exxos's Atari, Amiga & retro forum

rubber_jonnie wrote: 28 Nov 2023 14:10 Interesting, mine has a 9v battery to retain the settings, it's hidden under the Microdrive cover.

Indeed there is, but that's just the clock battery really. Inside, on the left of the motherboard is an upright, soldered in coin cell (with a plastic shield underneath which looks like it may be there to limit corrosion if the battery pops). ICL did think of most things in terms of servicability.

stephen_usher wrote: 28 Nov 2023 14:47

rubber_jonnie wrote: 28 Nov 2023 14:10 Interesting, mine has a 9v battery to retain the settings, it's hidden under the Microdrive cover.

Indeed there is, but that's just the clock battery really. Inside, on the left of the motherboard is an upright, soldered in coin cell (with a plastic shield underneath which looks like it may be there to limit corrosion if the battery pops). ICL did think of most things in terms of servicability.

Interesting I don't remember seeing that on mine, but maybe I'm remembering it wrong. Will have to check.

And there it is:


I'd totally forgotten about that.

The Mega 2 ST is fine, though the mouse was in a bit of a state and I think that I'm going to have to reflow the solder on the chip as the left-right motion is intermittent. Managed to get it working properly after pushing one of the pins onto the solder pad a bit harder. The mouse buttons are a bit iffy too.

The rollers were very gunked up and the sprung roller was completely seized. Managed to get those working and cleaned.

I've not booted into anything other than the desktop so I've not tried all the keys on the keyboard, but the feel of it is so nice. Definitely the best Atari keyboard I've ever used by a mile or ten actually.

Yup, I too think that the original Mega keyboards are some of the nicest actions of pretty much any keyboard (excluding music ones! :lol: :roll: ).

I have a couple (one bought new back in the late 80s when I had my ST in a DeskTopper case & one came with my Mega 4+Megafile 60 & loads of Steinberg kit).

Just please be careful not to do a @rubber_jonnie with ours & smash the case! :o :shock: :hide: :fire: :fire: :fire: :fire:

JezC wrote: 28 Nov 2023 22:20 Yup, I too think that the original Mega keyboards are some of the nicest actions of pretty much any keyboard (excluding music ones! :lol: :roll: ).

I have a couple (one bought new back in the late 80s when I had my ST in a DeskTopper case & one came with my Mega 4+Megafile 60 & loads of Steinberg kit).

Just please be careful not to do a @rubber_jonnie with ours & smash the case! :o :shock: :hide: :fire: :fire: :fire: :fire:

@PhilC to be fair I bought my Mega keyboard in an already smashed state, but it was cheap so ell worth it :)

rubber_jonnie wrote: 28 Nov 2023 22:28 @PhilC to be fair I bought my Mega keyboard in an already smashed state, but it was cheap so ell worth it :)

Also, I think you did rather a good repair job on it afterwards, so it was probably a good result in the end ;)

I'm keeping the keyboard safe, don't worry. :-)

JezC wrote: 28 Nov 2023 22:30

rubber_jonnie wrote: 28 Nov 2023 22:28 @PhilC to be fair I bought my Mega keyboard in an already smashed state, but it was cheap so ell worth it :)

Also, I think you did rather a good repair job on it afterwards, so it was probably a good result in the end ;)

Thank you :)

Tested the Mega ST further tonight. Diag cart + YAART + UltraSATAN and games, all good. The mouse needed a bit more work as the DB9 wasn't making good contact making it seem as if the mouse buttons were iffy. Some more contact cleaner and poking a wire down the holes and rubbing the contacts seemed to do the trick. Some of the keys on the keyboard weren't great, but exercising them, wobbling side to side, got them fine as well. I'm wondering if the machine was stored in a damp environment. That would explain the corrosion between the mouse ball and one of the rollers.

Oh, and on the OPD front, it does have a fault. When first turned on from cold the memory test fails as it can't clear four strips of memory on the left side of the screen. Once it warms up for a couple of minutes it's fine. I've got to try to work out the addresses of those lines. I'm guessing that this is an equivalent screen mode to the QL's Mode 4 (high res). Suggests maybe address demux issue which goes away with warmth. It's 8 pixels white (1s), 8 pixels normal, 8 pixels white etc. for four stripes and the memory test can't change them, so they're stuck high. As it's a block of 8 pixels that's two bytes.

stephen_usher wrote: 29 Nov 2023 23:07 Tested the Mega ST further tonight. Diag cart + YAART + UltraSATAN and games, all good. The mouse needed a bit more work as the DB9 wasn't making good contact making it seem as if the mouse buttons were iffy. Some more contact cleaner and poking a wire down the holes and rubbing the contacts seemed to do the trick. Some of the keys on the keyboard weren't great, but exercising them, wobbling side to side, got them fine as well. I'm wondering if the machine was stored in a damp environment. That would explain the corrosion between the mouse ball and one of the rollers.

Good news :)

stephen_usher wrote: 29 Nov 2023 23:07 Oh, and on the OPD front, it does have a fault. When first turned on from cold the memory test fails as it can't clear four strips of memory on the left side of the screen. Once it warms up for a couple of minutes it's fine. I've got to try to work out the addresses of those lines. I'm guessing that this is an equivalent screen mode to the QL's Mode 4 (high res). Suggests maybe address demux issue which goes away with warmth. It's 8 pixels white (1s), 8 pixels normal, 8 pixels white etc. for four stripes and the memory test can't change them, so they're stuck high. As it's a block of 8 pixels that's two bytes.

Could it be a cold joint somewhere? Could you use freeze spray or heat to see what it does when pushed either way?