response 3 of 20:

Jun 6 03:14 UTC 2001

Some Commodore 64s had soldered chips, some had socketed ones.  The earlier
ones were socketed, but they started penny pinching later by eliminating the
sockets.  If you'd said something before I moved I could have given you a
6502 out of a Commodore 1541 drive, but I threw it out.  (Drive was dead
anyway, so I couldn't guarantee the chip worked.) I think the C64 used a
6510 anyway, didn't it?  I thought it was the VIC-20 and PET that used a
6502.  The chips have the same instruction set but aren't pin compatible. 
Another source would be an old Apple ][ or ][+.  (The //e used a 6510.) As I
mentioned, the Commodore disk drives of that vintage all used 6502s...the
dual disk drive for the PET used *two* of them in a clever hack.

Jameco used to sell 6502s but I no longer see any in their catalog.  They do
sell Z80s and 6800s, though, if you can find any designs based on those. ;>

response 7 of 20:

Jun 7 03:06 UTC 2001

I'm probably going to get it wrong.  As I recall, though, the drive used two
6502 processors on the same bus, and using the same memory space.  It turns
out the 6502 only accesses the bus during a specific phase of the clock
cycle (high or low; I can't remember which) so to keep the two processers
from interfering with each other, they simply inverted the clock pulses of
one of them.

response 9 of 20:

Jun 7 23:55 UTC 2001

I think you can get oldish CPU chips from www.mouser.com and/or
www.digikey.com.

response 11 of 20:

Jun 9 20:01 UTC 2001

A //e would also have a 6502 in it (well it's a 65c02, but I imagine
that'd be close enough for this project--just adds a couple extra
opcodes but should be pin-compatible).  There should still be plenty
of //e's around to scavenge (try thrift shops, local schools, etc.).

response 13 of 20:

Jun 10 14:54 UTC 2001

Jameco should have some sort of inexpensive (less than $200) EPROM burner,
probably one that plugs into a parallel port on a PC.

response 15 of 20:

Jun 10 19:02 UTC 2001

I don't really know much about the EPROM process, so I can't recommend
anything in particular.  But I'm sure somebody here ought to know more.

EPROMs are "Erasable Programmable Read-Only Memory", and are erased by
uncovering a little window on top of the chip and sending in a lot of UV light
(no kidding).  

EEPROMs are "Electrically Erasable", but I'm not sure how that is usually
done.

response 17 of 20:

Jun 11 01:50 UTC 2001

Yes.

Jameco will also be able to sell you an EPROM eraser.  This is much 
quicker and more reliable than leaving them out in the sun. ;>

response 19 of 20:

Jun 11 15:05 UTC 2001

I once heard that you can also erase them by setting them out in the sun for
several hours.  I've never tried it but since sunlight has UV in it, it might
be worth a try.

Photons can turn transistors on.  That's one reason they don't package
most solid-state electronics in clear packages unless they are to emit light
or sense light.