test-drb

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101090 discussions

by allisonportable＠gmail.com

On 08/24/2018 07:06 AM, Rod G8DGR via cctalk wrote: > M8417 MSC8DJ?PDP8A 128K MOS? > > Clone of this > > > > Sent from Mail for Windows 10 > > From: Paul Anderson via cctalk > Sent: 24 August 2018 10:12 > To: General Discussion: On-Topic and Off-Topic Posts; cctech at vax-11.org > Subject: CESI VM8128 PDP8-A 128 K MOS? > > I have an idea what this might be, but I can't find anything to confirm it > on line. Can anyone shine some light on it? > > Thanks, Paul > its a 128 memory card If memory is right hex width for PDP-8A... The last of the omnibus 8s. That machine had extended the MMU used in earlier PDP-8 from 3 EMA lines to 5. Only fits the 8A chassis. Allison

8 years

11LOGO

by lars＠nocrew.org

Hello, I have a 1972 version of 11LOGO, which is the dialect of Logo which was done by the Logo group at MIT. Their computer was a PDP-11/45. I have it running in a PDP-11 simulator, 11SIM, which runs on the ITS operating system. If someone is interested in running it in some other simulator like SIMH, I can provide files and assistance. The nice thing about 11SIM is that it emulates the one-off TK display system which provides 8 vector displays. 11LOGO uses it to view turtle graphics. It would be interesting to add this capability to SIMH, but I'm pressed for time. I can provide documentation, though. There is a second application, the Dazzle Dart game, which uses this display as well. It doesn't run in 11SIM because it uses FP11 instructions which are not implemented. Best regards, Lars Brinkhoff

8 years

Apollo motherboard dated 1988 013034

by useddec＠gmail.com

I just found it while sorting. If you are interested, please contact me off list. Thanks , Paul

8 years

Event Announcement: DEC Legacy is back on 17th-18th Nov 2018, Windermere UK

by mark＠wickensonline.co.uk

DEC Legacy 2018 is on! The next DEC Legacy will take place Saturday 17th November 2018 - Sunday 18th at the Marchesi Centre in Windermere, North West UK. With a focus on Digital Equipment Corporation and their legacy of hardware, software and ethos I'm also extending an open invitation to those who are interested in SGI, HP, Sun, IBM and other high end hardware to come along and share their passion with us. Several formal presentations will be mixed with plenty of hands on time with hardware brought by enthusiasts. Enthusiasts are encouraged to bring along hardware and software to exhibit. The personal nature of the event brings a unique atmosphere within which friendships are easily forged. Registration is now open. Please visit http://declegacy.org.uk for more details. Regards, Mark Wickens, M0NOM

8 years

Microsoft DOS Fortran 5.1 graphics

by Martin.Hepperle＠MH-AeroTools.de

> I am looking for a sort of 'hello world' example and/or samples to use the > graphics library in this compiler, some sample code. My target is DOS and > the Compaq luggable mono display. > > > It looks like its all there, the library and include files for display adapters and > modes, but I cant find an example on the netwebs to get me started. > > > Anybody have a set of demo files or application source to study and to use > this? > > > I have TurboC running on this machine, and the graphics are great. Did > Microsoft have a similar set of examples for Fortran? > > > Randy > Randy, this compiler can generate executables for DOS, Windows and OS/2. It also came with the QuickWin libraries to create FORTRAN programs which output text and graphics in Windows. I am not 100% sure, but it is possible that the first release did not have the QuickWin libraries and it came with an update. When you install Microsoft FORTRAN 5.1 you have the option to install the SAMPLES. The README says: <cite> [...] \SOURCE\SAMPLES This directory also contains the source code for the graphics programs from chapters 11, 12, and 13 of the Microsoft FORTRAN Advanced Topics manual. Note that these examples require the graphics include files FGRAPH.FI and FGRAPH.FD. These files are copied to an INCLUDE directory by the SETUP program. In real mode (DOS), the programs must be linked with the graphics library GRAPHICS.LIB. In protected mode (OS/2), graphics is not supported, but you can compile text-only programs by linking with the text library GRTEXTP.LIB. The appropriate libraries are copied to your disk by the SETUP program. For example, use the following command line for DOS: FL COLTEXT.FOR GRAPHICS.LIB Or use the following command line for OS/2: FL COLTEXT.FOR GRTEXTP.LIB The programs are listed below: DOS only DOS or OS/2 -------- ----------- Chapter 11 CGA.FOR COLTEXT.FOR COLOR.FOR EGA.FOR GRAPHIC.FOR HORIZON.FOR REALG.FOR SINE.FOR Chapter 12 SAMPLER.FOR Chapter 13 ANIMATE.FOR CURSOR.FOR ARC.FOR MODES.FOR CGAPAL.FOR SCRTXWIN.FOR FIGURE.FOR SETROWS.FOR FILL.FOR TEXT.FOR FONTS.FOR WRAP.FOR MAGNIFY.FOR PAGE.FOR PALETTE.FOR STAR.FOR WINDOW.FOR [...] </cite> Those examples cover many aspects of the system. I only used the Windows part and I believe that under OS/2 there is no graphics, only cursor addressing. The graphics system offers similar capabilities to e.g. Borland's or Quick C's capabilities. regards, Martin

8 years

DEC PDP 11 RK05 DEC custom (?) bootstrap board

by billdegnan＠gmail.com

I have what I believe to be two DEC RK05 bootstrap boards each with a ROM labeled 802350 A. UNIBUS. The plastic handle tabs are Digital Equipm.'s but it could be an OEM as there is nothing printed on them. On the board is printed on what would be the bottom front side R-K ABBR BOOT P.C. BOARD 609395 REV B on one line and under that 802000 REV There is a round sticker on the back of the board written in pen that reads: LL 802000 Rev B 6-17-76 printed on the backside of the board near the sticker is 609395 REV B I use a M9312 to bootstrap from the monitor but I am curious how I'd attempt to use one of these. Any thoughts? Bill

8 years

A New Zealand-based early '80s microcomputer retailer talks about his experience

by terry＠webweavers.co.nz

This won't be of interest to everyone, but if you want to hear what it was like to open and run a microcomputer store in New Zealand back in the early 1980s, it's captured here. https://www.classic-computers.org.nz/blog/2018-08-23-viscount-electronics.h… Terry (Tez)

8 years

Color of Leaky Electrolyic Caps?

by marvin＠west.net

I was just checking out the leaky capacitors on the model 100 motherboard, and they are all colored black. And ditto for the HX-20. The ones that are both light and dark blue look to be fine (no leakage.) So am I just seeing an anomaly, or is this the experience of most people here?

8 years

Epson HX-20, TRS-80 Model 100 Capacitor Kits

by marvin＠west.net

Since I have at least four Model 100 and HX-20s, I've decided to just replace all the aluminum electrolytics before repair becomes much more difficult. So far, I see the project as fairly easy depending on how bad the corrosion from the leaking caps is. Is anyone interested in buying a kit or two of the capacitors? I'm guessing buying the parts from DigiKey at low quantity prices will result in about $3.50 or so for the bag of about 13 capacitors. US postage will probably run a couple of dollars or so, but I can also bring them with me to VCFMW. I'll be ordering what I need unless I hear others might want the kits as well. On a similar topic, has anyone given up on cleaning out the corroded plated-Thru-Holes, and just soldered on some SMD caps? If so, how did it work out? Finally, just some observations on the corrosion. I finally found some information about the corrosion caused by leaking aluminum caps. It sounds like the leaking fluid, besides possibly damaging the copper traces, also does something to the solder in the PTH such that a soldering iron won't melt the solder. Right now, the solder doesn't want to melt so I will use a pin vise and about a number 62 drill or so to hand drill out the PTH solder.

8 years

Strange third party board in PDP-11/45

by jnc＠mercury.lcs.mit.edu

> As to what _else_ it is doing, and why it has the cable to the main > card... I think that it must intercept MSYN from the processor and only > let it pass if there's no hit in the cache. > (To explain why it would need to do that... normally with the MS11, > there's a static partitioning between FastBus memory and UNIBUS A > memory. So when the CPU goes to do a memory cycle, it can put the > address out on both the UNIBUS and FastBus, with the certainty that it > will only get a reply on one. So, my guess was wrong there. I had _assumed_ that when doing a memory operation, the CPU started a cycle on both busses, to minimize the delay on the UNIBUS cycle if the MS11 on the FastBus didn't have that location. (I had previously checked, and there is an 'I have that location' signal which the MS11 sends back, making the concept of a cache possible.) Well, no. In the "KB11-A CPU Maintenance Manual" (DEC-11-HKBB-D), section 7.7.1 ("Bus Control Introduction"), it says: If the address applies to a Fastbus device, that device will respond in time to inhibit the UNIBUS MSYN signal (It turns out the KB11-A is very clever; it has to delay for a bit after asserting the address, etc, signals on the UNIBUS, for de-skew, before it can assert MSYN, and during that delay, in parallel, it checks to see if the MS11 has that location.) So my theory about what that double-card does (prevent an MSYN sent to main memory on a cache hit) is apparently wrong. Which leaves the question of what that card _does_ do... The cache _does_ need to have the A and B UNIBUS tied together, so that it can snoop UNIBUS memory cycles (which are on the A UNIBUS) via the B UNIBUS (which is what it has access to on the backplane), _but_ it doesn't need a special card, with i) active logic, and b) a cable back to the main board, to do that - a regular M9200 will do that. The cable back to the main card, and the logic on the two dual-width cards, mean it wants to interfere somehow in the connection between the A and B UNIBUS. But if not the MSYN thing, what else could it be? I have pondered that question, but I can't think of anything. It can't be doing anything with interrupts or DMA, I would think, so no grant interception. So what else could it be? Anyone have any ideas? Noel

8 years

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