If memory serves me right, Matthew Dillon wrote: > But, do you know what '02' does? On an original 6502? The 6502 > was a hardwired processor, which means that even the hex codes that > didn't have an official instruction did things. Weird things to be > sure, but things nontheless. They cleaned it up later on (in the 816) > but not in the PET/C64 era and not on the 6502 based 65xx series.
I'm not sure I've ever heard anyone ever call the 65816 a cleaned-up version of anything. Talk about a Jeckyl and Hyde processor! (For the uninitiated, it had these mode bits where you could set parts of the processor to be either 8-bit or 16-bit mode, along with things like the 8086's segment registers to give you this pseudo-24-bit addressing. I think they finally did use all 256 opcodes on that one.) Oh yeah, I think someone had to do some amount of "clean up" for the 65C02 since it had a few more (defined) opcodes than the original 6502. [Centipede game] Ob-65XXX hack: I once wrote a spreadsheet, starting from a numerics package, ProDOS, and a GUI toolkit. In assembler. Doing the infix expression parser was especially fun. If anyone remembers Pinpoint Publishing and their still-borne "Digit", well, that was it. I still have my code, in a couple of two-inch binders somewhere. > Somebody somewhere has a complete list of unsupported instructions > that nevertheless do interesting things. I have this odd feeling that such a list was either in the Zaks book or one of the Apple ][ reference manuals. Bruce. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
