claunia/86Box
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge remote-tracking branch 'origin/master' into c&t_69000

Browse Source
This commit is contained in:
Cacodemon345
2024-02-03 15:17:24 +06:00
parent 323c179cee 91494bab97
commit baa66cf0ce
3 changed files with 59 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
src/cpu/808x.c
View File

@@ -1223,34 +1223,48 @@ static void
add(int bits)
{
int size_mask = (1 << bits) - 1;
int special_case = 0;
uint32_t temp_src = cpu_src;
if ((cpu_alu_op == 2) && !(cpu_src & size_mask) && (cpu_state.flags & C_FLAG))
special_case = 1;
cpu_data = cpu_dest + cpu_src;
if ((cpu_alu_op == 2) && (cpu_state.flags & C_FLAG))
cpu_src--;
set_apzs(bits);
set_of_add(bits);
/* Anything - FF with carry on is basically anything + 0x100: value stays
unchanged but carry goes on. */
if ((cpu_alu_op == 2) && !(cpu_src & size_mask) && (cpu_state.flags & C_FLAG))
if (special_case)
cpu_state.flags |= C_FLAG;
else
set_cf((cpu_src & size_mask) > (cpu_data & size_mask));
set_cf((temp_src & size_mask) > (cpu_data & size_mask));
}
static void
sub(int bits)
{
int size_mask = (1 << bits) - 1;
int special_case = 0;
uint32_t temp_src = cpu_src;
if ((cpu_alu_op == 3) && !(cpu_src & size_mask) && (cpu_state.flags & C_FLAG))
special_case = 1;
cpu_data = cpu_dest - cpu_src;
if ((cpu_alu_op == 3) && (cpu_state.flags & C_FLAG))
cpu_src--;
set_apzs(bits);
set_of_sub(bits);
/* Anything - FF with carry on is basically anything - 0x100: value stays
unchanged but carry goes on. */
if ((cpu_alu_op == 3) && !(cpu_src & size_mask) && (cpu_state.flags & C_FLAG))
if (special_case)
cpu_state.flags |= C_FLAG;
else
set_cf((cpu_src & size_mask) > (cpu_dest & size_mask));
set_cf((temp_src & size_mask) > (cpu_dest & size_mask));
}
static void

47
src/dma.c
View File

@@ -949,16 +949,47 @@ dma_page_read(uint16_t addr, UNUSED(void *priv))
uint8_t convert[8] = CHANNELS;
uint8_t ret = 0xff;
addr &= 0x0f;
ret = dmaregs[2][addr];
if (((addr & 0xfffc) == 0x80) && (CS == 0xf000) &&
((cpu_state.pc & 0xfffffff8) == 0x00007278) &&
!strcmp(machine_get_internal_name(), "megapc")) switch (addr) {
/* The Amstrad MegaPC Quadtel BIOS times a sequence of:
mov ax,di
div bx
And expects this value to be at least 0x06e0 for 20 MHz,
and at least 0x0898 for 25 MHz, everything below 0x06e0
is assumed to be 16 MHz. Given that for some reason, this
does not occur on 86Box, we have to work around it here,
we return 0x0580 for 16 MHz, because it logically follows
in the sequence (0x06e0 = 0x0898 * (20 / 25), and
0x0580 = 0x06e0 * (16 / 20)). */
case 0x0081:
if (cpu_busspeed >= 25000000)
ret = 0x98;
else if (cpu_busspeed >= 20000000)
ret = 0xe0;
else
ret = 0x80;
break;
case 0x0082:
if (cpu_busspeed >= 25000000)
ret = 0x08;
else if (cpu_busspeed >= 20000000)
ret = 0x06;
else
ret = 0x05;
break;
} else {
addr &= 0x0f;
ret = dmaregs[2][addr];
if (addr >= 8)
addr = convert[addr & 0x07] | 4;
else
addr = convert[addr & 0x07];
if (addr >= 8)
addr = convert[addr & 0x07] | 4;
else
addr = convert[addr & 0x07];
if (addr < 8)
ret = dma[addr].page_l;
if (addr < 8)
ret = dma[addr].page_l;
}
return ret;
}

4
src/machine/machine_table.c
View File

@@ -4628,8 +4628,8 @@ const machine_t machines[] = {
.cpu = {
.package = CPU_PKG_386SX,
.block = CPU_BLOCK_NONE,
.min_bus = 0,
.max_bus = 0,
.min_bus = 16000000,
.max_bus = 25000000,
.min_voltage = 0,
.max_voltage = 0,
.min_multi = 0,