test-drb

test-drb@ccmp.vtda.org

101090 discussions

by tosteve＠yahoo.com

I received a Victor 9000 with monitor and lots of software, but no keyboard. If someone has one to spare, I'd appreciate it! Now, what can I do with all of these extra software copies? Steve. --------------------------------- You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost.

18 years

PDP-8 "Dumprest" experience?

by hachti＠hachti.de

Hi folks, I am just beginning to use Dave Gesswein's DumpRest from ftp://ftp.pdp8online.com/software/dumprest/. I successfully restored TD8-E DECtapes with it. That enabled me to install OS/8 on RK05 etc. I also (roughly) integrated the dumprest utilities into OS/8 (I can start them and they reboot OS/8 back to the monitor). And they now use a separate high speed rs232 port to connect to my PC (as my kermit does). When I use restrk05, I always get a checksum error. I just have read one RK05 disk - three times. What I get is always the same checksum error printout with the same checksum. And the generated files are identical as well. I can also successfully run them in SIMH. So what's wrong? Does anybody has a clue? Is that a known problem? Best wishes, Philipp :-)

18 years

HPIB Tape Drive Interface Protocol

by steerex＠ccvn.com

Hey, I have an ancient copy of the HPIB protocol specifications for 1/2 tape drives. I was going to send it to bitsavers for archival and re-distribution but, due to the number of errors and unreadability of the doc, I decided to go ahead and make the obvious editorial changes. I have placed a HTML version of the first draft at: http://www.steerex.com/hpib/7980_protocol At this time, there are a couple of sub-sections that are still missing. I'll add them in the coming days. I'll also be adding meaningful content, programming examples, tutorials, and HPIB pointers in the near future. Hope someone finds this stuff useful. See ya, Steve Robertson steerex [at] ccvn [dot] com

18 years

Looking for specific PDP-8 MAINDECs

by hachti＠hachti.de

Hi Folks, I have recently indexed my collection of PDP-8 software listings etc. You can find the list here: http://pdp8.hachti.de?docs I cannot find binaries for the following listings: Product Code: MAINDEC-08-DHKMC-A-D Product Name: PDP-8E Extended Memory Address Test (EA8E) Date Created: April 1975 Maintainer : Diagnostic Group Author : Vernon Frey, D.Macomber Product Code: MAINDEC-12-D8CD-D Product Name: KW12A Clock Test Date Created: December 1, 1971 Maintainer : Diagnostic Group Author : Raymond Shoop Product Code: MAINDEC-12-D8LA Product Name: A.I.P Instruction Test 1 Date Created: June 1, 1971 Maintainer : Diagnostic Group Author : Raymond Shoop Product Code: MAINDEC-08-DHRKC-E-D Product Name: RK8E Data Reliability Test Date Created: April 15, 1975 Maintainer : Diagnostic Group Author : John Vrobel Product Code: MAINDEC-8E-D8AB-D(D) Product Name: DK8E Clocks Diagnostic Date Created: June 1, 1971 Maintainer : Diagnostic Programming Group Author : John Vrobel Product Code: MAINDEC-8E-D6CA-D Product Name: VC8-E Display Diagnostic Date Created: June 21, 1971 Maintainer : Diagnostic Ggroup Author : Patrick Coyne Replaces : MAINDEC-8E-D3AB Product Name: TD8E DECTape Diagnostic Date Created: November 1, 1972 Maintainer : Diagnostic Group Author : E.Steinberger/B.Hansen Product Code: DEC-08-LHAA-D Product Name: "HELP" Loader Date Created: April 1, 1967 Maintainer : Software Services Group Product Code: Digital-8-5-U-Sym Product Name: Binary Punch (ASR33 or 75A) Date Created: March 1, 1965 Product Code: MAINDEC-08-D4A0-D Product Name: PDP-8, 8/I Memory Parity Checkerboard Date Created: May 14, 1968 Maintainer : Diagnostics Group If anybody has one or more of them, please send it to me! But please be aware that I am looking for the *exact* versions :-) Many thanks and best wishes, Philipp :-)

18 years

3rd party HP-IB drives, Bering 7320SC Econopac (Ebay 180230181732)

by rdbrown＠pacific.net.au

Bering 7320SC Econopac Hard Drive Item number: 180230181732 The drive isn't mentioned in their current (2005) Econopac list. and a non-HP-IB paper tape reader/punch. GNT 4604 READER PUNCH CNC - TAPE READER WITH MANUAL. Item number: 120241325099 3rd party HP-IB => SCSI et al disk hardware - I wonder if any of them would consider releasing their code for the HP-IB emulation under an Open Source, Hobbyist or Non-compete license. I wonder too whether they have HP-IB device protocol manuals that could be scanned for bitsavers. Looks like Bering may do Amigo, SS-80, CS-80 http://www.bering.com/home.htm (web page not recently updated, still in ylwbook.addresses.com phone book) Bering Technology, Inc. 1400 Dell Ave., Ste. B Campbell, CA 95008-6620 USA I think these guys are selling SS-80 9122 etc devices http://www.isa-j.co.jp/english/product/HP/HPIB_SCSI/ CS-80 drives targeting HP-1000 & HP-3000 systems (still in online phone book) http://www.reactivedata.com/2-LegacyDiskAndTapeEmulators/leghp1000.htm

18 years

Research Unix v9, v10

by slawmaster＠gmail.com

I've been thinking about some of the later versions of Research Unix, such as v9 and v10. If I could track down install tapes/disks, would I be able to run it on my VAXstation 4000-60? It seems that post-v7 didn't spread very far, so I guess I won't be too surprised if nobody knows :( John -- Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn

18 years

Suns available in Germany

by Arno_1983＠gmx.de

Hello fellow collectors, University is about to clean out storage space and there are a few older Sun workstations which will probably get their tickets: 4x SPARCstation 10 2x SPARCstation 20 5x Ultra 5 (both sBus and UPA versions) 2x Ultra 10 (or so) I did peek inside and didn't find anything particularly exciting (e.g. matched processors or unusual boards) so I suppose they will not warrant shipping and would have to be picked up at Erlangen University, southern Germany. Some do have memory and disks installed, others were robbed. So long, Arno -- Arno Kletzander Student Assistant // Studentische Hilfskraft Informatik Sammlung Erlangen www.iser.uni-erlangen.de Psst! Geheimtipp: Online Games kostenlos spielen bei den GMX Free Games! http://games.entertainment.gmx.net/de/entertainment/games/free

18 years

Apple ADB mouse optical conversion

by dgriffi＠cs.csubak.edu

Does anyone here have any ideas on how one would go about converting a ball-type Apple ADB mouse into an optical one? -- 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?

18 years

Dilog DQ132 question

by tiggerlasv＠aim.com

I guess my first question would be - If you're running on an 11/83 under RSTS/E, why WOULDN'T you want to use 22-bit addressing? Surely you're not "wasting" a perfectly good 11/83 on V6C or V7.0 ? ;-) But, to answer your question - My interpretation is that you can: Use 22-bit addressing, in which case RSTS/E (V8.0 and above) will see the controller as a TSV05, and will use 22-bit addressing to access memory above 256K (when applicable). You'll note that if you do a HAR LIST under RSTS/E V8.0 or above, it will flag this drive as "extended features enabled", indicating that it can use the full 22-bit address range. or Set 18-bit addressing, in which case RSTS/E (V7.0) will see the controller as a TS11, which will ONLY be able to access 256K of memory without modification to the device driver. (V8.0 and above might (properly) recognize it as a TSV05 either way, however, the "extended features" will be disabled, and it will only be able to access 256K of memory.) If I left anything out, I'm sure someone will chime in. . . . Tim

18 years

PDP 11 RL11/01 Address confusion.

by bqt＠softjar.se

"Tim Shoppa" <tshoppa at wmata.com> skrev: > Johnny writes: > >> The PDP-11 CPU is a 16-bit machine, so all code will always just deal >> with 16-bit values. >> >> The PDP-11 can have different buses, with different behaviours, but >> basically we can divide them into three groups. >> 16-bit bus >> 18-bit bus >> 22-bit bus >> >> Machines with a simple 16-bit bus is almost nonexistant, but there was >> some early Q-bus CPUs with a pure 16-bit address range, I seem to remember. >> >> 18-bit means all Unibus machines, as well as some Q-bus machines. >> >> 22-bit means most Q-bus machines. > > Obviously written from a 11M+ user's perspective. Ignore all those puny Unibus and Q-bus machines without MMU, will you? But they still run RT-11 just fine! Guilty as charged on the 11M+ part. :-) However, I think I covered machines without MMUs as well, I just didn't spell it out. Without MMUs are the same as machines with the MMU disabled. The one thing that differs is who puts out the extra bits on the address bus if there are more than 16 address bits, when you don't have an MMU. The CPU do, in those machines. Oh well. And I thought I'd done a real proper job. :-) Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

18 years

microvax 3800 available in NE ohio

by vax9000＠gmail.com

Hello people, I am dumping my small collection. If anybody is interested and is able to pick it up, you are welcome to get it. I do not ship or store. It was a complete microvax 3800 (upgraded to 3900) but I took the KA655 to fix my barebone 3900. You get the computer with RA7? DISK, DSSI disk controller, memory, ethernet card, tape card and tape drive. Plug in a KA655 and it is ready to go. vax9000 ----------------------------------------------------------------------------- Ever watched "American Beauty"?

18 years

LA180 doc finally all scanned

by mouse＠Rodents.Montreal.QC.CA

Some time ago (two months? I forget) someone sent me the "LA180 DECprinter I Maintenance Manual" to scan. Thanks to the good offices of our very own Dave Dunfield, the 8?x11 pages were easy. I finally went through the foldout pages, scanning them with my flatbed. What I have not done: (1) where two scans were necessary to cover a whole page (which was true of most of the foldout pages), I have not merged the two scans into a single image file; (2) I have not interfiled them into the PDF, largely because I've never bothered to create/find PDF building/busting tools (the only PDF-aware software I have at hand is ghostscript). However, the information is all there. See ftp.rodents.montreal.qc.ca:/mouse/docs/DEC/LA180/ - the .pdf is the 8?x11 scans; the scan.%03d.bz2 files are the scans of the foldout pages. I think the pages are in order - that is, if page N is before page M, all scans of page N have lower numbers than any scan of page M. Anyone who cares to is welcome to pick them up and put them somewhere more appropriate, like bitsavers - I suspect anyone doing that would want to do the things I mentioned above I didn't do, but, well, that calls for a Princess Bride quote.[%] Most of my scans were 300dpi 1bpp line-art scans. Two pages came out quite horrible when done that way; those I scanned as greyscale - you can identify them by the file sizes (scan numbers 003/004 and 022/023, as it happens). Some small number of my scans (two, I think) actually fit on an 8?x11 page, just sideways. Those scans have been rotated so they're right-ways-up when the image file is viewed the usual way. My scans are bzip2ed PBM (for the 1bpp) or PGM (for the greyscale) files. If someone needs something else, like TIFF or GIF, let me know and I'll see what I can do. Unfortunately the FTP daemon I'm running, while it supports conversion on request, does not grok *removing* suffixes to generate requested files. If you need bunzip2ed versions for some reason, let me know and I'll see what I can do. I still have the dead-tree version, so if you find anything that needs rescanning or any such, it's not out of the question. [%] "As you wiiiiiiiish!" /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

18 years

Dilog DQ132 question

by mcguire＠neurotica.com

Hey folks. I'm trying to get an Overland Data OD3610 drive working with a Dilog DQ132 controller in a PDP-11/83 running RSTS/E. The DQ132 manual documents dipswitch S8 as enabling 22-bit addressing, and it defaults to disabled. Here's the relevant paragraph from the manual: ------------- Switch S8 selects between 18- and 22-bit addressing. Only the TSV05 software handler supports 22-bit addressing on the Q Bus. The TS11/TU80 handler may require modifications to support 22-bit addressing on the Q Bus. Default value is S8 ON, selecting 18-bit main memory addressing. ------------- So am I to assume that it can be used as a TS11 in a 22-bit system, and the driver uses bounce buffers? Any idea? Thanks, -Dave -- Dave McGuire Port Charlotte, FL

18 years

Looking for a M8330 or a couple of SN74194's

by RodSmallwood＠mail.ediconsulting.co.uk

Hi Its not test gear that's the problem its access to the board. My Tek 465 will trigger on single pulses with no problem. However whilst it's recommended that the the first CPU board (the 8330) be in slot 2 (The front panel is in No1) its not mandatory. So I can move the boards back a bit and get to the front of the 8330. Manual I have, (very good) Schematics also (Awful) so bad I may even redraw at least the 8330. I have an A0 HP plotter so its easy to do drawings. Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Tony Duell Sent: 31 March 2008 22:52 To: cctalk at classiccmp.org Subject: Re: Looking for a M8330 or a couple of SN74194's > > > Not only did Cricklewood have them, but they arrived Saturday morning. I'm even luckier in that I live near enough to Cricklewood Electronics that I can pop over there and pick the chips up the same day ;-) > That effected a partial fix. > The timing generator is a string of four bit shift registers clocked > with 20Mhz. OK. > Various combinations of their outputs are used to set and reset > bistables made out of cross coupled 7440's. > As the problem I'm fixing is you can't load memory, which is a one > shot operation, its slow old work. I don;t know what test gear you have, but I find a simple logic probe to be more use than a 'scope for this sort of problem. The former can easily detect narrow pulses that are difficult, if not impossible, to see on a non-storage 'scope. Of course an 'Advanded Logic Probe' as HP called the LogicDart is even nicer, but... Do you have the maintenance manual? Not the printset (schematics), but the book which is a low-level circuit description? It's well worth reading!. I would have thought it wouldn't be too hard to keep on hitting the DEP key and seeing what, if any Omnius signals are generated. And then totrace back the missing one(s). [...] > I also return all systems to working order. Apart from a couple of > VT420's with ticking SMPSU's everything I have restored runs. (Three Any reason you';ve not fixed those? Ticking SMPSUs are often quite simple to fix, maybe just dried-up capacitors. -tony

18 years

What is a FINO? Need about Vff.

by pichotjm＠free.fr

Hi, Pls, have a look at this description of Signetics 25000 series 9046 XN component: http://pichotjm.free.fr/humr/2.html Can you explain me, what is Vff? Is it a good idea to decrease this voltage in order to increase reliability? But what will happen with our 50 Hz european supply? I need help... (please, answer with simple english) JM Pichot

18 years

Looking for a M8330 or a couple of SN74194's

by RodSmallwood＠mail.ediconsulting.co.uk

Not only did Cricklewood have them, but they arrived Saturday morning. That effected a partial fix. The timing generator is a string of four bit shift registers clocked with 20Mhz. Various combinations of their outputs are used to set and reset bistables made out of cross coupled 7440's. As the problem I'm fixing is you can't load memory, which is a one shot operation, its slow old work. A spare 8330 would confirm if that's where the problem is and I expect would speed up the repair on the current one. I'll continue with fixing it and keep an eye open for a spare. Getting one from the US would be an option. I also return all systems to working order. Apart from a couple of VT420's with ticking SMPSU's everything I have restored runs. (Three VAX's, Two alphas, a Rainbow 100+, DECMateII, Pro350, Pro380, a DS3100, a VS3100 and assorted LA printers and VT terminals) Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Tony Duell Sent: 28 March 2008 22:52 To: cctalk at classiccmp.org Subject: Re: Looking for a M8330 or a couple of SN74194's > > Hi Tony > I agree that the concept of originality is important in what we do. > The system I have is original in the sense that all the parts are from > the right era. However the current configuration is not that as stated > on the factory label. You could also say that any item with a If this is the machine I think it is, I know not only the chap you got it from, but also the owner before that. IIRC, it originally had a TU56 (single drive versiun, and no I don't mean a TU55) which is currently on my desk, hooked up to my PDP8/e. And the RX8/e is not original. If you look at one of the CPU logic boards, you'll see one of the chips (I forget what) has been replaced. I did that over 10 years ago to cure a problem with the top 4 data lines in some operation or other. The TU56 was 'payment' for that repair... > date of later than the manufacturing date and not the result of a > repair or upgrade is not original. True, and some museums, alas, take it that way, and refuse to instal replacement parts to keep their machines going, even if said parts are contemporarty with the machine. Personally, I like all my classics to run. However, I also like to use as few spares as possible. If your clock generator was missing, or physically cracked in half, or... then I would agree you need an M8330 board. But if you can get your old one to run again, even by using more modern parts (I would have no problems fitting LS chips if they would work electrically, for example), then I'd rather keep the spare board for somebody who really did need it. > > Thanks for the tip re Cricklewood I will contact them. They may only have LS or something like that. As I said, I needed some 7495s, a rather oscure shift register chip that I couldn't find anywhere. They had 74LS95, which worked fine in my HP9820. OK, not original, but at least I can use the machine again. -tony

18 years

PDP 11 RL11/01 Address confusion.

by tshoppa＠wmata.com

Johnny writes: > The PDP-11 CPU is a 16-bit machine, so all code will always just deal > with 16-bit values. > > The PDP-11 can have different buses, with different behaviours, but > basically we can divide them into three groups. > 16-bit bus > 18-bit bus > 22-bit bus > > Machines with a simple 16-bit bus is almost nonexistant, but there was > some early Q-bus CPUs with a pure 16-bit address range, I seem to remember. > > 18-bit means all Unibus machines, as well as some Q-bus machines. > > 22-bit means most Q-bus machines. Obviously written from a 11M+ user's perspective. Ignore all those puny Unibus and Q-bus machines without MMU, will you? But they still run RT-11 just fine! Lots of Unibus and Q-bus and not-anything-bus-11's all do quite fine with 16 bit address spaces. While the Unibus electrically has 18 address bits from the get-go, the Unibus 11's without memory management (or without the memory management option) don't use the last two. Even "later" Unibus CPU's like the 11/04 still came without MMU (and it was not an option, either!) Obviously "early" and "later" are taken to be Lasnerian. Tim.

18 years

Looking for a M8330 or a couple of SN74194's

by RodSmallwood＠mail.ediconsulting.co.uk

I don't suppose you still have the old M8330 do you? Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Charles H Dickman Sent: 02 April 2008 02:01 To: On-Topic and Off-Topic Posts Subject: Re: Looking for a M8330 or a couple of SN74194's Tony Duell wrote: > DEC scheamtics have the odd error on them (I've heard it claimed said > errors are deliberate, either to stop the machine being copied, or as > copyright traps on the diagrams themselves). They're also somewhat > unconventionally drawn (flip-flops may appear to have 4 outputs!), but > I've got used to them. I must say that if I need to re-draw a > sechematic, I use pen and paper, not a CAD system... > A year and a half ago I was playing with a PDP-8/e and trying to get an EAE working with it. I ended up needing a later version M8330. My original boards were rev 1 and the EAE didn't work until about rev 3. The drawings I found online were WAY different than the boards I had. For the EAE, it looked like there were some serious timing issues, so the later board revisions were quite significant. So, if your boards don't match the drawing rev, don't expect there to be a match. -chuck

18 years

Looking for a M8330 or a couple of SN74194's

by RodSmallwood＠mail.ediconsulting.co.uk

Hi Having worked for DEC for a number of years I'm used to the odd logic symbols. They do explain them in the manual. I don't use a CAD system but something much more useful. Visio. Define a DEC logic symbol once, add connection points in the right places, drop as many copies as you need, join connection points and print on A0 paper. Modify drawing as much as you like and print a new copy each time. Iv'e moved the boards back a bit and as soon as I get a few mins I'll see if I can spot why it won't write to memory. Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Tony Duell Sent: 01 April 2008 20:31 To: cctalk at classiccmp.org Subject: Re: Looking for a M8330 or a couple of SN74194's > > Hi > Its not test gear that's the problem its access to the board. My Tek > 465 will trigger on single pulses with no problem. > However whilst it's recommended that the the first CPU board (the > 8330) be in slot 2 (The front panel is in No1) its not mandatory. So I > can move the boards back a bit and get to the front of the 8330. All Omnius slots are the same, and in an 8/e backplane, AFAIK all slots are plain Omnibus. The only time the top connectors are used on the M8330 is if you have the EAE board set installed, I think. If you do, take it out for the moment (you don't need it when trying to sort out a timing generator problem). You can then put the M8330 in whatever slot you want. An extender board is useful, but by no means essential :-). Another trick that's worked for me in the past if I can't re-arrange the boards and don't have an extneder is to solder a hnadful of wires to useful testpoints on the board and put it back in the cardcage. Then probee the free ends of the wires (make sure they don't short to anything!). Normally 2 or 3 iterations of doing that will get me to the faulty chip. > > Manual I have, (very good) Schematics also (Awful) so bad I may even > redraw at least the 8330. I have an A0 HP plotter so its easy to do > drawings. DEC scheamtics have the odd error on them (I've heard it claimed said errors are deliberate, either to stop the machine being copied, or as copyright traps on the diagrams themselves). They're also somewhat unconventionally drawn (flip-flops may appear to have 4 outputs!), but I've got used to them. I must say that if I need to re-draw a sechematic, I use pen and paper, not a CAD system... -tony

18 years

What is a FINO? Need about Vff.

by pcoghlan+cctech＠vms.eurokom.ie

pichotjm <pichotjm at free.fr> wrote: > >Pls, have a look at this description of Signetics 25000 series 9046 XN >component: http://pichotjm.free.fr/humr/2.html It is not always necessary to go to the expense of buying a 25000 series chip. I found some WOM in my Dec Alphaserver 1000A recently. I'm not interested in this bleeding-edge stuff (besides its too new to be on-topic here) so I have now replaced it with some ordinary memory. I wonder if I could get a good price for the WOM on ebay? >Can you explain me, what is Vff? Is it a good idea to decrease this voltage >in order to increase reliability? 6.3Vac is a common voltage for valve (tube) filaments. Given that the 25000 series is implemented in VLSI (Vacuum large scale integration), I suspect Vff is the supply to the filaments for the integrated valves on the WOM chip. Decreasing Vff should reduce power dissipation and improve the lifetime of the chip. However, it may also result in poorer noise immunity. Either that or Vff is the reference voltage used by the flip-flops and decreasing it will unbalance the chip by creating an excess of flops over flips. >But what will happen with our 50 Hz european supply? Typically, these things are designed for the American market with no thought given to widely used standards in other parts of the world. I suspect we will have to use motor-generator sets to power this type of circuit. Solid state frequency converters will not be suitable for the critical power requirements here. >I need help... > >(please, answer with simple english) > >JM Pichot > Regards, Peter.

18 years

Adding a 3rd floppy to an old PC SCSI controller

by cclist＠sydex.com

Dwight asked: > Pardon me for asking but are you sure the chip can provide > enough drive? Most floppies expect to terminal with about > 150 Ohms. That is more than an unbuffered output of most > chips are designed for. > Just asking? Good point--but the datasheet states right in the opening remarks that it can be connected directly to the disk drive with its own internal 48 ma buffered output and schmitt inputs. The datahseet's easy to find on the web--several places have it. Here, for example: http://www.tranzistoare.ro/datasheets2/36/366021_1.pdf I like the DP8473--unlike the Intel 82077AA and later chips, it still knows how to do FM correctly--and will even write 128 byte sectored MFM, which is something that Intel was ever able to do. Don Maslin and I worked through a pile of FDC chips before we found this one. I think there was a Future Domain card (1680?) that brought all 4 floppy drives out to 2 headers--and I certainly could have added one to do that myself for 4 drives, but 3 on one cable was the easiest. Cheers, Chuck

18 years

PDP 11 RL11/01 Address confusion.

by doug＠stillhq.com

Hi Everybody I was reading some doco last night (specifically the DEC RL11/01 Disk Subsystem Training Handout), and I am confused. (That is nothing new...) In the "Subsystem commands section", the addresses specified for DAR and CSR are 774404, and 774400 respectively, but in the back of the document, under the 'toggle in programs' section, the DAR and CSR are shown as being at 174404 and 174400 respectively. Hmmm. I see three possibilities: 1. I have (re) discovered a documentation error - I wonder if DEC, no, HP, no Compaq, would be happy for me to submit an amendment :-) 2. The hardware throws away the upper bits so both references are correct. Hmmm Possibly not :-) 3. There is some other stuff happening that I missed... If anybody could shed some light on this I would appreciate it. The background to the problem is that I can not convince my shiny, wonderful, (and noisy) DL01 to perform the seek test - Me thinks there is a problem.... Doug

18 years

Looking for a M8330 or a couple of SN74194's

by RodSmallwood＠mail.ediconsulting.co.uk

Oh I forgot.. The 420's .. I have not done anything because a) It only happened last week b) I cant find any drawings. Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Tony Duell Sent: 31 March 2008 22:52 To: cctalk at classiccmp.org Subject: Re: Looking for a M8330 or a couple of SN74194's > > > Not only did Cricklewood have them, but they arrived Saturday morning. I'm even luckier in that I live near enough to Cricklewood Electronics that I can pop over there and pick the chips up the same day ;-) > That effected a partial fix. > The timing generator is a string of four bit shift registers clocked > with 20Mhz. OK. > Various combinations of their outputs are used to set and reset > bistables made out of cross coupled 7440's. > As the problem I'm fixing is you can't load memory, which is a one > shot operation, its slow old work. I don;t know what test gear you have, but I find a simple logic probe to be more use than a 'scope for this sort of problem. The former can easily detect narrow pulses that are difficult, if not impossible, to see on a non-storage 'scope. Of course an 'Advanded Logic Probe' as HP called the LogicDart is even nicer, but... Do you have the maintenance manual? Not the printset (schematics), but the book which is a low-level circuit description? It's well worth reading!. I would have thought it wouldn't be too hard to keep on hitting the DEP key and seeing what, if any Omnius signals are generated. And then totrace back the missing one(s). [...] > I also return all systems to working order. Apart from a couple of > VT420's with ticking SMPSU's everything I have restored runs. (Three Any reason you';ve not fixed those? Ticking SMPSUs are often quite simple to fix, maybe just dried-up capacitors. -tony

18 years

Adding a 3rd floppy to an old PC SCSI controller

by cclist＠sydex.com

> Date: Tue, 1 Apr 2008 10:47:25 +0200 (CEST) > From: Christian Corti > The 8473 directly supports four drives, so you can do the "trick" a second > time for a fourth drive. And even some motherboard Super I/O chips have > support for four drives, the outputs are simply not used. My needs and the number of spare conductors on the cable simultaneously gave out with 3 drives. Somewhere in my collection I've got a controller (may not even be SCSI; could be ESDI or MFM/RLL) that had a jumperable option to drive 4 floppies from a single cable by using the drive select jumpers and a common motor control line. The two downside issues are that your drives have to have 4 drive selects (or you had to be clever with your cable twists) and when one motor comes on, they all do. Better to use two headers and two cables, IMOHO. Cheers, Chuck

18 years

What is this? "DAMIUS"?

by jplist2007＠kiwigeek.com

Was waffling through the 'Worst Wiring' site this morning: http://www.darkroastedblend.com/2008/03/disturbing-wiring-part-3.html And the second to last picture is this: http://lh5.google.ca/abramsv/R-8VzPXRjMI/AAAAAAAANCE/jx8JYx24UY0/s800/20701… Is this a real machine? It might have nothing to do with computing at all, there's an awful lot of pot dial looking things on it. I'm still curious. Thanks all; - JP

18 years

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb