Hi all. I've just purchased a fresh batch of Rockwell 65C02 chips to build with and 3 old NMOS variants for collecting, however when I went for the purchasing decisions for SRAM and EEPROM, the only things I could find were something invented within the century.

I looked up on c64-wiki.com at all the old MOS chips that exist, and saw the 6540 and 6550. Looked online and all I can find are datasheets. Anywhere. Not a single result on Google "Shopping", no results on Australian eBay, (in actual fact I've found ONE listing for 6550), but anyway, nothing at all exists for 6540.

My question is, do these chips even exist anymore? Are they simply so rare that nobody has them anymore? Because of this, I'm having to use "newer" chips in my board which while I don't care, what about things like the 6522, 6560 and variants, and importantly for my project, the 8722. Does anybody know anywhere I can get these for Australia, and if they don't exist anymore, any newer variants that should work with the old CMOS 6502?

PS: This one single listing looks interesting... Anyone know if it's worth investing in these chips, not for moneys sake but for time's sake? I come from the current generation and sadly no hardware today has any value past their lifespan. These old chips are fantastic and won't be around much longer.

Welcome Finn!

I suspect the best way to get old chips is to buy old defective equipment which contains them. That's not necessarily going to be cheap, but it might be, as the value in defective equipment isn't obvious!

Those two chips you mention, for reference (as I'm sure you already know this) are the ROM and RAM for a PET:
http://www.cbmhardware.de/show.php?r=14&id=77

The 8722 is an MMU, and it seems there's a thread about it (maybe more than one - it's well worth searching this forum as there's an enormous amount of previous discussion):
viewtopic.php?f=10&t=4551

Thanks for the reply Ed!
I'm having a look at those links now as I'm having trouble finding any good links myself, thanks for supplying them.
As for where to source them, looks like I'll have to go digging. Do you happen to have any sources or a short list of computers that contain practically any MOS chip compatible with the 6502? If so, I would really appreciate it if you could point me in the right direction; the C64 wiki only really shows Commodore products that use them.

Welcome! See our sticky topic, "65xx parts sources" which we try to keep up to date. If there are any of the MOS parts available, it would be good to have that information there. When a source dries up, we'll edit it. A few like the VIC and SID chips might become available in programmable logic, as it becomes more and more practical for individuals to pull off such projects.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

I should add that many (if not most) of the new memory ICs will work fine with the NMOS 6502; but what I was referring to above is the 65xx peripheral ICs.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Beautiful! Thankyou Garth!
Just went on Gumtree and found someone who would be willing to sell broken C64's for $50 and working C64C's for $135, going to make an offer and see if I can strip the broken one for vintage parts, and stick in newer ones keeping the aesthetic, but the old chips in safe storage also.

Good luck Finn! I don't have any bookmarked resources to help - just keep hitting that favourite search engine!

Thankyou very much Ed!
Looks like I might be going ahead with a cheap broken purchase and a good working one. I wonder if it would be a good idea to salvage the chips out of the working one too and update the insides and store the old ones...

Finn.

There are certainly two schools of thought on this: one is preservation and conservation of computers, and the other is dismantling and salvaging the parts from them. As the C64 was produced in enormous quantities, it's probably not too important what you do. But for rare machines, it's a shame to hear that they've been stripped and dumped. It will be interesting to see what's missing in the broken C64s - it's possible the saleable chips, like the SID, have already been stripped out.

That's also an interesting thought I may want to keep in mind... If it's got nothing in it, I suppose I could probably use it as a base board to build one from scratch and keep the other intact. Will depend on how attached I get to the working one as to what I do with it... Never had an 8-bit computer as I was only born in 2000 but I did grow up with the old floppies and still keep them in perfect working order to this day.

Excellent that you have a historical interest. I was born in the 60s but I'm interested in computers from the 60s, 50s and even earlier - there's something about simpler technologies which makes them more accessible. And there's a surprising number of ideas in hardware and software which date back to the earliest decades. This is good:
https://www.youtube.com/watch?v=8pTEmbeENF4

Well, good news guys! The two C64's arrived in good condition, haven't powered up the working one yet as I need to get a video cable and am scared with all the news I see of overloading PSU's. Will try to use a regulator. Anyways, the broken one comes with all the chips onboard perfectly so I can just unsolder them, test and reuse the good ones. Thanks for the advice!

If you attach the images instead of hosting them elsewhere, that should work well. It's more robust too, as imaging hosting sites eventually die. Whereas 6502.org never will! (Once attached, don't use the 'display inline' feature for a very large image - you'll get a thumbnail for free.)

Hahaha thanks Ed! Looking much more sensible now.

Much better!