test-drb June 2018

test-drb@ccmp.vtda.org

106 participants
89 discussions

by jnc＠mercury.lcs.mit.edu

> From: Mattis Lind > Thanks Noel for sorting this out. Eh, de nada. But thank you. >> I wonder if the ucode in the two versions is identical? The uROM chip >> numbers should give it, (if they are the same on both versions, albeit >> in different locations on the board), but I have yet to check. Does >> anyone happen to know? OK, so the situation here is pretty complicated. To start with / make things worse, that CPU uses lots of PROMs. Lots and lots and lots and lots of PROMs. For the data paths board (M7260), both major versions appear to contain the same PROMs (going by the DEC part numbers), but the chip location (Exx) numbers are all different. For the control board (M7261), the C, E ('early' version) and F ('late' version) etch revisions each contain mostly the same PROMs, but apparently with slight differences between the sets of PROMs in each (as reflected in different DEC part numbers). For details see: http://gunkies.org/wiki/PDP-11/05#Control_PROMs to which I have just added all the gory details. As to getting the contents of all of them dumped in machine-readable form - oi vey! >> on the earlier version (prints for that version are in the GT40 prints >> online It turns out that I have hard-copy prints for the "C" etch revision of the M7261, which do not yet appear to be online; the GT40 prints have the "E" etch revision. I will scan the pages for that revision of the board, and put them up 'soon'. (I'm not doing the whole print set, it's about 1" thick, and most of them are for other things anyway, like MM11-L memory, etc.) Noel

3 years, 5 months

Motorola EXORciser M6800 System

by osi.superboard＠gmail.com

Since a few days, my EXORciser Development System is finally able to boot from floppy diskettes. Previous attempts have shown that the Motorola EXORciser M68SFDC1 floppy disk board used has a special modified ROM version. This was probably written for an 8-inch drive, in which the Write protect and Direction signal were inverted. For the sake of simplicity, I have used free inverter on the board to invert the signals accordingly. After adjusting the PLL frequency, reads and writes from the card are now error-free. And all without FDC, only clever programming by Motorola software engineers in the early 76? Originally, the EXORdisk system was a dual drive with two 8 "units. This I have replaced with a double drive of two 5.25 inch units. An Epson and a TEAC, which can be jumpered to 360 rpm. Luckily, 2HD floppy disks are easy to R&W. I also got a GOTEK floppy emulator running, which I can boot from. Thanks to Roland Huisman, Bitsaver has some interesting floppy disks that convert to HFE format work perfectly. This format makes the Gotek drive most reliable. Now to my question. The vintage computer forum at http://www.vcfed.org/forum/archive/index.php/t-44638.html mentioned some interesting manuals. Archive.org has some manuals, Bitsaver does not have manuals about the M6800 development system. If someone already owns scanned manuals to the following list M6800 Basic Interpreter Reference Manual M6800 Macro Assembler reference Manual M68SFDU Exordisk 11/111 Disk `Drive Unit Maintenance Manual M6800 Exorciser 11 User's Guide M6800 Exorciser User's Guide MEX68PP1 PROM Programmer Module Supplement M6800 Exorciser User's Guide I would welcome any feedback or questions --THOMAS

4 years, 8 months

anybody have MOVIE.BYU?

by rdawson16＠hotmail.com

The famous Brigham Young University 3D graphics program, by Dr. Hank Christensen. I am looking for the fortran source, it should be 7 files: DISPLAY SECTION UTILITY TITLE COMPOSE UPDATE MOSAIC Any docs related too. Thanks for letting me beg. Randy

4 years, 8 months

Free to a good home: Honeywell/Bull DPS-6 workstation / server (Seattle, WA)

by derschjo＠gmail.com

Hi all -- I picked this DPS-6 up over the summer and it's just taking up space (quite a bit of space) in the corner of my basement. This is a custom 16-bit, bitsliced, microcoded CPU from the early 80s with (I believe) 8mb of memory, and ethernet. It would originally have run a version of GCOS. It's about the size of a large-ish minifridge, but a bit deeper. It's also quite heavy! It's a neat machine, but it's very obscure and unfortunately incomplete (it is missing both mass storage and storage controllers). Otherwise, it is complete and in good condition (albeit a bit dirty). So you can see why you'd really want to have it in your collection . If anyone's up for a project, drop me a line. Local pick up in Seattle, WA. Thanks, Josh

5 years, 2 months

eBay: 1982 Prime Computer

by jnc＠mercury.lcs.mit.edu

This is listed under the informative title "vintage computer": http://www.ebay.com/itm/291934825422 which leads me to post it here under a more informative title, hoping that someone here has a soft spot for Primes! Noel

5 years, 4 months

mainframes and other stuff

by sales＠elecplus.com

Mainframes and other stuff Recycle center in NC is willing to save out "stuff" for people. No, no one can go in the back and scrounge. No, he does not want a lot of emails from people. Yes, he gets big blue and orange and beige 6 foot tall OLD mainframes in all the time. They squash them at the moment. Yes, he will package small orders, and will properly palletize larger orders. Local pick up will be available after the new year. So, if u can send me a picture with description and some part numbers, along with what you want to pay, I will consolidate things and make arrangements. Please don't ask for specific boards from DEC; they don't want to go into that much detail. QBUS will mean nothing to him. Big orange cabinet that says xxxxx is much more likely to get saved. They are moving to new warehouse 1st of the month, so all this will start happening after the 1st of the year. Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 830-792-3400 phone 830-792-3404 fax sales at elecplus.com AOL IM elcpls

5 years, 10 months

How to refurbish plotter pens?

by mattislind＠gmail.com

I am about to get our IBM1627 (rebranded Calcomp 565) going but the pens in the case is quite dry. What is the best method to refurbish those? What is the best solvent to get the old ink out? What ink to refill with? https://drive.google.com/open?id=0B-rp4vyPPYu1ZjVRbnlyczV4czQ

5 years, 11 months

Documation card readers for sale

by ball.of.john＠gmail.com

About six months ago I struck a deal with a place down in California for four Documation M1000's that I've been able to tell so far they all work but I really don't have space for more than one. I've been trying to sell them at a loss for months now over on the Vintage Computer Forums and Nekochan (if you got here you'll find pictures) but no bites. I swear there were people out there that were looking. Where did you folks go? Might anyone here be interested? I absolutely refuse to put them on the curb. -John

6 years

TU58 tape formatter (was Re: rebuilding DC100A cartridges?)

by shadoooo＠gmail.com

Hello. I have a VAX730 with both TU58 drives destroyed (capstan melted, need replacements). I also have a bunch of cassettes, but unfortunately all seem to have problems with the bend and/or bad spots on the tape. Possibly I would try to replace the broken bands (if I find a source) and/or replace the magnetic tape when damaged (I was thinking to try with audio cassette tape, don' t know if metal oxide high density tape could be good for it). Anybody has some information about the coercivity of original DEC TU58 tape? One problem indeed is the need of reformatting the tape, but: if I can emulate the TU58 drive using a serial, would it be possible to send raw commands to the drive using the serial and a PC? Andrea PS-If possible, some good-condition cassette would be very useful to me too. I'm located in Italy.

6 years, 1 month

IP address classes vs CIDR (was Re: Reviving ARPAnet)

by jnc＠mercury.lcs.mit.edu

> From: Eric Smith > which would respond to ARP requests for non-local addresses and reply > with the router's MAC address (on that interface), specifically in > order to make classful-only hosts work on a CIDR network. Yeah, Proxy ARP (an early RFC here: https://www.rfc-editor.org/rfc/rfc1027.txt but IIRC it was people at CMU who first came up with the idea; this RFC is >from people at UT-Austin, documenting it) was originally done to support subnetting (see https://www.rfc-editor.org/rfc/rfc917.txt for more) when it was first introduced - for hosts for which people didn't have the source, but needed to attach it to a subnetted network. Subnetting was a stage before CIDR (which took subnetting and Carl-Herbert Rokitansky's 'supernetting' and mushed them together). Noel

6 years, 1 month

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test-drb June 2018