ACKNOWLEDGMENT Thanks to Uwe Steller for his contribution of the AS740 cross assembler. Uwe Stellar Uwe dot Steller at t-online dot de The instruction syntax of this cross assembler uses the square brackets  to denote addressing indirection.
740 REGISTER SET The following is a list of the 740 registers used by AS740: a - 8-bit accumulator x,y - index registers 740 INSTRUCTION ADDRESSING MODES The following list specifies the format for each addressing mode supported by AS740: #data immediate data byte #data,*zp immediate data to zero page a accumulator addressing *zp zero page addressing (see .setdp directive) 0 <= dir <= 255 *zp,x zero page x addressing *zp,y zero page y addressing address = (offset + (x or y)) [*zp,x] indirect x addressing 0 <= offset <= 255 address = 2 bytes at location [(offset + (x or y)) mod 256] [*zp],y indirect y addressing address = 2 byte value at offset plus the value of the y register abs absolute addressing (2 byte) abs,x absolute x addressing (2 byte + x) abs,y absolute y addressing (2 byte + y) [abs] indirect addressing (2 byte) label branch label \special low order byte of address 0xFFnn BIT#,*zp bit set/clear zero page BIT#,A bit set/clear accumulator BIT#,*zp,label branch on bit set/clear in zero page BIT#,A,label branch on bit set/clear in accumulator The terms data, zp, abs, BIT , special, and label may all be ex- pressions. Note that not all addressing modes are valid with every in- struction, refer to the 740 technical data for valid modes.
740 INSTRUCTION SET The following tables list all 740 family mnemonics recog- nized by the AS740 assembler. The designation  refers to a required addressing mode argument. Inherent Instructions brk clc cld cli clt clv dex dey inx iny nop pha php pla plp rti rts sec sed sei set stp tax tay tsx txa txs tya wit Branch Instructions bcc label bhs label bcs label blo label beq label bmi label bne label bpl label bvc label bvs label bra label Single Operand Instructions asl  dec  inc  lsr  rol  ror  Double Operand Instructions adc  and  bit  cmp  eor  lda  ora  sbc  sta  Jump and Jump to Subroutine Instructions jmp  jsr  Miscellaneous X and Y Register Instructions cpx  cpy  ldx  stx  ldy  sty  Bit Instructions bit  bbc BIT#,,label bbs BIT#,,label clb BIT#, seb BIT#, Other Instructions div  mul  ldm #imm, com  tst  rrf 
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Last Updated: March 2021