The i8085 CPU is very similar to two other very popular CPUs, the z80 and the GameBoy’s LR35902 (z80-like) so I found it useful to have a chart of which opcode bytes differ between the i8085 and those two. So here it is, in SVG and other formats for anyone that may find it useful.

i8085 compatibility chart

Also available as a hi-res PNG, an inkscape SVG , a PDF document or the original ODS document.


Opcodes RIM and SIM (Bytes 0x20 & 0x30) on the i8085 correspond on both z80 and GameBoy to two of the conditional relative jumps, namely JR NZ and JR NC. This difference can be easily used to tell the z80 and the i8085 apart at run-time.

GBZ80 opcodes (LR35902)

The GameBoy CPU Has multiple opcodes missing or moved to other locations, trying to execute these i8085 opcodes will lock up the GameBoy CPU. The opcodes are: OUT IN XTHL CPO XCHG CPE CP CM. The remaining “incompatible” opcodes have a different function than the z80/i8085 and are better described on this gbdev wiki page. Like with the RIM/SIM opcodes, these differences can be exploited to tell the i8085/z80/GameBoy from each other at run-time.