ti83-sdk/tool/tilem-src/emu/x2/x2_io.c

208 lines
4.5 KiB
C
Raw Normal View History

2023-10-08 16:33:37 +00:00
/*
* libtilemcore - Graphing calculator emulation library
*
* Copyright (C) 2001 Solignac Julien
* Copyright (C) 2004-2009 Benjamin Moody
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see
* <http://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <tilem.h>
#include "x2.h"
byte x2_z80_in(TilemCalc* calc, dword port)
{
static const byte battlevel[4] = { 33, 39, 36, 43 };
byte v, b;
switch(port&0xff) {
case 0x00:
v = tilem_linkport_get_lines(calc);
if (calc->hwregs[HW_VERSION] == 1) {
/* HW version 1 uses separate PCR/PDR, as the
TI-85 does. */
b = (calc->hwregs[PORT0] >> 4) | 0xf0;
return ((calc->hwregs[PORT0] & b) | (v & ~b));
}
else {
/* HW version 2 uses a TI-83-like interface.
(Do the same if version is unknown, because
most code written for HW version 1 will
work fine with these values.) */
return (0xc0 | (v * 5));
}
case 0x01:
return(tilem_keypad_read_keys(calc));
case 0x02:
return(calc->hwregs[PORT2]);
case 0x03:
v = (calc->keypad.onkeydown ? 0x00: 0x08);
if (calc->z80.interrupts & TILEM_INTERRUPT_ON_KEY)
v |= 0x01;
if (calc->z80.interrupts & TILEM_INTERRUPT_TIMER1)
v |= 0x02;
return(v);
case 0x10:
return(tilem_lcd_t6a04_status(calc));
case 0x11:
return(tilem_lcd_t6a04_read(calc));
case 0x14:
/* FIXME: determine value of this port on old
hardware, and the values of bits 1-7. (As on
TI-83, probably mirrors port 0 in both cases.) */
b = battlevel[calc->hwregs[PORT4] >> 6];
return(calc->battery >= b ? 1 : 0);
}
tilem_warning(calc, "Input from port %x", port);
return(0x00);
}
static void setup_mapping(TilemCalc* calc)
{
unsigned int pageA, pageB;
/* FIXME: this is all rather hypothetical and untested, but it
makes sense based on how the TI-83 works */
if (calc->hwregs[PORT2] & 0x40) {
pageA = (0x08 | (calc->hwregs[PORT2] & 1));
}
else {
pageA = (calc->hwregs[PORT2] & 7);
}
if (calc->hwregs[PORT2] & 0x80) {
pageB = (0x08 | ((calc->hwregs[PORT2] >> 3) & 1));
}
else {
pageB = ((calc->hwregs[PORT2] >> 3) & 7);
}
if (calc->hwregs[PORT4] & 1) {
calc->mempagemap[1] = (pageA & ~1);
calc->mempagemap[2] = (pageA | 1);
calc->mempagemap[3] = pageB;
}
else {
calc->mempagemap[1] = pageA;
calc->mempagemap[2] = pageB;
calc->mempagemap[3] = 0x08;
}
}
void x2_z80_out(TilemCalc* calc, dword port, byte value)
{
switch(port&0xff) {
case 0x00:
calc->hwregs[PORT0] = value;
if (calc->hwregs[HW_VERSION] == 1) {
/* HW version 1 */
value = (((value >> 6) & (value >> 2))
| ((value >> 4) & ~value));
}
else if (calc->hwregs[HW_VERSION] == 0) {
/* HW version unknown: auto-detect */
if ((value & 0xc3) == 0xc0) {
value = ((value >> 2) | (value >> 4));
}
}
tilem_linkport_set_lines(calc, value);
break;
case 0x01:
tilem_keypad_set_group(calc, value);
break;
case 0x02:
calc->hwregs[PORT2] = value;
setup_mapping(calc);
break;
case 0x03:
if (value & 0x01) {
calc->keypad.onkeyint = 1;
}
else {
calc->z80.interrupts &= ~TILEM_INTERRUPT_ON_KEY;
calc->keypad.onkeyint = 0;
}
if (!(value & 0x02)) {
calc->z80.interrupts &= ~TILEM_INTERRUPT_TIMER1;
}
calc->poweronhalt = ((value & 8) >> 3);
calc->hwregs[PORT3] = value;
break;
case 0x04:
calc->hwregs[PORT4] = value;
/* Detect hardware version */
if (calc->z80.r.pc.d < 0x4000) {
if (value & 0x10)
calc->hwregs[HW_VERSION] = 1;
else
calc->hwregs[HW_VERSION] = 2;
}
/* FIXME: implement changing interrupt frequencies --
somebody needs to measure them. Also check if bit
4 works as on 83. */
setup_mapping(calc);
break;
case 0x10:
tilem_lcd_t6a04_control(calc, value);
break;
case 0x11:
tilem_lcd_t6a04_write(calc, value);
break;
}
return;
}
void x2_z80_ptimer(TilemCalc* calc, int id)
{
switch (id) {
case TIMER_INT:
if (calc->hwregs[PORT3] & 0x02)
calc->z80.interrupts |= TILEM_INTERRUPT_TIMER1;
break;
}
}