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?