exxos's Atari, Amiga & retro forum

OK, I have the caps in stock, so a bit of soldering this morning.

I'd forgotten how dinky the mono display is, one of the main problems I have is being able to have the thing out on account of the size of the display.

I'm now thinking that perhaps I should check the caps in my PSU too...

I set mine up as an answer machine once, and the damn thing worked really well. Of course it wouldn't let you leave a message, but it would answer the phone with the message you told it to use, and it was so simple to build a message from the library of words.

I feel these machines were quite ahead of their time with all the messaging functionality and built in business apps, especially on ROM. Better Microdrives too, though I'd suggest that was the weakest link in the whole system.

@stephen_usher FYI I just checked and I have a spare 'Welcome Pack' booklet and VT terminal cart if you want them. Thought I had more duplicated carts but they are all different apart from that one.

@rubber_jonnie the "Welcome Pack" would be useful but I already have the VT cartridge. Thanks anyway. :-)

Recapped the PSU low voltage side but because of really bad corrosion on the "under side" of the PCB in the high voltage side I gave up. I tried to get the start-up cap out but as soon as I applied head the trace started to lift. It was hell trying to get fresh solder onto the joint too. No idea how this area was damaged as the top and everything around is in very good condition.

Anyway, the cap replacement has fixed the horizontal shimmer and the display's looking nice.


Other than there's a slight vertical size twitch... That'll be caps on the monitor board. *sigh*

stephen_usher wrote: 26 Nov 2023 11:02 @rubber_jonnie the "Welcome Pack" would be useful but I already have the VT cartridge. Thanks anyway. :-)

OK, PM me your address and I'll stick it in the post. Not sure why there are 2 in my documentation pack, or why I have 2 VT carts, but there you go.

Both Microdrive drives serviced and working. Even managed to get 159 usable sectors on the manky cart which it came with. This is even more impressive as the cart left large lumps of its magnetic material stuck to the left drive head and pinch roller. That stuff was hard to get off. The cart had been left in the drive for decades! Of course, I had to re-felt the cart first.

I found on-line complete design info and ROM image for the Computer One floppy interface for the machine, which plugs into one of the ROM pack slots. The floppy format is... Apricot MSDOS 720K. That's quite useful, seeing as a have a few of those machines. I may build one up.

I opened up the machine tonight. It’s all clipped together so that was a bit worrying but the clips are easily undone.

There’s a VARTA lithium battery supplying a 2K SRAM chip holding the “permanent store” settings. Amazingly, after 38 years it’s still happily outputting 3.08V, which is within spec!

Drenched all the connectors in contact cleaner and also did the volume control which had been scratchy.

Discovered that the keyboard uses proper Cherry key switches and not a membrane, so it’s disappointing that the right shift key isn’t working. Tried squirting electrolube down the stem but it did no good. All the other keys work correctly.

And another machine arrives.. The Mega 2 ST.

It's all correctly in three pieces (base, keyboard and mouse). I'll have to see if it still works when I get it home.

The case is a bit sun tanned, but that's expected.

Well, the Mega ST starts, seeks the floppy and stops when I put a floppy in the drive, so it's probably working fine.

stephen_usher wrote: 27 Nov 2023 23:19 I opened up the machine tonight. It’s all clipped together so that was a bit worrying but the clips are easily undone.

There’s a VARTA lithium battery supplying a 2K SRAM chip holding the “permanent store” settings. Amazingly, after 38 years it’s still happily outputting 3.08V, which is within spec!

Drenched all the connectors in contact cleaner and also did the volume control which had been scratchy.

Discovered that the keyboard uses proper Cherry key switches and not a membrane, so it’s disappointing that the right shift key isn’t working. Tried squirting electrolube down the stem but it did no good. All the other keys work correctly.

Interesting, mine has a 9v battery to retain the settings, it's hidden under the Microdrive cover.