reuven wrote: > Do you have R65c02 Chip's for apple 2 ? I don't understand the question. Are you asking: (a) Can anyone here supply me with an R65C02 chip for use in an Apple II? or (b) Was the 65C02 used in the Apple II an R65C02? The answer to the second question is no. Apple never used the Rockwell variant of the 65C02 in the Apple II, but there isn't anything stopping an end user from replacing the supplied CPU with a Rockwell version. In particular, the extra instructions in the R65C02 are not commonly available, and they are incompatible with later processors in the 65xx family, namely the 65816 (used in the IIgs) and the 65802. The original Apple II used a MOS Technology 6502 (or an equivalent). Apple continued to use the 6502 until the unenhanced Apple IIe. The Apple IIc and enhanced Apple IIe use the Western Design Center (or equivalent) 65C02. The Apple IIgs uses the WDC (or equivalent) 65816. "GTE" seems to be a common brand for the CPUs I've noticed in more recent Apple II models. The WDC 65802 was available for a while as a third-party upgrade for 8-bit Apple II models. Accelerator cards for 8-bit machines generally use a 65C02 (some of which might be using an R65C02), but I imagine there were early ones that had a 6502. If you are writing a program which depends on the R65C02 instructions, you should definitely include code to test the CPU type (6502, 65C02, R65C02 or 65802/65816) before executing any instructions specific to the R65C02. There was a routine in Eyes & Lichty which detected most of these, and I worked out an extended version which identified all four major types (I'd have to do a bit of hunting to find it, or reconstruct it).