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ti99/genmod: Add option to decode high address lines for DDCC-1 so that it can be used with Genmod.

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This commit is contained in:
Michael Zapf 2022-06-12 01:18:34 +02:00
parent 7dcdf5db68
commit f44b654efd
4 changed files with 55 additions and 31 deletions
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59
src/devices/bus/ti99/peb/myarcfdc.cpp
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@ -95,19 +95,23 @@ offs_t myarc_fdc_device::get_address()
void myarc_fdc_device::debug_read(offs_t offset, uint8_t* value)
{
offs_t addrcopy = m_address;
m_address = offset;
if (m_pal->ramsel())
{
*value = m_buffer_ram->pointer()[m_address & 0x07ff];
}
if (m_pal->romen())
if (!m_dec_high || amabc_is_set(offset))
{
// EPROM selected
offs_t base = m_banksel? 0x1000 : 0;
*value = m_dsrrom[base | (m_address & 0x0fff)];
m_address = offset;
if (m_pal->ramsel())
{
*value = m_buffer_ram->pointer()[m_address & 0x07ff];
}
if (m_pal->romen())
{
// EPROM selected
offs_t base = m_banksel? 0x1000 : 0;
*value = m_dsrrom[base | (m_address & 0x0fff)];
}
m_address = addrcopy;
}
m_address = addrcopy;
}
/*
@ -116,12 +120,16 @@ void myarc_fdc_device::debug_read(offs_t offset, uint8_t* value)
void myarc_fdc_device::debug_write(offs_t offset, uint8_t data)
{
offs_t addrcopy = m_address;
m_address = offset;
if (m_pal->ramsel())
if (!m_dec_high || amabc_is_set(offset))
{
m_buffer_ram->pointer()[m_address & 0x07ff] = data;
m_address = offset;
if (m_pal->ramsel())
{
m_buffer_ram->pointer()[m_address & 0x07ff] = data;
}
m_address = addrcopy;
}
m_address = addrcopy;
}
/*
@ -135,6 +143,9 @@ void myarc_fdc_device::readz(offs_t offset, uint8_t *value)
return;
}
// If we have an AMA/B/C decoder and it delivers false, exit here
if (m_dec_high && !amabc_is_set(offset)) return;
if (m_pal->ramsel())
{
// SRAM selected
@ -175,6 +186,9 @@ void myarc_fdc_device::write(offs_t offset, uint8_t data)
return;
}
// If we have an AMA/B/C decoder and it delivers false, exit here
if (m_dec_high && !amabc_is_set(offset)) return;
if (m_pal->ramsel())
{
// SRAM selected
@ -346,6 +360,8 @@ void myarc_fdc_device::device_reset()
m_wdc = m_wd1770;
else
m_wdc = m_wd1772;
m_dec_high = (ioport("AMADECODE")->read()!=0);
}
void myarc_fdc_device::device_config_complete()
@ -366,7 +382,7 @@ void myarc_fdc_device::floppy_formats(format_registration &fr)
fr.add(FLOPPY_TI99_TDF_FORMAT);
}
static void ccfdc_floppies(device_slot_interface &device)
static void myarc_ddcc_floppies(device_slot_interface &device)
{
device.option_add("525dd", FLOPPY_525_DD); // 40 tracks
device.option_add("525qd", FLOPPY_525_QD); // 80 tracks
@ -397,6 +413,11 @@ INPUT_PORTS_START(myarc_ddcc )
PORT_DIPNAME( 0x08, 0x00, "DSK4 head step time" )
PORT_DIPSETTING( 0x00, "6ms")
PORT_DIPSETTING( 0x08, "20ms/2ms")
PORT_START( "AMADECODE" )
PORT_CONFNAME( 0x01, 0x01, "Decode AMA/AMB/AMC lines" )
PORT_CONFSETTING( 0x00, DEF_STR( Off ))
PORT_CONFSETTING( 0x01, DEF_STR( On ))
INPUT_PORTS_END
@ -438,10 +459,10 @@ void myarc_fdc_device::device_add_mconfig(machine_config& config)
DDCC1_PAL(config, PAL_TAG, 0);
// Floppy drives
FLOPPY_CONNECTOR(config, "0", ccfdc_floppies, "525dd", myarc_fdc_device::floppy_formats).enable_sound(true);
FLOPPY_CONNECTOR(config, "1", ccfdc_floppies, "525dd", myarc_fdc_device::floppy_formats).enable_sound(true);
FLOPPY_CONNECTOR(config, "2", ccfdc_floppies, nullptr, myarc_fdc_device::floppy_formats).enable_sound(true);
FLOPPY_CONNECTOR(config, "3", ccfdc_floppies, nullptr, myarc_fdc_device::floppy_formats).enable_sound(true);
FLOPPY_CONNECTOR(config, "0", myarc_ddcc_floppies, "525dd", myarc_fdc_device::floppy_formats).enable_sound(true);
FLOPPY_CONNECTOR(config, "1", myarc_ddcc_floppies, "525dd", myarc_fdc_device::floppy_formats).enable_sound(true);
FLOPPY_CONNECTOR(config, "2", myarc_ddcc_floppies, nullptr, myarc_fdc_device::floppy_formats).enable_sound(true);
FLOPPY_CONNECTOR(config, "3", myarc_ddcc_floppies, nullptr, myarc_fdc_device::floppy_formats).enable_sound(true);
}
ioport_constructor myarc_fdc_device::device_input_ports() const

3
src/devices/bus/ti99/peb/myarcfdc.h
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@ -103,6 +103,9 @@ private:
// Recent address
int m_address;
// AMA/B/C decoding active
bool m_dec_high;
};
// =========== Decoder PAL circuit ================

18
src/devices/bus/ti99/peb/peribox.cpp
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@ -796,18 +796,18 @@ void device_ti99_peribox_card_interface::interface_config_complete()
bool device_ti99_peribox_card_interface::in_dsr_space(offs_t offset, bool amadec)
{
if (amadec)
return (offset & 0x7e000)==0x74000;
else
return (offset & 0x0e000)==0x04000;
if (amadec && !amabc_is_set(offset)) return false;
return (offset & 0x0e000)==0x04000;
}
bool device_ti99_peribox_card_interface::in_cart_space(offs_t offset, bool amadec)
/*
Some cards do not decode the additional address lines AMA, AMB, AMC.
This leads to errors when using the card with Genmod. The typical procedure
to decode the lines is the same for each card.
*/
bool device_ti99_peribox_card_interface::amabc_is_set(offs_t offset)
{
if (amadec)
return (offset & 0x7e000)==0x76000;
else
return (offset & 0x0e000)==0x06000;
return (((offset >> 16)&0x07)==0x07);
}
} // end namespace bus::ti99::peb

6
src/devices/bus/ti99/peb/peribox.h
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@ -202,9 +202,9 @@ protected:
int m_cru_base;
// Methods to decide whether we are acccessing the 4000-5fff region (DSR)
// or the cartridge region
static bool in_dsr_space(offs_t offset, bool amadec);
static bool in_cart_space(offs_t offset, bool amadec);
bool in_dsr_space(offs_t offset, bool amadec);
bool amabc_is_set(offs_t offset);
};
/*****************************************************************************