test-drb August 2014

test-drb@ccmp.vtda.org

213 participants
244 discussions

by spacewar＠gmail.com

Has anyone ever seen any detailed tech info on the TRW/Motorola CPUAX, circa 1989? It's mentioned in Motorola's annual report and in some trade journals, but I can't find any info that wasn't just press release stuff.

9 years, 11 months

CMD CI? disk arrays

by aek＠bitsavers.org

http://www.ebay.com/itm/351154468219 the coax coming off of them got me wondering, are these CI attached disk arrays?

9 years, 11 months

Power supply debugging advice (Interact Model One)

by derschjo＠gmail.com

While I wait for PROMs to arrive for my 11/05 I've pulled another "back-burner" project off the shelf. It's an Interact Model One (http://oldcomputers.net/interact.html) and it's having power supply issues. The symptom: At initial startup after being off for any significant period of time (say, 10 minutes or longer) the +5V comes up for 2-3 seconds then drops to zero. The other supplies (+/- 12V) are fine. What I've done so far: - Recapped the electrolytics in the supply (I had the parts on hand, and it's three capacitors. Sorry for the shotgun approach, Tony :)). - Removed socketed 2114 RAMs (in case one was shorted). No change in behavior. The power supply and logic are incorporated into a single PCB, so it is difficult to separate the two (I guess I'd have to figure out what traces to cut, and I'd rather not mangle things if I can avoid it). The DC supply is fed by an external "wall wart" which I *believe* just contains a transformer -- it outputs several flavors of AC (16.5V and 19V), no DC. Any suggestions for where to start with this? Power supplies are voodoo to me, still. The power supply schematics can be found in here: http://www.thebattles.net/oddments/interact/InteractSchem.pdf (page 6, lower right corner). Thanks! Josh

9 years, 11 months

Some Altair questions, if I may.. (drlegendre .)

by dm561＠torfree.net

Good advice for me too ;-) - sorry about the subject line in my previous post... ----- Original Message ----- Date: Sun, 24 Aug 2014 10:48:46 -0500 From: "drlegendre ." <drlegendre at gmail.com> Now back to your original point, the one you felt I was missing.. > Pin #41 had the 470 to gnd, but no 330 to VT+, so it was at a true logic low, pulled down by the 470. This causes the 7404 output to go high, turning off the LED. When I connected the 330 part, Pin 41 came up to 2.8VDC (about 1/2 of VT+) which I guess the 7404 sees as a high (?) switching off the 7404 output and turning on the LED. > All good so far? -----Reply: Just like your misleading post about the LM309's output being connected to the 8V supply rail, you had specifically said that "there aren't *any* resistors connected to it, which is why it's sitting low. I checked that out." No mention of the 470 ohm pull-down resistor... Maybe you could save some time by checking more carefully before posting...

9 years, 11 months

cctalk Digest, Vol 132, Issue 49

by dm561＠torfree.net

----- Original Message ----- Date: Sun, 24 Aug 2014 10:48:46 -0500 From: "drlegendre ." <drlegendre at gmail.com> Now back to your original point, the one you felt I was missing.. > Pin #41 had the 470 to gnd, but no 330 to VT+, so it was at a true logic low, pulled down by the 470. This causes the 7404 output to go high, turning off the LED. When I connected the 330 part, Pin 41 came up to 2.8VDC (about 1/2 of VT+) which I guess the 7404 sees as a high (?) switching off the 7404 output and turning on the LED. > All good so far? -----Reply: Just like your misleading post about the LM309's output being connected to the 8V supply rail, you had specifically said that "there aren't *any* resistors connected to it, which is why it's sitting low. I checked that out." No mention of the 470 ohm pull-down resistor... Maybe you could save some time by checking more carefully before posting...

9 years, 11 months

RSX-PLUS-III

by mattislind＠gmail.com

Many years ago my father recovered a whole lot of documentation from a PDP-15 system at Philips in Stockholm that unfortunately already was gone (scrapped or given away). The lot is several meters worth of shelf space. I have put a photo of the cover of one of the manuals online: http://www.datormuseum.se/documentation-software/pdp-15-documentation I checked bitsavers quickly but didn't find a matching document. Are these documents already online somewhere or should I bother go through the whole lot and document what kind of document there are? /Mattis

9 years, 11 months

SerialTCP for Mac

by joecassara＠mac.com

Hi Retro fans, I have a cache of retro computers I wanted to grant access to the internet. As we all know, utilities exist to open and send TCP sockets to a serial port (Jim Brain's TCPSer is awesome), but getting them to work right on a Mac can be challenging. So, I wrote my own: http://cassarasoftware.com/serialtcp-for-mac/ It's rather bare bones at the moment, but gets the job done. I hope it helps everyone looking to get their old stuff online! ? Joe

9 years, 11 months

Incoterm SPD 900?

by mattislind＠gmail.com

In the early eighties we got a unit which we think is a Incoterm SPD 900 intelligent terminal. At that time it was running just fine. Until now we had it in store but it has not been tested again lately. Now I would like to see if it is possible to get it running again. It is quite interesting in that it is a display unit with built in computer. The CPU is a Incoterm proprietary implementation with a core memory. Attached to this display unit there is a disk unit that employs hard sectored diskettes. The machine was running an operating system called SPD/DOS. Actually there were all sorts of software for this machine as I recall. Even small games. An early personal computer in some sense. When searching the net I came across this post http://marc.info/?l=classiccmp&m=104965775322087&w=2 by Al Kossow. Well now, more than 12 years later, I can confirm that the disk found by Al is >from an Incoterm system running the SPD/DOS system. Anyway. I have put together a page with some information on it: http://www.datormuseum.se/peripherals/terminals/incoterm-spd-20-20 If there is anyone that can enlighten me more about this unit I would appreciate it. If there would be engineering drawings available I am very interested. During my searches on the net I found this page with mostly ex Incoterm people disussing: http://www.vintagecomputing.com/index.php/archives/33/window-to-the-sky-the… Another interesting thing is that the SPD/DOS reference manual still can loaned from a library in Sweden. http://miks.kib.ki.se/search*swe/?searchtype=X&SORT=D&searcharg=SPD%2FDOS&s… Apparently at Karolinska Institutet in Huddinge south of Stockholm. Maybe I should go and find it there... The reason for being available is probably that these terminals were used by the Swedish LIBRIS II system at several libraries in Sweden. /Mattis

9 years, 11 months

anybody need some Signetics 10144 or Nat Semi MM5292 chips?

by elson＠pico-systems.com

We were having a garage sale, and I stumbled on a box of Signetics 10144 chips, salvaged, these are, I think, 256 x 1 ECL static RAMs. Also a bunch of new in original tubes National Semi. MM5262 2K x 1 DRAM chips. I must have over 100 of each. Anybody need some to repair something QUITE classic? Jon

9 years, 11 months

Todd Goodman has been refunded-

by slandon110＠gmail.com

Todd goodman has been refunded for the error on my part, I apologize for any inconvenience this caused anybody and for the drama. Here is proof http://imgur.com/gSLu1Mm Thank You Steve

9 years, 11 months

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test-drb August 2014