I'm a hoarder! C64 crustyness inside!

[AmmoJammo]

Found this lot on Gumtree "make an offer"

Asked how much they wanted, they said $100, I offered $30... they said $50... I paid $30 :p

Anyhoo!

as well as the four C64's, there's also six tape drives, and one power supply, all missing their cords.... as well as a monitor that I wouldn't trust to power up right now...



One of them rattled, so of course that was the first one I dismantled...



Does anyone know what this is? used to be connected to a switch on the rear panel, but its been snapped off...

[AmmoJammo]

Next I pulled apart the one that appeared to be in the best condition... it was also heavier than the other two wedges, which made me curious...

But, looks can be deceiving! Its possible the case was the cleanest, as it had been rained on! :nervous:

[AmmoJammo]

None of these computers do anything...

Well, they appear to output a black screen on the S-Video output, but thats it....

[AmmoJammo]

Starting with the first C64 picture, I started swapping chips from another faulty board, that I already had (really not the best fault finding technique, I know!)

Put a standard rom chip back in, swapped the vic chip?

Then I swapped the clock generator thats next to the vic chip... and didn't even get a black screen anymore... oops, I think I found the issue with the "old" faulty board... lol

SO I guess its safe to say that the vic chip and clock generator are probably working...

Maybe I should at least check voltages kinda being lazy...

[AmmoJammo]

A ROM replacement of some kind; I'd guess JiffyDOS, probably.

Sweet haul

Its DolphinDOS!? Motherboard doesn't work, I plugged it into another motherboard...

The motherboard has also had one of the CIA chips replaced for some reason? Its now a 6526A for some reason?

[AmmoJammo]

Ah, no i didnt. But its red! :p

[AmmoJammo]

I've dubbed this one "BarnYard"

Thing is though, its the newer board, only one I've got actually... but it still has the old SID chip... might have been changed at some time...

[AmmoJammo]

Also came with these cartridges... but no VIC-20 :p

[AmmoJammo]

"Pirates Cove" was still wet under the label... :/

[AmmoJammo]

Socketed the PLA, no good!

[AmmoJammo]

That's certainly a farmyard of a computer. Get some compressed air on that mess!

Hopefully you'll get a couple of working systems out of them in the end.

At the very least, for $30, It seems I'll have quite a few spare chips.

In the first board I've tried to fix, all the following parts seem to work...

Basic ROM (switchable)
VIC II
Clock Generator
PLA

Maybe I should replace the crystal... just because the clock generator works in another board, doesn't mean its generating the clock in the bad board...

[AmmoJammo]

VIC chip gets warm after being on for a few minutes, not hot, just warm.

I assume that means its running right...

All the rom chips have been tested, cpu has been tested, one cia chip has been tested.

So, to recap.

working:
Basic ROM (switchable)
Kernal ROM
Character ROM
VIC II
Clock Generator
PLA
CPU
CIA x2

Probably should have come up with a better test method... :p

[AmmoJammo]

swapped the memory from the "barnyard" board onto the "DolphinDOS" board... not that I know if this memory works, as I have no working motherboards that only have the two ram chips..

doesn't work...

[AmmoJammo]

[AmmoJammo]

yeah, well, silly me....

I had +5v, +12v and the unregulated +9v....

What I didn't have was the +5v from the external supply itself?!?

The switch was bad, only switching the 9v AC....

And the final C64 is this breadbin, which can probably be fixed too....

"The Barnyard" and "The Little Mermaid" look too far gone to me.... (or maybe it was just the baryard, I forget now...)