test-drb

test-drb@ccmp.vtda.org

101090 discussions

by trixter＠oldskool.org

My best-condition 83-key keyboard suddenly developed a bum spacebar, right in the middle of writing some documentation. Before I unscrew the two screws on back to open it up and take a look, can anyone tell me if this is a common condition and if it's relatively easy to fix? I've *never* had a buckling-spring keyboard develop a bad key (maybe I haven't had enough frustrating debugging sessions yet ;-) so I'm at a slight loss as to how to start repairing it. Was there a tech ref for the keyboard at one point, perhaps? Slightly OT, here's an 83-key that is *gray* (several pictures): http://www.clickykeyboards.com/index.cfm/fa/items.main/parentcat/11066/subc… I've never seen a gray variant -- was it official? If so, what system was it intended for use with? I've seen "skinny" IBM keyboards that were intended for use with the PS/2 model 25, but I've never seen a gray 83-key before... -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Help our electronic games project: http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/ A child borne of the home computer wars: http://trixter.wordpress.com/

19 years, 1 month

FPGA CPU's (was: Re: wonderful assembly language book)

by mtapley＠swri.edu

At 12:02 -0500 5/6/07, Pat wrote: > > Au contraire. "Architecture" these days is whatever you want it to be > > cooked into an FPGA. .... FPGA designs are > > *very* popular for custom architectures these days. > >Sure, but no one (in their right mind) builds a general purpose CPU out >of them. Well, unless it's a research or "toy" project, a prototype >design, or something very unusual and high end[1], but even in that case >it's still not making a general purpose CPU out of it. Although I tend to agree with Pat about the "right mind" part of it, we routinely do this for spacecraft avionics. Both simple processors, like 8085, and more complex ones like SPARC architecture are implemented in FPGAs. The speed is generally far below what a "real" CPU would do, but because we can implement more functions than just the CPU into a single chip, and because we can often get an FPGA that has been tested to better radiation exposure levels than the corresponding (faster, smaller semiconductor feature) "real" CPU, it still turns out to be the best option in many cases. I really mourn the lack of availability of rad-hard CPU's anymore. Harris RTX2010 (a forth-oriented 8/16 bit) and the RAD6000 (a PowerPC-like unit) were both workhorses in the past. The FPGA's we use routinely come up with chip-level problems of one form or another (bad programming algorithms, power-up sequencing issues, etc.) that cause angst, board reworks, or other serious cost and schedule problems. That never used to happen with "real" CPUs. >I challenge you to come up with the name of a single product that someone >can purchase right now, which uses an FPGA-implemented CPU, which is >general-purpose, and reasonably widely available. :-) admittedly, I can't really claim our avionics boxes are "widely available", though we're always looking for new customers.... -- - Mark, 210-379-4635 ----------------------------------------------------------------------- Large Asteroids headed toward planets inhabited by beings that don't have technology adequate to stop them: Think of it as Evolution in Fast-Forward.

19 years, 1 month

Replacement belts for Amstrad CF floppy drives

by cclist＠sydex.com

Thanks to another cctalk-er, I've discovered an inexpensive replacement for the dreaded neoprene belt in Amstrad 3" CF drives. There's a product called "Plastibands" available at many office supply stores (or on Amazon.com) that are intended as a replacement for traditional rubber bands. They're made of polyurethane and have a considerable amount of "stretch"--and, the best part, don't disintegrate quickly. I slipped one of the 2" x 1/8" bands on my CF drive and it works like charm--plenty "grippy". A box of 100 on Amazon runs less than $5.00. That should keep you and your best friends in drive belts nearly forever. There's also a larger 4" x 1/4" size. The $64,000 question is "Can these be used as a replacement for the band in DC-600-ish QIC carts? My initial experimentation with the 2" model in a DC-2000 cart is "not quite"--the QIC application requires a bit of slip, which these don't appear to have--they're a bit too "grippy". However, I'm going to tumble a few in some molybdenium disulfide powder for a few days to see if a "slip" can be imparted to them. Stay tuned... However, I suspect that the larger belts might work with old 5.25" floppy drives that require a drive belt. Remember, as they stretch, they get narrower. Cheers, Chuck

19 years, 1 month

IBM 83-key questions (repair and color)

by Watzman＠neo.rr.com

Re: "The spacebar - beyond the switch - has a small "C" supporter that keeps the bar horizontal and makes any pressure in any point of the bar activate the switch" This is called an "equalizer" mechanism, and all keyboards have it on all large keys (it's usually present on the enter and shift keys as well as the space bar, and often on a few other keys). These can be a real bitch to get reconfigured properly, but it's a purely mechanical task, and with some patience, if this is the problem, it should be fixable. It's possible, however, that this isn't the problem. Do NOT take the back of the keyboard apart as a first step, rather, remove the space bar (being very careful not to break the equalizer mechanism and noting in detail how it is attached). There is a metal plate inside the "switch" that serves as the actual contact point, this can become dislodged. Or there might be dirt in the mechanism. It's very rare that these can't be fixed, and fixed without any new parts, unless something is really broken. More common it's just dirt or some mechanical part that has become misaligned.

19 years, 1 month

A local computer history group for my area . . .

by dgreelish＠mac.com

>> From: "Chuck Guzis" <cclist at sydex.com> >> Hi everyone, I have just started up a user group in my area to get >> together once a month and enjoy old computers and the history, etc. > David, some folks local to your area who are also on this list might > be more interested if you could nail down what you mean by "old". To > some, a Commodore 128 is "old"; others wear socks older than that. Hi Chuck, as a general guideline, I'm a big fan of the ten year rule, though I'd generally be weary still of anything PC based that is Pentium III and newer, and/or Win95 or newer. Thanks, David David Greelish classiccomputing.com The Classic Computing Podcast Home of Computer History Nostalgia Stan Veit's History of the Personal Computer Audio Book Podcast

19 years, 1 month

A local computer history group for my area . . .

by dgreelish＠mac.com

19 years, 1 month

sun4m floppy drive in a macintosh

by dgriffi＠cs.csubak.edu

In my hands is a floppy drive pulled from a Sun IPC: a Sony MP-F17W-F1. Looking at Ebay, I see a floppy from a Macintosh: Sony MP-F75W-02G. Would this IPC's drive be acceptable for a Mac? -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

19 years, 1 month

ET-3400A Schematic needed

by whipaway＠yahoo.com

Hello to All on the list, I need the schematic for the ET-3400A, which is different from the original ET-3400, which I already have. I have an ET-3400 that does not have the MCM6830A ROM. I have a ET-3400A that uses the 8316 ROM and one that uses a 2716 EPROM, which are interchangable. I want to create an interface circuit that will allow me to use a 2716 EPROM in the ET-3400. A schematic for the ET3400A will really be appreciated. Thanks in advance, whipaway at yahoo.com --------------------------------- Park yourself in front of a world of choices in alternative vehicles. Visit the Yahoo! Auto Green Center.

19 years, 1 month

Early MSC HD controller

by cclist＠sydex.com

I've posted a photo of my Microcomputer Systems Corporation SA4000-to- GPIB disk controller PCB here: http://www.sydex.com/durango/msc1088.jpg This is a large board (12"x19")that contains mostly 74LSxx logic. The two 24-pin cerdip packages at the top left side are AM2506DC 4- bit ALUs; the 28-pin package below them is a N8209 (Signetics) 64x9 bipolar RAM. The 40 pin package to the left of them is an Intel 8291 GPIB talker/listener. The Just thought I'd snap a photo before it went back into its box. The documentation for the board (just command definitions) is dated 1979. FWIW, Chuck

19 years, 1 month

NETRONICS ELECTRIC MOUTH documentation/software wanted

by wh.sudbrink＠verizon.net

Hi, I have one of these cards that I'd like to demo at VCF East this year. Does anyone have docs and/or software for it? Thanks, Bill No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 269.6.8/800 - Release Date: 5/11/2007 7:34 PM

19 years, 1 month

ftp archives disappearing?

by aek＠bitsavers.org

> Has anyone else noticed that ftp search services like archie seem to > have disappeared The web as subsumed all of this, in an inferior fashion, IMHO. You will notice that bitsavers looks exactly the same as it did as an anonymous ftp site on its previous host. > Should we be working to archive large FTP software repositories? Absolutely! And try to find old backups that you have. Make sure to use something that can preserve file dates of the files. The old recursive ftp programs didn't do this.

19 years, 1 month

Manuals being scanned

by aek＠bitsavers.org

> If you have any comments I would like to hear them. OK, I've downloaded some of them now. They are some of the ugliest, bloated pdf's I've ever seen. What are you doing to them to make them look so BAD. "Control Data-Cyber 70 Computer Systems Models 72,73,74,6000 Computer Systems.PDF" for example, appears to have a mix of six different fonts on a single line, where there should be one. The titles are poor. "IBM System-360 Operating System.pdf" is a program logic manual for the Fortran IV graphics programming services. At a minimum, you should have the document part number, date, and the REAL title. Y27-7152-0_F4_Graphic_Programming_Services_Program_Logic_Sep67.pdf provides some useful metadata Look at http://bitsavers.org/pdf for 10,000+ examples of how this SHOULD be done.

19 years, 1 month

USB drivers

by aek＠bitsavers.org

> A few weeks > ago I bought a few USB serial port adapters, and they work fine on a > variety of PCs running various versions of Windows. Not, though, on a > Mac, which doesn't even see them. Did they 'just work' or was a driver downloaded off the net to make them work? The curse of Windows is every vendor doing things their own way, and the need for thousands of incompatible drivers. You can extend this to USB drivers as well. A USB async adapter can be implemented a bunch of different ways, going as far back as Anchorchips devices that squirted code onto the adapter, up through the current reduced cost devices that barely offer any tech docs on how they work. Vendors really only care about Windows support, and grudgingly give out info to driver writers (or they have to reverse engineer the hardware to do it). They also want to lock you into their device, so they have no interest in common drivers. Getting back to the original topic, as long as the protocol for the floppy adapter is documented so that people can write USB drivers for it for other platforms, it should not be an issue.

19 years, 1 month

What's the classiccmp IRC address?

by evan＠snarc.net

I lost it.

19 years, 1 month

FC drive interconnects?

by ethan.dicks＠gmail.com

I was staring at a Seagate "fiber channel" drive today and trying to figure out what the most economical method of attaching a few to a box would be. Seagate made a line of STxxxxFC drives with a small D-connector (like a narrow SCA connector) that presumably has power, unit ID lines, and, of course, the drive's part of the FC loop for data in/out. I know there are a number of Sun boxes (3500? 5500?) that have compatible connectors right there in the CPU box - you just drop the drives into bays in the front of the machine and off you go. Presuming you have something older, with PCI or Sbus, say, what options are there for using these drives? I know there are PCI (PCI-X?) FC-AL-over-copper SCSI controllers. What has me puzzled is what the options are for the interconnects - drive bays, external connections (copper vs fiber) for said bays, copper-to-fiber converters, etc. If one wants to hang a wad of drives off of a server, it seems that an 8-drive bay or whatever, with a fiber attachment to an Sbus or PCI fiber card makes sense. If one has, say, a PCI SCSI controller with an FC-over-copper external connector, or just wants to hook up one or two drives, are there any inexpensive interconnect options, like, say, the SCA-to-68-pin adapter boards that are an inexpensive way to use an SCA drives in an non-SCA environment? Of course the answer might just be, "no... the drives are the cheap part of an FC-based storage scheme", but given how cheap FC drives seem to be these days (plus the added bonus of fiber-attached drives being allowed to be a couple of kilometers from your server via single-mode fiber ;-) it seems like an option worth exploring. My direct FC-AL experience is a bit old - I used to run SPARCserver 1000 with three pre-FC-AL disk boxes with 3 drawers each of up to seven 2GB SCA-connector drives. I think one or two members on the list might have one of these. It was nice in its day (10+ years ago), but a lot of juice and a lot of heat for your 42GB (you _might_ have been able to install 4GB drives, but no larger due to firmware limitations in the box). I did get to fiddle with what I think might have been an early proper FC-AL box with a stack of 9GB drives, but I didn't get to play with it long enough to have many details stick in my mind about it. For now, though, my best Sun box just has a couple of 18GB SCA-connector drives. Effective, but boring. Thanks for any info on FC-over-copper interconnects and adapters. -ethan

19 years, 1 month

[pic] retro computing tattoo (a little different...)

by blakespot＠gmail.com

A bit of a different post here, but I thought folks on this list might get a kick out of the tattoo I had inked this week, branding me for all eternity as one with retro computing in my blood (and on my skin). A sort of crude petroglyph from the walls of the cave of computing history. http://www.bytecellar.com/archives/000105.php bp -- Heisenberg may have slept here.

19 years, 1 month

Wirelist for HP9000/200 RS232 cable

by aek＠bitsavers.org

The schematic for the 98626 is at http://bitsavers.org/pdf/hp/9000_dio/98626-90000_RS232_May82.pdf

19 years, 1 month

Manuals being scanned

by aek＠bitsavers.org

> If you have any comments I would like to hear them. Do you have any other Memorex system documents? I have a fair bit on the MRX 70 under http://bitsavers.org/pdf/memorex/7x00 but I didn't have the RPG design document.

19 years, 1 month

Apple II Mockingboard schematic

by rcini＠optonline.net

All: I?ve done a bit of searching for this but can?t locate it. Does anyone have a scannable copy of the schematic for the Mockingboard sound board for the Apple II? Thanks. Rich -- Rich Cini Collector of Classic Computers Build Master and lead engineer, Altair32 Emulator http://www.altair32.com http://highgate.comm.sfu.ca/~rcini/classiccmp

19 years, 1 month

Floppy disc reader/writer status report

by classiccmp＠philpem.me.uk

Hi guys, I think I might be on something of a roll here - I spent the train ride to/from work (and a good chunk of my lunch break) playing about with state machine designs for the write side of the floppy disc writer. What I've come up with is a nifty little finite state machine that interprets instructions >from the acquisition RAM, then executes them and writes them to disc. The way I've done it, there are five instructions: 0nnn nnnn: Write Timer. Writes the 7-bit timer value 'n' to the timer, then outputs a pulse on the WRDATA line when the counter reaches zero 1111 1111: STOP. Sets the STOP flag and halts the state machine until it is reset. 1011 xxx0: Close Write Gate. Deactivates WRGATE, preventing the head from writing to the disc. 1011 xxx1: Open Write Gate. Activates WRGATE, allowing the drive head to write to the disc. 110n nnnn: Wait for 'n' INDEX pulses before continuing execution of SM instructions. 1100 0000: Wait for a hard-sector track index (sector zero marker) signal before continuing execution of SM instructions. As far as I can tell, this is the minimum instruction set required to allow both soft and hard sectored discs to be duplicated reliably. There is one 'spare' instruction -- 1110 xxxx -- if anyone can come up with a good use for it, I'm open to suggestions. The write hardware currently clocks in at 19 macrocells, read hardware is another 26, the track-index pulse detector (which allows hard-sectored discs to be read and written) is 18, and the MFM synchronisation detector (including the neat little state-machine data separator) is another 29. So that's a total of 92, which leaves 52 for the acquisition control circuitry and registers. Assuming I don't run out of any other chip resources first, that is. The disc interface is going to be a standard 34-pin "PC" floppy connector. It seemed like the best plan - wiring to 3.5 and 5.25" drives can be done with a standard cable, and 8" drives can probably be connected with a fairly simple adapter cable. I do need one thing confirming though - I've read that on hard-sectored discs, each sector is marked with an index pulse: ---+ +------------+ +---- | | | | +--+ +--+ And the start of the track (sector 1) looks like this - note the index pulse half-way between two other index pulses: ---+ +----+ +----+ +---- | | | | | | +--+ +--+ +--+ 1 2 3 My question is, does sector 1 start at 1, 2 or 3? I'm guessing 3, and that's what the sync detector's set up for at the moment. Basically, it has a timing window - if a second index pulse arrives within 0.75T (where T = time between two normal index pulses) of the last one, it is assumed to be a track index sequence. The threshold value is adjustable in software, so drive speed isn't an issue. Thanks. -- Phil. | (\_/) This is Bunny. Copy and paste Bunny classiccmp at philpem.me.uk | (='.'=) into your signature to help him gain http://www.philpem.me.uk/ | (")_(") world domination.

19 years, 1 month

8mm data cartridges

by julesrichardsonuk＠yahoo.co.uk

How common were drives which could read these? I suspect the answer is "not very"! If anyone has one, how reliable was/is the media? I've got a couple of such Sony cartridges here dating from 1991; one does call itself a data cartridge (QG-112M) - the other one is a PAL/SECAM 90-minute Video8 tape (P5-90MP). Going from the labels, both have backups from some UNIX system on them - but (helpfully!) no clue as to what that system was or what backup program wrote them. From the huge box of floppies that I found them in though, I suspect that they might be from an Olivetti 3B2 - in which case they're possibly just tar dumps. I'm not sure what my chances are of finding a drive to read them are though (and worse still, such a drive might not be SCSI and so require a proprietary interface card and drivers). The packrat in me wants to try reading them rather than just tossing them out though :-) cheers Jules

19 years, 1 month

Big pile of VAX documentation to be disposed

by jzg22＠drexel.edu

>There is a large pile of VAX and other documentation waiting for >disposal on the 7th floor of Disque Hall at Drexel University in >Philadelphia. >Disque hall is located on the former 32nd street between market and >chestnut streets, its the tall(~10 floors)) brick building. >Pretty much everything paper, and a working Phaser 370? printer (missing >its paper tray and missing the centronics->microcentronics adapter but >otherwise working) is free for the taking. >This documentation originally went along with the VAX machine which >someone from the list rescued from there about 2 years ago when it was >being disposed. This is all still there. I found the VAX installation manual and license PAK buried in a seperate pile behind some fuzzy wall panels (I have it cached at home now), so there's also some networking manuals and other stuff behind there in grey binders in additional to the 22 orange binders of VAX stuff. This stuff IS going to be disposed of eventually, so I suggest anyone who wants it to get it QUICK. Theres also a bunch of printouts, schematics, software manuals, and source code listings for some old CERN-associated neutrino experiment which was run years ago, if anyone is interested in that. Jonathan Gevaryahu

19 years, 1 month

Manuals being scanned

by gilcarrick＠tx.rr.com

We are probably going to be drastically curtailing our museum efforts and perhaps shifting to a new affiliation if I can pull it off. As a start to lightening the load we are scanning as many of the manuals as we can. (We have a pretty nice scanner and some office assistants who occasionally have extra time that they need to look busy in.) I will be placing the scanned manuals on our web site, but for the time being there will be no link to the directory. You may feel free to download any of them you like. If you want to download everything that will be OK, but try to do it in the early morning hours U.S. Central Standard time. The university has a pretty good connection, but we don't want to swamp it during the day. If you seen anything that you would like to have in hard copy I will be happy to mail it to you. Payment of the postage and some token payment for the manual would be appreciated. You can contact me via email to arrange such a payment. If you see anything here that you think should not be available because of copyright limitations please let me know. I assume that since these manuals are all nearly 30 years old that nobody will care. Of course something may slip through the cracks and some large vendors still exist and might care for legal reasons, but I don't have time to sort that all out right now. Here is the link: http://www.cse.uta.edu/TheMuseum at CSE/Manuals%20Scanned/ If you have any comments I would like to hear them. Gil -- A. G. (Gil) Carrick, Director The Museum at CSE University of Texas at Arlington Department of Computer Science & Engineering Box 19015, 471 S Cooper Street Arlington, TX 76019 817-272-3620 http://www.cse.uta.edu/TheMuseum at CSE/

19 years, 1 month

DDS vs Audio DAT

by aek＠bitsavers.org

> I've never seen an audio cart used in a data drive, > and we had a lot of customers using them.. Audio DATs don't have the media recognition burst, and will be rejected by DDS drives. DDS tapes used as audio DAT tapes overwrite the DDS data, and are unusable as data tapes after doing that. Early audio DAT recorders (TEAC DA-30) will accept 90M data tapes, later TEAC drives will reject them. At one point we had about 6 DA-30's at KFJC, which have all developed transport problems after using a lot of 90M data tapes in them. We're slowly migrating 100's of DATs to optical or IDE disc media because of the problems preserving data recorded to DAT.

19 years, 1 month

How much of the FOG collection is archived?

by aek＠bitsavers.org

A few weeks ago, CHM received a donation of the entire floppy collection of the First Osborne Group (FOG). It is literally thousands of 5" floppies, and I am trying to get a feeling for what of the collection has already been archived. I believe NODE51 has the CPM portion on line, but FOG morphed into a general users group including support for the DOS world through the 80's. It will be a LOT of work to read the collection, so I'm trying to get a feeling for how to prioritize what's there.

19 years, 1 month

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test-drb