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Z80SCC : fixed zbus access ; c900 : used Z80SCC for the terminal
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@Robbbert
Robbbert committed Aug 10, 2018
1 parent 455950e commit 6168192
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Showing 2 changed files with 72 additions and 72 deletions.
76 changes: 50 additions & 26 deletions src/devices/machine/z80scc.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -69,6 +69,26 @@ DONE (x) (p=partly) NMOS CMOS ESCC EMSCC
Improved reg handl Y Y Y Y
-------------------------------------------------------------------------
x/p = Features that has been implemented n/a = features that will not
How to calculate the required clock, given the wr contents and the needed
baud rate:
- let's say B = baud rate (usually 9600).
- Check wr11
-- for RX, bits D6,D5 = 1,0
-- for TX, bits D4,D3 = 1,0
-- for TRxC, bits D1,D0 = 1,0
-- let's say T = time constant (wr13 * 256 + wr12) +2. (don't forget the +2)
-- in the unlikely case of T == 0, pretend T = 1.
- If the required wr11 bits are set:
-- let's say M = wr4 D7,D6 if 1,1 M = 64; if 1,0 M = 32; if 0,1 M = 16 else M = 1
-- so, the required clock on the MCFG_DEVICE_ADD line = 2*T*B*M.
- If the required wr11 bits are not set:
-- add a line: MCFG_Z80SCC_OFFSETS(X, 0, Y, 0), where X = channel-A-baud * T,
and Y = channel-B-baud * T.
***************************************************************************/

#include "emu.h"
Expand Down Expand Up @@ -834,31 +854,28 @@ int z80scc_device::m1_r()
//-------------------------------------------------
READ8_MEMBER( z80scc_device::zbus_r )
{
int ba = 0;
int reg = 0x20; // Default point to a non register number
offset &= 31;
bool ba = BIT(offset, 4);
u8 reg = offset & 15;
uint8_t data = 0;

/* Expell non- Z-Bus variants */
/* Expel non- Z-Bus variants */
if ( !(m_variant & SET_Z80X30))
{
logerror(" zbus_r not supported by this device variant, you should probably use the universal bus variants c*_r/w and d*_r/w (see z80scc.h)\n");
return data;
}

switch ((m_chanB->m_wr0) & 7)
if ((m_chanB->m_wr0 & 7) == WR0_Z_SEL_SHFT_RIGHT)
{
case WR0_Z_SEL_SHFT_LEFT: ba = offset & 0x01; reg = (offset >> 1) & 0x0f; break; /* Shift Left mode */
case WR0_Z_SEL_SHFT_RIGHT: ba = offset & 0x10; reg = (offset >> 1) & 0x0f; break; /* Shift Right mode */
default:
logerror("Malformed Z-bus SCC read: offset %02x WR0 bits %02x\n", offset, m_chanB->m_wr0);
LOG("Malformed Z-bus SCC read: offset %02x WR0 bits %02x\n", offset, m_chanB->m_wr0);
return data;
ba = BIT(offset, 0);
reg = offset >> 1;
}

if (ba == 0)
data = m_chanB->scc_register_read(reg);
else
if (ba)
data = m_chanA->scc_register_read(reg);
else
data = m_chanB->scc_register_read(reg);

return data;
}
Expand All @@ -868,29 +885,36 @@ READ8_MEMBER( z80scc_device::zbus_r )
//-------------------------------------------------
WRITE8_MEMBER( z80scc_device::zbus_w )
{
int ba = 0;
int reg = 0x20; // Default point to a non register number
offset &= 31;
bool ba = BIT(offset, 4);
u8 reg = offset & 15;

/* Expell non- Z-Bus variants */
/* Expel non- Z-Bus variants */
if ( !(m_variant & SET_Z80X30))
{
logerror(" zbus_w not supported by this device variant, you should probably use the universal bus variants c*_r/w and d*_r/w (see z80scc.h)\n");
return;
}

switch ((m_chanB->m_wr0) & 7)
if ((m_chanB->m_wr0 & 7) == WR0_Z_SEL_SHFT_RIGHT)
{
case WR0_Z_SEL_SHFT_LEFT: ba = offset & 0x01; reg = (offset >> 1) & 0x0f; break; /* Shift Left mode */
case WR0_Z_SEL_SHFT_RIGHT: ba = offset & 0x10; reg = (offset >> 1) & 0x0f; break; /* Shift Right mode */
default:
logerror("Malformed Z-bus SCC write: offset %02x WR0 bits %02x\n", offset, m_chanB->m_wr0);
LOG("Malformed Z-bus SCC write: offset %02x WR0 bits %02x\n", offset, m_chanB->m_wr0);
ba = BIT(offset, 0);
reg = offset >> 1;
}

if (ba == 0)
m_chanB->scc_register_write(reg, data);
else
m_chanA->scc_register_write(reg, data);
switch (reg)
{
case 2:
case 9:
m_chanA->scc_register_write(reg, data);
m_chanB->scc_register_write(reg, data);
break;
default:
if (ba)
m_chanA->scc_register_write(reg, data);
else
m_chanB->scc_register_write(reg, data);
}

return;
}
Expand Down
68 changes: 22 additions & 46 deletions src/mame/drivers/c900.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,18 +17,23 @@ It has a 6508 CPU.
Disk drive is a Matsushita JA-560-012
Our implementation of z80scc is currently incomplete and therefore unusable.
Increasing the amount of RAM stops the error message, however it still keeps running
into the weeds (jumps to 00000).
into the weeds (jumps to 00000). Due to lack of banking, the stack is pointing at rom.
To Do:
- Banking
- Pretty much everything
- Need schematics, technical manuals and so on.
- Eventually, will need software.
- Disassembler needs fixing
*******************************************************************************************/


#include "emu.h"
#include "cpu/z8000/z8000.h"
//#include "machine/z80scc.h"
//#include "bus/rs232/rs232.h"
#include "machine/z80scc.h"
#include "bus/rs232/rs232.h"
#include "machine/terminal.h"
#include "machine/z8536.h"
#include "emupal.h"
Expand All @@ -40,21 +45,14 @@ class c900_state : public driver_device
c900_state(const machine_config &mconfig, device_type type, const char *tag)
: driver_device(mconfig, type, tag)
, m_maincpu(*this, "maincpu")
, m_terminal(*this, "terminal")
{ }

DECLARE_READ16_MEMBER(key_r);
DECLARE_READ16_MEMBER(stat_r);
void kbd_put(u8 data);

void c900(machine_config &config);
void data_map(address_map &map);
void io_map(address_map &map);
void mem_map(address_map &map);
private:
uint8_t m_term_data;
required_device<cpu_device> m_maincpu;
required_device<generic_terminal_device> m_terminal;
};

void c900_state::mem_map(address_map &map)
Expand All @@ -71,32 +69,13 @@ void c900_state::data_map(address_map &map)
void c900_state::io_map(address_map &map)
{
map(0x0000, 0x007f).rw("cio", FUNC(z8036_device::read), FUNC(z8036_device::write)).umask16(0x00ff);
//AM_RANGE(0x0100, 0x011f) AM_DEVREADWRITE8("scc", scc8030_device, zbus_r, zbus_w, 0x00ff) // range for one channel
map(0x0100, 0x0101).r(FUNC(c900_state::stat_r));
map(0x0110, 0x0111).r(FUNC(c900_state::key_r));
map(0x0111, 0x0111).w(m_terminal, FUNC(generic_terminal_device::write));
map(0x0100, 0x013f).rw("scc", FUNC(scc8030_device::zbus_r), FUNC(scc8030_device::zbus_w)).umask16(0x00ff);
map(0x0ff8, 0x0ff9).nopw();
}

static INPUT_PORTS_START( c900 )
INPUT_PORTS_END

READ16_MEMBER( c900_state::key_r )
{
uint8_t ret = m_term_data;
m_term_data = 0;
return ret;
}

READ16_MEMBER( c900_state::stat_r )
{
return (m_term_data) ? 5 : 4;
}

void c900_state::kbd_put(u8 data)
{
m_term_data = data;
}

/* F4 Character Displayer */
static const gfx_layout c900_charlayout =
{
Expand All @@ -122,24 +101,21 @@ MACHINE_CONFIG_START(c900_state::c900)
MCFG_DEVICE_DATA_MAP(data_map)
MCFG_DEVICE_IO_MAP(io_map)

MCFG_DEVICE_ADD("terminal", GENERIC_TERMINAL, 0)
MCFG_GENERIC_TERMINAL_KEYBOARD_CB(PUT(c900_state, kbd_put))
MCFG_DEVICE_ADD("gfxdecode", GFXDECODE, "palette", gfx_c900)
MCFG_PALETTE_ADD_MONOCHROME("palette")

MCFG_DEVICE_ADD("cio", Z8036, 6'000'000)

//MCFG_DEVICE_ADD("scc", SCC8030, 6'000'000)
//MCFG_Z80SCC_OFFSETS(326400, 0, 326400, 0)
/* Port A */
//MCFG_Z80SCC_OUT_TXDA_CB(WRITELINE("rs232a", rs232_port_device, write_txd))
//MCFG_Z80SCC_OUT_DTRA_CB(WRITELINE("rs232a", rs232_port_device, write_dtr))
//MCFG_Z80SCC_OUT_RTSA_CB(WRITELINE("rs232a", rs232_port_device, write_rts))
//MCFG_Z80SCC_OUT_INT_CB(WRITELINE(*this, lwriter_state, scc_int))

//MCFG_RS232_PORT_ADD ("rs232a", default_rs232_devices, "terminal")
//MCFG_RS232_RXD_HANDLER (WRITELINE ("scc", scc8030_device, rxa_w))
//MCFG_RS232_CTS_HANDLER (WRITELINE ("scc", scc8030_device, ctsa_w))
MCFG_DEVICE_ADD("scc", SCC8030, 6'000'000) // 5'850'000 is the ideal figure
/* Port B */
MCFG_Z80SCC_OUT_TXDB_CB(WRITELINE("rs232", rs232_port_device, write_txd))
MCFG_Z80SCC_OUT_DTRB_CB(WRITELINE("rs232", rs232_port_device, write_dtr))
MCFG_Z80SCC_OUT_RTSB_CB(WRITELINE("rs232", rs232_port_device, write_rts))
//MCFG_Z80SCC_OUT_INT_CB(WRITELINE(*this, c900_state, scc_int))

MCFG_DEVICE_ADD("rs232", RS232_PORT, default_rs232_devices, "terminal")
MCFG_RS232_RXD_HANDLER (WRITELINE ("scc", scc8030_device, rxb_w))
MCFG_RS232_CTS_HANDLER (WRITELINE ("scc", scc8030_device, ctsb_w))
MACHINE_CONFIG_END

ROM_START( c900 )
Expand Down

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