test-drb November 2010

test-drb@ccmp.vtda.org

162 participants
241 discussions

looking for dump of Tektronix 4023 chargen ROMs

by jonnosan＠gmail.com

Howdy, I'm currently putting together a simulation of the "SacState 8008 machine" (the machine described at http://www.digibarn.com/stories/bill-pentz-story/ ) This computer was a series of custom cards that plugged into a Tektronix 4023 terminal, and used the 4023 for I/O. Therefore in order to simulate the SacState 8008, I need to start by emulating the 4023 terminal. Having a copy of the character generator ROMs would help a lot with making that emulation authentic. According to the 4023 service manual, the chargen ROMs are: Upper Case ROM A - part number 156-0147-00 Lower Case ROM A - part number 156-0401-00 Optional Ruling ROM B - part number 156-0401-00 Would anyone have a dump of any/all of these chargens? Regards Jonno

13 years, 11 months

Installing Ultrix 4.4 on a DECstation 5000 Model 240

by robert.jarratt＠ntlworld.com

I am trying to install Ultrix on to this machine and it is failing very early in the process. It is failing at the stage of detecting the disks with an "invalid block size" error. I am using a CR-506 CD-ROM drive and the disks I have are RZ56 and RZ57. The disks already have NetBSD installed and I intend to replace NetBSD on one of the disks. I am not sure if the error is referring to the CD-ROM (despite the fact that it has already booted off the CD-ROM) or if perhaps it does not like something about the way the hard disks are formatted. Or is it some other problem? The system runs NetBSD just fine, so I don't think the disks are faulty. Any suggestions? Thanks Rob

13 years, 11 months

1103/A trivia question

by mark.kahrs＠gmail.com

To Tony: The non-A needed precharge. That's what the Alto memory refresh task does. What do I win?

13 years, 11 months

1103s

by tshoppa＠wmata.com

> Sometimes the data sheets for an SARM (or whatever) indicate the > row/column structure. Not that it matters, I've not come across an SRAM > that has, say, faster access time from a change in row address than a > change in column address When I once asked why there were so many different PDP-11 memory diagnostics, (beyond just unmapped vs mapped vs whatever processor diffs) I was told that it was because each was structured to hit the row/column drivers and induce known pattern-sensitive failure modes particular to the core stack or chips in use. Tim.

13 years, 11 months

(DiscFerret): First prototype built, photos available!

by classiccmp＠philpem.me.uk

Hi guys, The parts for my soldering iron finally arrived this morning, thus I spent the day playing with solder paste and SMD stencils. I've got one working DiscFerret built on a 0J28 board, using the same 2C8 FPGA and Cypress RAM chip I used on the previous two prototypes. The key difference here is that this unit is RoHS-compliant, built entirely with lead-free parts, and was assembled using a modified Argos mini-oven. The extent of the modifications? I installed an eCAL E6C PID controller and a Crydom EZ480F18 solid state relay. After a few hours spent reading the "concise operator's manual" for the PID controller, I finally got the Kester Pb-free and SnPb profiles loaded, and the thing is as happy as a pig in muck! (Oh, it turns out Multicore RA15 and 318LF work fine with the Kester profiles... for anyone who cares). Here's the Hardware Overview I've just written: http://www.discferret.com/hardware/ And, for the impatient, here's the 1280x712 photo of the very first DiscFerret: http://www.discferret.com/hardware/discferret_pcb.jpg This board has been allocated the serial number "GB0K1801", which decodes as: GB: "Great Britain", i.e. "Made in England," of course :) 0: 0 years after 2010 K: 11th month, i.e. November 18: 18th day of the month 01: First unit built on that day The plan is to clear out my stocks of 2C8 FPGAs, which should (in theory!) leave me with six saleable units in total, based on the stock of parts I have available. Tomorrow should be fun. It took me four hours to make this one board. If I can scrape together enough table space, I should be able to paste-and-place three or four boards at the same time, then oven-bake them in turn (which takes 5-10 minutes a piece). The fun part is, as always, clearing up all the solder bridges :( -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

13 years, 11 months

MEK6800D2 restoration

by wim＠hackbox.be

I'm in the process of restoring a Motorola MEK-6800-D2 evaluation kit. The kit was adapted and has its RAM on a separate board through an EXORciser backplane. After putting everything together and verifying that all looks good, I've applied +5V from an ATX power supply. The '-' prompt appeared, the JBUG monitor program is working and I even dumped the ROM and some EPROMs over the cassette port and decoded them on a PC :) So far so good, but to do anything cool I need the RAM board going. The problem is that this (custom wire-wrapped board) is using 16 MCM4116 chips. They need also -5V and +12V. Ok, these are available on the ATX power supply but I'm affraid of doing anything stupid that might blow up something. What would you check before applying these additional power levels ? I've been verifying a bit with an ohm meter that the -5V and +12V leads are not by accident connected to anything they shouldn't but not sure if that's a good way. I also read in the datasheet that you need to apply -5V before the others and removing it after the others. How would you do that ? I was thinking on having the -5V and GND permanently connected. So after switching on the power supply it will have -5V right away. Then manually connect a additional cable having GND, +5V and +12V. On power off do the reverse. Is that a good idea ? Not very handy but if it works I'll live with it. Thanks for any advice, Wim. -- hackbox dot be slash museum

13 years, 11 months

1103s

by tshoppa＠wmata.com

> They had non-multiplexed addresses I think. Later DRAMs had multiplexed > address inputs. of course. Was there a good reason for this other than to > save package pins? I wouldn't call it a necessity but the RAS/CAS/refresh coordination works out very nicely when address inputs are multiplexed in this way. So much so that I can't think of a DRAM since the 4116 that hasn't used this scheme. SRAM's almost always have the concepts of "row" and "column" select internally but rarely is it obvious from the outside. Tim.

13 years, 11 months

OT: Bluetooth

by evan＠snarc.net

Totally off-topic .... it's 3:20am EST here and I need to test something on my new headset .... anyone awake so I have someone to call for the test? (Please reply off-list. evan at snarc.net) Thanks.

13 years, 11 months

RF31s available

by binarydinosaurs＠gmail.com

Folks, Before I send a DEC R400X expansion box to the recyclers does anyone want the RF31s contained within? There's 5 plus a single DSSI variant of the RZ26. All are in the later pluggable backplane type enclosure and I need to know by next tues (23rd). Shipping isn't a problem as long as you pay for it :) Cheers -- adrian/witchy Owner of Binary Dinosaurs, the UK's biggest home computer collection? www.binarydinosaurs.co.uk

13 years, 11 months

Ebay Sperry Unisys Boards (leaknoil)

by jonas＠otter.se

Some kind of US Military Standard Electronic Module, see http://www.tpub.com/content/MIL-SPEC/MIL-M/ (the marking M28787 is the MIL-M number) Referred to here: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.129.4343&rep=rep1&… No idea what they are/were used in. If you Google for M28787 there are dozens of surplus supply outfits selling these. /Jonas

13 years, 11 months

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test-drb November 2010