I made a thing! For those 3-4 people in the Fediverse who tinker with #Nascom and #GeminiMicrocomputers, I present: The 80-Bus Stop - convernient and safe storage for your 8x8" expansion cards. Enjoy ;-)

https://www.thingiverse.com/thing:7258329

#vintagecomputing #3d

Here's a weird thing I found, while restoring my old #CPM computers from #GeminiMicrocomputers: while there were models available with Winchester drives (that's harddisks for you young folks), the setup was a little weird. This was the time of the #MFM and RLL harddrives, used by other systems such as the IBM 5150. Easily recognizable by having two flat ribbon cables instead of just one for each drive. RLL was a little more tightly packed with capacity, but basically the same concept - required slightly different controllers though.

Anyway, back to the Gemini. It featured a #SASI interface, which is sort of an early version of #SCSI. Did you connect a drive directly to it? Noooo. You connected a #Xebec SCSI/MFM controller. Did that require a lot of weird SCSI commands for telling the Xebec what disk was attached? Of course. Compared to how it's done today, very backwards.

Which meant I had zero luck with my new #zuluscsi device. https://zuluscsi.com/

I've got a plan B though.

Anyone up for a game of #Zork on a GM905 system from #GeminiMicrocomputers featuring a #z80 processor, 64K memory and dual #gotek floppy emulators running #FlashFloppy? Eh? 😜

#CPM #vintagecomputing

Is your 40+ years old #vintagecomputer suffering from ribbon cable bird's nest syndrome? Don't delay! Print my ribbon cable chassis connector housing thing today! 🙂 Also, be gentle - I'm new to #3d :-)

https://www.thingiverse.com/thing:6953672

#vintagecomputing #vintagerepair #cpm #GeminiMicrocomputers

Booting #CPM on the #GeminiMicrocomputers system with new #gotek enclosure.

It's done! I figured "if you're gonna build a old school vertical #gotek enclosure, why not do it with some style?". I'm aiming for that early 80s style, and I'm quite happy with the result, although the OLED sticks out a bit. It is terribly practical for navigating disk images though. What do you think?

Video of the unit booting CP/M in thread.

Model available here: https://www.thingiverse.com/thing:6939095

#vintagecomputing #CPM #floppydisk #GeminiMicrocomputers

As promised: a complete deep clean of the late #70s #GeminiMicrocomputers parallel #keyboard by #Rotec. Everything disassembled, cleaned, lubed, rubber liners treated with silicone and brand new rubber feet installed. All keys are working, but some don't sit as well in their sockets as they used, so I expect the keys to stay in place if I hit someone with it! :D Also some electrical issues with scanning of the key matrix being incredibly slow - but it lives!! 🙂

And yeah, the "DISASSEMBLE FROM PCB SIDE" sticker was added by me. Taking this apart the wrong way will end in disaster. Learned that the hard way.

No spiders were hurt in this cleaning, although they had clearly taken up residency at some point.

#vintagecomputing #cpm #keyboards

First bath in 42 years. Much needed.

#vintagecomputing #GeminiMicrocomputers #keyboards #80s #norgb

I'm designing a 5.25" front for the Gotek floppy emulator that will go in my #GeminiMicrocomputers. It's vertical, has a #rotaryencoder, a 1.3" OLED display and a big fat red 5mm LED. I think it's going to look sort of period correct, if you disregard the presence of the OLED.

And yeah, this is a test run so dimensions are minimal and color is whatever was on the #Prusa #3dprinter.

#vintagecomputing

@teksttv Later on, #GeminiMicrocomputers made a sleeker looking serial keyboard with more keys on it, but the caps lock stayed in place. See https://mstdn.dk/@saustrup/113885322777396391

@kobza No, it uses #GeminiMicrocomputers own parallel interface. I'll try to restore it, but I'm a little worried some of the switch parts might break in the process. They might be a bit brittle at this point. Any suggestions for spare parts?

I'm drowning in work right now, but yesterday I did manage to pop the lid of my #GeminiMicrocomputers parallel #keyboard.

It's a full #metal frame #mechanical keyboard with silver pad style switches, way before everything had to go click. It's covered a thick layer of dirt, but I'm doing an in-depth cleaning when I have a little more time.

Also, it's untested and currently doesn't have a cable. I'll look into that as well.

The ROM contained "(C)1978 INTEL CORP".

A small teaser from my next restauration project:

#keyboards #GeminiMicrocomputers #england #z80 #80s

The #GeminiMicrocomputers comes with two types of #keyboard - a large old school parallel and a more modern, sleek programmable serial version. I have 6 or 7 systems, of which one now seems to work, but only two keyboards - one of each type. Naturally, they're not compatible with anything except the #Gemini systems. The serial keyboard pictured here was covered in dirt and marked "defect". A capacitor was changed, everything was cleaned, reassembled and tested. It works! 🙂

The really cool thing? The first F key is zero, and is written FØ. I love that detail.

Next mission is to put the parallel keyboard through the same process. Honestly, I kinda like the bulky parallel one better. And it's got brown caps! 😂

#vintagecomputing

Hell yeah! I managed to assemble a working 40+ years old #GeminiMicrocomputers from the lot of dead ones I inherited. #z80 CPU card repaired, Super Video Controller repaired, floppy controller configured, #gotek configured and attached. Keyboard cleaned and repaired. #CPM loads and demo program runs.

#vintagecomputing

Random memory: Some 45-50 years ago, my dad sold and serviced #CPM machines, specifically #GeminiMicrocomputers from the #UK. His customers seemed to be primarily people connected to printing and the press. One guy represented a printing house, which I believe also doubled as a #Buddhist #monastery, and visited my dad's shop quite frequently.

The thing that triggered this memory, was that apart from #Buddhism and printing, my dad's customer - friend if I'm not mistaken - also did a bit of recreational programming. He was in fact the author of a Danish #Pacman clone called "Gufferen" which translates to something along the lines of "the muncher". At the time, it was a breath taking action game in 80x25 character resolution, and I'm absolutely gutted that I will probably never see it again.

Good times.

#vintagecomputing #cpm80 #z80

So my dad and I went on a last #roadtrip together. We rarely spoke, and almost never about personal things. He had two other families after mine, and gave most of his attention to the people right in front of him. That unfortunately meant that both of his grandchildren missed out on their grandfather and vice versa, which is probably the thing I'm most sad about. Fortunately we managed to catch up a bit during the last three months before he died.

When we spoke, we spoke about electronics and computers. The car is full of ancient vintage computers I saved from his estate. For the curious, it's Z80 based, #Nascom compatible computers from #GeminiMicrocomputers. More about that later.

So here he is, and so are some of his things. Peculiar how I'm flooded with emotion, when I hold some of the tools that I remember from growing up in his computer workshop. It was one of the few things we shared and he taught me - #computers and #electronics.

#loss #death #urn #dads

@simonjust A most excellent post indeed! :-) I grew up on CP/M - as mentioned before, my dad ran a business in the 80s and early 90s that imported microcomputers from the UK. As I recall, it started out with #GeminiMicrocomputers, which were from the heavy duty metal plating business era and sported a highly moduler 80 bit system bus. They ran CP/M-80 and - if I recall correctly - were compatible with Nascom? Obviously some of these systems eventually ended up on the desk of the resident teenager, and the rest is - as they say - history.

Link to the Gemini Galaxy 1 - one of the first systems they made: https://www.computinghistory.org.uk/det/11357/Galaxy-1/