Which chips should I salvage out of non-functional C64s?

[eebuckeye]

I realize some of them may not work but I hate to get rid of all the chips if some could be spares.

 

Thanks!

Edited June 20, 2015 by eebuckeye

[+OLD CS1]

I always pull 8701 clock generator, PLA, SID, VIC-II, and both CIAs. Color RAM is also a good thing to pull. The ROMs are dime-a-dozen and JiffyDOS is prefered over the original Commodore ROMs, anyway.

 

Of course, if the computer is non-functional any of these components could be culprit or victim, so YMMV.

[CPUWIZ]

The SID is the most valuable chip.

[7800fan]

PLA is also quite valuable since they frequently fail. But only in older style C64 motherboard. If you have the long skinny board that are usually in later 64Cs, the PLA have been combined with other common chips and integrated into a 64 pin MMU which rarely fails (and hard to remove if you don't have good desoldering skill)

Edited June 21, 2015 by 7800fan

[eebuckeye]

What are the chip numbers so I know which to pull?

[CPUWIZ]

What are the chip numbers so I know which to pull?

 

https://en.wikipedia.org/wiki/MOS_Technology_SID

[+OLD CS1]

6526 (CIA,) 6581 or 8580 (SID,) 6567 (VIC-II,) 8701 (clock generator,) 906-114 or 82S100 (PLA,) and I think the color RAM is a 2116.

 

Note that Individual Computers sells the Super PLA v3 (with the interesting note: SuperPLA V3 does not work with the "Epyx Fastload cartridge", which was popular in the US) now which replaces the original PLA. And, as I was pointed in another thread, the C64 Reloaded.

 

The 6526 are easy to fry and get popped often, and a failed PLA is a common C64 cause of death.

[RobertB]

Note that Individual Computers sells the Super PLA v3 (with the interesting note: SuperPLA V3 does not work with the "Epyx Fastload cartridge", which was popular in the US) now which replaces the original PLA.

Oh-oh, I wonder if it will work with Warpspeed, another Fastload-type of cartridge. Marty Franz, a creator of Warpspeed, told me that Fastload was thoroughly examined before Warpspeed was built. (In fact, the board design of Warpspeed is almost exactly like that of Fastload!)

 

Returned from the Back in Live Time 2015 in Brighton, England,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 2015 -

http://www.portcommodore.com/commvex

[+OLD CS1]

Oh-oh, I wonder if it will work with Warpspeed, another Fastload-type of cartridge. Marty Franz, a creator of Warpspeed, told me that Fastload was thoroughly examined before Warpspeed was built. (In fact, the board design of Warpspeed is almost exactly like that of Fastload!)

 

Returned from the Back in Live Time 2015 in Brighton, England,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 2015 -

http://www.portcommodore.com/commvex

 

Good question. I love my WarpSpeed carts -- I have both a version which is 1581-compatible and the other not. I carry the non-1581-compatible with my SX64.

 

Makes me wonder what is so special about the Epyx FastLoad cartridge.

[eebuckeye]

Thanks for all the information! I figure I'm going to pull all the chips that are socketed which appears to vary depending on what year the motherboard was manufactured.

[+OLD CS1]

Thanks for all the information! I figure I'm going to pull all the chips that are socketed which appears to vary depending on what year the motherboard was manufactured.

 

For the most part, but often chips, irrespective of year, are in sockets for no apparent reason. I have had boards on which both 6526s are in sockets, others with neither in socket, and then others with just one -- no seeming rhyme nor reason. If you can test them, it is worth desoldering certain chips, like the SID, PLA, and CIAs.

[Oge]

Which chips should I salvage out of non-functional C64s?

 

 

Every chip is important. There are chips which are prone to failure (DRAMs, PLA, SID, CIAs, 8701) and chips which are more rugged but every single IC has to be salvaged.

 

 

Cheers,

Oge

[+OLD CS1]

 

Every chip is important. There are chips which are prone to failure (DRAMs, PLA, SID, CIAs, 8701) and chips which are more rugged but every single IC has to be salvaged.

 

I figured the DRAMs could be replaced by something manufactured more recently?

[7800fan]

Yes, and it can even be replaced with SRAM as well. A creative hacker can find a way to piggyback battery watchdog onto the SRAM so you can shut off in the middle of the game, and come back next day without having to wait 10 minutes to load the game from the disk drive.

[eebuckeye]

One of the video chips I pulled has gold pins and looks different than the others. I believe it says R9 but I have another R9 that is different.

 

Has anyone noticed this?

[7800fan]

There have been numerous design variations among the chips. I think the gold pins are the earlier productions.

[+OLD CS1]

Yes, and it can even be replaced with SRAM as well. A creative hacker can find a way to piggyback battery watchdog onto the SRAM so you can shut off in the middle of the game, and come back next day without having to wait 10 minutes to load the game from the disk drive.

 

I think you know what I meant, but to clarify, I mean that I see those RAM chips in places like Jameco and Mouser every so-often.. But, yeah, if you are handy with a soldering iron, why not grab them.

 

One of the video chips I pulled has gold pins and looks different than the others. I believe it says R9 but I have another R9 that is different.

 

Has anyone noticed this?

 

Hold onto those. Believe it or not, there are some nuts out there who will pay extra for the ceramic chips at the right time.

[danny_galaga]

If you have the room, just leave them on the board until you need them...