Daniele Verducci 🧉Mar 7
I've got a #philips PCD-103 like this one (photo by the Internet) that has been in storage for over a decade and now I'd like to restore it.

#retrocomputing #dos #intel8088
Show threadDaniele Verducci 🧉Mar 7
I startes taking it apart to see how's the inside.
And, #horror ! Can you see it?

#retrocomputing #dos #intel8088
Show threadDaniele Verducci 🧉Mar 7
It's #batterybombed 😱
A spicy #varta still inside!
Show threadDaniele Verducci 🧉Mar 7
A better #motherboard view before removing the battery

#retrocomputing #dos #intel8088
Show threadDaniele Verducci 🧉Mar 7
Uuuuh some interesting #bodgewire !
It reminds me of some old #Commodore...
Show threadDaniele Verducci 🧉Mar 7
I think they are from the factory. I found a photo on an auction of a board with the sane wires and components attached...
Show threadDaniele Verducci 🧉Mar 7
I removed the battery and trying to clean the PCB with alcohol vinegar

...GROSS! 🤢
Show threadDaniele Verducci 🧉Mar 7
Cleaned all the traces the better I could, it doesn't seem the acid eaten them all the way down... so I tried to follow them and test them for continuity. They seem all to be still connected 🙂

#retrocomputing #dos #intel8088
Show threadDaniele Verducci 🧉Mar 7
I like to test the #powersupply before connecting the motherboard, but this one doesn't seem to start. It starts for a split second and it stops immediately...
Show threadDaniele Verducci 🧉Mar 7
No, wait! It needs some load on the 5v rail, like a lot of the switching PSU of the era!
And, sure enough, al voltages are spot on! 5,12v and 11.99v!
Show threadDaniele Verducci 🧉Mar 7
Let's try to start it.
Unfortunately I don't have a CGA or MDA screen here, but what I've got is an ISA VGA card that can be set to 8 bit mode!
Let's try...

We are ready!!! Ignition?
Show threadDaniele Verducci 🧉Mar 7
NO. WAY.
I've got a video output and it's clearly running! It's counting memory!
It has 640k, as usual

#retrocomputing #dos #intel8088
Show threadDaniele Verducci 🧉Mar 7
I'm not sure if the floppy drive is 720 or 1.44, but for food measure I popped in a 720k floppy from the #amstrad ppc-640 luggable pc.
...and it reads it correctly! It's booting DOS!!!
Let's find a compatible keyboard and play something!

#retrocomputing #dos #intel8088
Show threadDaniele Verducci 🧉Mar 7
UH-OH.

Every time I press a key, either it doesn't do anything or it prints a bunch of unrelated characters. It also beeps a lot of times, like if the keyboard's buffer was full, but it still prints characters 🤷‍♂️
I never debugged a keyboard problem and, honestly, have no idea how an #AT #keyboard works...

#retrocomputing #dos #intel8088
Show threadDaniele Verducci 🧉Mar 7
The keyboard connector is very distant from the zone interested by the battery leakage. I don't think it's related.
I redone all the soldering on the keyboard connector, just in case, but it doesn't seem to make any difference
Show threadDaniele Verducci 🧉
Ok, I'm probing the #keyboard with the #oscilloscope.
The yellow trace is the clock pin, the blue is the data pin.
When I press a key, a lot of times it doesn't send anything: no clock, no data. But sometimes it triggers and there is a clean clock and data signal (or atleast it's what seems to me 🤷‍♂️).
Mar 7 at 3:59pmWeb