Falcon030 Repair

[jamesrhq]

I'd not used WSL before, I have to say I'm massively impressed! It just works... :o

[jamesrhq]

I've had a bit more time for the Falcon Box! :)

The soft power control for the ATX PSU is working nicely. You can use one button (or more accurately currently a pair of tweezers to short a header) for power on, reset and power off depending on how long you push the button and what state the PSU is in at the time. The hard reset is done via the keyboard connector. The external keyboard jack is also working well, so you can use Mega and TT keyboards with it. There's actually the possibility I could monitor the keyboard traffic to look for specific key combos to do a hard reset too, but that's something for the future. :)

Next is the more involved bit of seeing if flashfloppy is going to work and extending that with the extra user interface things I want for the external FDD option, etc. So far though, very good! :)

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[dml]

New VIDEL arrived, so I installed it. Nice clean job in the end, despite my cack handed essential tremor! I used a new set of GAL's I burnt and initially I just got a screen full of crap as you'd expet if the video hadn't been initialised. Checked the CPU, no activity. So I seemed to have gone backwards.

Backtracked to my original test setup which involved an original Atari set of GAL's, and what do you know, I got a black screen and CPU activity. Swapped the newly programmed GAL's in one by one until I found one which caused the machine to hang again. Verified it, fauilty. Tried programming it again, failed. Good old AliExpress parts... :roll: Programmed up a new one and now getting a black screen. Result.

I remember going through the same stuff when I swapped a COMBEL & GALs - I ended up using GALs I flashed myself and kept the originals (including a bad one) in storage for reference.

At the time the blank GAL ICs were cheap so long as you grabbed whole tubes at a time so I ended up with a stock of them. The VIDEL / COMBEL chips however... that's another matter :/

Looks like a nice project you are pulling together overall :)

[jamesrhq]

Getting GALs is definitely becoming trickier now, I’ve stocked up with a few at least! It’s amazing you can still get videl and combel NOS though, and not too expensive either given what they are. The postage is somewhat of a gyp though. USPS international is crazy priced.

And thanks! This project may take a little while to come to fruition, but hopefully it will be pretty much the ultimate modern Falcon box! I obsess a bit over detail, hence the ridiculous combined custom flashfloppy, ATX PSU controller, etc. rather than just buying some off the shelf bits! But if you’re going to do something, you may as well aim for perfection I guess! :lol:

[jamesrhq]

I've had a play and got the custom flashfloppy working. Oddly the biggest issue was a solder bridge between 3 legs of the STM which is didn't see for AGES. Even with a rework scope it's very easy to miss bridges! :(

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[alexh]

Nice. I don't tend to use floppy with falcon, mine is networked and I just transfer files to the internal SD card (ide)

[jamesrhq]

Yep, I think you’re right. I have a feeling the floppy won’t get used as much as on an ST, however this ATX / floppy interface board and case would fit an ST just as well. So hopefully this will make a good basis for an expanded ST also.

[jamesrhq]

Can anyone tell me the height of one of the SIMM RAM expanders for the Falcon? I.e. the total height from bottom of the PCB to the highest part of the SIMM socket, or SIMM if that's higher than the socket. I just have the regular PCB type.

I want to make sure I leave enough room above the RAM expansion on the PCB before the floppy drive.

[HigashiJun]

IIRC, all RAM expanders had their SIMM sockets beneath the PCB and not above it.

[dml]

IIRC, all RAM expanders had their SIMM sockets beneath the PCB and not above it.

Yep, the one I have mounts the simm under the board so the height is the same as a chip-on-board version.

12mm total height for the expansion board including the pins, or 11mm just from the expansion header to the top of the board, ignoring the pins.