test-drb January 2015

test-drb@ccmp.vtda.org

175 participants
253 discussions

by rickb＠bensene.com

I have an RK05J drive that has been sitting around for a long time, and I want to prepare it for going back into service on my PDP 8/e system. Here's what I've done so far: - I have replaced the foam that isolates the blower motor from the housing, as it had started to deteriorate. - I vacuumed out the entire drive very carefully - I removed the head-lock that was put in when the drive was transported from its original location to my location - I ran the drive without a cartridge (and not connected to a system) for about 6 hours with the old absolute filter in place - I removed all of the circuit boards and cleaned the edge connectors and sockets - I tested all of the front panel lamps, and found all to be good - I replaced the absolute filter and ran the drive for another few hours to circulate air and get any last particles of stuff filtered out. - I very carefully cleaned the heads... they were extremely clean. I used a lint-free swap, and a commercial solution that I have that I've used for floppy disk head cleaning that seems to work well. I used this solution on the first RK05's heads, and it worked with no problems. However, the first drive was in service on the PDP 8/e when I got it, and was running fine. This second drive came off a PDP 11 system, and has been sitting for a very long time (years). I plan on running the drive without a pack in it for about 2 hours before I try loading a pack. I'm wondering if there is anything else that I should do before add the drive to the chain (this would be the second drive on the system)? I am also wondering, that since I have very few PDP8-sectored RK05 packs, and a ton of PDP-11 sectored packs, if , when I first power up the drive after it has been connected up to the RK8E , I can put one of my PDP 11 packs in there and spin it up, if the controller will be able to load the heads? I'd much rather sacrifice one of these packs if there are problems rather than risk one of my precious PDP-8 sectored packs. Thanks in advance for any suggestions/answers. Rick Bensene

9 years, 4 months

1972 Univac 8008 Micro - an early 8-bit system

by craig＠solomonson.net

A few years ago I inquired about an early 8-bit micro in my collection that I did not know the background on. Recently I found out the background of the computer and thought I would share it with the history buffs here. It was built by the Univac R&D Division in St. Paul, Minnesota in 1972. They were carefully monitoring the developments at Intel with regard to their 4004 and 8008 microprocessors being developed. Part of their research was to construct actual computer systems to research and then build an application using the 8008. They started by building a 4-bit system similar to the one I have using the SIM4-01 and MP7-01 boards. That unit was completed and being demonstrated by March of 1972. They ordered the 8-bit system (SIM8-01 and MP7-02) when it was announced in April of 1972 and construction took place during the summer of 1972. Univac designed and built their own interfaces for these systems and used a Teletype for I/O. The Univac 8008 "8-Bit Micro Computer System" in my collection was complete and being demonstrated to various Univac divisions and military organizations by early fall of 1972. I visited with one of the Univac engineers that did some of the programming and he said that only very simple programs were used in demonstrations--like doing simple math operations or it asked for your name, you typed it in on the teletype and it printed some phrase using your name. Univac spared no expense in developing this system as seen in the construction and fabrication of the cases which are thick, deep red translucent plastic. Not only is it a very aesthetically designed, but it has to be one of the very first 8-bit computers fully assembled and operational. Here is a photo of the system: http://solomonson.net/computers/Univac.8008.TTY.jpg I have also done a You Tube video telling more about the system: https://www.youtube.com/watch?v=9KojS1ezQIY

9 years, 4 months

hp16500c mainframes, denver

by emu＠e-bbes.com

Hi all, anybody in Denver Area looking for some? I have two I don't need anymore, and for a small fee, you can pick em up. Sorry, no shipping, no accessories ...

9 years, 4 months

Need AT&T 3B2/300 EPROM images to replace ones missing in my system

by bear＠typewritten.org

Esteemed listmembers; I have started working on restoring a 3B2/300, and right away I've discovered the probable cause for the machine's catatonic state. Three of the system board EPROMs are missing. Anybody got a /300 they can dump the EPROMs on? For some reason the AATKL ROM (3/4) is still fitted, so technically speaking I only need images of the AATKJ (1/4), AATKK (2/4), and AATKM (4/4) EPROMs. I may also be after a copy of the AARAM (2/2) ROM from the NI (ethernet) board. My EPROM programmer can't get a good connection on pin 1 of that device and reads it as all zeros. It may still be okay in the socket on the board. ok bear. -- until further notice

9 years, 4 months

PDP-8/I at the RICM

by michael.99.thompson＠gmail.com

We did more debugging on the PDP-8/I today. The individual CLA and CMA instructions work OK, but the combined CLA CMA instruction does not set all of the AC bits to 1s. Tracing with a 'scope found that the AC ENABLE signal was not active during the combined CLA CMA instruction. Replacing the M160 in slot E30 fixed the missing AC ENABLE signals and fixed the combined CLA CMA instruction. The Instruction Test 1 and Instruction Test 2 diagnostics ran OK, so the processor is probably working fine. The TC01 DECtape diags did not run as expected so we need to read the manual before we try it again next week -- Michael Thompson

9 years, 4 months

Making Sergey's XT-CF-Lite board work

by dgriffi＠cs.csubak.edu

I ordered a couple XT-CF-Lite boards as described in http://www.malinov.com/Home/sergeys-projects/xt-cf-lite. Has anyone else here built and used this? I have a problem with the BIOS. Either Sergey specified the wrong size EEPROM or provided the wrong BIOS image. The specified EEPROM holds 8192 bytes while the BIOS image is 32,768 bytes. I sent an email to Sergey, but I thought I'd ask here too. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

9 years, 4 months

Bay Area: IBM 4341 and HP3000

by silent700＠gmail.com

Not mine, not near me, not known to me: http://sfbay.craigslist.org/pen/sys/4837367667.html

9 years, 4 months

Found an EEPROM programmer that works with Linux

by dgriffi＠cs.csubak.edu

I just thought I'd let everyone know, for the record, that I found an inexpensive USB-interfaced EEPROM programmer that works with Linux. This is the Model TL866CS which is often sold as "MiniPro Programmer". These can be found on Ebay for around $50. It feels substantial and solidly built. The software I used to control it can be found at https://github.com/vdudouyt/minipro. The software has some nits[1] but it does work. There's a QT-based front-end at https://github.com/wd5gnr/qtl866. That one has a potential showstopper bug in that it does not surround the device name with quotes when calling the minipro software. So, for those of you (like me) who have posted from time to time looking for a chipburner that works with Linux, here's a solution. [1] udev rules aren't installed in the right place. No option to emit a list of supported devices. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

9 years, 4 months

Motorola Envoy PDA?

by evan＠snarc.net

> Anyone out there interested in a Motorola Envoy of the MagicCap era of personal devices, circa 1994? Interested as in buying, or interested as in a valid cctalk discussion subject? No to the former. Yes to the latter.

9 years, 4 months

Motorola Envoy PDA?

by jfoust＠threedee.com

Anyone out there interested in a Motorola Envoy of the MagicCap era of personal devices, circa 1994? - John

9 years, 4 months

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test-drb January 2015