The first computer I ever owned. Decades later, I enjoy repairing and modifying these as a hobby. Hopefully keeping track of my progress will actually inspire me to get these all done.

Serial No. S00031606

Silver label, very low serial number, 326298 board, Revision A. Bought second hand in College Station, TX. It’s clearly been refurbished at least once before by the prior owner(s). Here’s what it looks like they did:

  • All DIN plugs and RF box re-soldered for stability.
  • Original VIC-II replaced with 6567R8 2684.
  • Jumper wire on U20.
  • U4 (KERNAL ROM) socketed.
  • U17 (PLA) was probably replaced.

My goal with this unit was to restore it to 100% working condition as advertised in 1982. Apparently 326298 boards are worth more if it has all original 1982 components, but that wasn’t my goal here. I want to use this machine as it was intended to be used. That meant replacing components as they die or become incompatible. For example, the PLA included in this unit was notorious for causing cartridge compatibility issues, so that’s been replaced with a modern PLAnkton.

Here’s the current state of things:

  • U1 (CIA): 6526 “1982”, original to unit.
  • U2 (CIA): 6526 “1982”, original to unit.
  • U3 (BASIC ROM): 901226-01 2682, original to unit.
  • U4 (KERNAL ROM): 901227-01 3082, original to unit.
  • U5 (Character ROM): 94132C-2177 “1982”, original to unit.
  • U7 (CPU): 6510 1882, original to unit.
  • U17 (PLA): PLAnkton. Original was N82S100N 8222 w/ sticker that said “C64 REV3 8411”.
  • U18 (SID): 6581 2382, original to unit.
  • U19 (VIC-II): 6567R8 2684, original replaced by prior owner.

Installed metal heatsinks on all of the above except for the PLAnkton.

Replaced capacitors:

  • C19 (16v 2200uF) w/ 16v 2200uF
  • C88 badly corroded (35v 470uF) w/ ChongX 50v 470uF
  • C90 (35v 470uF) w/ ChongX 50v 470uF
  • C91 (25v 100uF) w/ 25v 100uF
  • All others (25v 10uF) w/ 50v 10uF

I also replaced C48 and C93, since these caused the diagnostic cartridge to fail the SID for not being able to read the paddle potentiometers properly. This is a common problem with 326298 boards.

Replaced both VR1 (12V) and VR2 (5V) regulators.

Changed the location of VR2 to sit on top of the video section metal housing. Later model C64 boards had beefy heatsinks for this, but this early revision does not. Used some thermal paste under the regulator to help with the conductivity.

Modified the video section metal housing to accomodate above, plus allow regular height capacitors to stick through, and use standalone heatsinks on the VIC-II.

C64 diagnostic now reports 100% OK.

Serial No. SC0156082

Bottom says “Made in Canada”. 250407 board, Version A, Revision B. Ceramic VIC-II.

Replaced bad CIA’s (6526R4’s, 2083) with 6526’s (0483/1483).

Replaced capacitors:

  • C19 (16v 2200uF) w/ 16v 2200uF
  • C88 (50v 470uF) w/ ChongX 50v 470uF
  • C90 (50v 470uF) w/ ChongX 50v 470uF
  • C91 (16v 100uF) w/ 25v 100uF
  • C107 (25v 10uF) w/ 25v 10uF
  • C108 (25v 10uF) w/ 25v 10uF
  • All others (25v 10uF) w/ 50v 10uF

Installed metal heatsinks on all IC’s.

Installed SD2IEC Internal w/ mounting bracket. I’m not sure if I got this printed with the wrong type of plastic or what, but the retaining brace at the end of the bracket snapped off very easily. I’ve held it all together with hot glue, which seems to work for now, but I might need to upgrade to something that binds better (such as superglue or epoxy).

  • Blue: +5V
  • Purple: Ground
  • Grey: IEC Attention
  • White: IEC Clock
  • Black: IEC Data

This machine is my main go-to machine when playing games. Used in combination with a Framemeister.

Todo: Replace the unused RF box with something like RFOUT!

This machine also has some weird problems with color changes happening every now and then. It also doesn’t load things correctly 100% of the time. I suspect this might be a problem with the 74LS373, similar to Jan Beta’s issue here.

Serial No. P00690784

250407 board, Version A, Revision B.

Missing PLA and SID. Some rust, mostly on the RF box, and has screws that penetrated through the bottom plastic shell.

Todo: Might be a candidate to fix and replace the RF box with something modern?

Serial No. P01426344

250407 board, Version A, Revision B.

Untested. Lots of unsocketed chips here.

A/V output has a resistor soldered to it, probably to improve S-Video output. VR1 salvaged for another machine.

Serial No. P01568379

250407 board, Version A, Revision C.

Fails the dead test.

Serial No. P01618548

250407 board, Version A, Revision C.

Passes the dead test, but no video.

Serial No. P01625103

250407 board, Version A, Revision C.

Fails the dead test, no video. In good condition.

Todo: Diagnose and fix.

Serial No. P02069119

250407 board, Version A, Revision A.

Passes all tests. In good condition.

Serial No. P02081021

250425 board made in Hong Kong, Version B. Has piggybacked diodes on R29 and R30.

Bad RAM. Missing the VIC cover box.

Todo: A lot of chips without sockets, so probably need to re-socket everything.

Serial No. P02387457

250425 board, missing the PLA. No RF shield/heatsink. Untested.

Serial No. P02395981

Has a sticker on it that says “dead IEC bus”, but I haven’t tested it yet.

Serial No. P05246675 “B”

Empty shell, no idea where the board went. It was probably a 250425 based on the serial number.

Serial No. P05247967 “B”

250425 board, has some busted pastic underneath. Metal RF shield/heat skinks intact.

Untested.