Delete comment from: Ken Shirriff's blog
Very interesting information. I've heard that 8085 "undocumented" instructions and flags were not documented intentionally. These instructions didn't have matching instructions in the upcoming 8086 processor, which was supposed to be backward compatible with 8080 (and 8085). So if users were to use these instructions it would complicate porting programs to 8086.
It would be interesting to see similar information about 8086/88, and particularly if there are any differences between various 8086/8088/80C88 steppings or manufacturers.
Aug 30, 2015, 4:12:59 PM
Posted to Silicon reverse engineering: The 8085's undocumented flags