From 5d36aeb8856fa17d491b0c8c18d6593a9ec4997a Mon Sep 17 00:00:00 2001 From: vin Date: Sat, 29 Jun 2024 09:51:12 -0400 Subject: [PATCH] fix ADC bug where V is calculated with new A instead of old A --- cpu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/cpu.c b/cpu.c index 66dbd4c..5d36d37 100644 --- a/cpu.c +++ b/cpu.c @@ -218,11 +218,12 @@ adc(uint8_t arg) uint16_t sum; // 16-bit sum makes it easier to determine carry flag sum = regs.a + arg + regs.status.carry; - regs.a = sum & 0xFF; regs.status.carry = sum > 0xFF; /* overflow flag formula: https://stackoverflow.com/a/29224684 */ regs.status.overflow = (~(regs.a ^ arg) & (regs.a ^ sum) & 0x80) != 0; + regs.a = sum & 0xFF; + STATUS_UPDATE_ZERO(regs.a); STATUS_UPDATE_NEGATIVE(regs.a); }