Recent content by 1980s_john

I've got some diagrams of pinouts including the PC-8001 here: https://vintagecomputers.sdfeu.org/general/leads.html Note a MSX cassette lead should work fine. Regards, John PS DIN connectors are described here: https://en.wikipedia.org/wiki/DIN_connector (so thanks WP for the diagrams)

Thanks Tofro, Google found an advert in Digital Design (June 1981) for Two-Day Corp printer mechanism, the matching one is the GPM-80-A (or B), with 80 columns, 8" platen and 60 lpm. Now need to find some other printers that used this mechanism to help find some ribbons. Regards, John

Hello, I'm looking for a new printer ribbon for a 1980 dot matrix printer (Nascom IMP). Attached are some photos, was this compatible with any other printer please? I doubt Nascom designed s custom ribbon. Note on the base is a slotted axle for winding the ribbon. Thanks, John

Apologies, I see there are two versions of this manual on archive.org, this has the missing pages: https://archive.org/details/Rainbow_100_CP-M_86-80_Users_Guide/ Regards, John

Thanks to all the people who scanned in this and the many other Rainbow manuals. I spotted a gap in the CP/M manual, it jumps from page 123 to 140 so if anyone has an original a scan of these would be fantastic. Regards, John

Thanks! Don't know why I couldn't find it, I guess I searched for DEC Rainbow, not Rainbow 100. Regards, John

Hi, Has anyone got a scan of such a manual please? I've found the CP/M technical manual on archive.org which has some useful info on ports and disk formats, but I'm looking for more basic info. One question I have (yet to try out) is how to adjust serial baud rate. I assume if I change it in the...

Update: Kermit archive for CP/M-80 is now here: http://www.columbia.edu/kermit/archive.html

Hi, Thanks desaster for the info. He is probably too modest to mention it, but he has made a couple of very useful Youtube videos on bringing up his Rainbow 100A: Unfortunately the http://www.softsector.aplaholm.se/computers/ is down (for me?), so has anyone else got a copy of RFMAT.ZIP, I...

Thanks Mattis, Glad you got to the bottom of this. The Q1 Lite is still an interesting machine, but not a 'Pre-Altair Microcomputer' so apologies for posting in this section of the forum. So looks like there is only one known Q1 (1972) machine left? Is it on shown somewhere? Regards, John

Ok, please let the interestingengineering.com people know, and also Kingston university who are showing it at an exhibition: https://www.kingston.ac.uk/news/article-amp/2920/13-feb-2024-worlds-first-microcomputer-goes-on-display-alongside-range-of-other-vintage-computers-in-public-exhibition/...

Anyone come across the Q1? This article: https://interestingengineering.com/innovation/worlds-first-desktop-computers-unearthed-in-london-house-clearance claims the Q1 microcomputer was launched in 1972 (using the Intel 8008), so about the same same as the Datapoint 2200 came out with the...

Thanks for making these videos, it's always interesting to see working examples of historical machines I would otherwise never come across. Regards, John

Thanks, the NEC C2373 looks like a package with two diodes back to back. Normally one of the output voltages is fed back to a control circuit on the primary side. Regards, John

Hi, I don't know details about the 6001 but can comment about PSUs in general. Were you measuring the supply outputs with any dummy loads attached? Often you need to draw the rated current from the +5V output (which is normally regulated) which then causes the +12V / -12V outputs (unregulated)...