/*
* 86Box A hypervisor and IBM PC system emulator that specializes in
* running old operating systems and software designed for IBM
* PC systems and compatibles from 1981 through fairly recent
* system designs based on the PCI bus.
*
* This file is part of the 86Box distribution.
*
* Emulation of the TI CF62011 SVGA chip.
*
* This chip was used in several of IBM's later machines, such
* as the PS/1 Model 2121, and a number of PS/2 models. As noted
* in an article on Usenet:
*
* "In the early 90s IBM looked for some cheap VGA card to
* substitute the (relatively) expensive XGA-2 adapter for
* *servers*, where the primary purpose is supervision of the
* machine rather than real *work* with it in Hi-Res. It was
* just to supply a base video, where a XGA-2 were a waste of
* potential. They had a contract with TI for some DSPs in
* multimedia already (the MWave for instance is based on
* TI-DSPs as well as many Thinkpad internal chipsets) and TI
* offered them a rather cheap – and inexpensive – chipset
* and combined it with a cheap clock oscillator and an Inmos
* RAMDAC. That chipset was already pretty much outdated at
* that time but IBM decided it would suffice for that low
* end purpose.
*
* Driver support was given under DOS and OS/2 only for base
* functions like selection of the vertical refresh and few
* different modes only. Not even the Win 3.x support has
* been finalized. Technically the adapter could do better
* than VGA, but its video BIOS is largely undocumented and
* intentionally crippled down to a few functions."
*
* This chip is reportedly the same one as used in the MCA
* IBM SVGA Adapter/A (ID 090EEh), which mostly had faster
* VRAM and RAMDAC. The VESA DOS graphics driver for that
* card can be used: m95svga.exe
*
* The controller responds at ports in the range 0x2100-0x210F,
* which are the same as the XGA. It supports up to 1MB of VRAM,
* but we lock it down to 512K. The PS/1 2122 had 256K.
*
*
*
* Authors: Sarah Walker,
* Miran Grca,
* Fred N. van Kempen,
*
* Copyright 2008-2018 Sarah Walker.
* Copyright 2016-2018 Miran Grca.
* Copyright 2017-2018 Fred N. van Kempen.
*/
#include
#include
#include
#include
#include
#include <86box/86box.h>
#include <86box/io.h>
#include <86box/timer.h>
#include <86box/mem.h>
#include <86box/rom.h>
#include <86box/device.h>
#include <86box/video.h>
#include <86box/vid_svga.h>
typedef struct {
svga_t svga;
rom_t bios_rom;
int enabled;
uint32_t vram_size;
uint8_t banking;
uint8_t reg_2100;
uint8_t reg_210a;
} tivga_t;
static video_timings_t timing_ti_cf62011 = { .type = VIDEO_ISA, .write_b = 6, .write_w = 8, .write_l = 16, .read_b = 6, .read_w = 8, .read_l = 16 };
static void
vid_out(uint16_t addr, uint8_t val, void *priv)
{
tivga_t *ti = (tivga_t *) priv;
svga_t *svga = &ti->svga;
uint8_t old;
#if 0
if (((addr & 0xfff0) == 0x03d0 || (addr & 0xfff0) == 0x03b0) &&
!(svga->miscout & 1)) addr ^= 0x60;
#endif
switch (addr) {
case 0x0102:
ti->enabled = (val & 0x01);
return;
case 0x03d4:
svga->crtcreg = val & 0x3f;
return;
case 0x03d5:
if (svga->crtcreg & 0x20)
return;
if ((svga->crtcreg < 7) && (svga->crtc[0x11] & 0x80))
return;
if ((svga->crtcreg == 7) && (svga->crtc[0x11] & 0x80))
val = (svga->crtc[7] & ~0x10) | (val & 0x10);
old = svga->crtc[svga->crtcreg];
svga->crtc[svga->crtcreg] = val;
if (old != val) {
if (svga->crtcreg < 0xe || svga->crtcreg > 0x10) {
svga->fullchange = changeframecount;
svga_recalctimings(svga);
}
}
break;
case 0x2100:
ti->reg_2100 = val;
if ((val & 7) < 4)
svga->read_bank = svga->write_bank = 0;
else
svga->read_bank = svga->write_bank = (ti->banking & 0x7) * 0x10000;
break;
case 0x2108:
if ((ti->reg_2100 & 7) >= 4)
svga->read_bank = svga->write_bank = (val & 0x7) * 0x10000;
ti->banking = val;
break;
case 0x210a:
ti->reg_210a = val;
break;
default:
break;
}
svga_out(addr, val, svga);
}
static uint8_t
vid_in(uint16_t addr, void *priv)
{
tivga_t *ti = (tivga_t *) priv;
svga_t *svga = &ti->svga;
uint8_t ret;
#if 0
if (((addr & 0xfff0) == 0x03d0 || (addr & 0xfff0) == 0x03b0) &&
!(svga->miscout & 1)) addr ^= 0x60;
#endif
switch (addr) {
case 0x0100:
ret = 0xfe;
break;
case 0x0101:
ret = 0xe8;
break;
case 0x0102:
ret = ti->enabled;
break;
case 0x03d4:
ret = svga->crtcreg;
break;
case 0x03d5:
if (svga->crtcreg & 0x20)
ret = 0xff;
else
ret = svga->crtc[svga->crtcreg];
break;
case 0x2100:
ret = ti->reg_2100;
break;
case 0x2108:
ret = ti->banking;
break;
case 0x210a:
ret = ti->reg_210a;
break;
default:
ret = svga_in(addr, svga);
break;
}
return ret;
}
static void
vid_speed_changed(void *priv)
{
tivga_t *ti = (tivga_t *) priv;
svga_recalctimings(&ti->svga);
}
static void
vid_force_redraw(void *priv)
{
tivga_t *ti = (tivga_t *) priv;
ti->svga.fullchange = changeframecount;
}
static void
vid_close(void *priv)
{
tivga_t *ti = (tivga_t *) priv;
svga_close(&ti->svga);
free(ti);
}
static void *
vid_init(const device_t *info)
{
tivga_t *ti;
/* Allocate control block and initialize. */
ti = (tivga_t *) malloc(sizeof(tivga_t));
memset(ti, 0x00, sizeof(tivga_t));
/* Set amount of VRAM in KB. */
if (info->local == 0)
ti->vram_size = device_get_config_int("vram_size");
else
ti->vram_size = info->local;
video_inform(VIDEO_FLAG_TYPE_SPECIAL, &timing_ti_cf62011);
svga_init(info, &ti->svga, ti,
ti->vram_size << 10,
NULL, vid_in, vid_out, NULL, NULL);
io_sethandler(0x0100, 2, vid_in, NULL, NULL, NULL, NULL, NULL, ti);
io_sethandler(0x03c0, 32, vid_in, NULL, NULL, vid_out, NULL, NULL, ti);
io_sethandler(0x2100, 16, vid_in, NULL, NULL, vid_out, NULL, NULL, ti);
ti->svga.bpp = 8;
ti->svga.miscout = 1;
return ti;
}
const device_t ibm_ps1_2121_device = {
.name = "IBM PS/1 Model 2121 SVGA",
.internal_name = "ibm_ps1_2121",
.flags = DEVICE_ISA,
.local = 512,
.init = vid_init,
.close = vid_close,
.reset = NULL,
{ .available = NULL },
.speed_changed = vid_speed_changed,
.force_redraw = vid_force_redraw,
.config = NULL
};