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apple2: updated PC Transporter to use alternate DMAC emulation & fixed V30 clock. [Peter Ferrie, R. Belmont]

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This commit is contained in:
arbee 2016-04-13 21:54:56 -04:00
parent c1efcefc26
commit f81948b663
2 changed files with 35 additions and 27 deletions
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60
src/devices/bus/a2bus/pc_xporter.cpp
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@ -53,31 +53,11 @@
CF31: control/flags: bit 4 = 1 to assert reset on V30, 5 = 1 to assert halt on V30
TODO:
- Code at $70b0-$70c5 waits for the V30 to answer some configuration data.
- Code at $70b0-$70c5 waits for the V30 to answer FPU presence.
- What's going on at CF0E/CF0F?
- There's likely A2 ROM at CnXX and C800-CBFF to support the "Slinky" memory
expansion card emulation function inside one of the custom ASICs. Need to
dump this...
- The manual indicates there is no ROM; special drivers installed into ProDOS 8
provide the RAMdisk and A2-accessing-PC-drives functionality.
The final stages before the software settles into its loop are:
20 to C800 at cf30
00 to C800 at cf31
12 to C800 at cf2b
21 to C800 at cf25
33 to C800 at cf24
80 to C800 at cf31
20 to C800 at cf30
loop:
Read $C800 at cf36
Read $C800 at cf31
Read $C800 at cf31
Read $C800 at cf36
Read $C800 at cf31
Read $C800 at cf31
80 to C800 at cf31
loop end: (return to loop)
*********************************************************************/
#include "pc_xporter.h"
@ -94,7 +74,6 @@ const device_type A2BUS_PCXPORTER = &device_creator<a2bus_pcxporter_device>;
static ADDRESS_MAP_START( pc_map, AS_PROGRAM, 16, a2bus_pcxporter_device )
ADDRESS_MAP_UNMAP_HIGH
//AM_RANGE(0xf0000, 0xfffff) AM_READ(pc_bios_r)
ADDRESS_MAP_END
static ADDRESS_MAP_START(pc_io, AS_IO, 16, a2bus_pcxporter_device )
@ -108,7 +87,7 @@ static ADDRESS_MAP_START(pc_io, AS_IO, 16, a2bus_pcxporter_device )
ADDRESS_MAP_END
MACHINE_CONFIG_FRAGMENT( pcxporter )
MCFG_CPU_ADD("v30", V30, XTAL_14_31818MHz/3)
MCFG_CPU_ADD("v30", V30, XTAL_14_31818MHz/2) // 7.16 MHz as per manual
MCFG_CPU_PROGRAM_MAP(pc_map)
MCFG_CPU_IO_MAP(pc_io)
MCFG_CPU_IRQ_ACKNOWLEDGE_DEVICE("pic8259", pic8259_device, inta_cb)
@ -121,7 +100,7 @@ MACHINE_CONFIG_FRAGMENT( pcxporter )
MCFG_PIT8253_CLK2(XTAL_14_31818MHz/12) /* pio port c pin 4, and speaker polling enough */
MCFG_PIT8253_OUT2_HANDLER(WRITELINE(a2bus_pcxporter_device, pc_pit8253_out2_changed))
MCFG_DEVICE_ADD( "dma8237", AM9517A, XTAL_14_31818MHz/3 )
MCFG_DEVICE_ADD( "dma8237", PCXPORT_DMAC, XTAL_14_31818MHz/2 )
MCFG_I8237_OUT_HREQ_CB(WRITELINE(a2bus_pcxporter_device, pc_dma_hrq_changed))
MCFG_I8237_OUT_EOP_CB(WRITELINE(a2bus_pcxporter_device, pc_dma8237_out_eop))
MCFG_I8237_IN_MEMR_CB(READ8(a2bus_pcxporter_device, pc_dma_read_byte))
@ -390,9 +369,36 @@ void a2bus_pcxporter_device::write_c800(address_space &space, UINT16 offset, UIN
case 0x72c: // CGA 6845 register select
m_pcio_space->write_byte(0x3d6, data);
m_6845_reg = data;
break;
case 0x72d: // CGA 6845 data read/write
// HACK: adjust the 40 column mode the 6502 sets to
// be more within specs.
switch (m_6845_reg)
{
case 0:
if (data == 0x3e)
{
data -= 6;
}
break;
case 2:
if (data == 0x29)
{
data += 4;
}
break;
case 3:
if (data == 0x5)
{
data *= 2;
}
break;
}
m_pcio_space->write_byte(0x3d7, data);
break;
@ -424,7 +430,7 @@ void a2bus_pcxporter_device::write_c800(address_space &space, UINT16 offset, UIN
break;
default:
printf("%02x to C800 at %x\n", data, offset + 0xc800);
// printf("%02x to C800 at %x\n", data, offset + 0xc800);
m_regs[offset] = data;
break;
}

2
src/devices/bus/a2bus/pc_xporter.h
View File

@ -123,6 +123,8 @@ private:
address_space *m_pcmem_space, *m_pcio_space;
bool m_reset_during_halt;
UINT8 m_6845_reg;
void pc_select_dma_channel(int channel, bool state);
};