Msg: 5319 *Conference*
08-15-94 01:31:37
From: COMET _
To : RON WIESEN
Subj: REPLY TO MSG #5280 (UNDOCUMENTED 80C85 OPCODES)
My ROM2/Cleuseau manual says that the instruction DEHL byte [which is hex 28, BTW] has an action of HL<=HL+byte. I believe this is an error--shouldn't the action be DE<=HL+byte? The RST V (hex CB) opcode is not listed at all; I believe it causes a branch to hex 0040 if the V flag [Umm, I forget what flag this is] is set. Of course, this is useless, since this is a ROM address where the BASIC command table lies.... The Flags register doesn't document bit 4, the half-carry flag. It also doesn't mention bit 1, the overflow bit, set if carry into sign bit <> carry out of sign bit. [This happens when an operation on 2 signed bytes cannot fit the result in a single signed byte.] If you [or anybody else ] know of any other erratum for the ROM2/Cleuseau, please let me know! Similarly for addenda, of course.