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Add special behavior for a reserved 440BX bus speed bit for the Virtual PC 2007 machine

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RichardG867
2020-07-24 15:00:58 -03:00
parent 9efdf74b51
commit 763b61c469
1 changed files with 6 additions and 1 deletions
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7
src/chipset/intel_4x0.c
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@@ -29,6 +29,7 @@
#include <86box/keyboard.h>
#include <86box/chipset.h>
#include <86box/spd.h>
#include <86box/machine.h>
enum
@@ -442,9 +443,11 @@ i4x0_write(int func, int addr, uint8_t val, void *priv)
break;
case INTEL_440BX: case INTEL_440ZX:
regs[0x51] = (regs[0x50] & 0x70) | (val & 0x8f);
if (!strcmp(machines[machine].internal_name, "vpc2007"))
regs[0x51] |= 0x10; /* Virtual PC 2007 BIOS requires a reserved bus speed bit to be set */
break;
case INTEL_440GX:
regs[0x51] = (regs[0x50] & 0x88) | (val & 0x08);
regs[0x51] = (regs[0x50] & 0x88) | (val & 0x08);
/*regs[0x51] = (regs[0x50] & 0x88) | (val & 0x77);*/
break;
}
@@ -1551,6 +1554,8 @@ static void
regs[0x51] |= 0x20;
else if ((cpu_busspeed > 66666667) && (cpu_busspeed <= 100000000))
regs[0x51] |= 0x00;
if (!strcmp(machines[machine].internal_name, "vpc2007"))
regs[0x51] |= 0x10; /* Virtual PC 2007 BIOS requires a reserved bus speed bit to be set */
regs[0x57] = 0x28; /* 4 DIMMs, SDRAM */
regs[0x58] = 0x03;
regs[0x60] = regs[0x61] = regs[0x62] = regs[0x63] = regs[0x64] = regs[0x65] = regs[0x66] = regs[0x67] = 0x01;