line >came it was accomplished through a separate IO but was the old reduced >current logic removed? > Hi Randy That is a good question? I would guess that it went the way of the FM ability. When they were looking for things to cut, a magnitude comparitor would have sticked out like a sore thumb. Dwight

21 years, 5 months

2
1
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Media Longitevity/Care

by Saquinn624＠aol.com

Coming in on this a little bit late, but if you haven't checked out the Library of Congress you should. www.loc.gov/preserv gives you a basic run down of ways to care for archived materials, and the NIST/CLIR puts out Special Publication 500-252 "Care and Handling of CDs and DVDs - A Guide for Librarians and Archivists" (e-version available). Other tips- gold disks, AZO dye are reputed to last longer. The phenomenon of failure from the outside in has interesting possibilities- have software write a known pattern in the outermost section of the disc and pop up a warning when it starts to deteriorate. Hopefully this would give enough time to move data to another disk. - Scott Quinn

21 years, 5 months

5
8
0 0

PerSci 277 floppy drives

by doc＠mdrconsult.com

I just received a pair of PerSci 8" floppy drives, with a PerSci 1070 S-100 controller (and a mountain of docs, including data sheets, sales literature, and schematics). Unfortunately, I won't have an S-100 system for a few more weeks. It's stuck in Arizona till I get out there to ship it. The question is, is this one of the drives that plays nicely with a PC FDC? I have a couple of older ISA IDE/FD controllers, and an Adaptec 1542 if I can dig it up. That would still entail getting one of the DBit cable adapters, but it would nicely solve the issue of an enclosure and PSU for this YE-Data YD-180. When I get a hance to make a detailed list of this documentation, I'll post it. I think that most of it's already out there, though. Doc

21 years, 5 months

5
17
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Slightly OT ceramic caps - not in DECs

by dwight.elvey＠amd.com

>From: "Geoffrey Thomas" <geoffreythomas at onetel.com> ---snip--- > >That is not quite as unusual for monolithic caps of that vintage. What you >are seeing is silver dendrite growth through cracks in ceramic. ---snip--- Hi This seems to be worse on the glass encapulated, "Mil Spec" capacitors. I've replaced quite a few of these. Many more than the older disc and epoxy ones. In pinball machines, failed disc caps are quite common on the switch sense lines. So, it seems that this is a common source of failure. Dwight

21 years, 5 months

1
0
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Age

by pete＠dunnington.u-net.com

On Mar 13 2005, 20:00, Nico de Jong wrote: > 55 listmembers have answered. I was going to send a reply, but it got a bit long, and the gremlins ate it while I left it lying around to be edited. +1 to the "50-54" category. -- Pete Peter Turnbull Network Manager University of York

21 years, 5 months

9
10
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8" drive support on PC's

by pete＠dunnington.u-net.com

On Mar 17 2005, 16:04, Randy McLaughlin wrote: > There is confusion over pin 2 use at least in my head. The first use was > with the SA800 interface for reduced write current. Today on the 34 pin > connector that is what it is now used for even for 3.5" drives. > Traditionally the write current line was used completely differently from > how it is used today. Traditionally it changed according to where on the > disk the data is being written, for today's drives it is for the entire > media. Yes, that's right. > That is a side issue to my question about 765 TG43 controls. > > On a real 765 it generates the reduced write signal and outputs it on the > same controller pin as the direction signal. > > Today the 765 is emulated via VHDL code and I am curious as to whether the > TG43 logic was kept. I can and will experiment on my systems but I would > like to know if others are familiar with the issue. > > Obviously all PC's that use a real 765/8272 does generate the signal and > does bring it out to the 34 pin connector, it just happened to be hidden on > pin 18. I question if it is still there? Well, I looked at the data sheet for the WD37C65, which used to be fairly common, and the answer is "sort of". Pin 39 is the one that you'd be interested in. It's an output labelled "/RWC,/RPM" and when it's low, and the controller is in Base Mode, it says it causes a reduced write current when bit density is increased towards the inner tracks, being active when track > 28 (I think that refers to 40-track drives, which would be 56 on an 80-track drive). This is very similar to to the TG43 signal, except for being relative to a different track, but it's not on the same pin as /DIRECTION (Pin 31). I can't help wondering if "28" is a misprint for "23" or something like that, but I checked two separate printings of the data sheet and both said "28". It also says this function changes when in AT/EISA mode (it then becomes completely under program control, and appears to be intended to be used to set the density and/or speed for the whole disk) :-( However, if you have control over the FDC rather than letting the BIOS or DOS do it for you, you could make it do what you wanted. I also looked at the Intel 82078 FDC, which is a successor to the 8272, in either a 64-pin QFP package or a 44-pin PLCC, either 5V or 3.3V,. and it was an antecedent of many of the multi-I/O chips. Unfortunately it doesn't give enough detail. Lastly, I looked at the NatSemi DP8473. It has /DIRECTION on pin 4 (PLCC version), and /LC (low current) on pin 51. Pin 51 just goes high for HD media and low for SD/DD media (actually it goes low when 250kbps or 300kbps data rates are set, instead of 500kbps). So it doesn't look like that does what you'd want, either. -- Pete Peter Turnbull Network Manager University of York

21 years, 5 months

2
1
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TU56/TC11 restoration - VARIAC question

by dvcorbin＠optonline.net

> I do not own a variac, so I will need to get one of these to > properly reform the TU56 capacitors. I see several different > varietieson eBay. What would I need exactly? > For re-forming the cap'sin my unit, my plan is to (hopefully this weekend), disconnect the screw terminals and use a programmable power supply [DC] applied direcly to the terminals. Current will be limited and the voltage slowly increased. If I can get the lab computer working, then it will be a nice slow smooth increase over a 12-24hr period. If I resort to adjusting the supplies manually I will end up making larger steps and watching the current..not as clean but still better than a full "bang".

21 years, 5 months

2
1
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Fwd: Used IBM equipment in Green Bay, WI USA

by jfoust＠threedee.com

>Subject: Used IBM equipment in Green Bay >Date: Thu, 17 Mar 2005 16:43:34 -0500 >From: "Justin Nemeth" <Jnemeth at EPLUS.com> >To: <jfoust at threedee.com> > >John, >I have a customer in Green Bay looking to get sell, scrap, get rid of the following equipment I think they are fairly large boxes.. > >Let me know whether or not your interested > >Thanks > >Regards, >Justin Nemeth >ePlus Group, Inc. (Midwest) >Ph:630-790-2203 > > >Equipment: >IBM 3745-210 Communication Controller -- > with the following features: > (8) 1561 - Channel Adapters > (2) 4720 - Low Speed Scanner > (1) 4770 - Token-Ring Adapter Type 2 > (1) 4900 - Lic Unit > (6) 4911 - Lic Type 1 > (5) 4931 - Lic Type 3 > (1) 7100 - Storage Incement 4 MB > (2) 9720 - Basic Low speed Scanner > (1) 9763 - Tsst Board With Tra Option > (8) 9911 - Basic Lic Type 1 > > Approximate Date Available - April 2005 > > (2) IBM 9393-T82 Virtual Array Units > (1) 9393-X82 Virtual Array Unit > >

21 years, 5 months

1
0
0 0

8" drive support on PC's

by dwight.elvey＠amd.com

>From: "Randy McLaughlin" <cctalk at randy482.com> > >On the Nec 765 (Intel 8272) the direction pin is also use for reduced write >current (TG43). > >When the step line pulses the direction pin controls the direction. All >other times it is high if the track counter is 43 or less, low if the track >counter is greater than 43. > >The current disk controllers are based on the 765. > >Does anyone know if the direction pin does the same on the newer clone >chips? I have started looking at the datasheets but so far I have not found >any reference to that function on "modern" parts. > >If it's true then the 34 to 50 pin cable I use (and others) can be made to >include TG43 without using an adapter like FDADAP. > >It may turn out some do and some don't but since everyone is basically using >the same licensed core I would expect all newer chips to act the same. The >question is was TG43 support kept from the original 765? > > >Randy >www.s100-manuals.com Hi Randy See web page: http://www.dbit.com/fdadap.html You'll note that it mentions that a normal PC does not supply the TG43 signal. Their adapter includes what looks like a uP to keep track of the current track to generate this signal for writing to 8 inch disk. If you were doing software to write 8 inch disk, I would guess that you could double up this function on the step direction wire. There is otherwise no signal to do this for you. Don Maslin's connection was primarily to be used for reading 9 inch disk. It may also be assuming that the drive has a built in track 43 sensor. I think this is were the confusion over pin 2 comes in. This is usually uses as a speed control on PC's but historically it was a write current control. Dwight

21 years, 5 months

2
1
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S-100 SASI setup info needed

by rcini＠optonline.net

All: I'm longing to add a hard disk system to the Altair emulator. I came across a 3-part series in BYTE (March - May 1983) for a host-computer adapter manufactured by ASC Associates connected to a XEBEC-S1410 based 10mb SASI Winchester drive. In part 3 of the article, BYTE printes the complete CBIOS, but the article stops in the middle of the code around page 400 of the issue. I have a nearly-complete series of BYTEs and I haven't found a reference to the code in any subsequent issue. So, here's the question...does anyone have a copy of the complete CBIOS from the article *or* have a CBIOS for another XEBEC-based setup? Any help is appreciated. Thanks. Rich

21 years, 5 months

2
1
0 0

CCTALK Message Format required

by shanits＠cygnus.stpp.soft.net

-------------------------------------------------------------------------------- Hi, of late we have had been trying to develop a software for a London based music company which uses Jukeboxes that works on CC-TALK BACTA Protocol.We have tried our level best to find the Message Format which the cctalk understands both for serial and Parallel port interfaces , but unfortunately we couldnt find one.There were documents that made allusive expalination about the message formats but nothing in detail as to what all means in the colection of bytes that constitue a port communication. Can you on behalf of CCtalk respond back with a manual that addresses the same.Apart from that may I be obliged by one further level by you with any sample software program in any language that deals with CCTalk Messsge handling logic. I am eagerly looking forward for a positive response at your earliest convenience. Regards Shaneit Cygnus Software Pvt Ltd 568 Narayan Peth 4Th Floor Kesri Wada Pune - 411030 --------------------------------------------------------------------------------

21 years, 5 months

2
1
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Age, My computing history.

by trash3＠splab.cas.neu.edu

For those that are interested. I sent my age previously, and was guilty of waiting too long. Hardware experience: somewhat chronological Some IBM EAM (machines) with the big patch boards Control Data Corp 6600 PDP 11/10 PDP-12 PDP-8 IBM 360 CDC 7200 IBM 370 PDP 11/34 PDP 11/44 PDP 11/60 Data General Nova 3 DG Nova 4 Some S100 bus stuff (Imsai, Altair, etc) Some STD bus stuff DEC LSI-11 DEC LSI-11/2 DEC LSI-11/23 Rockwell 6502 Zilog Z80 Intel 8080/8085 Zilog Z8 Motorola 68008 IBM PC IBM PC/XT DEC LSI-11/73 IBM PC/AT Basic Stamp 486, pentium, etc. Programming experience (not just using equipment) Assemblers: IBM 360 and 370 DEC PDP 8 and 12 DEC PDP-11 CDC 6600/7200 (Cyber 7200) Nova 3 and 4 6502 8080/8085 Z8 Z80 68000 Basic Stamp Higher level languages: (some not so proficient and some pretty forgotten by now) Cobol Fortran Basic, Visual Basic Dibol Pascal Turbo C C, C+, Visual C Java Perl Joe Heck

21 years, 5 months

1
0
0 0

TU56/TC11 restoration - VARIAC question

by dwight.elvey＠amd.com

>From: "Guy Sotomayor" <ggs at shiresoft.com> > >On Thu, 2005-03-17 at 11:00 -0500, Ashley Carder wrote: >> I do not own a variac, so I will need to get one of these to >> properly reform the TU56 capacitors. I see several different varieties >> on eBay. What would I need exactly? > >If I'm not mistaken the whole reforming capacitors discussion was for >electrolitic capacitors (ie DC). The motor run capacitors are AC. I'm >not sure the reforming process would be the same (or if it is even >possible). > >Anyone want to comment? >-- > >TTFN - Guy > > Hi AC electrolytics can be similarly reformed, using a current limited AC source. Many run capacitors are electrolytic but may also be large oil and paper. Most anything over 10 mf is probably an AC electrolytic. Dwight

21 years, 5 months

1
0
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TU56/TC11 restoration - VARIAC question

by dwight.elvey＠amd.com

>From: "John Allain" <allain at panix.com> > >> 20amps, wow. Someone give me this for christmas! > > >I now have Two nice machines (Tek scope, VT100) that blow >fuses and have been dancing aound the issue to get one for a >few weeks now. I'm not really an electronics guy but I've been >led to believe that a variac is the single best thing to get to help >remedy fuse blows. Any strong yes or no votes towards this >decision? > >John A. > Hi If you've hit a capacitor hard enough to blow a fuse, it is not likely to recover through reforming. Reforming must be done before applying full voltage. Most issues of blowing fuses can be located by isolation and use of an ohm meter. Dwight

21 years, 5 months

1
0
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Bootstrapping modern file-transfer tools...

by tomj＠wps.com

I'm trying to find a way to get a modern file-transfer protocol program into my Nova 4/X. I'm close to abandoning the Kermit source I have for Data General RDOS... I got it from U Columbia's Kermit site; it's the FORTRAN5 output of a RATFOR preprocessor, there's no RATFOR source, and though it compiles, it seems to not talk to the console. Since it's algorithmic output it's very hard to read. On simulogics.com is a KERMIT in dump format (similar to LBR files, functionally) but it's binary. I've got a decent FORTRAN IV compiler, what I can't find is a FORTRAN IV kermit. There's a bunch of mainframey fortran kermits, but no one seems to think about portability (eg. putting all the console/serial I/O in stub functions) and none are careful to use portable libraries, and all that. Worse, Kermit seems to have abandoned the idea of a bootstrap system (except for one unix version) with utterly base-minimal compliance and features. Anyone have code? I am considering writing a proprietary system that transfers fixed-length line-oriented blocks consisting only of ASCII numbers and line control; real FORTRAN IV doesn't do text (some proprietary libraries do). The only thing I have now is minicom as terminal emulator. sending/receiving paced ASCII67 text (thanks Jules for the tip on ascii-xfer).

21 years, 5 months

2
2
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Xerox 820 documentation.

by gsarno＠nortel.com

Hi I own an Old Xerox 820 machine, Can anyone help to find documentation for it ? Also is there a way to download programs onto it using the serial/parallel port ? I have seen some info at http://www.classiccmp.org/pipermail/cctech/2002-September/002642.html <http://www.classiccmp.org/pipermail/cctech/2002-September/002642.html> but I couldn't find more. Thanks.

21 years, 5 months

3
2
0 0

Apology to the list

by msokolov＠ivan.Harhan.ORG

Dear Fellow ClassicCmp'ers, I want to apologize for my recent behavior here. I'm sorry that I was pushed over the edge by John's innocent suggestions of using some more modern technology. I was clearly in the wrong state of mind when I wrote that the purpose of my life was in using old technology and nothing new and that I would shed blood (whether my own or anyone else's) over it. Of course no piece of technology, old or new, is worth shedding blood over. I don't know what came over me when I wrote that. Those who know me more closely know that I've been leaning more and more over to alternative spirituality and metaphysics and that technology of any kind, old or now, currently plays a very small part in my life. So certainly I'm not going to kill over it. But I promise I won't bring up any more off-topic stuff here. Technology can be fun, and even I am open to some modernisation. Like I'm trying to transition from a VT320 to a VXT X11 terminal. To bring this back on topic, I'll soon be working on a MOP server for 4.3BSD-Quasijarus for netbooting these VXTs, and getting X11R4 to run on my 4.3BSD-Quasijarus hosts. Fun fun fun. Blessed Be everyone, MS

21 years, 5 months

2
1
0 0

USB Universal Floppy Disk controller

by dwight.elvey＠amd.com

>From: "Barry Watzman" <Watzman at neo.rr.com> > > >I remain convinced that USB, not parallel, is the "right" way to go for >interfacing a Universal Floppy Disk controller. > Hi Barry I tend to agree with you. We should be thinking this way. Still, I believe that development work should be done in an environment that is handy and convenient. The USB is just a machine interconnect. One just has to keep in mind what the final product will be like. In other words, don't lock the design into one specific format. The only issue I have with USB is that it requires drivers for each machine it is connected to. These have to be specific to the USB device we use to interface with. RS-232 is generic enough that we could run things from text files using simple terminal modes on almost any machine. I just wish that USB was that simple. Dwight

21 years, 5 months

10
16
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TU56/TC11 restoration - VARIAC question

by dwight.elvey＠amd.com

>From: "Ashley Carder" <wacarder at usit.net> > >I do not own a variac, so I will need to get one of these to >properly reform the TU56 capacitors. I see several different varieties >on eBay. What would I need exactly? > >Ashley > > Hi You can always use a voltage source and a limiting resistor. You don't need a variac ( although they are real handy ). Dwight

21 years, 5 months

1
0
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archiving data, was RE: Media Longitevity/Care

by dwight.elvey＠amd.com

Hi One other thought is that one should have a way to transfer the raw data from what ever media you have. This allows one to have redundent information stored on the same media. If you depend on normal file systems, you run the risk of the file system not allowing you to access the data simply because a small part is damaged. I think most have been using normal file tools that are not dealing with things in this sense. Most of these types of systems have a weak link problem. Dwight

21 years, 5 months

1
0
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Kinda OT: Keyboard Adapters for PCs

by dvcorbin＠optonline.net

> ...and you never have to take your hands off of the keyboard. in most environments I work in the cord is not long enough to reach the mens room...so I don't think "never" really applies....

21 years, 5 months

1
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Opinions? BeOS

by lproven＠gmail.com

On Thu, 10 Mar 2005 20:13:19 -0800, Zane H. Healy <healyzh at aracnet.com> wrote: > It would have been nice to see it continue, but after Apple bought > NeXT rather than Be, Inc. they sort of started to run out of steam. > I might be typing this on a dual 2Ghz G5 running Mac OS X, but I > can't help but thinking how much better the system would be if it had > been BeOS based, rather than OPENSTEP based. The good thing about > them buying NeXT was getting Steve Jobs back, but BeOS was a far more > efficient OS. And yes, I've run OPENSTEP and BeOS on the same system. I know what you mean, but after a few years, and actually building up an old PowerMac 7300/166 I got given for free with a load of bits off eBay - paying money for hardware, most unlike me! - and actually getting to *use* Mac OS X, I came to the conclusion that Apple did the right think. BeOS was gorgeous. My favourite PC OS ever. Everything I used to really like about systems like Acorn RISC OS, Psion EPOC and so on, or AmigaOS. Like those early proprietary 16-bit and 32-bit OSes, BeOS was small, blindingly fast, had a clean, simple GUI and came with an assortment of useful apps. It had a small but competent portfolio of useful software. Unlike most of them, it had networking and Internet capabilities built in, supported memory protection, virtual memory and multiprocessor hardware. And unlike any of them, it ran on cheap generic hardware, What's not to like? But whereas it would have made for a small and blisteringly fast Mac OS X, which with a bundled or integrated copy of SheepSaver would have happily run Classic MacOS & all its apps under the new OS, that's *all* it would have made. BeOS was unique. POSIX-like, but not Unix. Proprietary GUI but one with no unique advantages. Traditional C/C++ development model. Proprietary environment with all that that entails with programmers having to learn it. NextStep/OpenStep represented something different. Yes, all the clutter and kludge of Unix, but: - a new, simple development system using Objective C, Interface Modeller & a vast & comprehensive class library (arguably the best development system and tools for GUI apps there has ever been) - deep thorough object orientation - based on Unix, so familiar to millions of existing programmers, users and techies - based on /open source/ Unix, freeing Apple from the burden of developing & maintaining the entire OS on their own - a solid open networking system build deep into the OS - designed, like BeOS, by former Apple engineers - unlike BeOS, commercially successful (in a small way) for a decade in the open market on various hardware and software platforms - a new and revolutionary GUI based on Display Postscript (now Display PDF, but it's the same difference) - one that offers compelling advantages for designers, users and developers, with powerful new capabilities, but that's already based on known, widespread technology. Up front, BeOS would have made a better successor Mac OS. NextStep had to go through a lot of painful development to make it look and work like MacOS and the result was initially slow and clunky. However, /every/ successive release has made it sleeker and faster, bucking the trend of every other OS in the industry. But that's not what's important. What is important is that along with bringing over all the Mac developers with Carbon, it brought in lots of Unix developers with the Mach/BSD underpinnings, and tempted PC C coders with a different dialect of C, and Java coders with good Java support. Then to all of them it offered, /for free in the box/, the most remarkably polished and effective GUI development environment there is. Getting programmers behind a new OS is essential. It's paramount. That, I think, was the basis of Apple's decision. The result? OS X is by almost any standard the single most polished, friendly, usable, attractive, flexible desktop OS on the planet, and it's attracting lots of new and interesting software development. But by the same token, it's Unix, so if you want to drive it with EMACS and X tools from a /bash/ prompt, you can. BeOS could never have been that. -- Liam Proven Home: http://welcome.to/liamsweb * Blog: http://lproven.livejournal.com AOL, Yahoo UK: liamproven * ICQ: 73187508 * MSN: lproven at hotmail.com

21 years, 5 months

2
1
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Re; Age

by dvcorbin＠optonline.net

> I first programmed in high school in FORTRAN on an IBM > 1620 and shortly thereafter.... I read this as "...on an IBM **IN** 1620..." and thought we really had a winner on the oldest programmer.... ...oh, the coffee is ready....BRB....

21 years, 5 months

2
1
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Re; Age

by r.stek＠snet.net

I'm 56.4166666... or thereabouts. I first programmed in high school in FORTRAN on an IBM 1620 and shortly thereafter in Autocoder on a 1401, around 1965-66. I still remmeber reading in a column in Popular Science that "scientists predict that in the future computers would be the size of shoe boxes..." Since I was a teenager and was already an expert on computers (and most everything else), I laughed at this silly idea... until 10 years later. Bob Stek Saver of Lost Sols

21 years, 5 months

2
1
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OT: Longevity of DVD-R and CD-R / 2-Media Hedge

by dwight.elvey＠amd.com

>From: "Jules Richardson" <julesrichardsonuk at yahoo.co.uk> > >On Mon, 2005-03-14 at 23:51 +0100, Nico de Jong wrote: >> The fact is, that the development of drives is so quick, that even if you >> _could_ save a tape or disk or CD or whatever for 30 years, you wouldnt find >> the proper drive, and even if you did, it wouldnt be supported anymore. >> Let's go back 30 years; what were the dominant media at that time ? 1600 bpi >> reel-to-reel tapes, 7.25 or 30 MB harddisk (IBM 2311/2314), and 8" floppy >> discs. Some of my customers _still_ accept 8" disks and reels for financial >> transactions. > >Philosophical question. As performance of a device goes up, does the >need for more performance (by the average user) go down? > >In other words do we hit a point where the storage technology of the day >is so good for what the typical/power user needs that there is no >incentive for manufacturers to built anything better? > >Curious as to what people think. I'm sure they'll always be innovation >in the lab and on specialist high-budget projects, but maybe one day >they'll just be nowhere left to go for Joe Public. HI Hardly. The requirement for more space will continue. Serial data, such as CDROM's have some limits coming up but not the hunger for more data space. Access time is becoming a limiting factor that technology will sortly overcome( or we are doomed ). Dwight

21 years, 5 months

5
4
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Longevity of DVD-R and CD-R (Rewrite from original poster)

by bristol22＠softhome.net

I am the scoundrel that made the original post on this topic that opened a flood of discussion. Members brought up details that I never addressed; and I learned from everyone's posts. Thank you! This may be useless, beating a dead horse, and off topic. I am re-submitting here my original 6 point comment with corrections and links, and with ADDITIONS as points: 7, 8, 9, 10, 11, and 12 to cover other areas people have brought up, etc. Richard Bristol ---------------------------------------------------------- Archival longevity of DVD and CD media may be a good topic for the computer preservationist. I have studied this quite a bit. My first conclusion, including from crude accelerated life and torture tests I made myself, is that the "100 year" claims some people made are likely baloney. A research article appeared in the German version of Q't magazine (unless I miss-spelled that), where they did some tests on raw error rate on just burned DVD+R media, using some $50,000 equipment. None of the media they tested had a low enough raw error rate to meet the requirements of the DVD+R standard. Yet they sell it. (Mitsubishi did the best.) Then there are many hobbiests looking at raw error rates on DVD media using Lite-On drives with firmware than can report on raw errors. For example, hobbiests measure and post on sites like: http://www.cdrinfo.com/Sections/Reviews/Print.aspx?ArticleId=11657 My overall conclusion is that most DVD media on the market sold by no-names, and by the names Sony, Maxell, Memorex, 3M Imation, etc is not very good. These companies re-badge whaterver is cheapest this month from whatever factory. My least favorite factory is CMC Magnetics Corporation in Europe. Next worst in my view are some Korean and Taiwanese factories (K-Well, In Young, and Lead Data=Great Quality=GQ). TDK seems to be the only advertised brand that makes their own DVD-R that you can actually buy in a USA retail store (although one member said maybe they don't make it themselves), unless the store carries Verbatim. I just verified that Pioneer and Verbatim buy their media from the good Japanese companies, Mitsubishi (MCC), Taiyo Yuden (TY), and Mitsui. Anyway, Pioneer and Verbatim consistently have low raw error rates. A low error rate when freshly burned gives greater margin that as the errors increase as the media ages, error correction can still take care of it. Also, these companies have better engineering about the life span of the organic dyes and such used in the data layer. So when I want it to last, I do this: 1) Use a good burner with low raw error rate after burn/read and good media-to-other-machine cross compatibility. I used to recommend the Pioneer DVR-105 and below, but the DVR-107 and DVR-108 are poor at this. Now I recommend BenQ DW1620 ($52) DVD+-RW double layer drive. Most burners have new firmware you can flash even if you bought it yesterday. A lot of the effort in the new firmware is decreasing the error rate on some media, so it is often worth flashing it. 2) My first choice of media is either Pioneer or Verbatim DVD-R, followed by DVD+R from the same two makers. Third choice brand is TDK. I don't trust much else. Double sided and double layer DVD are a little imature at this point. 3) The freeware Windoze program DVDinfo.exe will tell you who made your mysterious media (reads it off the media). E.g. MCC001 is made by Mitsubishi. 4) All RW media (DVD-RW DVD+RW CD-RW) have poor archival life. Think about it: with RW, instead of burning a pit in the data layer, you are fooling around with glossy or matte finish depending on how quickly a melted liquid re-freezes. Official tests, and my own tests, show poor life. A little sunlight-UV can erase it. 5) I don't burn more than 85% of the capacity of a DVD. DVDs are a sandwich, lexan (polycarbonate) on both sides, data layer chemistry in the middle. The spiral starts on the inside (opposite LP records). If you leave 3/4" unused at the outside edge, it will take longer before the Ozone and 02 and other environmental exposures that attack the data chemistry at the edges of the lexan sandwitch actually reach your data. So on a "4.7GB" disk which in real life could hold 4.3GB, I burn 3.8GB. 6) DVD-R or DVD+R is better than CD-R, because it is a sandwich. DVD also has stronger error correction. CD-R often dies from the label side, by getting bumped against the drive tray, the jewel case, a pen... The paint layer that protects your data on the label side is very thin and fragile. CD-R also die from chemical errosion from ozone, fingers, marking pens, etc on the label side. I write on them only in the center no-data area. DVDs, being a sandwich, don't have those problems. 7) If you really care about it's archival life, hedge your bets by burning two copies, on DIFFERENT media. Select two good media types made by different companies. Each may have, just a guess, a 10% chance of self-destructing within 20 years. This would be because of a design or implimentation mistake. For example perhaps the sandwich adheasive includes a chemical that eventually reacts badly with the data, or some impurity in manufacturing at that time. If the two media are very different, their probabilty of failure approaches statistical indpendence; and if independent then the chance that both are unreadable would approach 0.1 * 0.1 or only a 1% chance. 8) Because the data is sandwiched in plastic, my belief is that single-layer single-sided DVD-R or DVD+R as a class will last longer then CD-R as a class. However, some applications require CD-R. For archival CD-R I have used extensively and can recommend "BASF by EMTEC" (Emtec in USA) "Ceram Guard" CD-R BASF CD-R74 Maxima Ceram DA (really made by Taiyo Yuden). (Beware some different Emtec/Basf CD-R are made by CMC and are poor.) However "Ceram Guard" is truely hard to buy in the USA. I bought mine for $2 each from the retail chain "Guitar Center" in person (guitarcenter.com). They were marked "for audio use" but that does not matter. They are NOT gold. Their feature is that a ceramic coating is vacumn sputter-coated on the labeled. You could probably use a ball point pen on it. They are by a mile the most sturdy CD-R I have ever seen. Unlike most CD-R, taps to the label side don't kill them. Out of about 1000 CD-R I have seen or used "in the field", I have seen about 25 dead CD-R's (that were once good) And 22 of those 25 were at least slightly abused. (Sun, moisture, tap on drive tray on label side when inserting, or tap on jewel case) Only 3 of 25 appeared to die from purely with "from the inside bit rot". Of those 3, 2 were made by one company: GQ Great Quality, Taiwan. So I am mostly interested in the label side coating. These ceramic coated disks are mentioned here: http://www.cdmediaworld.com/hardware/cdrom/basf.shtml BASF/Emtec also sells these as "archival" but I would want to know who made it for them before buying. They are real gold: BASF/Emtec CD-R Gold Digital Photo BASF/Emtec DVD+R Digital Video Gold Occasionally you can find "Kodak InfoGuard". They are expensive. They have a very tough label side, and use gold. They are semi-discontinued, and were sold to medical and business markets. If you have a Kodak "Picture CD" from film processing you may have one there. Kodak digital science InfoGuard, maker: Kodak Japan Limited, Phthalocyanine 1X - 4X Kodak Gold Ultima InfoGuard, maker: Kodak Japan Limited, Phthalocyanine 1X - 4X More practically speaking, you CAN actually buy Mitsui "MAM Gold CD-R" for about $1 each now. They use real gold, and have a decent paint layer they call "diamond coat". (But it's not anywhere near the toughness of "Ceram Guard" or even "InfoGuard".) Described for sale here: http://store.mam-a-store.com/standard---archive-gold.html 9) I don't know if high-spin readers contribute to media death. But too high a speed definitely contributes to "can't read Table of Contents" and "ECC Error" on read, and marginal quality burns. Plextor CD-R burners come with PlexTools(?) software specifically to slow them down. You can sometimes read a CD-R this way that otherwise can't be read on newer faster readers. To read a CD-R whose errors are too high for most all readers, I prefer these to read it: Plextor 4x CD-RW drive, or 12x (not 8x). Plextor 20x and above are not as good. Cheap and I have a few: Panasonic 12x just plain reader. Sometimes other 4x readers by NEC, Panasonic, Pioneer, Sony. 10) I like to try, when burning, for the lowest raw-error-rate (that some machines can tell you when you read). Published tests show excessive speed hurts. My rule of thumb when burning is: Never exceed the lesser of the media's rated speed, or 2/3 of the burner's maximum speed. So if a CD-R burner will burn at 48x, and the media says it is 80x, I will burn it at around 12x or 24x. There is such a thing as too slow also, for a particular burner. The sweet spot gives you a lower raw error rate, and greater cross-compatibility when reading it on many different drives. 11) A disk that takes a long time to "settle" (usually light goes out) on insertion is a possible indication of a high error rate and likelyhood of complete table of contents failure later. 12) The free Windoze program md5summer.exe will generate a text file with .md5 ending for any directory tree of files. Each line in the file is the md5, a space, *, and then the pathname; one line per file. I put one of these .md5 files in the top level of my CD-R or DVD-R burns. Then, in Windoze a couple years later, double click that .md5 file and it does the opposite, and confirms the md5 of each file on the media. I have seen a few CD-Rs that were damaged, that in Windoze gave no error message at all when read, but the data read back was actually wrong. I use md5summer also before ftp etc. transfers. Will someone better informed say how this is best done and commonly done in linux and unix? Perhaps find . -exec md5sum '{}' \; > md5sum_list or something? And the checking later? Richard Bristol (the same guy who recently asked for help reading 9-track tar tapes)

21 years, 5 months

1
0
0 0

itsy bitsy Unix

by waisun.chia＠gmail.com

On Wed, 16 Mar 2005 22:00:12 -0800, Zane H. Healy <healyzh at aracnet.com> wrote: > At 9:32 PM -0800 3/16/05, Cameron Kaiser wrote: > >Does anyone know a true (not a homebrew hack) multitasking environment that > >will run in 16K or less, preferably with available source? > > uCOS-II. (http://www.ucos-ii.com) Real-time, pre-emptive multitasking, embedded. Comes with source-code, have to buy the book to be legal. Heck it even has a TCP/IP module. Quote (page 72) of the said book: "A minimal kernel for an 8-bit CPU that provides only scheduling, context switching, semaphore management, delays and timeouts should require about 1 to 3kB or code space." So theoretically it'd be possible to port this to a 16kW PDP.

21 years, 5 months

1
0
0 0

Can't read CP/M disks on PC

by vcf＠siconic.com

So now that I've got the 8" drive running well on the PC, I am trying to read 8" CP/M disks. 22Disk is giving me sector not found errors (cylinder 2, side 0, sector 1) and the DOS CP/M tools are giving me "Unknown floppy disk format", even on disks that read fine on my NEC APC. I tried reading in a sector using debug but I also get read errors. Any ideas? The drive is a Tandon TM 848-02. Very little information online, but it seems to support DSDD. -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

21 years, 5 months

26
43
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Longevity of DVD-R and CD-R (Was MagTapes)

by elf＠ucsd.edu

Richard Bristol wrote: > (5) I don't burn more than 85% of the capacity > of a DVD. DVDs are a sandwich, lexan (polycarbonate) > on both sides, data layer chemistry in the middle. > The spiral starts on the inside (opposite LP records). > If you leave 3/4" unused at the outside edge, it will > take longer before the Ozone and 02 and other environmental > exposures that attack the data chemistry at the edges > of the lexan sandwitch actually reach your data. So on > a "4.7GB" disk which in real life could hold 4.3GB, I > burn 3.8GB. Interesting approach. Curious though ... why do the edges get attacked first? Are the disks slapped together in some sort of fashion such that there exists a potential breach at the edges?

21 years, 5 months

6
8
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FPGAs was USB Universal Floppy Disk controller

by swtpc6800＠comcast.net

Eric wrote: > However, I don't *really* think you want to spend the rest of your > life writing your own FPGA development software. It's a hard problem > and there are hundreds of thousands of man-years of development effort > in the Xilinx software. By the time you got your own software working > for one family, that family would have long since been discontinued. Scott wrote: > I would suspect that while there might be hundreds of thousands of man > hours, that there just can't possible be hundreds of thousands of man > *years* involved.

21 years, 5 months

1
0
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TU56/TC11 restoration - Power supply question

by pete＠dunnington.u-net.com

On Mar 16 2005, 17:53, der Mouse wrote: > Well, I've never had a cap in a power supply go bang. But I did once > put together a circuit and carelessly use a cap rated for about half > the expected voltage - I was checking only the capacitance, my bad. I've had two electrolytics fail spectacularly. The first was one that had just aged. It was a large PSU electrolytic in a valve[1] PA amplifier. I'd had the amp running several times, for an hour or so at a time, but on one occasion, it just blew. It made a loud hissing noise, and ejected a stream of white fumes. The second was a non-polarised electrolytic in an Atari monitor. The original had failed, so I looked through the catalogues for a similar type. The only one I found of the same capacitance and voltage claimed to have a suitably large ripple current capacity, but was quite a lot smaller than the original. I was a bit skeptical, but hey, technology moves on and capacitors get smaller every year, right? It lasted about 90 seconds. The bang was spectacular, and the amount of fibrous padding that came out of such a small space was really impressive. The ceiling still has the dent in it, but the monitor now has a polypropylene cap instead. [1] British for "vacuum tube" -- Pete Peter Turnbull Network Manager University of York

21 years, 5 months

2
1
0 0

TU56 restoration

by dvcorbin＠optonline.net

> Can I easily test the mechanics, on/off switches, lamps, motors, > etc, without hooking up the TC11? I think there is a local > mode switch and wondered what all could be tested easily > without hooking up the TC11. I will be studying the documentation > to get a better idea about things. I have a TC11 that also needs > to be cleaned up. It has a layer of dust on it and needs a couple > boards, which should be here soon. > I am also hoping to start firing up my PDP-8 and TU56 in the next few weeks [the lab is almost re-built!!!!!] so perhaps Ashley and I could coordinate our (limited) knowledge and run various tests in parallel....

21 years, 5 months

4
5
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TU56 restoration

by djg＠drs-c4i.com

You will probably need to pull the hubs and clean and lubricate the spring loaded friction bushing behind the hubs. If you turn it by hand and it is quite stiff or springs back after you release the hub then they need cleaning. Most of the hubs are screws in the plastic so a easy to strip when tightining so don't over do it. They may come pre stripped. The manual goes into how to put the hubs on. Try somewhat tight and if they slip tighten some more. The screws are serrated head so may need to be replaced if slipping and worn. A little slipping won't hurt for initial testing but will wear the shaft long term. I used some epoxy thread repair material since some of mine were prestripped. It sort of worked but wasn't really strong enough. Putting in a helicoil might be better but I didn't go that far. The tape motion can be tested in local mode and the manual has adjustments for clean stopping. When no tape in installed both reels should turn in opposite directions. With a tape on it should not turn until you hit forward or backward. The lights may be burned out. They were sold as assemblies but they are a custom order now. You can open them up and carefully solder in a new bulb inside. I bought a couple similar bulbs from Mouser and picked the one I liked. Since mine had no good bulbs I can't say what was the closest match. The capacitors have been discussed. The 4 motor capacitors are obvious if they are going, junk will be coming out the vent. Altough after shipping it may of all broken loose. The power supply in the back also has a big capacitor in it for the motor drive voltage (36V?). It wouldn't hurt to reform that one. I haven't always reformed the capacitors most of the time its powered up ok but did have them fail in one item. I use the current limited supply method. Also note you provide either 5V or 10V, not both. I have a video of operation of my unit online if you need to see what it looks like running. David Gesswein http://www.pdp8.net/ -- Run an old computer with blinkenlights. Have any PDP-8 stuff you're willing to part with?

21 years, 5 months

1
0
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HP9915B with PSU problems

by vp＠cs.drexel.edu

Hi, I have returned to my HP9915B that blows its fuse as soon as you power it up. I followed Tony's advice and checked the two large capacitors (C46 and C58), and the PIC645 and they are all OK. I then checked the U30 (3524) in the chopper sense circuit and its OK as well. I checked the parts after removing them from the PCB to ensure that there was no interference by other components. So now I am really at a loss and wonder if anybody has any ideas. Best Regards **vp

21 years, 5 months

2
1
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RQDX3 on an 11/23?

by pete＠dunnington.u-net.com

On Mar 16 2005, 8:46, Pete Turnbull wrote: > On Mar 15 2005, 23:01, Ethan Dicks wrote: > > > I have never used an RQDX3 except in a BA23 or BA123, but the schemes > > I've seen described in this thread to manufacture a direct > RQDX3->hard > > drive should all work. > It's certainly easier and likely neater to use the real thing, if you > have it. But if you want to "roll your" own, I already published my > distribution board layout and the RQDXn pinout, and later today I'll > put the M9058 RQDX distribution board layout and circuit, and the > circuit diagram for the Write-Protect/Ready switch panel up as well. OK, done. http://www.dunnington.u-net.com/public/RQDX/ DU.COR patch for DU.MAC to use RQDX3 under RT-11 V5.01 DUX.TXT explanation of above DistrOVL.ps component overlay for my RQDX distribution board DistrPCB.ps PCB layout artwork for above M9058_layout.ps component overlay for M9058 distr.board in BA123 M9058_schematic.ps schematic diagram for M9058 RQDXn_LEDs_switches.ps schematic of the WR.PROT + READY switches/LEDs RQDXn_pinout.ps list of pins and signal descriptions for RQDXn RX50_substitute.ps notes on using floppy drives other than RX50 The first two are flat-ASCII; all the files with ".ps" extensions are PostScript. If you don't have a PostScript viewer (eg Ghostscript or one of the Corel packages), you can send them straight to a PostScript printer. The ROM images for RQDX1, RQDX2, and RQDX3 are in http://www.dunnington.u-net.com/public/DECROMs/ See the file "00ReadMe" for information, "ROMlist" for a table of part-numbers/module-numbers/versions, and "Wanted!" for, well, "wanted" :-) -- Pete Peter Turnbull Network Manager University of York

21 years, 5 months

1
0
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RQDX3 on an 11/23?

by pete＠dunnington.u-net.com

On Mar 16 2005, 12:46, John A. Dundas III wrote: > At 2:05 PM -0500 3/16/05, Ethan Dicks wrote: > >You can literally pull the CPU and/or memory from a MicroVAX I/II and > >drop in a KDF11 or KDJ11 and required memory, and *bam* - a > >MicroPDP... > > I've done the J-11 <--> uVaxII exchange with pretty good success. > Having the Console Panel (in the back, CK-KA630-A) for the uVax seems > to be a necessity; not needed for the J-11. > > I have not tried the F-11 in a generic BA23, though I would expect it > to work. Will the J-11 correctly mate with the RUN/START/drive lock > panel in the front? How is that best handled without an actual 11/23 > or 11/23+ front panel? The DC_OK/RUN/START/HALT and drives LED/switch panel on the front is the same for all the microVAX and microPDP-11 series in a BA23. Only the badges get changed (they unclip). The DC OK and RUN LEDs, and the HALT and RESTART switches, connect directly to the backplane, and the drive switches/LEDs connect to the signal distribution board, which in turn would be connected to the RQDXn by a 50-way ribbon cable. The console panel on the back for the KDJ11-B and KDJ11-F is different to the microVAX one, of course. It has a 2-digit display, a DB25M instead of a DE9F, and only one rotary switch. Interestingly, it uses the same connectors and cables, so maybe it would work. The important bit would be the SLU cable, which is the 10-way ribbon. I expect that's the same, though I've never tried it. You can set the console baud rate, word size and parity with the DIP switches on the KDx11-B itself. -- Pete Peter Turnbull Network Manager University of York

21 years, 5 months

1
0
0 0

Xerox 820 documentation.

by James＠jdfogg.com

> Hi I own an Old Xerox 820 machine, > Can anyone help to find documentation for it ? > Also is there a way to download programs onto it using the > serial/parallel port ? Doesn't it have 8 inch diskette drives?

21 years, 5 months

2
1
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TU56/TC11 restoration - Power supply question

by dwight.elvey＠amd.com

>From: "Ashley Carder" <wacarder at usit.net> ---snip--- > >I'd be interested in hearing any horror stories relating to exploding >capacitors and more info on the proper caution that needs to be >exercised when messing with old power supplies. > >Ashley > > Hi When I used to work for Intel, we'd do incoming inspection on powersupplies. We had a box called the coffin that we'd power them up in. I'd never been at the test location when one went off but there were enough dents in the box from the inside to attest to the explosive forces. Dwight

21 years, 5 months

1
0
0 0

Belay that last request... HHC info.

by zmerch＠30below.com

Awrighty... 1) I opened up a super-sized can of dammitallanyway, and found a used Spectroline PR-320T for about $30 more; $130 shipped, give or take. I *really* don't need that much of an eraser, but WTF - I guess I'm really loaded for bear now. (the sucker'll do 42 eproms in 6-11 minutes... or so the dox say) -- It's a $729 eraser new. 2) I read the HHC Basic eprom, it appears to have read good. Opening up the .bin file in goatpad [ erm; notepad ] I found the 2-letter error prefixen, the Microsoft Basic copyright thingy, and a reference to: NEIL K & HENRY L ... I'm guessing these are the programmers; or at least the guys who ported it over to the HHC. 3) So far, I have a list of people (4 currently) who want Basic chips... I think this is fair[1]; and should cover my costs & whatnot: First Basic chip: $8 - each additional Basic chip, $3 and US shipping of $3.50 (USPS Priority). I'll throw in 4 extra empty[2] chips for free if you want 'em. If you're not in the US, lemme know where ya live, and I'll quote ya the difference in shipping... but with such a small package, I doubt it would be much. (The last time I shipped something that small to Great Britain, it was less than /pounds 5, IIRC.) Trades may well still be an option, but I'm not willing to trade for an EPROM eraser anymore... ;-) I'm throwing in the double-padded mailers, static bags, other whatnot, etc... Anyway, lemme know what y'all think! Laterz, Roger "Merch" Merchberger [1] If you don't think so, lemme know! [2] Now that I'll be able to make 'em forget en masse... -- Roger "Merch" Merchberger -- SysAdmin, Iceberg Computers zmerch at 30below.com Hi! I am a .signature virus. Copy me into your .signature to join in!

21 years, 5 months

2
1
0 0

TU56/TC11 restoration - Power supply question

by dwight.elvey＠amd.com

>From: "Ashley Carder" <wacarder at usit.net> > > >> > On a related note...any special concerns on an initial powerup of a >> > TU-56 that has not been turned on for possibly 5+ years....?? >> >> Any solid DC supplies that match the requirements of the TC11/TU56 >> should be fine. The TU56 on my 8-e has a non-DEC supply and it seems to >> work fine. > >Guy said: >> Other than the usual caution about capacitors in power supplies.... > >Since I am fairly new to the hardware end of this stuff and just started >messing with it less about 8 or 9 months ago, can you give me >a little primer on the caution of capacitors in power supplies? > >Ashley Hi Ashley There is an issue with dry tantalum capacitors blowing up. As far as I know, there is nothing that can be done other than hitting them with the power and replacing those that blow. It helps to have a power supply that can handle a momentary shorts or that is fused so it doesn't damage the supply. Wet electrolytics have a problem in that they tend to degrade over time. During normal running, they produce a small amount of gas that is intended to diffuse through the seal. This is a normal part of maintaining the capacitor. The problem is that when you turn one on that has been sitting for a few years, it can do one of two things. One is that it will reform the capacitor but out gas fast enough to burst the seal. This will cause total failure after a short period of time because of evaporated electrolyte. The next is that it will over heat and short. It will usually burst the seal as well. Not much to do here other than replace. One can reform old electrolytics that are still sealed by bringing the voltage up slowly. Here is where many have different opinions. Some say to use a variac and bring the voltage up slowly over many hours to days. I don't like this method but have used it successfully in the past. I prefer connecting the capacitors ( removed from the curcuit ) to a limiting source and allowing the voltage to float up as the capacitor forms. This is a good way to deal with capacitors that are screw mounted. I use a limited source that will allow no more than 5 to 10 ma or 1/4w ( which ever is first depending on voltage for larger capacitors ). Some computer grade capacitors are very leaky when good and may require more than 10 ma but I find few will recover with much more leakage. One should also take care with switching supplies. Many supplies will blow up if the input voltage is below the specified operating range for any length of time. Some switchers will do OK if there is no load and the input is low while some will go crazy with no load. For switchers you really have to form the capacitors by disconnecting and not using a variac. Dwight

21 years, 5 months

1
0
0 0

TU56/TC11 restoration - Power supply question

by dvcorbin＠optonline.net

> So the moral of the story is to bring a long-dormant power > supply up slowly, using a variac and loads, and to be vigilant > for any signs of cap leakage, swelling, getting suddenly warm, > or hissing sounds coming from one. > The trick here being that the "HUGE" cap's are NOT part of a powersupply per se [which is external to the unit], but rather are part of the internal electronics [motor control].

21 years, 5 months

1
0
0 0

Hardware offer: intellec mds

by jbglaw＠lug-owl.de

Hi all! A friend of me got an intellec mds, with adaptors and two 8" FDDs, to be given to a good home. We've even found a "system" labeled floppy in one of the drives, but we've not attempted to switch on the machine. It stood on the board for about 10 years, so at least a PSU check and a bit of cleaning (for being unused for about 10 years it's however quite clean...). So basically, here's an intellec mds, untested, available in Bielefeld, Germany, for free (excl. shipping costs). If anybody wants to get it, please drop me an email. MfG, JBG -- Jan-Benedict Glaw jbglaw at lug-owl.de . +49-172-7608481 _ O _ "Eine Freie Meinung in einem Freien Kopf | Gegen Zensur | Gegen Krieg _ _ O fuer einen Freien Staat voll Freier B?rger" | im Internet! | im Irak! O O O ret = do_actions((curr | FREE_SPEECH) & ~(NEW_COPYRIGHT_LAW | DRM | TCPA));

21 years, 5 months

3
4
0 0

I have a VAX 6400 that I don't want anymore

by kapteynr＠cboe.com

I know that it's not a desktop. I have seen VAX installations as big as a semi trailer, and then I've seen the desk sized ones. So far I have limited my collection to "hobbyist" classics like my Altair and H8. But a "business" machine like a VAX could be cute too. Especially if it has a front panel with lots of lights and switches ? I tried to find photos on the web, but no quick success. Thanks, -Rob -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]On Behalf Of Zane H. Healy Sent: Wednesday, March 16, 2005 12:22 PM To: 9000 VAX; General Discussion: On-Topic and Off-TopicPosts Subject: Re: I have a VAX 6400 that I don't want anymore At 12:21 PM -0500 3/16/05, 9000 VAX wrote: >On Wed, 16 Mar 2005 10:38:33 -0600, Kapteyn, Rob <kapteynr at cboe.com> wrote: >> I am really close to this and I have storage space, but I don't >>know exactly what the 6400 is. >> I worked with an 11/780 in college, and that's too big for me to handle. >> A desk sized VAX (like a microVAX) would be fun to play with. > >It is desk size, if you lay it down. It is narrow and tall, but the >volume is similar to that of a desk. Somehow I think he meant desktop sized :^) Unless of course he's planning to get a pair of BA123's or BA23's and put piece of plywood on top to use them as a desk :^) Zane -- -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

21 years, 5 months

5
6
0 0

RQDX3 on an 11/23?

by dbetz＠xlisper.mv.com

I have a PDP-11/23 and would like to add a hard disk. Would the RQDX3 be the way to go? What do I need besides the board itself and an MFM drive? Obviously, I need some sort of cable to connect the two. Is there anything else I need? Will RT-11 V5 support an MFM drive on an RQDX3?

21 years, 5 months

5
10
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OT: What is a .SC4 document?

by healyzh＠aracnet.com

Does anyone happen to know what a .SC4 file is. It was written on a Linux system in 1998 (most likely Red Hat), and I think it was some sort of spreadsheet. Any idea what I can open it with? Zane -- -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

21 years, 5 months

5
7
0 0

VCF East 3.0 ?

by news＠computercollector.com

They're planning for Indiana (Purdue U.). FYI, there are several other events (and related events still interesting to we nerds) listed on my web site. I plan to update the list again soon; submissions are encouraged! --- Jim Leonard <trixter at oldskool.org> wrote: > Bob Brown wrote: > > When/where will the VCF Midwest be? > > Oo! Please say Illinois! Evan's personal homepage: www.snarc.net *** Tell your friends about the Computer Collector Newsletter! - It's free and we'll never send spam or share your email address - Publishing every Monday(-ish), ask about writing for us - Mainframes to videogames, hardware and software, we cover it all - W: http://news.computercollector.com E: news at computercollector.com - We're approaching 700 readers: win a prize!

21 years, 5 months

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Hardware offer: intellec mds

by dwight.elvey＠amd.com

>From: "Jan-Benedict Glaw" <jbglaw at lug-owl.de> > >On Wed, 2005-03-16 13:03:31 +0100, Jan-Benedict Glaw <jbglaw at lug-owl.de> >wrote in message <20050316120331.GX19265 at lug-owl.de>: > >> So basically, here's an intellec mds, untested, available in Bielefeld, >> Germany, for free (excl. shipping costs). If anybody wants to get it, >> please drop me an email. > >Some question for the aftermath, which I'd better had prepared >beforehand. How is hardware transfer "normally" done on this list? Give >it to the first person who replied (discriminating those who can only >read emails once a day, or those that are currently asleep). Or shall I >wait a week and cast a lot? ...or pick the one that actually offered >money, hardware or beer in exchange? > >I (read that: my friend) don't want to make a fortune, it's only about >finding a new, good home. So you who already replied to me, please do it >once again with a suggestion how to solve my unpreparedness :) Hi I would first wait for 24 hours. Next select out any that are willing to pay a rediculously high price or are willing to pick it up locally. Then write email to all those others that requested to let them know that they are not currently being considered. Of the selected group, request from each a description of why they believe they should be selected ( less than 1K words ). Make your choice then. Also let the others know that they were not selected as well but if the first person backed out, they might still have a chance. Just my thoughts Dwight PS wish I was in Germany. > >MfG, JBG > >-- >Jan-Benedict Glaw jbglaw at lug-owl.de . +49-172-7608481 _ O _ >"Eine Freie Meinung in einem Freien Kopf | Gegen Zensur | Gegen Krieg _ _ O > fuer einen Freien Staat voll Freier B??rger" | im Internet! | im Irak! O O O >ret = do_actions((curr | FREE_SPEECH) & ~(NEW_COPYRIGHT_LAW | DRM | TCPA)); > >

21 years, 5 months

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TU56 restoration

by dvcorbin＠optonline.net

> David, do you have all the TU56 manuals and prints that you need? I > have several TU56 manuals and the TC11 manual and prints (which > would not apply to your PDP-8 implementation). > NO! [are they available on BitSavers????]

21 years, 5 months

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OT Troubleshooting: Old computers with modern parts

by dwight.elvey＠amd.com

>From: "Tom Jennings" <tomj at wps.com> > >CMOS isn't *THAT* sensitive; easy, benign, reasonable precautions >are more than adequate. Ben, the days of early MOS/CMOS >hypersensitivity to static are long gone. Even 1970's 4000 series >had input-protection diodes. The 4051,4052 and 4053 were very static sensitive. But it is try that most were relatively insensitive. Still, if you are hitting a part with a spark large enough to make a sound, you are most likely doing some damage, even if it doesn't show right away. Dwight

21 years, 5 months

8
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I have a VAX 6400 that I don't want anymore

by kapteynr＠cboe.com

I am really close to this and I have storage space, but I don't know exactly what the 6400 is. I worked with an 11/780 in college, and that's too big for me to handle. A desk sized VAX (like a microVAX) would be fun to play with. Rob -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]On Behalf Of Dawson, Jim (Itasca, IL) Sent: Wednesday, March 16, 2005 9:35 AM To: classiccmp at classiccmp.org Subject: I have a VAX 6400 that I don't want anymore Know anyone interested? It's in the Chicago area. Jim Dawson Manager of PC/LAN WEST (Mid-America, Central, Pacific S./Desert Mt., Pacific N.) Office 630-875-7950 Cell ph 708-363-1561 Fax 770-659-4683 or jim at 7706594683

21 years, 5 months

4
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Qumetrak 242 drive

by birs23＠zeelandnet.nl

Can anybody give me any information about this drive ? Would I for example be able to connect it to any more or less modern machine ? Thanks! Stefan Mansier. ------------------------------------------------------- http://www.oldcomputercollection.com

21 years, 5 months

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Tektronix vector graphics terminal on eBay - USA

by john_a_s2004＠hotmail.com

If anyone on this list is interested, as a buy-it-now for $25, location Rio Rancho, NM United States. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=2560430340 Tektronix TEK 4114 Engineering Work Station. Suit someone with loads of space! Regards, John

21 years, 5 months

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I have a VAX 6400 that I don't want anymore

by DawsoJ01＠unisourcelink.com

Know anyone interested? It's in the Chicago area. Jim Dawson Manager of PC/LAN WEST (Mid-America, Central, Pacific S./Desert Mt., Pacific N.) Office 630-875-7950 Cell ph 708-363-1561 Fax 770-659-4683 or jim at 7706594683

21 years, 5 months

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TU56 restoration

by wacarder＠usit.net

I am supposed to be getting a TU56 DECtape unit today. I believe it was functional when it was retired, but it supposedly now has a grimy film on it. My plan is to assess its condition, then clean it up. I need to study the manual and technical drawings, but my question is: Can I easily test the mechanics, on/off switches, lamps, motors, etc, without hooking up the TC11? I think there is a local mode switch and wondered what all could be tested easily without hooking up the TC11. I will be studying the documentation to get a better idea about things. I have a TC11 that also needs to be cleaned up. It has a layer of dust on it and needs a couple boards, which should be here soon. The goal is to get it hooked up to my 11/40 eventually. I have a number of DECtapes. Thanks for any advice that anyone might have, Ashley

21 years, 5 months

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Apology to the list

by msokolov＠ivan.Harhan.ORG

Forgot to add: yes, the Amish ARE peace-loving people, and I'm really trying to learn their way. I really am trying, it's just hard for me sometimes when I let myself go overboard. Blessed Be everyone again, and Blessed Ostara to those who know what it means :-) MS

21 years, 5 months

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Age??!!

by kandres＠epssecurity.com

I didn?t reply to CCTech, I replied off list, but I am 50-54 also. Is a new compilation coming up? I?m curious. Kevin J Andres Senior Technician Engineered Protection Systems Inc. HYPERLINK "mailto:kandres at epssecurity.com"mailto:kandres at epssecurity.com -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.7.3 - Release Date: 3/15/2005

21 years, 5 months

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Age/History

by kandres＠epssecurity.com

Paxton Hoag wrote: >> When this survey started I really enjoyed the list of early computers >> used that people added. >> It would be both on topic and fun to continue. Yes! Earliest experience SWTP. Bootloader binary from switches to run a cassette file loader. Vaguely remember an IMSAI something, Believe it was 8088. Also a weird little strip printer in a wood side case with smoked glass cover that went with either the SWTP or the IMSAI. Commodore PET ?Chiclet?, still have it, run issues. Ohio Scientific Superboard used as an embedded device for alarm system printing. Still have one, haven?t run in years. Dual 5.25 floppies in case that were connected to Superboard at one time in office. Most of what we did was cassette loaded due to field volatility of disk drives, (heavy handed field personnel). 8088 dedicated processor for audible coding of fire system and graphic LED displays. Various DEC over the years. 11/23 comes to mind. Think I still have manuals in a drawer with schematics for older DEC equipment here somewhere. Data General Micro Nova used as a central Station monitoring system. Have the processor, lost the 10 Meg disk drives. Big on serial ports, All printers and terminals were serial LSI?s. Had one of those for a while, Eventually caved to ?wife? and got rid of the terminal. Various embedded 8749 machines over the last 14 years. I tend to do the hardware and another gent here writes the code. I learned in 6502 machine code, completely missed the assembly era. I have no idea where I was. Then jumped into various compilers. Kevin J Andres Senior Technician Engineered Protection Systems Inc. HYPERLINK "mailto:kandres at epssecurity.com"mailto:kandres at epssecurity.com -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.7.3 - Release Date: 3/15/2005

21 years, 5 months

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Logical Devices UV Eprom eraser QUV-T8 deal?

by zmerch＠30below.com

I need an EPROM eraser, and I found a Logical Devices UV Eprom eraser QUV-T8 for just under $100 shipped. Is this a good deal? I'll get it tonite if I'm not getting bent over... ;-) Thanks, Roger "Merch" Merchberger -- Roger "Merch" Merchberger | "Bugs of a feather flock together." sysadmin, Iceberg Computers | Russell Nelson zmerch at 30below.com |

21 years, 5 months

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Byte sizes, still tastes like nothing

by dm561＠torfree.net

-------------Original Message: From: "Steven Canning" <cannings at earthlink.net> Subject: Re: Byte sizes, still tastes like nothing Tom, Though I am inclined to agree with you in principle..... how can we discuss technology if we do not agree on the terminology? <snip> -------------Reply: Doesn't look like we're about to _agree_ on this any more than anything else (except maybe our appreciation of Jay & the others toiling on our behalf); no shortage of opinions though... mike

21 years, 5 months

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ProComm Plus

by dm561＠torfree.net

-----------Original Message: Date: Tue, 15 Mar 2005 15:58:16 -0600 From: "Keys" <jrkeys at concentric.net> Subject: ProComm Plus Was someone looking for ProComm Plus awhile back? I found a copy on 3.5 FD today in the warehouse along with several manuals of different versions. Let me know what you need from it. John ---------------------- That might have been me; thanks muchly, but I was (and still am) looking for a comm package called ProCALL. Anybody ever heard of it? Thanks, mike

21 years, 5 months

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I still cannot send emails to cctech, so this is a test

by jbglaw＠lug-owl.de

Hi! This is another test. I couldn't send emails to cctech either, but I've even got hardware to offer, which is hard if one cannot even send emails that reach their recipients... MfG, JBG -- Jan-Benedict Glaw jbglaw at lug-owl.de . +49-172-7608481 _ O _ "Eine Freie Meinung in einem Freien Kopf | Gegen Zensur | Gegen Krieg _ _ O fuer einen Freien Staat voll Freier B?rger" | im Internet! | im Irak! O O O ret = do_actions((curr | FREE_SPEECH) & ~(NEW_COPYRIGHT_LAW | DRM | TCPA));

21 years, 5 months

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I still cannot send emails to cctalk, so this is a test

by jbglaw＠lug-owl.de

Hi! I wasn't able to send emails to cctalk, so here's another test. I've even got some hardware to offer, but that's hard to do if one's emails just disappear... MfG, JBG -- Jan-Benedict Glaw jbglaw at lug-owl.de . +49-172-7608481 _ O _ "Eine Freie Meinung in einem Freien Kopf | Gegen Zensur | Gegen Krieg _ _ O fuer einen Freien Staat voll Freier B?rger" | im Internet! | im Irak! O O O ret = do_actions((curr | FREE_SPEECH) & ~(NEW_COPYRIGHT_LAW | DRM | TCPA));

21 years, 5 months

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Parity Checking in CPUs (was: Byte sizes...)

by bqt＠Update.UU.SE

On Tue, 15 Mar 2005 Roger Merchberger <zmerch at 30below.com> wrote: > Rumor has it that William Donzelli may have mentioned these words: > > >Parity checking is the job of the memory controller, not the processor. In > >fact, I am having a hard time thinking of a processor that did its own > >parity checking in software (yes, I know any processor could do it, but > >did any really do it?). > > 8085? There's a P bit in the condition code register (in 6809 speak) -- I > think it's called the PSW -- Program Status Word? I'm just beginning > learning assembly on my Tandy 10x/200 machines... Anyway, there are several > arithmetic operations that automatically set the Parity bit and there are > branch and return instructions that utilize the status of the P bit. Unless the 8085 differs from the Z80 (which both come from the 8080) this P-bit is used as parity very loosely speaking. It's actually P/V-bit. For arithmetic operations, it indicates overflow (V), while for logical operations it indicates parity of the result (P). Logic ops simply count the number of "1"s in the result, and set the P bit if the number is odd. Can be useful if you want to generate or check parity for data you're communicating. (Serial communication sometimes don't have hardware parity implemented for example). Parity for memory is never something dealt with by software. It would be a chicken and egg situation. > > Even if the parity checking is a lowly 74180, like > >in a microcomputer - it is still not boggin down the processor. The > >processor really doesn't need to know about parity, unless things go bad. > > Altho it's not a *huge* need, it can be handy for serial I/O... that would > be a function that uses parity, but is not reliant on the memory controller. Yes. But this is two different parity issues. Parity for memory is dealt with by hardware. Parity for communication might be dealt with by hardware or software. Johnny Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at update.uu.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

21 years, 5 months

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PS/2 to AT keyboard adapter (was USB Universal Floppy Disk controller)

by vp＠cs.drexel.edu

spc at conman.org (Sean 'Captain Napalm' Conner) wrote: > I'm having difficulty finding a PS/2 to AT keyboard adapter try http://www.cyberguys.com/templates/searchdetail.asp?T1=131+0410 or http://www.cyberguys.com/templates/searchdetail.asp?T1=131+0420 (both have the same picture, but one is male the other female. Either one costs $1.28 **vp

21 years, 5 months

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RQDX3 on an 11/23?

by pete＠dunnington.u-net.com

On Mar 15 2005, 23:01, Ethan Dicks wrote: > I have never used an RQDX3 except in a BA23 or BA123, but the schemes > I've seen described in this thread to manufacture a direct RQDX3->hard > drive should all work. If you can lay your hands on a BA23, however, > that would greatly simplify things, as you would have the distribution > wiring included, as well as a write protect switch and activity light > (for one drive, at least... there's an uncommon BA23 front panel that > _can_ support two hard drives and no floppies, or one can make some > hardware mods... apologies if this is confusing... ignore it if you > plan to use only one hard drive, and just know that it will work fine > in a standard BA23). It's certainly easier and likely neater to use the real thing, if you have it. But if you want to "roll your" own, I already published my distribution board layout and the RQDXn pinout, and later today I'll put the M9058 RQDX distribution board layout and circuit, and the circuit diagram for the Write-Protect/Ready switch panel up as well. -- Pete Peter Turnbull Network Manager University of York

21 years, 5 months

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RQDX3 on an 11/23?

by pete＠dunnington.u-net.com

On Mar 15 2005, 16:16, Eric Smith wrote: > Peter wrote: > > RT-11 V.5.x will recognise an RQDX controller and > > drive, but it needs to be V.5.03 or higher for an RQDX3 (earlier > > version of V5 have a bug that causes it to fail to initialise RQDX3 > > controllers properly -- though I wrote a patch if you need it). > > Does the bug affect any other MSCP controllers? I'd be interested in > looking at the patch to see what the RQDX3 does differently than other > MSCP controllers. It might. Basically the bug is that the driver assumes the SA register is zero, except during initialisation (when it returns various data in confirmation of the initialisation process, and one of four flag bits indicating which step it is performing) or in case of an error (when bit 15 is set). That's fine for an RQDX1 or RQDX2, but not for an RQDX3. On an RQDX3, SA will usually be found to contain a copy of the interrupt vector as well as the above flags/data. The MSCP docs don't actually say it should be zero other than the flag bits, just what certain flag bits mean. At certain points in the code, the SA register is checked to see if bit 15 is set (the error flag). However, the V5.01 code uses BNE, which of course branches if *any* bit is set, instead of BMI, which checks only bit 15. Here's my original (1994) patch, a file called DU.COR to patch DU.MAC: \ -23 ; ; Added (commented) fixes in 4 places, to use with RQDX3. ; Fixes concern use</interpretation of SA register. -561,563 ; BEQ DISPAT ; OK if RQDX1 or RQDX2 running ; BIT #ISTEP4,R5 ; see if doing</done last step in init seq ; BNE DISPAT ; OK if so - go to function dispatch bit #104000,R5 ; error ? or (externally-triggered) reset ? beq dispat ; dispatch function if not, INIT if either set -634,634 ; BNE INIT ; old code for RQDX 1 or 2 bit #170000,r5 ; see if in init sequence or error bne init ; yes if any set -846,846 ; BNE 4$ ; for RQDX3, check error with BMI... bmi 4$ ; not BNE... could have vector as well as flag -852,852 ; BNE 4$ ; likewise, I'm sure ! bmi 4$ / If you want a bit more of the context, look in http://www.dunnington.u-net.com/public/RQDX/DUX.TXT I spent ages working this out. Someone on Compuserve also published a fix, but it was incomplete and didn't always work. -- Pete Peter Turnbull Network Manager University of York

21 years, 5 months

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OT: What is a .SC4 document?

by waisun.chia＠gmail.com

If it is SC, then it is a ASCII *nix-based spreadsheet using Curses. http://freshmeat.net/projects/sc/ p.s. SC is current version 7.x, so perhaps it was at v4.x during 1998? On Tue, 15 Mar 2005 23:35:17 -0800, Zane H. Healy <healyzh at aracnet.com> wrote: > Does anyone happen to know what a .SC4 file is. It was written on a > Linux system in 1998 (most likely Red Hat), and I think it was some > sort of spreadsheet. Any idea what I can open it with? > > Zane > > -- > -- > | Zane H. Healy | UNIX Systems Administrator | > | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | > | | Classic Computer Collector | > +----------------------------------+----------------------------+ > | Empire of the Petal Throne and Traveller Role Playing, | > | PDP-10 Emulation and Zane's Computer Museum. | > | http://www.aracnet.com/~healyzh/ | >

21 years, 5 months

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OT: What is a .SC4 document?

by dhbarr＠gmail.com

On Tue, 15 Mar 2005 23:35:17 -0800, Zane H. Healy <healyzh at aracnet.com> wrote: > Does anyone happen to know what a .SC4 file is. It was written on a > Linux system in 1998 (most likely Red Hat), and I think it was some > sort of spreadsheet. Any idea what I can open it with? At or about that time, there was a spreadsheet program named "SC" in it's 4.1 revision, at least according to this site: http://www.rocketaware.com/math/matrix/. It seems plausible that SC6.8 (available here: ftp://ftp.uu.net/usenet/comp.sources.unix/volume23/sc6.8/ ) ...should be able to read such a beastie. If not, try 4.1 here: ftp://ftp.uu.net/usenet/comp.sources.unix/volume11/sc4.1/ ...or a BSD port available here: ftp://ftp.netbsd.org/pub/NetBSD/packages/pkgsrc/math/sc/README.html Good Luck, -dhbarr.

21 years, 5 months

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OT: SPAMMAGE: TEST

by gordon＠gjcp.net

Sorry about this. I suspect I've fallen off the list. Gordon.

21 years, 5 months

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Frieden calculator

by petouche＠uci.edu

Do you still have the calculator ? And perhaps a picture of it, as I really don't know what the ,model designation means. And finally, a manual of operation ? My interest is sentimental. Paul Touchette Paul E. Touchette, Psychologist Developmental Disabilities Service Department of Pediatrics University of California, Irvine voice: 714-957-5487 fax: 714-957-5354 petouche at uci.edu

21 years, 5 months

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Longevity of DVD-R and CD-R (Was MagTapes)

by dwight.elvey＠amd.com

>From: "Eric Smith" <eric at brouhaha.com> > > >Yes. They are laminated with adhesive, just as laser videodiscs were. >The adhesive leaks O2 even when it's working well, and as it degrades >it leaks worse. > Hi It sounds like the only way to deal with this is to store disk in an innert environment. N2 or argon are reasonable options. Only expose the disk to UV and O2 when actually used to recover data. They should last for 1000's of years this way. Dwight

21 years, 5 months

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RQDX3 on an 11/23?

by pete＠dunnington.u-net.com

On Mar 15 2005, 13:31, David Betz wrote: > I have a PDP-11/23 and would like to add a hard disk. Would the RQDX3 > be the way to go? What do I need besides the board itself and an MFM > drive? Obviously, I need some sort of cable to connect the two. Is > there anything else I need? Will RT-11 V5 support an MFM drive on an > RQDX3? A SCSI controller might be better, insofar as SCSI drives are easier to find. Unfortunately they tend to be expensive, and you need to be aware that some only support tapes, not disks. An RQDX3 should be fine if you can find a suitable drive. It needn't be a genuine DEC drive, as the formatter for the RQDX3 can be told what the drive parameters are. They're a pain to work out from scratch (I've done it) but the formatter contains tables for several standard drives, including one or two standard Seagate drives, and if you don't mind using less than 100% of the theoretical capacity, there's usually at least one table entry that will do. Avoid RQDX1 and RQDX2 boards, unless they're free, as they have a number of limitations. For example, RQDX1 doesn't pass grant signals, so it has to be the last device on the bus. RQDX1/2 are fussy about the drives; they have internal tables of drive parameters and play tricks to see what's connected. They're slower, too. You want to make sure you get the latest (or next-to-latest) RQDX3 firmware ROMs (not hard, and most have them anyway) and you'll need a bootable copy of XXDP and the formatter program (ZRQCxx). You also need either a signal distribution board, which splits out the signals >from the 50-way connector on the RQDXn to the usual 34+20 ribbon connectors, and has provision for the front-panel buttons (which control online/offline and write-protect). I made my own (two versions), or you could just make up a fancy cable. You want the button panel, or a homemade substitute (you can get away with some jumpers and a pullup resistor or two, if necessary). Once formatted, for which you need XXDP and ZRQCxx, or a MicroVAX with its diagnostics, RT-11 V.5.x will recognise an RQDX controller and drive, but it needs to be V.5.03 or higher for an RQDX3 (earlier version of V5 have a bug that causes it to fail to initialise RQDX3 controllers properly -- though I wrote a patch if you need it). If you get an RQDX3, it can also control one or two RX33 floppies, which are rebadged TEAC FD-55-GFR 5.25" floppy drives. Layouts for my signal distribution board are on my website, along with a document listing the RQDX3 pinouts, and a bunch of ROM images: http://www.dunnington.u-net.com/public/RQDX/ http://www.dunnington.u-net.com/public/PDP-11/XXDP.pdf http://www.dunnington.u-net.com/public/DECROMs/ROMlist http://www.dunnington.u-net.com/public/DECROMs/ -- Pete Peter Turnbull Network Manager University of York

21 years, 5 months

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Advin Systems PAL/EPROM programmer Sailor-PAL

by frustum＠pacbell.net

I picked up an older pal/eprom programmed from Advin systems at Weirdstuff warehouse when I was in Sunnyvale recently, $5. I knew I was talking a risk, but for $5, who cares? This unit is labeled "SAILOR-PAL". Anyway, Advin is still around, and their web site has manuals and software for their programmers -- anything since 1996 or so. This unit is from 1986. Does anybody on this list happen to have documents or software for this programmer and is willing to share? I contacted Advin and their terse reply was: this system is no longer supported. Searching on google turned up a few references to this programmer but nothing useful. My main interest is as an EPROM reader, so even if it isn't perfectly calibrated, it should be fine for the purpose. If I can't come up with the software, I guess I'll do what I have done before: used a BASIC Stamp to drive the address pins and read the data pins. The programmer would just be more convenient is all. Thanks.

21 years, 5 months

1
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Who invented DOS?

by swtpc6800＠comcast.net

> All I want to know is who decided to use \ instead of / for > directory separators (warming up the tar and holding feathers). I use Windows and Solaris. The driectory separator drives me batty. One thing that DOS got right is to retain the file date when a file is copied to another directory. ------------------------------- Michael Holley www.swtpc.com -------------------------------

21 years, 5 months

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Who invented DOS?

by melamy＠earthlink.net

I thought it was Gore... or was that the internet???

21 years, 5 months

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Data General Nova 4/x -- update on Kermit

by tomj＠wps.com

Well with Bruce's help (and a bit of actually paying attention to what I was doing) I got Kermit to compile -- properly -- on RDOS. Kermit for RDOS consists of about 20+ smaller source files, separately compiled, and linked with the linking loader. THe source is D.G. FORTRAN5, and the output of a seemingly-lost RATFOR preprocessor. Kermit was archived as one big file containing all of the sources, with comments to indicate where to break them into files: CCCCCCCCCCCCC STDIO.FT CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C code here.... ... Bruce game me an awk script that does it, but since I don't have any way to get files in/out to RDOS (except open-loop "text download" through the console) I did it locally with an nspeed command, looks like teco: 1WMGRKERMIT.FR$<NCCCCCCCCCCCCC ^T$T1BC1BS10KS $-1D1KBS0GCGW^B1$(^)!I;>GC$$ $ is escape key, ^T is Control-T, etc. < ... > is a loop; the semicolon is a conditional exit (if the search fails). N is "yank pages, copying to the output file, buffer-fulls of text until 'CCCCCCCCCCCCC ^T' is found". ^t means any number of space characters. The transmission line noise is really copying the current line, under the virtual cursor, to buffer 1, stripping the comments off the embedded filename and building a command to create anoutput file...

21 years, 5 months

1
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cctalk Digest, Vol 19, Issue 61

by yannetti＠yannetti.com

Hi Fred; Glad you signed on. I have been waiting for someone older than myself to speak up. Just didn't want to be the oldest. Born 1930 and I will be 75 in April. Started playing around with an Atwater Kent radio around 1939, went to a Radio Mech. course at a Vocational School , 1944 to 45. Left school and joined the Army where I served 5+ years as a brass pounder and comm. chief. Two years of which were at the Signal Corps Evans Lab. After the service went to work for the Navy, mostly on Shipboard radar and taught in their apprentice program ( Math and Physics ) Moved to the FAA when they opened their Research Center at Pomona, N.J. in 1960. Worked mostly on Radars and Auto Landing Systems. All Analog stuff. Was assigned to the ATC Labs in early 1970 and it didn't take long to realize I was in a "Mushroom Farm" so I went back to school for a degree in Information Science. That is when I got into computers. I remember the 1401, 7090, sigma 7 and the IBM 360's ( we called them 9020's ). the ATC program was being developed in JOVIAL. My language however was FORTRAM. Retired in 1981. Fred if you look hard enough you will find a few of us are still here. Bob Yannetti, age 74 going on 75

21 years, 5 months

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Longevity of DVD-R and CD-R (Was MagTapes)

by Watzman＠neo.rr.com

Ironically, the DVD-R media that I've had the best luck with -- and my experience with this brand has been superb, no failures, perfect burns, and perfect subsequent readability -- is a bargain private-label off-brand. It's "K-Hypermedia" brand, sold by OfficeMax (and, very rarely, by other retailers). I've gone through over 10 25-packs over a period of 2 years, 1x (which burn well at 2x on Pioneer burners) and 4X, and my experience with these has been wonderful. And they are cheap, sometimes on sale for as little as $5 for a 25-pack (more commonly $10 for a 25-pack). On my Pioneer A04 burner, I could burn the 1X media at 2x by default. On my A08, I had to get "hacked" firmware to allow me to select any burn speed with any media. But in both cases, 2x works fine for the nominally 1X media. I'm now also using 4X media with equally good results. [They have a DVD+R product as well, I have used one spindle of it, it was fine, but my experience suggests that when given a choice, "-" is the format to prefer. Cheaper, more available and more likely to be readable, not withstanding that the "propaganda" says just the opposite.]

21 years, 5 months

1
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VT-100 terminal wanted

by elf＠ucsd.edu

Ashley Carder wrote: > Anyone out there have a working VT-100 terminal > and keyboard they'd be interested in selling? I > need to get one to replace one that I'm giving > away with a system. Funny -- I was about to post the same "Wanted" message last week. Let me jump in line here behind Ashley for anyone out there with a working VT-100 terminal they feel like parting with (for $'s, or for trade). Contact me off-list. Eric F.

21 years, 5 months

1
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PerSci 277 floppy drives

by Watzman＠neo.rr.com

I have quite a bit of experience with these (and, by the way, I'm looking for one or two ....). The Persci drives for the most part are single full-size drives that accept two different media in the same drive. They are not quite the same thing as "dual drives" because there is only one head positioner for both drives. However, it's a huge voice coil and it's very fast (1 millisecond per track). The drives have a horrendous number of very, very different configuration achieved by about 4 dozen jumpers. There are several dozen "standard" configurations, and many of them are quite non-interchangeable. The interface is a standard 8" floppy interface (50-pin connector), and they can be used with most controllers ***IF*** they are properly jumpered/configured. However, some of their quirks are very, very unique. One is the single positioner, moving the head of the "A:" drive also moves the head of the "B:" drive, and vice-versa. This requires a different BIOS for Persci drives vs. a more conventional configuration of two separate drives. Another thing is seek timing. The seek speed is very, very fast, and the servo system is capable of dynamic acceleration and deceleration. To use this, which is all but mandatory, instead of sending step pulses at, say, 6 nSec. per pulse (track), the step pulses are sent at a VERY high rate, over 100,000 pulses per second. The drive buffers them, and dynamically accelerates the head to max speed for the seek, and dynamically decelerates it at the end of the seek. There is a new interface signal "seek complete" to tell you when the head has arrived at the desired track. This is totally different than a normal stepper motor drive, and requires both some minor hardware changes (which are supported by almost all LSI-based S-100 controllers, e.g. Western Digital) and some software changes. It's not difficult and it works well, BUT it means that a BIOS for a conventional stepper motor drive and a Persci drive are two separate BIOS'. These drives are a wonder to behold, the main board is huge (something like 200 square inches) and beautiful. But they are almost unserviceable, since parts are not available and they used some very unique components, and also they are quite fragile (there is a special insert required for shipment, and they are unlikely to survive shipment without that insert). I personally scanned all of the Persci service data on the 270/277 drives and they are up on Howard's site for download, so at least documentation is available. If you have any questions, I'll try to help, but if they are "dead" or grossly non-functional, the chances of resurrecting them are slim.

21 years, 5 months

1
0
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Parity Checking in CPUs (was: Byte sizes...

by dwight.elvey＠amd.com

>From: "Eric Smith" <eric at brouhaha.com> > >river wrote: >> Yes, the 8080/8085/8086 series chips did parity checking. The PSW had a >> flag for odd/even parity. Naturally, the Z80, being a superset of the 8080, >> also had this ability. > >In that regard, the Z80 is not a proper superset of the 8080. The >parity flag is usurped to act as an overflow flag after arithmetic >operations. It is still partity after moves and logical operations. > >Eric > > Hi Giving it some thought, the only compute application for parity that I can think of would be reverse bit swapping. This is generally done on an address though and might not be all that useful on a byte value. ( FFT's often need this function ). Dwight

21 years, 5 months

1
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HHC Basic Status

by zmerch＠30below.com

Been kinda busy (especially at home - which is where all the fun stuff is supposed to happen...) However, on Sunday, I did get enough of a chance to dead-bug connect 2 24-pin wirewrap sockets together, and wirewrap the legs - this made a hackish but working adapter for the HHC Roms. I read several different Roms into the PC, verified 'em, looked at .bin files and I can say that everything that looked like it should be text looked like text. The Basic ROM just came in today - and despite the lack of anti-stat looks to be in fair shape. It also looks like the seller put 2 dabs of epoxy on the chip so it couldn't be removed from the carrier and copied. (I say that because I could still smell the epoxy - Everything that I've ever epoxied stopped smelling after 2-3 weeks; a month at most.) Of course, my adapter doesn't give a whit about that... ;-) I'm looking to snipe an EPROM eraser on ePay tonite about 10pm EST... If I don't get that one tonite, I'm just gonna buy one so I'll be able to burn new EPROMs very soon. If anyone just wants the code and can make their own EPROMs, I'll have that available soon; prolly tonite. ;-) I'll keep in touch, "Merch" -- Roger "Merch" Merchberger | A new truth in advertising slogan SysAdmin, Iceberg Computers | for MicroSoft: "We're not the oxy... zmerch at 30below.com | ...in oxymoron!"

21 years, 5 months

1
0
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Parity Checking in CPUs (was: Byte sizes...

by river＠zip.com.au

Hi, >Rumor has it that William Donzelli may have mentioned these words: >>Parity checking is the job of the memory controller, not the processor. In >>fact, I am having a hard time thinking of a processor that did its own >>parity checking in software (yes, I know any processor could do it, but >>did any really do it?). >8085? There's a P bit in the condition code register (in 6809 speak) -- I >think it's called the PSW -- Program Status Word? I'm just beginning >learning assembly on my Tandy 10x/200 machines... Anyway, there are several >arithmetic operations that automatically set the Parity bit and there are >branch and return instructions that utilize the status of the P bit. Yes, the 8080/8085/8086 series chips did parity checking. The PSW had a flag for odd/even parity. Naturally, the Z80, being a superset of the 8080, also had this ability. I assume that the later generations of x86 series chips, for backward compatability, also had the ability to check for parity. The TMS9900 series also did parity checking. >From a cursory glance at the status registers of the 6809 and 68000 processors, it appears these devices did not have inherent parity checking. river

21 years, 5 months

4
3
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PDP-11 Success Story.

by gordon＠gjcp.net

Long story short, I got it working. Want some pictures? http://www.gjcp.net/~gordonjcp/pdp-11.html Want to play? Get me in #classiccmp on irc.freenode.net sometime tonight. I plan on going to bed about midnight, and I will be turning the noisy bloody contraption off. Failing that, get me tomorrow. Gordon.

21 years, 5 months

10
10
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HP Integral : running !

by jos.mar＠bluewin.ch

So i got my newest toy, a HP Integral running. Problem turned out to be cold solder joint at the Powerok signal. Strangely enough the current carrying pins nearby were OK. Thanks to Tony and Joe for the pointers... A mechanical problem with the floppy will be sorted later. First impressions : this thing badly needs a harddisk.... Second : if this is HPUX 5.0, what must HPUX 1.0 have been.... Of course i do no have software and manuals. Am i wrong to believe that the system is only really usable with a harddisk, or am i overlooking something ? Jos

21 years, 5 months

5
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Byte sizes

by bqt＠Update.UU.SE

On Mon, 14 Mar 2005 woodelf <bfranchuk at jetnet.ab.ca> wrote: > der Mouse wrote: > > >Well, it sounds reasonable, but probably isn't the most useful, as it > >would mean that, for example, the PDP-8 had 12-bit bytes. > > > > > > > Umm words... it has six bit bytes. I think the lack of 18 bit byte > cpu's has limited > the use of 9 bit bytes. ( No comment from any 36 bitters ) What, the PDP-8? No, it don't have six bit bytes. The architecture don't have any byte view (unless you count the BSW instruction in the 8/e and newer, which might be argued as a byte instruction). Software implemented bytes in various ways on the PDP-8. You have sixbit, 8 bit, and 12 bit bytes. OS/8 for instance packs 3 8-bit bytes in two 12-bit words. > >>The PDP-10 is an excellent example of when this isn't true. > >>The smallest addressable unit is a word, which is 36 bits. > >>A byte is, as noted, anything between 0 and 36 bits. Bytes are > >>stored in a word, as many as can be fitted. To access bytes on a > >>PDP-10, you have a byte pointer, which consist of a word address, and > >>a bit pointer, and byte size. > >> > >> > > > >That sounds a whole lot like a hardware-supported way of addressing an > >object of an arbitrary size in bits. And that would mean that bytes of > >any size *are* individually addressible. > >Or have I misunderstood? > > > I belive so, but I have not programmed a 10. I suspect this is in > regards to string operations > rather say accessing character sized data data. Two different things. No difference between a string, or character sized data. Character sized data layed out in sequence becomes a string. The instruction that deals with bytes only handles one byte at a time. Chug through several characters and you have processed a string. > >>The fact that people today seem to believe that byte addressable is > >>the only possible thing, along with a byte being 8 bits, is plain and > >>simply because they haven't seen any other. > >> > >> > Well in most cases a byte is a unsigned 1/2 half word. I still like view > of the PDP-11 a byte > is signed data. I think the lack of real byte access has forced the C > standard to have unsigned > bytes because the machines ( 8080,Z80) can't handle real bytes . Huh? What are you talking about??? All these machines (as well as most anything past 1960) uses 2-complement, so there is no need to differentiate between signed and unsigned, it's just a matter of interpretation. The one time it makes a difference is when checking results, and the PDP-11 have both signed and unsigned branch conditions, so it don't view a byte as either one or the other. It's up to the programmer to choose. The same with a Z80. I would assume that the 8080 also have the same status flags, and thus you can pick wether you want to play signed or unsigned at will. And a byte on a PDP-11 is not 1/2 half word, but just a half word. A word is 16 bits. That's why, on a VAX, a 32-bit thing is called a longword. But for some reason some other manufacturers decided to call 32 bits a word, so 16 bits became a "half word", but let's keep that away from the PDP-11, please. No revisionst stuff here. :-) Johnny Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at update.uu.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

21 years, 5 months

3
2
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age

by pechter＠pechter.dyndns.org

Add another one to the 50-54... I'm 50 now hitting 51 in June. Bill

21 years, 5 months

2
1
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Also still looking for a VT-50

by wacarder＠usit.net

I'm also still looking for a VT-50 for my Wofford Witch computer center to add the authenticity factor to it. The VT52 terminals that I have are filling in quite nicely, and yes, they are a better terminal than the VT50, but I would like to find a working VT50 just to make a system a more authentic replica of the original 1978 computer center. Ashley

21 years, 5 months

1
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VT-100 terminal wanted

by wacarder＠usit.net

Anyone out there have a working VT-100 terminal and keyboard they'd be interested in selling? I need to get one to replace one that I'm giving away with a system. If anyone has one for sale, send me a private reply to wacarder at usit.net. Thanks, Ashley

21 years, 5 months

1
1
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ProComm Plus

by jrkeys＠concentric.net

Was someone looking for ProComm Plus awhile back? I found a copy on 3.5 FD today in the warehouse along with several manuals of different versions. Let me know what you need from it. John

21 years, 5 months

1
0
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Your age statistics

by hatfield＠bellsouth.net

At the risk of tilting your age spectrum report, I must admit to possibly being the eldest computer nut on the list. I noticed a complete lack of cohorts in this age group, they must be either all deceased or devastated by Alzheimer's.... Fred Hatfield, age 76.

21 years, 5 months

2
1
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Longevity of DVD-R and CD-R / 2-Media Hedge

by bristol22＠softhome.net

Richard wrote: > 4) All RW media (DVD-RW DVD+RW CD-RW) have poor archival life. > Think about it: with RW, instead of burning a pit in the data > layer, you are fooling around with glossy or matte finish > depending on how quickly a melted liquid re-freezes. Official > tests, and my own tests, show poor life. A little sunlight-UV > can erase it. Eric wrote: >It was my understanding (perhaps wrong?) that RW media uses a phase >change to store the data, and that it takes significantly more energy >to induce the phase change than to induce a chemical change in dye >for write-once media. That's why it can't be written as quickly. >If it really works that way, one would reasonably expect RW media to >have *better* longevity than write-once media. >So is my premise wrong? Does rewritable media not use a phase change? >Or is the activation energy comparable or lower than that for write-once >media? I don't know about activation energy. Sorry. But the resultant RW disk is less reliable, and has shorter archival life. Richard: > My least favorite factory is CMC Magnetics Eric: >They seem to make about the worst CD media, so it's unsurprising >that they make poor DVD media. Richard: > I think Pioneer and Verbatim buy their media from > the good Japanese companies, Mitsubishi, Taiyo Yuden, and Mitsumi. Eric: >By "Mistumi" you must have meant "Mitsui"? For CD media, Taiyo Yuden >and Mitsui are definitely the best. Richard: Yes, I meant Mitsui. It was a typo. Mitsumi is I think a maker of floppy disk drives in Japan, and not media. Mitsui and Taiyo Yuden make good media, and sell organic dyes and other chemicals to many of the lesser media making companies. Richard: > TDK seems to be only advertised brand that makes their own Eric: >I used to buy TDK CD-R media at Costco because it was made by >Taiyo-Yuden. Then they switched to CMC Magnetics, and after >using one spindle of that (with >50% reject rate), I refuse to >ever buy media from them again. >I'm surprised that TDK would make their own DVD media when they don't >make their own CD-R media. More likely they're contracting out >manufacture and getting the vendor to mark the metadata as TDK. >Eric Richard: I'm sorry to hear that. I know their media code says TDK, but you are correct, maybe they didn't make it. But it tested well. ========== ADDITION TO RICHARD's PREVIOUS POST ===== In my original message, I forgot to add: ... 7) If you really care about it's archival life, hedge your bets by burning two copies, on DIFFERENT media. Select two good media types made by different companies. Each may have, just a guess, a 10% chance of self-destructing within 20 years. This would be because of a design or implimentation mistake. For example perhaps the sandwich adheasive includes a chemical that eventually reacts badly with the data, or some impurity in manufacturing at that time. If the two media are very different, their probabilty of failure approaches statistical indpendence; and if independent then the chance that both are unreadable would approach 0.1 * 0.1 or only a 1% chance. Richard Bristol bristol22 [at] softhome [dot] net

21 years, 5 months

5
4
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Byte sizes (was Re: 2.8M 3.5' floppy

by dvcorbin＠optonline.net

> Just like stating raw clock speedtoday for marketing. >I can buy a N GHZ machine but can anybody tell me > the real speed of instruction abc on data xyz? Sure, if you know all of the environmental issues (condition of pipeline, status of cache, etc). I have worked on a significant number of Pentium (and other pipelined multi-level cached) based systems for engineering projects, and *sometimes* we do have to actually still calculate this stuff out to prove that a design will work under various system and data conditions.

21 years, 5 months

1
0
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USB Universal Floppy Disk controller

by Watzman＠neo.rr.com

I remain convinced that USB, not parallel, is the "right" way to go for interfacing a Universal Floppy Disk controller. The whole purpose of the device is to be a "bridge" between old and new. The "old" side is fixed, it's the drives we want to interface to. But the new side is "today's PCs", only "today" really doesn't mean "today" but really today and tomorrow. Parallel and serial ports are disappearing RIGHT NOW. Some new PCs -- most new notebooks -- already don't have them (and yes, I might want to use this with a notebook). It's 2005 now, and we are talking about designing a device that doesn't exist yet. What about 2008, 2009 ..... even 2015? USB interfaces essentially "started" in about 2003 and in my view will likely exist for about as long as RS-232 devices existed, e.g. decades. Why? What was RS-232 used in? Electronic equipment, LOTS of it, but almost NO consumer equipment. What is USB used in? Electronic equipment, lots of it. AND ... Digital Cameras, MP3 players, cell phones, GPS receivers .... the list is endless. USB is both just starting, and so completely ubiquitous (and, very importantly, in BOTH "lab" equipment AND "consumer" equipment) that it's going to be around for decades to come. Parallel port? The primary use has always been printers. But you can't even find a printer with a parallel port easily, and parallel ports in PCs are already starting to disappear. This is a device that we want to be useful now and in the future, and I firmly believe that any serious analysis will conclude that USB is the way to go. [Someone questioned if the speed was adequate. USB 1.x is 12 megabits per second, USB 2.x is 480 megabits per second. The target devices are floppy disk drives, to which the maximum write bitrate is 1 megabit per second. Clearly USB 2 can do absolutely anything that would be relevent, and there's not much, if anything, that USB 1 couldn't do.]

21 years, 5 months

1
0
0 0

Got Videotrax card working

by James＠jdfogg.com

> Anyway, I'd really like to know more about your experience if > you can remember any details. Well, it was a looong time ago. It was a short card with two RCA (phono) jacks as I recall. I had it installed in a Hyundai (yes, same as the car maker) 386/DX20. I seem to recall I'd get somewhere in the middle of the tape during a restore and it would fail. I don't remember the nature of the failure. I also seem to recall it corrupting restored files on my disk. There is a small chance that I still have it hiding in a box somewhere. It would be in the corner of the basement that I'm working my way toward cleaning. Perhaps I'll find it this spring. I'm not known for throwing stuff out ;-) Over the years I've learned to never trust tape of any kind. I expect a backup system to be completely trustworthy and until recently I haven't found any I'd trust that much. Maybe I shouldn't now, either - but I haven't been burned lately.

21 years, 5 months

13
18
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My Data General Nova 4/x page, update

by tomj＠wps.com

I know it's not a crucial new announcement or anything, just an update... Just fyi, I've reorged my Nova 4 website (http://wps.com/NOVA4/) a bit. Took some of photos of internals, such as the disk drive (when I re-cleaned the heads after 20 hours of operation -- utterly spotless, whew!) last week. Changed are mainly organization, plus added photos, and a tiny bit of software, including classic (sic) MORE. I've been an idiot about this Kermit program, I'm workign on it now.

21 years, 5 months

3
2
0 0

Got Videotrax card working

by msokolov＠ivan.Harhan.ORG

Ethan Dicks <ethan.dicks at gmail.com> wrote: > in the case of Qbus and Unibus boards, since the > fingers are gold, it has to be due to oxide build up on the backplane > pins. Aren't the backplane contacts also gold-plated? MS

21 years, 5 months

3
2
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USB Universal Floppy Disk controller

by dwight.elvey＠amd.com

>From: "Jules Richardson" <julesrichardsonuk at yahoo.co.uk> > >On Mon, 2005-03-14 at 11:55 -0800, Dwight K. Elvey wrote: >> >From: "woodelf" <bfranchuk at jetnet.ab.ca> >> >Look what you are doing is building a generic floppy disk controler. >> >The only high speed device what you use to sync the data/clock pulses >> >to the system cpu clock. The rest is software. I'd sooner use a CPLD >> >designed for generic bit sampling but a PIC would also work with >> >a digital data/clock seperator. Now would getting the people who do >> >cat-weasel create a USB version be a better goal? >> >Ben alias woodelf >> >PS. What about hard-sectored floppy disks, that too may need reading >> >too? >> >> Hi >> I think you are missing what I am saying. The SPI is just >> a shift register that takes an external clock. It can be programmed >> to automatically DMA transfer into memory. It is the perfect zero >> additional logic circuit to use. You don't need to build a >> data/clock separator or anything. Just sample the data. >> One could even make the output SPI provide write data. These >> chips are designed to load their programs from a single >> flash or EPROM so the entire hardware requirement is almost >> nothing. >> I see others on comp.os.cpm talk about using a 50MHz variant >> of a Z80. I think most miss the point. These DSP's are 30 MIPS+ >> not just 50 MHz clocks. They have enormous capabilities in >> a relatively small package. It was like they were designed for >> this project. You don't need to create a CPLD since the hardware >> part is already done for you. > >What about cost? (irrespective of how the device physically connects to >the host machine) > >I forsee four goals to make it useful: > > o Cheap Hi When one considers how much hardware one saves over a PIC solution, the DSP is cheap. They are in the $10 range. > o Simple to build by anyone with a few electronics skills. A little tough here. 50 mil spaces surface mount. Some soldering skills required. > o Open 'source' (all schematics etc. available) No issue here. > o Easy / quick connectivity Although, most computers come with a parallel port, using the port on a newer XP for other than normal purposes may be a pain. > >Catweasel seems to lose out on 1, 3, and 4 - and 2 isn't relevant in its >case. Can't comment on how nice its software API is as I haven't looked >at it yet, but doubtless a bunch of us on this list could come up with >something that'd cater for all tastes (plus the really low-level >software would all be open source anyway!) > >Personally I'm not a fan of a USB version though; I'd rather have >parallel as pretty much any machine has a parallel port - USB limits me >to newer PCs and Macs (plus software interfacing *might* be harder). > >Priorities seem to me to be (highest first): > > o Reading disks Should be easy. > o Writing back a disk image I see only minor issues here ( pre-comp ) > o Decoding disk data on host machine Just requires some one to do it. > o Modifying disk data on host machine, re-encoding back to floppy If one can do the above, this one comes along, almost for free. Later Dwight > >Happily, that's probably order of complexity too, easiest first :) (I am >coming at this from a preservation point of view, rather than being able >to create disk images for use with emulators, say) > >cheers > >Jules > >

21 years, 5 months

4
3
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Two on-topic posts at Slashdot today

by news＠computercollector.com

NPR interview with Donald Knuth at http://tinyurl.com/5zs35 and community efforts to save abandonware at http://tinyurl.com/5xk9p. - Evan Evan's personal homepage: www.snarc.net *** Tell your friends about the Computer Collector Newsletter! - It's free and we'll never send spam or share your email address - Publishing every Monday(-ish), ask about writing for us - Mainframes to videogames, hardware and software, we cover it all - W: http://news.computercollector.com E: news at computercollector.com - We're approaching 700 readers: win a prize!

21 years, 5 months

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