On 08/09/2011 07:34 PM, Hársfalvi Levente wrote: > Hi Gerrit, > > > Welcome to the list! Thank you. > At least my original 8501 obviously gave up the run; as its counterpart > TED is a late 1986 piece, I'm assuming it must have also been > manufactured in 1986. (Don't know for sure, I don't have that chip > anymore, unfortunately.) Could be, but then I have seen at least one board with a 7501R1 from 1984 and a 8360 from 1986 so the production year of the TED doesn't mean much in respect to the CPU. I wouldn't be surprised if at the end they just threw together what they had. >> 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. > > Not sure (never seen die photos of these newer models), but some bits of > the onboard CPU I/O port are unimplemented in these three CPUs, and the > bit positions (ie. exactly which bits are unimplemented) don't match - > I'm assuming they'd have at least had to customize the chips before > packaging, which looks unlikely. The idea I had was that the die inside the package has more than 40 pads including a full 8 Bit port and all the other signals. So that when bonding the die the machine can be programmed to produce the desired pinout... It would have made production cheaper since you only needed one mask set for all 3 CPUs. >> 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. > > I've got a couple of them for sure :-) (even more 8501s, but, err... :-D > ), no problem if they're really looking for some... Just contact them... I mailed them a broken 8501 a few weeks ago. When they get around to depackage it and upload the photographs we might find ouf whether my theory of 'one die for 8500/1/2' is correct or not. I'd like to see a VIC-II and TED hi res die shot side by side. Since some of the display tricks from VIC also work on TED, I expect to see some parts looking identical. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2011-08-09 19:00:17
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