Files
open-roms/c64/basic/commands/cmd_sys.s
T

75 lines
1021 B
ArmAsm

#if ROM_LAYOUT_STD || (ROM_LAYOUT_M65 && SEGMENT_BASIC_0)
cmd_sys:
jsr basic_end_of_statement_check
bcc !+
// SYS requires an argument
jmp do_SYNTAX_error
!:
//
// XXX Temporary ugly hack to support 'SYS PI*656'
//
ldy #$00
cmd_sys_hack_loop:
lda (TXTPTR), y
cmp cmd_sys_hack_str, y
bne cmd_sys_hack_not_needed
lda (TXTPTR), y
beq cmd_sys_hack_apply
iny
bne cmd_sys_hack_loop // branch always
cmd_sys_hack_apply:
lda #<2060
sta LINNUM+0
lda #>2060
sta LINNUM+1
bne cmd_sys_setup_call // always jumps
cmd_sys_hack_not_needed:
//
// XXX End of hack
//
jsr basic_parse_line_number
cmd_sys_setup_call:
lda #$4C // JMP opcode
sta USRPOK
lda LINNUM+0
sta USRADD+0
lda LINNUM+1
sta USRADD+1
// Setup the register values
lda SPREG
pha
ldy SYREG
ldx SXREG
lda SAREG
plp
// Call the routine.
jsr USRPOK
jmp basic_execute_statement
//
// XXX Temporary ugly hack to support 'SYS PI*656'
//
cmd_sys_hack_str:
.byte $FF, $AC, $36, $35, $36, $00
#endif // ROM layout