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NEAT: The chipset has its own A20 toggle, it cannot alter the external one as that's an input to the chipset, fixes #5332.

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OBattler
2025-04-12 14:54:35 +02:00
parent 8aa15fa21f
commit 1f9f0a0d6e
1 changed files with 3 additions and 2 deletions
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5
src/chipset/neat.c
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@@ -956,8 +956,9 @@ neat_write(uint16_t port, uint8_t val, void *priv)
dev->ems_size);
}
mem_a20_key = !(val & RB12_GA20);
mem_a20_alt = !(val & RB12_GA20);
mem_a20_recalc();
flushmmucache();
break;
default:
@@ -987,7 +988,7 @@ neat_read(uint16_t port, void *priv)
if ((dev->indx >= 0x60) && (dev->indx <= 0x6e))
ret = dev->regs[dev->indx];
else if (dev->indx == 0x6f)
ret = (dev->regs[dev->indx] & 0xfd) | (mem_a20_key & 2);
ret = (dev->regs[dev->indx] & 0xfd) | ~(mem_a20_alt & 0x02);
break;
default: