test-drb

test-drb@ccmp.vtda.org

101090 discussions

by jnc＠mercury.lcs.mit.edu

> I'm going to need this info real soon ... so I'll probably start on > this later today if nobody has the info. > ... > write a two-instruction loop .. which writes a word with only a single > '1' bit, hook up a 'scope ... to a DRAM input, and walk the bit through > ... just disable ECC, and write all 0's to all the ECC bits > ... > I think that ... it'll go reasonably quickly, actually; the more bits > I ID, the fewer values I'll have to try on each succeding DRAM chip. That was pretty easy; thanks for knocking my brain into gear! :-) The first couple of bits I had to fish around, but pretty quickly it became apparent there was a system, and for the rest it was just 'confirm that this chip does indeed hold that bit'. I now have the chip<->bit table for the even words, and most of the ECC bits for them (there are two that have resistor headers next to them, so I can't easily get a DIP clip on them to see which is which), but I'm getting bored, I'll do the odd ones tomorrow. Probably they'll be very similar (the array looks like a mirror image of the one for the evens). Also, I was using a 1MB card, so I only had the low bank to worry about; so then I'll have to do the high bank - again, probably pretty easy, from here. The blasted card doesn't have the usual DEC Exx chip numbers, though! I had to make up my own for it... > I'll add the info to the MSV11-J page on the CHWiki, once I have it. Alas, it's down at the moment (the server is actually up, but its DNS entry has gone away again), but once it's back, I'll get them right up. Noel

8 years, 2 months

MOS 6500/1 ROM archival service

by brain＠jbrain.com

I realize it's been a while since this happened: http://e4aws.silverdr.com/hacks/6500_1/ But, I have pulled my hacked reader out from mothballs to read a CPU someone is sending, so I thought I would inquire if others have 6500/1 units that want read. Jim -- Jim Brain brain at jbrain.com www.jbrain.com

8 years, 2 months

Looking for North star software

by dkelvey＠hotmail.com

I have a machine that I'm just now bringing up. I have some boot software but it is TSS/A that is the accounting multi-user package. I'd really like the TSS/B floppies instead. I'd settle for images. Dwight

8 years, 2 months

Fwd: Looking for Tektronix 4051 or 4052 Display Board

by pete＠petelancashire.com

---------- Forwarded message --------- From: Pete Lancashire <pete at petelancashire.com> Date: Tue, Jul 3, 2018, 2:18 PM Subject: Re: Looking for Tektronix 4051 or 4052 Display Board To: Monty McGraw <mmcgraw74 at gmail.com> Yeah the two display boards went to Europe. If anybody needs three perfectly good 11 inch CRTs, deflection yolks excetera come to Portland Oregon and they're yours or have somebody pick them up for you they're in the scrap pile and scrap is going in about a month. Each CRT contains about $35 worth of gold. On Tue, Jul 3, 2018, 2:12 PM Monty McGraw <mmcgraw74 at gmail.com> wrote: > Pete, > > I'm in Texas near Houston. > > The Display Board is the vertical board to the left of the CRT. It has > several cables at the bottom to pin headers and the cable to the neck of > the CRT. > It also has connectors to the power transistors that simply unplug when > you remove the Display Board. > > Here is a picture of a display board: > https://drive.google.com/file/d/0Bxd4qJinVzkNOFZacFZSYVJwaHc/view?usp=shari… > > Monty > > On Tue, Jul 3, 2018 at 4:01 PM, Pete Lancashire <pete at petelancashire.com> > wrote: > >> Is 206 Washington ? I have the remains of a 4051 4052 and 4010 terminal >> sitting outside in the scrap pile. Parts have gone to Europe but they're >> still pieces left over >> >> >> They were about 25 miles west of Portland Oregon. >> >> >> >> On Tue, Jul 3, 2018, 1:35 PM Ian Finder via cctalk <cctalk at classiccmp.org> >> wrote: >> >>> These systems are rare enough that it's probably worth fixing instead of >>> treating the board as a simple FRU. There are schematics on bitsavers for >>> that board, and they are complete. >>> >>> On Tue, Jul 3, 2018 at 1:21 PM, Monty McGraw via cctalk < >>> cctalk at classiccmp.org> wrote: >>> >>> > I've been repairing my Tektronix 4052. >>> > >>> > I've got the digital logic working - but the text and graphics are >>> messed >>> > up. >>> > >>> > I posted photos of the screens in my Tektronix 4052 troubleshooting >>> thread >>> > on vcfed. >>> > >>> > With a scope on the final X amplifier stage - it is oscillating - so I >>> see >>> > weird horizontal strokes instead of dots for text. I know from the >>> service >>> > manual that this circuit includes a feedback loop, and with the scope >>> I see >>> > oscillation all around the loop - so I haven't found the source. >>> > >>> > Does anyone have a spare Tektronix 4052 (or 4051) Display Board that I >>> > could buy? >>> > >>> > Thanks, >>> > Monty >>> > >>> >>> >>> >>> -- >>> Ian Finder >>> (206) 395-MIPS >>> ian.finder at gmail.com >>> >>> >

8 years, 2 months

Looking for North star software

by stephen.m.pereira.sr＠gmail.com

I believe that Mike Douglas has a utility program that you can get into a Northstar Horizon, and then it can receive a .DSK image sent from the terminal and it will write the disk for you in the Horizon. It?s called PCtoFlop and I think he has it in his archive here: http://deramp.com/downloads/north_star/ <http://deramp.com/downloads/north_star/> Good luck! smp - - - Stephen Pereira Bedford, NH 03110 KB1SXE > ------------------------------ > > Message: 14 > Date: Tue, 3 Jul 2018 00:16:45 +0000 > From: dwight <dkelvey at hotmail.com> > To: Fred Cisin <cisin at xenosoft.com>, "General Discussion: On-Topic and > Off-Topic Posts" <cctalk at classiccmp.org> > Subject: Re: Looking for North star software > Message-ID: > <MWHPR14MB160074267AEE4604C5918AE5A3420 at MWHPR14MB1600.namprd14.prod.outlook.com> > > Content-Type: text/plain; charset="us-ascii" > > I was thinking someone has already done this. If no, as you say, it is not an impossible task. > > The TSS/B is suppose to be their scientific package. It at least has BASIC in it. I have another disk marked CP/M in the same box. I should be able to put something together under CP/M. > > It is a North Star Horizon. There seems to be some images out there so I don't know how they are being captured. > > Dwight > >

8 years, 2 months

Looking for Tektronix 4051 or 4052 Display Board

by mmcgraw74＠gmail.com

I've been repairing my Tektronix 4052. I've got the digital logic working - but the text and graphics are messed up. I posted photos of the screens in my Tektronix 4052 troubleshooting thread on vcfed. With a scope on the final X amplifier stage - it is oscillating - so I see weird horizontal strokes instead of dots for text. I know from the service manual that this circuit includes a feedback loop, and with the scope I see oscillation all around the loop - so I haven't found the source. Does anyone have a spare Tektronix 4052 (or 4051) Display Board that I could buy? Thanks, Monty

8 years, 2 months

Preserved LGP-30

by lproven＠gmail.com

The Moravian Galley in Brno has an exhibition on "Computer Art 1968". The only actual computer is a very well-preserved German LGP-30. I took a few photos of it yesterday... and got told off for handling the paper tape, which only has some diagnostics on it: blocks of "lace" alternating with unpunched blocks. https://www.flickr.com/photos/lproven/albums/72157696907302261 It was used by Zde?ek S?kora in his early abstract art. https://en.wikipedia.org/wiki/Zden%C4%9Bk_S%C3%BDkora -- Liam Proven - Profile: https://about.me/liamproven Email: lproven at cix.co.uk - Google Mail/Hangouts/Plus: lproven at gmail.com Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven UK: +44 7939-087884 - ?R (+ WhatsApp/Telegram/Signal): +420 702 829 053

8 years, 2 months

MSV11-J engineering info

by jnc＠mercury.lcs.mit.edu

> From: Glen Slick > There are 88 41256 256Kx1 DRAMs on a 2MB MSV11-J. Each 512KB bank has > 22 256Kx1 DRAMs organized as 16 data bits plus 6 ECC bits. Umm, I think the internal organization is paired banks (one for even word addresses, one for odd); the manual talks about doing double-word reads (although only one word gets transferred over the bus at a time, but the PMI has some optimization for double-word cycles, IIRC). > If someone was sufficiently motivated I suppose they could probe each > of the 88 DRAMs while writing various bit patterns of data to various > memory locations and work out the mapping that way. ... I'm not sure > which would be more work, probing one or a small number of DRAMs at a > time Oh, that's an improvement on what I was thinking of as a fall-back, if nobody has the info (which was to tie the outputs of individual DRAM chips high or low - depending on how they implement their output stages - through a suitably-sized resistor, and look to see what effect it had on writing and then reading - all 0's or 1's, depending on the tie - still a lot less work than pulling chips :-). Dunno why it wasn't obvious this would be easier! :-) I would/will just write a two-instruction loop (in the PARs) which writes a word with only a single '1' bit, hook up a 'scope (I'm too lazy to hook up a logic analyzer :-) to a DRAM input, and walk the bit through the odd and even words until I see it on the 'scope. I thought about doing the ECC bits first, using the maintenance mode (to walk a '1' through the ECC bits), to avoid getting confused by 1's being written to them during the above process, but that would be a lot more work, since I'd have to look at all the chips in the array to find the one that's getting the '1' ECC bit. It'll probably be a lot easier to just disable ECC, and write all 0's to all the ECC bits while doing the data bit discovery (above); once those are done, the remaining chips are known to be ECC, and I can walk a '1' through the ECC bits to work them out. > From a brief look at the manual it might be possible to use diagnostic > modes to write specific ECC bit patterns and work out the ECC bit > mappings as well. Yup, that was my take too. Although I'm having to re-read the manual a few times to fully grok how all the various mode bits interact! > Might be very tedious, so might need lots of motivation. I think that using the procedure above, it'll go reasonably quickly, actually; the more bits I ID, the fewer values I'll have to try on each succeding DRAM chip. > If I ever get really bored some day maybe I'd take a look and try to > see just how tedious it might be. I'm going to need this info real soon (to hopefully fix a broken MSV11-J), so I'll probably start on this later today if nobody has the info. I'll add the info to the MSV11-J page on the CHWiki, once I have it. Noel

8 years, 2 months

Revealing a new project (non-VCF)

by cctalk＠snarc.net

Time to reveal a personal project related to vintage computing and unrelated to my role at VCFed. In the past two years, while getting neck-deep in the historic Lego 9700 "Technic Control Center" set, I learned that there is a TON of information about this set (and about various related sets) -- but most of that information is missing from the web or at best scattered. What these programmable robotic sets all have in common is they're all >from the 10 years BEFORE the modern Mindstorms series, and they run on vintage computers! I decided a few months ago to make a web site about it. I call the site www.mindsbeforethestorm.com. The site is under construction but you can visit now and see where it is going. I'm asking for contributions to the project. I make a very modest living through my work as a freelance tech journalist and additionally through VCFed fundraising. Many of you will also recall that a personal fundraiser is what enabled publishing of my computer history book in 2015. That was a positive experience. I do not plan to sell anything on this new site, only to offer helpful information that isn't currently available or is very difficult to find. As such, I cannot promise any Kickstarter-style rewards: I don't have any ideas about what a good reward for this might be (open to suggestions). Instead, I appeal to your altruism: fund this project because it is a good thing. Please visit my new site. If you think it exemplifies how the web should be used, if you'd like to see it get finished, and if you would like me to continue to be able to pay my rent and eat food, then please make a contribution via https://fundrazr.com/61N3ef?ref=ab_74VRia. Thanks, -Evan

8 years, 2 months

MSV11-J engineering info

by jnc＠mercury.lcs.mit.edu

Hi, I'm looking for engineering info on the MSV11-J. I was unable to find any prints online, or even a technical manual. (I have the User Manual, but it doesn't have much detail.) The main issue I'm after is working out which bits go into which chips. I have some other QBUS memory boards with no documentation where I created the mapping by just pulling chips, e.g.: http://gunkies.org/wiki/Q-RAM_11 but, alas, on all the MSV11-J's I've seen, the DRAM chips are not socketed - unlike QBUS memory boards by almost all the other manufacturers (e.g. National Semiconductor, Camintonn, etc - in fact, pretty much everyone _except_ DEC). Anyway, if anyone _does_ have an MSV11-J with the chips in sockets, I'd _really_ appreciate hearing from them! I'm not sure it's going to be possible to work it out from looking at board traces, since the MSV11-J is ECC memory, and I expect all the data lines just disappear into the two huge gate array chips. Anyway, I would appreciate hearing from anyone with anything on the MSV11-J. Noel

8 years, 2 months

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