Yup supposed to be compatible. Make sure you have the same speed grades. If you have a scope take it around the pins and make sure everything look right or at least similar from pin to pin. (go from ground to 4.75volts, only stops at other voltages when floating. Now the interesting thing is that your number is returned as floating point. Somehow that makes me think that there may have been a mask stepping where some bug with overflows or dec math or something may have been fixed. -----Original Message----- From: firstname.lastname@example.org [mailto:email@example.com] On Behalf Of Rob Clarke Sent: Tuesday, April 10, 2012 6:42 PM To: firstname.lastname@example.org Subject: Synertek 6502 compatibility Hello gentlemen, Does anyone know if the Synertek 6502 is 100% compatible with its MOS cousin? I have one which I tried in an otherwise working PET and I get "31653.4784 BYTES FREE" instead of 31743, which is 89.5216 bytes short :-/ I know some of the later CMOS incarnations did not have the same behaviour with undefined op-codes but a) this a 1984 chip and b) I can't believe the PET kernal would use them anyway. It is also possible that this chip is just duff of course. Rob Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2012-04-14 18:00:04
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