Seller was *gc_supermarket*
On Friday, August 15, 2014 1:14:48 PM UTC-6, Rich Leary wrote: > > I purchased some 65C02's on eBay in June to use on my V1 6502 CPU board. > While my wire-wrap CPU board used a 'C02' (GTE 65SC102-2 to be a little > more definitive) I had never written any code that used the 'C02' added > opcodes, addressing modes, or other features. My DOS/65 code uses strictly > NMOS 6502 opcodes etc. > > I wrote a short utility that used BRA instead of JMPs and in one spot used > an INC A opcode. The utility would not work leading me to question whether > I had the residual brain cells to have fun with computers. I changed the > code to remove any 'C02' opcodes etc. and the utility worked fine. I was > now suspicious. > > I then used the few lines of code that perform BCD arithmetic as the NMOS > 6502s do not correctly handle the flags when doing BCD arithmetic. The CMOS > versions do correctly set the flags. This test clearly indicated that what > was labeled a 65C02 (specifics in a minute) was not a 65C02 but was an NMOS > 6502. > > Bottom line - the ICs appear to be intentionally mislabeled. So if you see > an eBay add for a 65C02 with the following lines and with the Rockwell logo > to the right of the first three lines be careful. > > R65C02P4 > 11450-13 > MEXICO > 0815 S11468-4 > > I did a quick eBay check and more than seller in China had IC pictures > with this marking. Some may be correct but I suspect many are not. > > By the way, when I pulled the new 6502 V1 board and put my 30+ year old > wire wrap board in my system to run the same tests on the GTE IC, it > refused to start. I guess I really do need the V1 6502 CPU! > > Rich Leary > -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
