C103253 REV.5 - STFM

STFM motherboards.
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rubber_jonnie
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C103253 REV.5 - STFM

Post by rubber_jonnie » Fri Jan 05, 2018 1:21 pm

And here's the C103253 REV.5 that just arrived. It's been a good day!
IMG_20180105_130550__01.jpg
IMG_20180105_130550__01.jpg (5.87 MiB) Viewed 726 times
Interesting board, as odd RAM chips. This board did come with a SIMM adaptor that sits atop the MMU and has a shifter adaptor, but I've removed that for the purposes of the picture. You can see a jumper on there for the adaptor, I left this on so I know where it goes, and it isn't getting in the way.

I will attempt to get running with no other HW fitted before I try to use the Adaptor.

DMA is a -38 and FDC is a VL1772.

EDIT 06/01/2018. The board runs after removing the RAM add in and re-soldering the resistor that had been 'jumped' elsewhere.
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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Maeke
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Re: Atari Mainboard revisions

Post by Maeke » Fri Jan 05, 2018 4:04 pm

indeed the stfm is an interesting board.
As for the ste only the post 91 ones had an ajax from factory, yours is too old (89-90).
Looking back, not far, it's a really early 91 (sixth week) before the revision when the blitter was integrated in another ic.
If i take too long to reply, sorry my cat is sleeping on my laps.

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