Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-06-05 12:26:35 +03:00
Code Issues Actions 4 Packages Projects Releases Wiki Activity

polyfdc: Update notes (nw)

Browse Source
This commit is contained in:
AJR 2019-10-04 14:41:02 -04:00
parent 6eecd47fb1
commit b9e9ba7edc
1 changed files with 38 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
src/devices/bus/s100/polyfdc.cpp
View File

@ -4,9 +4,9 @@
PolyMorphic Systems Disk Controller
This board controls up to three Shugart SA-400 drives using only
generic serial and parallel interface chips and TTL (and an onboard
4 MHz XTAL). No schematics for this board have been found.
This board controls up to three Shugart SA400 Minifloppy drives using
only generic serial and parallel interface chips and TTL (and an
onboard 4 MHz XTAL).
****************************************************************************/
@ -39,8 +39,8 @@ private:
void pc_w(u8 data);
// object finders
required_device<mc6852_device> m_ssda;
required_device<i8255_device> m_ppi;
required_device<mc6852_device> m_usrt;
required_device<i8255_device> m_pio;
};
DEFINE_DEVICE_TYPE_PRIVATE(S100_POLY_FDC, device_s100_card_interface, poly_fdc_device, "polyfdc", "PolyMorphic Systems Disk Controller")
@ -48,8 +48,8 @@ DEFINE_DEVICE_TYPE_PRIVATE(S100_POLY_FDC, device_s100_card_interface, poly_fdc_d
poly_fdc_device::poly_fdc_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
: device_t(mconfig, S100_POLY_FDC, tag, owner, clock)
, device_s100_card_interface(mconfig, *this)
, m_ssda(*this, "ssda")
, m_ppi(*this, "ppi")
, m_usrt(*this, "usrt")
, m_pio(*this, "pio")
{
}
@ -59,12 +59,12 @@ void poly_fdc_device::device_start()
u8 poly_fdc_device::s100_sinp_r(offs_t offset)
{
if ((offset & 0xf000) == 0x2000)
if ((offset & 0x00f0) == 0x0020)
{
if (BIT(offset, 11))
return m_ppi->read(offset & 3);
return m_pio->read(offset & 3);
else
return m_ssda->read(offset & 1);
return m_usrt->read(offset & 1);
}
return 0xff;
@ -72,37 +72,54 @@ u8 poly_fdc_device::s100_sinp_r(offs_t offset)
void poly_fdc_device::s100_sout_w(offs_t offset, u8 data)
{
if ((offset & 0xf000) == 0x2000)
if ((offset & 0x00f0) == 0x20)
{
if (BIT(offset, 11))
m_ppi->write(offset & 3, data);
m_pio->write(offset & 3, data);
else
m_ssda->write(offset & 1, data);
m_usrt->write(offset & 1, data);
}
}
void poly_fdc_device::pa_w(u8 data)
{
// PA0, PA1 are decoded onto drive select lines
// DS1- (pin 10) = ~(~PA1 & PA0)
// DS2- (pin 12) = ~(PA1 & ~PA0)
// DS3- (pin 14) = ~(PA1 & PA0)
}
u8 poly_fdc_device::pb_r()
{
return 0xff;
// PB0 = SC0+ (from index/sector counting circuit)
// PB1 = SC1+
// PB2 = SC2+
// PB3 = SC3+
// PB4 = TR0+ (inverted from SA400 pin 26)
// PB5 = WPRT+ (inverted from SA400 pin 28)
// PB6 = PB7 = GND
return 0;
}
void poly_fdc_device::pc_w(u8 data)
{
// Port B interrupt
// PC0 = INT+ (buffered onto VI5-)
// PC2 = SCTR-
// PC3 = MTRON+ (inverted onto SA400 pin 16)
// PC4 = WCMD+
// PC5 = RCMD+
// PC6 = DS+ (inverted onto SA400 pin 18)
// PC7 = STEP+ (inverted onto SA400 pin 20)
m_bus->vi5_w(BIT(data, 0) ? ASSERT_LINE : CLEAR_LINE);
}
void poly_fdc_device::device_add_mconfig(machine_config &config)
{
MC6852(config, m_ssda, 4_MHz_XTAL / 4); // actual clock unknown
MC6852(config, m_usrt, 0); // E generated from PDBIN+ and PWR-
I8255(config, m_ppi);
m_ppi->out_pa_callback().set(FUNC(poly_fdc_device::pa_w));
m_ppi->in_pb_callback().set(FUNC(poly_fdc_device::pb_r));
m_ppi->out_pc_callback().set(FUNC(poly_fdc_device::pc_w));
m_ppi->tri_pc_callback().set_constant(0xfe);
I8255(config, m_pio);
m_pio->out_pa_callback().set(FUNC(poly_fdc_device::pa_w));
m_pio->in_pb_callback().set(FUNC(poly_fdc_device::pb_r));
m_pio->out_pc_callback().set(FUNC(poly_fdc_device::pc_w));
m_pio->tri_pc_callback().set_constant(0xfe);
}