Welcome to Mr. Latch-up's C64 DTV Advice Column

Featured Dilemma:

How can I tell which Rev I have?

Dear Mr Latch, Do you have suggestion for determining which ASIC revision is in the current machine from software? What is the alias for the $d000 addresses on the V1? I know it is $80 for the V2/V3 with $d03f=1, because that's how I check if I have a V2/V3 or a C64. /Daniel Kahlin <tlr> http://www.kahlin.net/daniel/dtv/

Dear tlr,   Rev1 has a lot of little buggy things you can look for.  The easiest would be to execute some of the illegal opcodes, which most should come back as NOP's in Rev1.  You could also try to blit which doesn't exist on Rev1.   The only way I can think of telling the difference between Rev2 & 3 is to do a transparent blit and see if every 4th value is forced to 0.  There should be no other differences between Rev2 & 3