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mwillegal
January 9th, 2019, 11:20 AM
Couple of questions related to this video card that was initially designed for the Mark-8, but also used with other systems, such as the SCELBI. I'm interested in having one to go with my growing array of SCELBI peripheral devices.

1) Does anyone have or know of one that may be for sale?

2) I'm pretty much assuming that the answer to 1 will be no, so am considering building a reproduction. The information needed is already available, so that isn't an issue. Is anyone else on this list interested in building a reproduction? If I can't find an original, once I get the CAD work done, I'd be building a small batch, but the size of the batch partly depends upon interest in the hobby community. More people interested equals lower per unit cost.

regards,
Mike Willegal

smp
January 9th, 2019, 11:25 AM
I can't help directly with any of what you're asking, but I saw earlier today there's a Digital Group system up for sale.

https://www.ebay.com/itm/Vintage-1976-The-Digital-Group-Z80-Computer-VERY-RARE-CP-M-CAPABLE-MACHINE/123586438552?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

Are any of the cards shown with it the video card you are interested in?

Just a long shot...

smp

mwillegal
January 9th, 2019, 11:50 AM
that is a later system, which I understand, has an evolved version of the video card in it

-Mike

falter
January 9th, 2019, 12:55 PM
Pretty much the only person I know of that has one is Bryan (Byte Collector). I'm a big dg fan and I've never seen one in the wild. I expect I won't.. they look too much like random circuit board junk to be something people will save.

I'm actually working on a replica myself for my Mark-8 project... basically borrowing from scans and such from Bryan's site. I want mine on vintage PCB stock so it looks correct, but I'd probably be interested in a 'produced' version too.

mwillegal
February 5th, 2019, 07:16 AM
A short update on my Digital Group video card project.

I have acquired all the really hard to source parts, which wasn't too difficult or costly. I have also started on the PCB layout. Seems like no real blockers in sight. It will be interesting to see if there is much difference between the schematics and the board pictured at: https://bytecollector.com/m8_docs.htm

The PCB layout might take a while, as I have a lot of different projects competing for my limited free time.

regards,
Mike Willegal

8008guy
February 5th, 2019, 07:37 PM
Hi Mike, a few years back I designed a video card that is compatable with my Mark 8. It is all mostly ttl. I use one of the ic sync generators available at the time. The only "cheat" was a modern negitive voltage generator for the -12 sync generator. I designed and built a pcb for mine. If you are interested I can send you the info.

8008guy
February 5th, 2019, 07:40 PM
Pictures here:

http://i8008.net/MARK8/

And the actual card

http://i8008.net/MARK8/PICS/video_card.JPG

8008guy
February 5th, 2019, 07:50 PM
Oh, and BTW if you design a video card for the Scelbi I am interested in a board.

Are you going to do a run of any more keyboards?

Len

mwillegal
February 6th, 2019, 05:12 AM
The retro keyboard idea is something I've started and stopped about 3 or 4 times over the last decade. I think I keep stopping mostly because of the cost of quality keycaps and keyswitches.

I could share the CAD file/Gerber files of the Datanetics Rev B, if anyone is interested in making a batch. I'm not likely to do it because you basically have to part out 2 Apple II plus keyboards, just to find enough key switches to build one.

regards,
Mike Willegal



Oh, and BTW if you design a video card for the Scelbi I am interested in a board.

Are you going to do a run of any more keyboards?

Len

glitch
February 6th, 2019, 11:41 AM
Dave Fenyes over at osiweb.org has done a run of keycaps for a new OSI keyboard. The OSI uses just a key matrix, we'd been thinking it might be neat to have a microprocessor controller that turns the OSI key matrix into a parallel ASCII keyboard, since those are getting expensive and hard to find. Perhaps there's enough interest between all the different groups that might want vintage-style keyboards to do a larger run and get the price down?