ATTENTION EVERYONE! I have acquired a non-working Commodore C64, the machine is in excellent condition but does not work, it seems to only output a black screen with no video sync, but it was cheap enough to take a puntMy sister had a C64c back in the day, around the same time I had my Spectrum 128 Toastrack
The top, bottom and close up of the label, nerds like me like to see serial numbers
There are a couple of marks on the bottom that should clean off easily
On the right side there are two Atari compatible joystick ports, a power switch, and the power socket. No reset buttons live here, at least not as standard
The left side is void of ports
The rear of the unit has (from the left) a cartridge slot, RF trimmer adjustment, RF output to a TV, video port, serial port for disk drives and printers, a Datassette port, and a user port
Pretty standard power supply, there seemed to be two models, this one and the angled version like the PSU from my Plus4, however the C64 version was beige.
Interestingly my original Plus 4 had the same PSU style as this C64, which died and took out the computer, it was replaced with the angled version I have now
Because this square PSU blew up my original Plus 4, I don't trust these versions.
Voltage wise it outputs 9.6VAC and 5.2VDC with no load, as with all Commodore 8 bit machines, the C64 is not tolerant of even the smallest over voltage, so it's strongly recommended to use a modern PSU, or an in-line saver device.
The Commodore Datassette, this is what we had to suffer in the UK instead of disk drives. The moulded part of the plug is missing, and I taped up the metal earth lead just in case it hits an expansion port and blows something up (this did really happen back in the day)Because the plug is exposed you can see ferrite cores around each wire next to the plug
In operation, it fast forwards slowly, rewinds ok, but won't play. This may be the cassette as the rotational force applied to the take up reel and spindle/pinch roller seems ok, I haven't tested any other cassettes yet
These are the joysticks that came with the machine, a Commodore C1311 that likely came with the C64, and a Spectravideo 318-102 joystick, which is a re-branded Quickshot 2
When powered up there is no sync and what appears to be a blank screen, the LCD can't find the signal and just mutes the screen, so I had to dig out the CRT. The image in the picture is the most stable I could tune the TV to, but it's still flickering. According to the Pictorial C64 fault guide a loss of sync is the capacitor at C19 which causes the loss of the 5V rail, I tested VR2 and it outputting 5V as normal, so while I suspect the PLA has gone (which is common on these older C64's), some further investigation is required...
However U2 (CIA 2) is getting very hot...
The main board, a 250407 Rev B.
The suspect PLA is at the top right of the bank of chips next to the modulator, the 6510 CPU is to the left, and the SID is directly underneath
You may notice this is an earlier board where most of the chips are soldered direct to the board, which complicates fault finding somewhat
Once (if) this machine is up and running, heat sinks will be applied to the main chips to protect them
Notable IC's
CIA 1 and 2, they are the same chips, but do different functions, swapping them over can assist in tracking down faults. The top IC here (U2) gets extremely hot within a few seconds of power on, so it's likely this chip has shorted internally, this could be pulling down the 5V rail causing the symptoms of the missing 5V rail, this will need removing to confirm, but it's soldered to the board.Also all the other chips on the board stay cool, the VIC gets warm, but not too warm so it's seems to be operating normally
The PLA, this is the chip I originally suspected to have blown, but it stays cool
The 6581 SID, removing this chip changes nothing
The 6510 CPU
From the top, Character, Kernel, and BASIC ROM's
The large chip with thermal paste on it is the VIC II, this is normally covered by a metal shield with copper strip touching the chip acting as a heat sink, it's a good idea to remove the metal shield and fit proper heat sinks to the VIC II, PLA, and CPU
The middle eight OKI branded chips are the system RAM, each chip is 8k meaning 64k in total
Voltage regulators VR1 and VR2
I will need to remove CIA 2 (U2) from the board and boot the machine to see if there's any improvement...
Machine two
I bought this recently, it turns out to be an early version breadbin with a later keyboard fitted, however it was sold as fully working
Excuse the crappy lighting. This machine looked for all the world like a C64G in the advert, but it wasn't sold as one, and it isn't one, and wasn't priced as one, I took a gamble thinking the seller didn't know what they had, but no dice
Normal breadbin rear ports
Normal breadbin joystick ports
An after market power supply, whether this version is any more reliable or not I don't know, the voltages are 4.9Vdc and 10.2Vac, so good enough to test for a moment, it has a really old plug that needed the cable rewired
Board version 250425, this is an early one with the ICs soldered to the board, which is annoying
I'm happy to report that this machine works, so now I finally have my working breadbin C64
Software
This is what came with the machine, and is all I have at the moment
Mr Wimpy
Donated software
Another Datasette
Afterburner
Potty Painter in the Jungle
Kwick Snax
Solid Gold Tape 1, Gauntlet, Leaderboard/Ace of Aces
Super Pipe Line
Voidrunner
Murder on the Waterfront
Matrix
Go Crazy Tape 3, Bad Cat, Jinks
Robocod
Knightmare
Bubble Bobble (Special edition)
Double Dragon II The Revenge
Updates
I picked up two user guides from a local car boot sale
Commodore 64 Micro Computer User Manual and C64 User Manual English
?FILE OPEN ERROR