<What were the Z80 instructions? I'd like to test them on a SBC and documen <them for the future. <Thanks, <-Dave Found this on my disk. Allison ***************************************************************** Undocumented Z80 Instructions (apply only to Z80) The Z80 IX/IY operators are missing (byte ops) mnemonic: IN ,(C) OP code: 0EDh,070h Description: Same as IN A,(C) except the A register isn't changed (flags are set as if it was changed). NOTES: This instruction can be used to test and discard the value of a port without destroying any registers. mnemonic: SLAS B OP code: 0CBh,030h Description: Shift Left Arithmetic Special B. Same as SLA B except bit 0 of B is set instead of cleared. mnemonic: SLAS C OP code: 0CBh,031h Description: Shift Left Arithmetic Special C. Same as SLA C except bit 0 of C is set instead of cleared. mnemonic: SLAS D OP code: 0CBh,032h Description: Shift Left Arithmetic Special D. Same as SLA D except bit 0 of D is set instead of cleared. mnemonic: SLAS E OP code: 0CBh,033h Description: Shift Left Arithmetic Special E. Same as SLA E except bit 0 of E is set instead of cleared. mnemonic: SLAS H OP code: 0CBh,034h Description: Shift Left Arithmetic Special H. Same as SLA H except bit 0 of H is set instead of cleared. mnemonic: SLAS L OP code: 0CBh,035h Description: Shift Left Arithmetic Special L. Same as SLA L except bit 0 of L is set instead of cleared. mnemonic: SLAS (HL) OP code: 0CBh,036h Description: Shift Left Arithmetic Special (HL). Same as SLA (HL) except bit 0 of (HL) is set instead of cleared. mnemonic: SLAS A OP code: 0CBh,037h Description: Shift Left Arithmetic Special A. Same as SLA A except bit 0 of A is set instead of cleared. *****************************************************************