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- *
- * Emulator register definitions
- * Note, only leaves D0-D1/A0 free for use by entire
- * program without saving registers for temporary use.
- *
- return equr A6 ;JMP (return) is fast return to MLOOP.
- pseudopc equr A5 ;Emulated program counter
- opptr equr A4 ;Address of opcode dispatch table
- pseudosp equr A3 ;Emulated stack pointer
- flagptr equr A2 ;Address of flag lookup table
- targbase equr A1 ;Address of emulated address space
- regs equr A1 ;Base pointer to emulated registers
- regcon0e equr D7 ;Register-based constant #$E (for speed)
- regcon01 equr D6 ;Register-based constant #$1
- regcon0f equr D5 ;Register-based constant #$F
- regconff equr D4 ;Register-based constant #$FF
- regf equr D3 ;Emulated flag register
- rega equr D2 ;Emulated accumulator
- *
- * Target processor's data registers (offsets into storage area)
- * The emulated accumulator and flag register are kept in data registers.
- * The emulated program counter and stack pointer
- * are kept in address registers.
- *
- regb equ -22 ;B
- regc equ -21 ;C
- regd equ -20 ;D
- rege equ -19 ;E
- regh equ -18 ;H
- regl equ -17 ;L
- regix equ -16 ;IX
- regxh equ -16
- regxl equ -15
- regiy equ -14 ;IY
- regyh equ -14
- regyl equ -13
- regb2 equ -12 ;Alternate register set for Z-80
- regc2 equ -11
- regd2 equ -10
- rege2 equ -9
- regh2 equ -8
- regl2 equ -7
- rega2 equ -6
- regf2 equ -5
- regi equ -4 ;Interrupt page address register (I)
- regop1 equ -3 ;Operand 1 for DAA storage
- regop2 equ -2 ; " 2 " " "
- regop3 equ -1 ; " 3 " " "
-