test-drb January 2005

test-drb@ccmp.vtda.org

254 participants
551 discussions

by william.layer＠comcast.net

Hey all, Thanks for all the background and help on the Altair project. I'll be taking some pics of the pile for a 'before and after' set. Hopefully there will be an after worth mentioning ;-) Now on to Intel / Intellec MDS systems. I've got one that is alternately described as an MDS225 or and MDS800. IIRC, the dual-disk unit is marked MDS800, (blue in color) and the main chassis is marked MDS225 (white in color, has a monitor, kb, and a series of pushbuttons with LED indicators). Information on these units is pretty sparse on the web; multiple google searches have yielded little more than years of manufacture, and some price info. One question that should amuse the more veteran members of classiccmp is this: What exactly is meant by "Microcomputer Development System"? It's like that old joke about "Repairing Robots".. Are they referring to the process of repairing a robot, or to robots that perform repairs? Is the MDS a system for developing microcomputers, or is it a microcomputer that is used for other forms of hardware / software development, or a little of both? I'm getting the feeling that the latter might be the case. Secondly, what kind of operating system, applications, etc can one of the MDS units run? I'm told that it is an ISIS based system, but I really don't know much about ISIS. I assume it's a disk operating system, but beyond that I'm clueless. I'd like to think that there is some general-purpose OS I could run on it, play some wumpus, trek or life, amortize my mortgage, or maybe fire up a terminal emulator and get into the BBS scene. I'm clearly no expert in this old stuff, but I'm at least wise enough to realize what I *don't* know. Can someone fill in a few of the gaps? My MDS has an 8080A CPU card in it, some kind of memory card, and a disk controller. Also, a card that connects to a large ICE pod "Intel ICE-51", if that helps. TIA, Bill

19 years, 10 months

manual file types

by Saquinn624＠aol.com

Sounds like the most useful file types for scans of manuals would be one of: TIFF file (big) OCRed ASCII text (ugly) compressed PostScript of OCRed text (depending on OCR, could be nice). Is this right? -Scott Quinn

19 years, 10 months

ISA bus hack

by frustum＠pacbell.net

Mentioning my old employer, Calera Recognition Systems, reminded me of this ISA bus "hack." The OCR accelerator cards that Calera sold were able to find a free space in the memory map of the ISA bus and could even support multiple cards on one bus. No flash, jumpers, or dipswitches were involved, and this was before any Plug and Play. How it worked was this. The cards had a 68020 on them, along with a couple megabytes of memory and a few ASICs that accelerated key parts of the OCR algorithm. The 68020 would wake up from reset and "spin" -- meaning it would program a control register to indicate what address it was located at. It would park there for a while waiting to get written to by the host x86. If it didn't receive a write, it would move to the next address range, etc, and go around again and again util it was told to stay put. Complicating all of this was that the card very well might map to an address where some other card or memory already lived. The OCR card, in this mode, did not drive any signals, and was able to handle to 0 wait state writes. If the x86 was writing to or reading from RAM where the card was also located, the 68020 would see these and ignore them unless they followed a very complicated asymptotically approaching 0 probability sequence such that a card, seeing the sequence, was certain that it was the x86 trying to talk to it. Once a card received the sequence and was told to become visible, it would then turn on any handshake logic and could respond to reads and writes. The next layer of the onion was that multiple cards could be in the system at the same time. You don't want two cards to "wake up" at the same address in memory and then have a tristate catfight. Instead, part of the wake up sequence involved a one bit at a time arbitrartion process based on the card's unique serial numbers. Finally, the memory system attached to the 68020 wasn't fast enough to receive the reads and writes with zero wait state performance. However, the reset and interrupt request logic was, so that is what was used to signal to the 68020. The magic sequence of writes was seen on the 68020 as a sequence of interrupts and resets that followed a certain pattern (the logic could tell apart a hard reset from a soft reset; we were worried that the 68020's internal state wouldn't persist through soft reset, so we used a register that was inside one of the ASICs that was known to not get reset to hold the required tracking state). Parts of the implementation were overly complicated due to the fact that none of it was designed up front. It was implemented after we realized that we really didn't need to use the dip switches. Although it was all stochastic, all of the shenanigans would typically take less than a second so that nobody really noticed, and not having dip switches made the card a snap to install.

19 years, 10 months

extracting H/V sync from sync-on-green video signal?

by pete＠dunnington.u-net.com

On Jan 30 2005, 21:08, der Mouse wrote: > > I keep on finding sync combining circuits that'll do seperate sync to > > sync on green everywhere, but nothing to do the reverse! > > I thought the right thing there was to simply connect the green output > to both the green video input and the sync input. > > However, that's coming from someone who has never tried it (at least > not knowingly - I may have used adapters designed to do just that) and > who does not really understand the signals involved.... Hmm, now that you mention it, I remember trying something like that several years ago, when we had to have an SGI (RGB, SOG) drive a video projector (RGB, CSYNC). We had a 13W3-to-3xBNC cable and put a BNC T-piece on the green, with a short coax to the CSYNC BNC on the projector. It worked well enough, even though the T-piece and cable were 50-ohm cheapernet parts. -- Pete Peter Turnbull Network Manager University of York

19 years, 10 months

Help to ID Emulex board

by ddl-cctech＠danlan.com

On Jan 29 2005, 10:05, Vintage Computer Festival wrote: | | What is this board? | | Made by Emulex. Has ASSY# SU0210401. ROM on board says |"SC0210201-AXC W/ | Boot Strap". | | Has on top two 26-pin connectors and one 60-pin. Note that this board uses a 10MHz SMD interface so it will not support the Saber drives or even the Eagles. (An SC03 would handle the latter but not the former.) Dan Lanciani ddl(a)danlan.*com

19 years, 10 months

11/34 stuff response

by jwest＠classiccmp.org

Wow. I think the entire list responded with interest on this. It sounds like several people are very interested in bidding on this - and I'm certainly not going to stand in the way. My primary interest is one RK05, an RK11D set, and some of the memory boards which could be used in my 11/45 restoration. Since so many people have already said they will bid on it, perhaps the best thing I can do is stand back and let everyone fight it out. However, bear in mind that I'm in St. Louis, 20 minutes from the guy. So I'd be willing to help out locally if the winning bidder wants, and would like to deal on the above mentioned stuff. Jay

19 years, 10 months

DG NOVA4/X runs

by tomj＠wps.com

Well I just put a cord on it, plugged it in and powered on. No smoke escaped. The CPU passes self-test (no idea what it really checks, but it alleges to be thorough) after I seated the memory board (I forgot just how tough to seat the 15 in square DG boards are). I can poke memory, registers, etc just fine. Took a bit to get the console wired right (to minicom on a laptop, 9600/8/n/1) as the sample cable (from the orig. install) was misleading. The tape drive probably has a bad vacuum sensor; I'll look at it Tuesday again. Might be cable fell off. It otherwise loads the tape and one vac col does the right thing. Other functions seem to work. I have a 2nd tape drive, not yet tested. The disk (10 fixed, 10 removable) is not behaving right. Problem with load/ready. Looks mechanically OK but I will do one more test before the covers come off and the scope and DVM come out. Tom Jennings <tomj(a)wps.com>

19 years, 10 months

Many things

by dwight.elvey＠amd.com

>From: "Ashley Carder" <wacarder(a)usit.net> > >I, too, like my vintage systems as much as the next guy, but lately I've >been finding >myself using the HyperTerminal app on my modern Win2K PC as the console >when I'm doing things on my 1973 PDP-11/40. I can toggle over to the web >browser while I'm copying RK05 disk packs, cut and paste the output of the >PDP-11/40 RT11 DIR command into an email on Outlook, and use simh to >test and run the RL01 disk image that I just sent from the 11/40 to my PC ---snip--- Hi Ashley I use my laptop as a replacement for papertape as well as a terminal. Dwight

19 years, 10 months

VMS 5.5-2?

by dholland＠woh.rr.com

I'm getting back around to seeing if I can get the data off that Vax 4000/300 I've got, and thought I'd be a good idea to have OS media handy. So, anyone have VAX VMS 5.5-2 (and TCP/IP) handy, that I can beg/borrow/mooch? (ISO images are perfectly good). (AFAICT, 5.5-2 is not available through the Hobbyist program.) Thanks, David

19 years, 10 months

VAXStation 100

by aek＠spies.com

Is a graphics display system that interfaced to a 780 through a unibus card and fibre optic link. An ACM article on it his here, if you have an account portal.acm.org/ft_gateway.cfm?id=357336&type=pdf It was the display that the original version of the X Window System was developed on.

19 years, 10 months

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test-drb January 2005