resurrecting my old 520STFM

Problems with your machine in general.
Post Reply
thesofa
Posts: 49
Joined: Wed Jun 30, 2021 3:51 pm
Location: Co. Durham, UK

resurrecting my old 520STFM

Post by thesofa »

Hi, after about 25 years I am trying to resurrect my old Ataris, The one I am trying first is my original 520STFM, TOS 1.0, 512 MB
the following mods were professionally fitted many years ago
  1. 4MB XTRA-RAM DeLuxe with 4 x 9 chip 1 MB simms from Frontier Software.
  2. Compo Software dual TOS so I could have tos 1 for games and 2.06 for Applications, switchable through a side mounted toggle switch on the case.
  3. HD floppy disc and some work was done to the floppy controller chip by fitting a COMPU-WARE HD MOGUL module on it. It all worked fine 25 or so years ago but now when I booted it up in TOS1.0 all I get is the desktop(Green) with no icons and TOS 2.06 just gives me a white screen.
I have none of the original manuals or set up sheets, the TOS switcher was fitted by COMPO, the HD was fitted by a shop in Newcastle upon Tyne, long since defunct and I think the RAM was fitted by Atari Workshop
motherboard is C070523-001 REV D, with the original 512 ram along the front and the tos roms on the right of mobo
Suggestions please as to what to do?

Blurred detail of MMU connection?
Blurred detail of MMU connection?
20210930_163629.jpg (282.08 KiB) Viewed 1086 times
cable from RAM board to MMU?
cable from RAM board to MMU?
20210930_163545.jpg (283.84 KiB) Viewed 1086 times
tos switcher board under the FDD
tos switcher board under the FDD
20210930_163528.jpg (369.81 KiB) Viewed 1086 times
Detail of XTRA-RAM board
Detail of XTRA-RAM board
20210930_163518.jpg (487.76 KiB) Viewed 1086 times
Xtra ram board plus loads of spare wires
Xtra ram board plus loads of spare wires
20210930_163507.jpg (414.44 KiB) Viewed 1086 times
TOS switcher
TOS switcher
20210930_163502.jpg (578.48 KiB) Viewed 1086 times
TT030 with Storm with 256 Mb Ram, Thunder with a CF drive and Lightning, HxC floppy emulator and one of Codekiller's magical Mono/Colour switchers, also 3 STS one has TOS1.0 AND 2.06 switchable with an HD drive, the other two are untested as yet, just bought for spares!!
Steve
Posts: 2570
Joined: Fri Sep 15, 2017 11:49 am

Re: resurrecting my old 520STFM

Post by Steve »

Got to systematically work things out.... the connections for these old upgrades corrode and oxidise over time... Firstly I would remove everything, clean all the connections, chips, sockets etc with de-oxit. Re-assemble. The fact that one version of TOS works but not the other, would suggest the TOS ROMS need cleaning for sure.
thesofa
Posts: 49
Joined: Wed Jun 30, 2021 3:51 pm
Location: Co. Durham, UK

Re: resurrecting my old 520STFM

Post by thesofa »

I thought you might say that, way beyond my capabilities.
TT030 with Storm with 256 Mb Ram, Thunder with a CF drive and Lightning, HxC floppy emulator and one of Codekiller's magical Mono/Colour switchers, also 3 STS one has TOS1.0 AND 2.06 switchable with an HD drive, the other two are untested as yet, just bought for spares!!
Steve
Posts: 2570
Joined: Fri Sep 15, 2017 11:49 am

Re: resurrecting my old 520STFM

Post by Steve »

Well you could send it to me if you want (I re-capped your TT PSU) Just send me a PM if you like.
Post Reply

Return to “HARDWARE ISSUES”