Apple-2-Tools
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izapple2
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This commit is contained in:
Ivan Izaguirre 2019-01-30 00:11:35 +01:00
parent ff1b116163
commit 3ac61fed59
1 changed files with 2 additions and 0 deletions
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2
execute.go
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@ -26,6 +26,7 @@ const modeRegisterY = 11
// https://www.masswerk.at/6502/6502_instruction_set.html
// http://www.emulator101.com/reference/6502-reference.html
// https://www.csh.rit.edu/~moffitt/docs/6502.html#FLAGS
// https://ia800509.us.archive.org/18/items/Programming_the_6502/Programming_the_6502.pdf
func getWordInLine(line []uint8) uint16 {
return uint16(line[1]) + 0x100*uint16(line[2])
@ -160,6 +161,7 @@ func buildOpUpdateFlag(flag uint8, value bool) opFunc {
func buildOpBranch(flag uint8, value bool) opFunc {
return func(s *state, line []uint8, opcode opcode) {
if s.registers.getFlag(flag) == value {
// This assumes that PC is already pointing to the next instruction
pc := s.registers.getPC()
pc += uint16(int8(line[1]))
s.registers.setPC(pc)