264 Series and their chips

Hello,

I came about an archive of this mailing list when looking for some 
information about the 264 series (C16/116/+4) online.

Maybe some of the readers here have an idea...

We all know that the 8501 and the 8360 have a pretty high failure rate 
if used without a heatsink (all the ones I have in active use have a 
heatsink (removable of course)). The chips used in the C64, especially 
the 6569-VIC can get pretty hot without failing so fast.

What I noticed is that there seems to be no other large 7xxx-Chip 
(HMOS-I) besides the 7501 and the 7360 and that the 8501 and 8360 
usually have date codes of xx84 while the other known 8xxx-Chips are at 
least xx85. The C64 was still using 6xxx NMOS well into late 1986 and 
all the C128 I have seen have 8xxx-Chips with datecodes of 1986 and later.

Could it be possible that the CPU and TED of the 264 series were 
Commodore's first attempt at HMOS-I and later HMOS-II and they didn't 
have the process down at the beginning? If that's true, 8501 and 8360 
produced later should be less prone to failure. I know that both were 
still made in 1986 and later. Then, a 8501R4 made 4986 is in my 
collection, so there were some changes to the CPU later on.

Also... were there ever any 8360 in Ceramic package seen in the wild? 
Reason is I have a TED in Ceramic, it works but whoever had it before me 
glued a heatsink on and didn't write the markings onto the bottom. The 
type of heatsink used suggests it was done at Commodore. Could it be a 7360?

Another thing I was wondering about is whether the 8500, the 8501 and 
the 8502 are the same die inside with just different bonding. The 
pinouts suggest the possibility. Same for the 8501R4 since it was made 
after the 264 series died.

Finally, if anyone here has a defective TED and is willing to donate it, 
contact the folks at http://visual6502.org they are looking for one to 
depackage and take high resolution photographs of the die.

  Gerrit


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