def lda_imm(comp: Computer):
comp.pc += 1
data = comp.getat(comp.pc)
comp.accum = data
def lda2(comp: Computer):
ptr = getat_pages(comp, True)
data = comp.getat(ptr)
comp.accum = data
def ldy_imm(comp: Computer):
comp.pc += 1
data = comp.getat(comp.pc)
comp.regy = data
def ldy2(comp: Computer):
ptr = getat_pages(comp, True)
data = comp.getat(ptr)
comp.regy = data
def ldx(comp: Computer):
ptr = getat_pages(comp)
data = comp.getat(ptr)
comp.regx = data
def getat_pages(comp: Computer, pageswitch: bool = False):
if pageswitch:
comp.pc += 2
return comp.getat(comp.pc - 1) * 256 + comp.getat(comp.pc)
comp.pc += 1
return comp.getat(comp.pc)
def sub2(comp: Computer):
ptr = getat_pages(comp, True)
data = comp.getat(ptr)
comp.accum -= data
comp.overflow = comp.accum < 0
comp.accum %= 256
def sbi(comp: Computer):
comp.pc += 1
data = comp.getat(comp.pc)
comp.accum -= data
comp.overflow = comp.accum < 0
comp.accum %= 256
def add2(comp: Computer):
ptr = getat_pages(comp, True)
data = comp.getat(ptr)
comp.accum += data
comp.overflow = comp.accum > 255
comp.accum %= 256
def adi(comp: Computer):
comp.pc += 1
data = comp.getat(comp.pc)
comp.accum += data
comp.overflow = comp.accum > 255
comp.accum %= 256
def sti2(comp: Computer):
ptr = getat_pages(comp, True)
comp.pc += 1
data = comp.getat(comp.pc)
comp.setat(ptr, data)