test-drb November 2006

test-drb@ccmp.vtda.org

220 participants
452 discussions

by jwest＠classiccmp.org

I can't seem to find any docs on this unit and it's unibus controller. Anyone have docs I could copy or better yet, electronic format? Thanks! Jay

18 years, 1 month

Large Peripherals on Large Systems (was Re: Discussion of large systems)

by ethan.dicks＠gmail.com

On 11/1/06, Richard <legalize at xmission.com> wrote: > I agree, which is why I started collecting in two areas: serial > terminals and graphics boxes. "Graphics boxes" includes things like > dial boxes, button boxes and graphics tablets and even plotters. Cool. I've always been fascinated by dial boxes and button boxes, but, DECUS aside, never got the chance to play with many. I know they were big with SGI systems, but my experiences tended to run to DEC and Sun more than SGI. (here's an ASCIIfied doc I found on the VAX 8000 dial box - very cool... now I want one ;-) http://deathrow.vistech.net/~cvisors/DEC94MDS/vsxdatm1.txt > However, I see things like large line printers and other such early > printing peripherals seem to be rare. They only seem to appear in > people's collections if they were part of a big bundle. I have a LP05-type line printer and several smaller DEC printers (LA-180, LA36...) The LP05 is awaiting some attention, but my first LA-180 saw a lot of use its first few years... I bought it from Newman Computer Exchange in the mid-1980s to hang off of my PDP-8/a when they sent me a "free shipping on your next order" coupon. I looked through their catalog and picked out the heaviest item I thought I could get some use out of. A few days later, a van shows up with a palletized printer. Fortunately for me, a couple of years later, I got a contract job writing PDP-11 software and really _needed_ that printer (and equally fortunately, the $300 PDP-11/23 I picked up to do the work already had an LPV11 installed). I can't say that I had as much need for a true line printer fifteen years later, but they are cool to watch work. > Any other peripheral collectors out there? I collect CPUs _and_ peripherals, if that counts. -ethan

18 years, 1 month

M9312 boot roms

by jwest＠ezwind.net

To all who wanted M9312 boot roms burned, I've completed that today. I'll have them out in the mail by the end of the week. Expect an email after they are sent with total cost. Jay

18 years, 1 month

A question regarding floppy drives functionality..

by ajp166＠bellatlantic.net

> >Subject: A question regarding floppy drives functionality.. > From: Marian Capel <marian.capel at bluewin.ch> > Date: Tue, 31 Oct 2006 18:26:22 +0100 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Since this list has a number of people that are very knowledgable on the >subject : > >Am i correct in thinking that, given a custom FDC, i could run a modern >1.44 floppy in FM mode, and at much lower data rates i.e. (say 50 KHz.) ? You may not be able to run that slow but you could test by recording square waves of varying frequencies and look at what comes back. >Background : I am musing on how to give a small amount of storage, say >around 100kb, to a very small low tech cpu. >I do not care about speed and efficiency. Myself for 100k I'd use a EEprom. Eprom or even 128k ram with a battery. >I am aware that IDE-based solutions are simpler, both hard- and software >wise, but I would prefer a floppy based solution. FYI the slowest floppies are the oldest 5.25 like the SA400 and TM100 as they will reach down to 64khz, I did some testing once. I'd suspect some of the later 360k drives would do well (slow data) too. I do know that most of the 360k drives work fine at FM (single density) data rates (125khz). Allison

18 years, 1 month

dec /34a issue

by jwest＠ezwind.net

I just brought up my /34a and apparently it's sick. It has one DD11-PK. Configuration is as follows: 1 - M8266 (A-F) 2 - M8265 (A-F) 3 - M9312 (A-B), M7859 (C-F) 4 - M7891 (A-F) 5 - Grant (D) 6 - Grant (D) 7 - Grant (D) 8 - Grant (D) 9 - M9302 (A-B), Grant (D) What works: Storing & retreiving various patterns from ram via the front panel works fine in all cases. Looping on CLR PC loops as expected Looping on BR . loops as expected Trap catcher works (first pass halts at 1030 filling ram, then a BR . loops as expected). The memory address test program fails though. It halts at 246 indicating a memory addressing error. R1 points to 422. Examining memory via the front panel shows the following: 420 420 422 177355 424 177353 426 177351 430 177347 So it looks to me like it is able to store 420 in 420, but nothing after that. I would normally think there is a problem with the memory board (M7891). However, I have replaced that board with 2 others, and all 3 boards fail at the same address AND with the same values. I find that likely to rule out the memory board as really being bad. In addition, I can deposit and examine values to locations 420 through 430 via the front panel just fine. It's my understanding that the KY11-LB puts data in memory via the unibus, so I would think this makes it somewhat unlikely to be a backplane issue. Is it a strong likelyhood that the problem is the cpu set itself then, as that's what would be writing the values to memory during the address test? And as I type this, I just noticed something interesting. The numbers stored in ram at 422 through 430 are the right numbers, just inverted logic. More specifically if you invert all the bits in 177355 you get 422, if you invert all the bits in 177353 you get 424, inverting 177351 gives 426 (all the latter values being what I'd expect). I'm guessing there's a dead inverter on the cpu set somewhere perhaps? But if that's the case, why does 420 get set to 420 correctly?? Any advice is most appreciated :) Jay West

18 years, 1 month

Discussion of large systems

by aek＠bitsavers.org

> Now that you have the only purely German mainframe (TR-440), is there any > software with it, like BSM or PS440 or TEXAS etc.? Any software for the > Zuse machines? CHM won't have the machines until early December. The material on the TR 440 that I've put up on bitsavers was from the existing corporate archive. There is one entire container of documentation and software, and there were Telefunken tapes and documentation there. A simulation would be an obvious thing to attempt. It will be difficult to do here, though, since most of the documentation will be in German.

18 years, 1 month

Printer Heads: How To Clean Without Wasting Ink

by safehaus＠webhart.net

Hi Is there a way to clean printer heads from the outside, rather than allowing so much ink to be wasted by the machine blowing the ink through the heads to clean them. (This must be in a FAQ. I just need to be pointed to where this has been discussed a thousand times already.) A bit of background: I have an Epson CX6600 printer/scanner that has suddenly quit printing. The company sent the machine to me to replace an earlier model that developed the same problem. Maybe this machine has the same problem, or maybe it just needs head a more aggressive cleaning. I've "blown the jets" a few times, using over half the ink in the cartridges to do it, and the machine still barely leaves an image on the paper. (I keep a towel over my printers when I don't use them, and no one smokes in the house.) I'm hoping to avoid taking the time to crate and ship this machine as well. I'm not really interested in another replacement anyway. Thanks in advance for any help. Greg P.

18 years, 1 month

EBCDIC

by Billy.Pettit＠wdc.com

Zane H. Healy wrote: You mean you don't have how to create your own EBCDIC table memorized? I memorized it over 16 years ago, and oddly enough I still remember it. Zane Sorry. I grew up in the world of BCD and 6 bit characters. CDC finally started cutting in ASCII in the late 60's, but with little enthusiasm. EBCDIC is something I only encounter when restoring old IBM et al machines. And even then, usually it is just the codes that were perverted into vendor unique control characters that I have to question. Billy

18 years, 1 month

dude...yer gettin' a Dell

by chrism3667＠yahoo.com

or it's progenitor rather: http://cgi.ebay.com/Collectible-Personal-Computer-PCs-Limited-brand_W0QQite… funny, you can get a new Dell for less cash though. Ouch. And that appears to be a goofy Tandy monitor sitting atop. Don't that really sweeten the pot. ____________________________________________________________________________________ Want to start your own business? Learn how on Yahoo! Small Business (http://smallbusiness.yahoo.com)

18 years, 1 month

More ePay items

by cclist＠sydex.com

If anyone's interested, I've just listed a NIB Micro Solutions 3.5" Backpack drive and a NIB CompatiCard IV for auction. Thanks, Chuck

18 years, 1 month

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test-drb November 2006