Msg: 5232 *Conference*
07-29-94 20:36:35
From: COMET _
To : ALL
Subj: 80C85 UNDOCUMENTED OPCODES
I recently received a ROM2/Cleuseau and learned of the following undocumented opcodes: DEC/HX Instruction action Zf Cf Pf Sf 40/28 DEHL byte HL<=HL+byte . . . . 56/38 DESP byte DE<=SP+byte . . . . 8/8 HLMBC HL<=HL-BC x x h x 253/FD JTM label If TSf=1thenJMP . . . . 221/DD JTP label If TSf=0thenJMP . . . . 237/ED LHLI HL<=w[DE] . . . . 24/18 RDEL rot DE L thru Cf . x . . 217/D9 SHLI w[DE]<=HL . . . . 16/10 SHLR sh HL R (sgn ext) . . . . Do any of the programs here, especially the [dis]assemblers recognize these opcodes? And what about the byte 203/CB? Is this a hole in the instruction set?