Added the following new machines:

- Olivetti M19. - Olivetti M240. Implemented mainboard jumper settings for Olivetti M24 machine: - Like on a real M24, onboard video card can be disabled, and other video cards can be installed. - Renamed m_olivetti_m24.c to m_xt_olivetti.c, as it handles all XT-class Olivetti machines. Decoupled Olivetti OGC (640x400 extended CGA) from M24 machine code: - OGC exists both as 16-bit proprietary card and 8-bit ISA card (GO708). - Implemented underlined text handling in 80x25 character mode. - Like Compaq CGA, replaced code portions common to CGA with calls to vid_cga.c.
2020-12-05 20:15:53 +01:00
parent 57ff5a0441
commit 9daf161aee
13 changed files with 1798 additions and 1007 deletions
--- a/src/video/vid_ogc.c
+++ b/src/video/vid_ogc.c
@@ -0,0 +1,693 @@
+/*
+ * 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 Olivetti OGC 8-bit ISA (GO708) and 
+ *      M21/M24/M28 16-bit bus (GO317/318/380/709) video cards.
+ *
+ *
+ *
+ * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
+ *		Miran Grca, <mgrca8@gmail.com>
+ *		Fred N. van Kempen, <decwiz@yahoo.com>
+ *		EngiNerd, <webmaster.crrc@yahoo.it>
+ *
+ *		Copyright 2008-2019 Sarah Walker.
+ *		Copyright 2016-2019 Miran Grca.
+ *		Copyright 2017-2019 Fred N. van Kempen.
+ *		Copyright 2020 EngiNerd.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <wchar.h>
+#include <86box/io.h>
+#include <86box/video.h>
+#include <86box/86box.h>
+#include <86box/timer.h>
+#include <86box/mem.h>
+#include <86box/pit.h>
+#include <86box/rom.h>
+#include <86box/device.h>
+#include <86box/vid_cga.h>
+#include <86box/vid_ogc.h>
+#include <86box/vid_cga_comp.h>
+
+
+
+/*
+ * Current bugs: 
+ * - Olivetti diagnostics fail with errors: 6845 crtc write / read error out 0000 in 00ff
+ * - Dark blue (almost black) picture in composite mode
+ */
+
+#define CGA_RGB 0
+#define CGA_COMPOSITE 1
+
+#define COMPOSITE_OLD 0
+#define COMPOSITE_NEW 1
+
+
+
+static video_timings_t timing_ogc      = {VIDEO_ISA, 8,16,32, 8,16,32};
+
+static uint8_t		mdaattr[256][2][2];
+
+void
+ogc_recalctimings(ogc_t *ogc)
+{
+    double _dispontime, _dispofftime, disptime;
+
+    if (ogc->cga.cgamode & 1) {
+	disptime    = ogc->cga.crtc[0] + 1;
+	_dispontime = ogc->cga.crtc[1];
+    } else {
+	disptime    = (ogc->cga.crtc[0] + 1) << 1;
+	_dispontime = ogc->cga.crtc[1] << 1;
+    }
+
+    _dispofftime = disptime - _dispontime;
+    _dispontime  *= CGACONST / 2;
+    _dispofftime *= CGACONST / 2;
+    ogc->cga.dispontime  = (uint64_t)(_dispontime);
+    ogc->cga.dispofftime = (uint64_t)(_dispofftime);
+}
+
+void
+ogc_out(uint16_t addr, uint8_t val, void *priv)
+{
+    ogc_t *ogc = (ogc_t *)priv;
+
+	// if (addr >= 0x3c0 && addr <= 0x3cf){
+	// 	addr = addr + 16;
+	// }
+
+    switch (addr) {
+	case 0x3d4:
+	case 0x3d5:
+	case 0x3d8:
+	case 0x3d9:
+		cga_out(addr, val, &ogc->cga);
+		break;
+
+	case 0x3de:
+		/* set control register */
+		ogc->ctrl_3de = val;
+		/* select 1st or 2nd 16k vram block to be used */
+		ogc->base = (val & 0x08) ? 0x4000 : 0;
+		break;
+	}
+}
+
+uint8_t
+ogc_in(uint16_t addr, void *priv)
+{
+    ogc_t *ogc = (ogc_t *)priv;
+
+	// if (addr >= 0x3c0 && addr <= 0x3cf){
+	// 	addr = addr + 16;
+	// }
+
+    uint8_t ret = 0xff;
+
+    switch (addr) {
+	case 0x3d4:
+	case 0x3d5:
+	case 0x3da:
+		/* 
+		 * bits 6-7: 3 = no DEB expansion board installed
+		 * bits 4-5: 2 color, 3 mono
+		 * bit 3: high during 1st half of vertical retrace in character mode (CCA standard)
+		 * bit 2: lightpen switch (CGA standard)
+		 * bit 1: lightpen strobe (CGA standard)
+		 * bit 0: high during retrace (CGA standard)
+		 */
+		ret = cga_in(addr, &ogc->cga);
+		ret = ret | 0xe0;
+		if (ogc->mono_display)
+			ret = ret | 0x10;
+		break;
+	}
+
+    return(ret);
+}
+
+
+void
+ogc_waitstates(void *p)
+{
+    int ws_array[16] = {3, 4, 5, 6, 7, 8, 4, 5, 6, 7, 8, 4, 5, 6, 7, 8};
+    int ws;
+
+    ws = ws_array[cycles & 0xf];
+    sub_cycles(ws);
+}
+
+
+void
+ogc_write(uint32_t addr, uint8_t val, void *priv)
+{
+    ogc_t *ogc = (ogc_t *)priv;
+	int offset;
+
+    ogc->cga.vram[addr & 0x7FFF]=val;
+	if (ogc->cga.snow_enabled) {
+		/* recreate snow effect */
+		offset = ((timer_get_remaining_u64(&ogc->cga.timer) / CGACONST) * 4) & 0xfc;
+		ogc->cga.charbuffer[offset] = ogc->cga.vram[addr & 0x7fff];
+		ogc->cga.charbuffer[offset | 1] = ogc->cga.vram[addr & 0x7fff];
+	}
+	egawrites++;
+    ogc_waitstates(&ogc->cga);
+}
+
+uint8_t
+ogc_read(uint32_t addr, void *priv)
+{
+    
+	ogc_t *ogc = (ogc_t *)priv;
+    int offset;
+
+	ogc_waitstates(&ogc->cga);
+
+	if (ogc->cga.snow_enabled) {
+		/* recreate snow effect */
+		offset = ((timer_get_remaining_u64(&ogc->cga.timer) / CGACONST) * 4) & 0xfc;
+		ogc->cga.charbuffer[offset] = ogc->cga.vram[addr & 0x7fff];
+		ogc->cga.charbuffer[offset | 1] = ogc->cga.vram[addr & 0x7fff];
+	}
+	
+	egareads++;
+    return(ogc->cga.vram[addr & 0x7FFF]);
+}
+
+void
+ogc_poll(void *priv)
+{
+    ogc_t *ogc = (ogc_t *)priv;
+    uint16_t ca = (ogc->cga.crtc[15] | (ogc->cga.crtc[14] << 8)) & 0x3fff;
+    int drawcursor;
+    int x, c, xs_temp, ys_temp;
+    int oldvc;
+    uint8_t chr, attr;
+    uint16_t dat, dat2;
+    int cols[4];
+    int oldsc;
+	int blink = 0;
+	int underline = 0;
+	uint8_t border;
+    
+	//composito colore appare blu scuro
+
+	/* graphic mode and not mode 40h */
+	if (!(ogc->ctrl_3de & 0x1 || !(ogc->cga.cgamode & 2))) {
+		/* standard cga mode */
+		cga_poll(&ogc->cga);
+		return;
+	} else {
+		/* mode 40h or text mode */
+		if (!ogc->cga.linepos) {
+			timer_advance_u64(&ogc->cga.timer, ogc->cga.dispofftime);
+			ogc->cga.cgastat |= 1;
+			ogc->cga.linepos = 1;
+			oldsc = ogc->cga.sc;
+			if ((ogc->cga.crtc[8] & 3) == 3) 
+				ogc->cga.sc = ((ogc->cga.sc << 1) + ogc->cga.oddeven) & 7;
+			if (ogc->cga.cgadispon) {
+				if (ogc->cga.displine < ogc->cga.firstline) {
+					ogc->cga.firstline = ogc->cga.displine;
+					video_wait_for_buffer();
+				}
+				ogc->cga.lastline = ogc->cga.displine;
+				/* 80-col */
+				if (ogc->cga.cgamode & 1) {
+					/* for each text column */
+					for (x = 0; x < ogc->cga.crtc[1]; x++) {
+						/* video output enabled */
+						if (ogc->cga.cgamode & 8) {	
+							/* character */
+							chr = ogc->cga.charbuffer[x << 1];
+							/* text attributes */
+							attr = ogc->cga.charbuffer[(x << 1) + 1];
+						} else
+							chr = attr = 0;
+						/* check if cursor has to be drawn */
+						drawcursor = ((ogc->cga.ma == ca) && ogc->cga.con && ogc->cga.cursoron);
+						/* check if character underline mode should be set */
+						underline = ((ogc->ctrl_3de & 0x40) && (attr & 0x1) && !(attr & 0x6));
+						if (underline) {
+							/* set forecolor to white */
+							attr = attr | 0x7;
+						}
+						blink = 0;
+						/* set foreground */
+						cols[1] = (attr & 15) + 16;
+						/* blink active */
+						if (ogc->cga.cgamode & 0x20) {
+							cols[0] = ((attr >> 4) & 7) + 16;
+							/* attribute 7 active and not cursor */
+							if ((ogc->cga.cgablink & 8) && (attr & 0x80) && !ogc->cga.drawcursor) {
+								/* set blinking */
+								cols[1] = cols[0];
+								blink = 1;
+							}
+						} else {
+							/* Set intensity bit */
+							cols[0] = (attr >> 4) + 16;
+							blink = (attr & 0x80) * 8 + 7 + 16;
+						}
+						/* character underline active and 7th row of pixels in character height being drawn */
+						if (underline && (ogc->cga.sc == 7)) {
+							/* for each pixel in character width */
+							for (c = 0; c < 8; c++) 
+								buffer32->line[ogc->cga.displine][(x << 3) + c + 8] = mdaattr[attr][blink][1];
+						} else if (drawcursor) {
+							for (c = 0; c < 8; c++) 
+								buffer32->line[ogc->cga.displine][(x << 3) + c + 8] = cols[(fontdatm[chr][((ogc->cga.sc & 7) << 1) | ogc->lineff] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;
+						} else {
+							for (c = 0; c < 8; c++) 
+								buffer32->line[ogc->cga.displine][(x << 3) + c + 8] = cols[(fontdatm[chr][((ogc->cga.sc & 7) << 1) | ogc->lineff] & (1 << (c ^ 7))) ? 1 : 0];
+						}
+						
+						ogc->cga.ma++;
+					}
+				} 
+				/* 40-col */
+				else if (!(ogc->cga.cgamode & 2)) {
+					for (x = 0; x < ogc->cga.crtc[1]; x++) {
+						if (ogc->cga.cgamode & 8) {
+							chr  = ogc->cga.vram[((ogc->cga.ma << 1) & 0x3fff) + ogc->base];
+							attr = ogc->cga.vram[(((ogc->cga.ma << 1) + 1) & 0x3fff) + ogc->base];
+						} else {
+							chr = attr = 0;
+						}
+						drawcursor = ((ogc->cga.ma == ca) && ogc->cga.con && ogc->cga.cursoron);
+						/* check if character underline mode should be set */
+						underline = ((ogc->ctrl_3de & 0x40) && (attr & 0x1) && !(attr & 0x6));
+						if (underline) {
+							/* set forecolor to white */
+							attr = attr | 0x7;
+						}
+						blink = 0;
+						/* set foreground */
+						cols[1] = (attr & 15) + 16;
+						/* blink active */
+						if (ogc->cga.cgamode & 0x20) {
+							cols[0] = ((attr >> 4) & 7) + 16;
+							if ((ogc->cga.cgablink & 8) && (attr & 0x80) && !ogc->cga.drawcursor) {
+								/* set blinking */
+								cols[1] = cols[0];
+								blink = 1;
+							}
+						} else {
+							/* Set intensity bit */
+							cols[0] = (attr >> 4) + 16;
+							blink = (attr & 0x80) * 8 + 7 + 16;
+						}
+
+						
+						/* character underline active and 7th row of pixels in character height being drawn */
+						if (underline && (ogc->cga.sc == 7)) {
+							/* for each pixel in character width */
+							for (c = 0; c < 8; c++) 
+								buffer32->line[ogc->cga.displine][(x << 4) + (c << 1) + 8] = 
+								buffer32->line[ogc->cga.displine][(x << 4) + (c << 1) + 1 + 8] = mdaattr[attr][blink][1];
+						} else if (drawcursor) {
+							for (c = 0; c < 8; c++)
+								buffer32->line[ogc->cga.displine][(x << 4) + (c << 1) + 8] = 
+								buffer32->line[ogc->cga.displine][(x << 4) + (c << 1) + 1 + 8] = cols[(fontdatm[chr][((ogc->cga.sc & 7) << 1) | ogc->lineff] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;
+						} else {
+							for (c = 0; c < 8; c++)
+								buffer32->line[ogc->cga.displine][(x << 4) + (c << 1) + 8] = 
+								buffer32->line[ogc->cga.displine][(x << 4) + (c << 1) + 1 + 8] = cols[(fontdatm[chr][((ogc->cga.sc & 7) << 1) | ogc->lineff] & (1 << (c ^ 7))) ? 1 : 0];
+						}
+						
+						ogc->cga.ma++;
+						
+					}
+				} else {
+					/* 640x400 mode */
+					if (ogc->ctrl_3de & 1 ) {
+						dat2 = ((ogc->cga.sc & 1) * 0x4000) | (ogc->lineff * 0x2000);
+						cols[0] = 0; cols[1] = 15 + 16;
+					} 
+					else {
+						dat2 = (ogc->cga.sc & 1) * 0x2000;
+						cols[0] = 0; cols[1] = (ogc->cga.cgacol & 15) + 16;
+					}
+					
+					for (x = 0; x < ogc->cga.crtc[1]; x++) {
+						/* video out */
+						if (ogc->cga.cgamode & 8) {
+							dat = (ogc->cga.vram[((ogc->cga.ma << 1) & 0x1fff) + dat2] << 8) | ogc->cga.vram[((ogc->cga.ma << 1) & 0x1fff) + dat2 + 1];
+						} else {
+							dat = 0;
+						}
+						ogc->cga.ma++;
+						
+						for (c = 0; c < 16; c++) {
+							buffer32->line[ogc->cga.displine][(x << 4) + c + 8] = cols[dat >> 15];
+							dat <<= 1;
+						}
+					}
+				}
+			} else {
+				
+				/* ogc specific */
+				cols[0] = ((ogc->cga.cgamode & 0x12) == 0x12) ? 0 : (ogc->cga.cgacol & 15) + 16;
+				if (ogc->cga.cgamode & 1) {
+					hline(buffer32, 0, (ogc->cga.displine << 1), ((ogc->cga.crtc[1] << 3) + 16) << 2, cols[0]);
+					hline(buffer32, 0, (ogc->cga.displine << 1) + 1, ((ogc->cga.crtc[1] << 3) + 16) << 2, cols[0]);
+				} else {
+					hline(buffer32, 0, (ogc->cga.displine << 1), ((ogc->cga.crtc[1] << 4) + 16) << 2, cols[0]);
+					hline(buffer32, 0, (ogc->cga.displine << 1) + 1, ((ogc->cga.crtc[1] << 4) + 16) << 2, cols[0]);
+				}
+				
+			}
+
+			/* 80 columns */
+			if (ogc->cga.cgamode & 1)
+				x = (ogc->cga.crtc[1] << 3) + 16;
+			else
+				x = (ogc->cga.crtc[1] << 4) + 16;
+
+			if (ogc->cga.composite) {
+				if (ogc->cga.cgamode & 0x10)
+					border = 0x00;
+				else
+					border = ogc->cga.cgacol & 0x0f;
+
+				Composite_Process(ogc->cga.cgamode, border, x >> 2, buffer32->line[(ogc->cga.displine << 1)]);
+				Composite_Process(ogc->cga.cgamode, border, x >> 2, buffer32->line[(ogc->cga.displine << 1) + 1]);
+			}
+
+
+			ogc->cga.sc = oldsc;
+			if (ogc->cga.vc == ogc->cga.crtc[7] && !ogc->cga.sc)
+				ogc->cga.cgastat |= 8;
+			ogc->cga.displine++;
+			if (ogc->cga.displine >= 720) 
+				ogc->cga.displine = 0;
+		} else {
+			timer_advance_u64(&ogc->cga.timer, ogc->cga.dispontime);
+			if (ogc->cga.cgadispon) ogc->cga.cgastat &= ~1;
+			ogc->cga.linepos = 0;
+			/* ogc specific */
+			ogc->lineff ^= 1;
+			if (ogc->lineff) {
+				ogc->cga.ma = ogc->cga.maback;
+			} else {
+				if (ogc->cga.vsynctime) {
+					ogc->cga.vsynctime--;
+					if (!ogc->cga.vsynctime)
+					ogc->cga.cgastat &= ~8;
+				}
+				if (ogc->cga.sc == (ogc->cga.crtc[11] & 31) || ((ogc->cga.crtc[8] & 3) == 3 && ogc->cga.sc == ((ogc->cga.crtc[11] & 31) >> 1))) { 
+					ogc->cga.con = 0; 
+					ogc->cga.coff = 1; 
+				}
+				if ((ogc->cga.crtc[8] & 3) == 3 && ogc->cga.sc == (ogc->cga.crtc[9] >> 1))
+					ogc->cga.maback = ogc->cga.ma;
+				if (ogc->cga.vadj) {
+					ogc->cga.sc++;
+					ogc->cga.sc &= 31;
+					ogc->cga.ma = ogc->cga.maback;
+					ogc->cga.vadj--;
+					if (!ogc->cga.vadj) {
+						ogc->cga.cgadispon = 1;
+						ogc->cga.ma = ogc->cga.maback = (ogc->cga.crtc[13] | (ogc->cga.crtc[12] << 8)) & 0x3fff;
+						ogc->cga.sc = 0;
+					}
+				} else if (ogc->cga.sc == ogc->cga.crtc[9] || ((ogc->cga.crtc[8] & 3) == 3 && ogc->cga.sc == (ogc->cga.crtc[9] >> 1))) {
+					ogc->cga.maback = ogc->cga.ma;
+					ogc->cga.sc = 0;
+					oldvc = ogc->cga.vc;
+					ogc->cga.vc++;
+					ogc->cga.vc &= 127;
+
+					if (ogc->cga.vc == ogc->cga.crtc[6]) 
+						ogc->cga.cgadispon=0;
+
+					if (oldvc == ogc->cga.crtc[4]) {
+					ogc->cga.vc = 0;
+					ogc->cga.vadj = ogc->cga.crtc[5];
+						if (!ogc->cga.vadj) {
+							ogc->cga.cgadispon = 1;
+							ogc->cga.ma = ogc->cga.maback = (ogc->cga.crtc[13] | (ogc->cga.crtc[12] << 8)) & 0x3fff;
+						}
+						switch (ogc->cga.crtc[10] & 0x60) {
+							case 0x20:
+								ogc->cga.cursoron = 0;
+								break;
+							case 0x60:
+								ogc->cga.cursoron = ogc->cga.cgablink & 0x10;
+								break;
+							default:
+								ogc->cga.cursoron = ogc->cga.cgablink & 0x08;
+								break;
+						}
+					}
+					if (ogc->cga.vc == ogc->cga.crtc[7]) {
+						ogc->cga.cgadispon = 0;
+						ogc->cga.displine = 0;
+						/* ogc specific */
+						ogc->cga.vsynctime = (ogc->cga.crtc[3] >> 4) + 1;
+						if (ogc->cga.crtc[7]) {
+							if (ogc->cga.cgamode & 1)
+								x = (ogc->cga.crtc[1] << 3) + 16;
+							else
+								x = (ogc->cga.crtc[1] << 4) + 16;
+							ogc->cga.lastline++;
+
+							xs_temp = x;
+							ys_temp = (ogc->cga.lastline - ogc->cga.firstline);
+
+							if ((xs_temp > 0) && (ys_temp > 0)) {
+								if (xsize < 64) xs_temp = 656;
+								/* ogc specific */
+								if (ysize < 32) ys_temp = 200;
+								if (!enable_overscan)
+									xs_temp -= 16;
+
+								
+								if ((ogc->cga.cgamode & 8) && ((xs_temp != xsize) || (ys_temp != ysize) || video_force_resize_get())) {
+									xsize = xs_temp;
+									ysize = ys_temp;
+									set_screen_size(xsize, ysize + (enable_overscan ? 16 : 0));
+
+									if (video_force_resize_get())
+										video_force_resize_set(0);
+								}
+								/* ogc specific */
+								if (enable_overscan) {
+									if (ogc->cga.composite) 
+										video_blit_memtoscreen(0, (ogc->cga.firstline - 8), 0, (ogc->cga.lastline - ogc->cga.firstline) + 16,
+												xsize, (ogc->cga.lastline - ogc->cga.firstline) + 16);
+									else
+										video_blit_memtoscreen_8(0, (ogc->cga.firstline - 8), 0, (ogc->cga.lastline - ogc->cga.firstline) + 16,
+												xsize, (ogc->cga.lastline - ogc->cga.firstline) + 16);
+								} else {
+									if (ogc->cga.composite) 
+										video_blit_memtoscreen(8, ogc->cga.firstline, 0, (ogc->cga.lastline - ogc->cga.firstline),
+												xsize, (ogc->cga.lastline - ogc->cga.firstline));
+									else
+										video_blit_memtoscreen_8(8, ogc->cga.firstline, 0, (ogc->cga.lastline - ogc->cga.firstline),
+												xsize, (ogc->cga.lastline - ogc->cga.firstline));
+								}
+							}
+							frames++;
+
+							video_res_x = xsize;
+							video_res_y = ysize;
+							/* 80-col */
+							if (ogc->cga.cgamode & 1) {
+								video_res_x /= 8;
+								video_res_y /= (ogc->cga.crtc[9] + 1) * 2;
+								video_bpp = 0;
+							/* 40-col */
+							} else if (!(ogc->cga.cgamode & 2)) {
+								video_res_x /= 16;
+								video_res_y /= (ogc->cga.crtc[9] + 1) * 2;
+								video_bpp = 0;
+							} else if (!(ogc->ctrl_3de & 1)) {
+								video_res_y /= 2;
+								video_bpp = 1;
+							}
+						}
+						ogc->cga.firstline = 1000;
+						ogc->cga.lastline = 0;
+						ogc->cga.cgablink++;
+						ogc->cga.oddeven ^= 1;
+					}
+				} else {
+					ogc->cga.sc++;
+					ogc->cga.sc &= 31;
+					ogc->cga.ma = ogc->cga.maback;
+				}
+
+				if (ogc->cga.cgadispon)
+					ogc->cga.cgastat &= ~1;
+				
+				if ((ogc->cga.sc == (ogc->cga.crtc[10] & 31) || ((ogc->cga.crtc[8] & 3) == 3 && ogc->cga.sc == ((ogc->cga.crtc[10] & 31) >> 1)))) 
+					ogc->cga.con = 1;
+			}
+			/* 80-columns */
+			if (ogc->cga.cgadispon && (ogc->cga.cgamode & 1)) {
+				for (x = 0; x < (ogc->cga.crtc[1] << 1); x++)
+					ogc->cga.charbuffer[x] = ogc->cga.vram[(((ogc->cga.ma << 1) + x) & 0x3fff) + ogc->base];
+			}
+		}
+	}
+}
+
+void
+ogc_close(void *priv)
+{
+    ogc_t *ogc = (ogc_t *)priv;
+
+    free(ogc->cga.vram);
+    free(ogc);
+}
+
+void
+ogc_speed_changed(void *priv)
+{
+    ogc_t *ogc = (ogc_t *)priv;
+
+    ogc_recalctimings(ogc);
+}
+
+void
+ogc_mdaattr_rebuild(){
+	int c;
+    
+	for (c = 0; c < 256; c++) {
+		mdaattr[c][0][0] = mdaattr[c][1][0] = mdaattr[c][1][1] = 16;
+		if (c & 8)	mdaattr[c][0][1] = 15 + 16;
+		else		mdaattr[c][0][1] =  7 + 16;
+	}
+
+	mdaattr[0x70][0][1] = 16;
+	mdaattr[0x70][0][0] = mdaattr[0x70][1][0] = mdaattr[0x70][1][1] = 16 + 15;
+	mdaattr[0xF0][0][1] = 16;
+	mdaattr[0xF0][0][0] = mdaattr[0xF0][1][0] = mdaattr[0xF0][1][1] = 16 + 15;
+	mdaattr[0x78][0][1] = 16 + 7;
+	mdaattr[0x78][0][0] = mdaattr[0x78][1][0] = mdaattr[0x78][1][1] = 16 + 15;
+	mdaattr[0xF8][0][1] = 16 + 7;
+	mdaattr[0xF8][0][0] = mdaattr[0xF8][1][0] = mdaattr[0xF8][1][1] = 16 + 15;
+	mdaattr[0x00][0][1] = mdaattr[0x00][1][1] = 16;
+	mdaattr[0x08][0][1] = mdaattr[0x08][1][1] = 16;
+	mdaattr[0x80][0][1] = mdaattr[0x80][1][1] = 16;
+	mdaattr[0x88][0][1] = mdaattr[0x88][1][1] = 16;
+}
+
+/* 
+ * Missing features
+ * - Composite video mode not working
+ * - Optional EGC expansion board (which handles 640x400x16) not implemented
+ */
+void *
+ogc_init(const device_t *info)
+{
+    // int display_type;
+	ogc_t *ogc = (ogc_t *)malloc(sizeof(ogc_t));
+
+    memset(ogc, 0x00, sizeof(ogc_t));
+    video_inform(VIDEO_FLAG_TYPE_CGA, &timing_ogc);
+
+    loadfont(L"roms/video/ogc/ogc graphics board go380 258 pqbq.bin", 1);
+    
+	/* composite is not working yet */
+	// display_type = device_get_config_int("display_type");
+    ogc->cga.composite = 0; // (display_type != CGA_RGB);
+    ogc->cga.revision = device_get_config_int("composite_type");
+    ogc->cga.snow_enabled = device_get_config_int("snow_enabled");
+	
+	ogc->cga.vram = malloc(0x8000);
+
+	cga_comp_init(ogc->cga.revision);
+    timer_add(&ogc->cga.timer, ogc_poll, ogc, 1);
+    mem_mapping_add(&ogc->cga.mapping, 0xb8000, 0x08000,
+		    ogc_read, NULL, NULL,
+		    ogc_write, NULL, NULL,  NULL, 0, ogc);
+    io_sethandler(0x03d0, 16, ogc_in, NULL, NULL, ogc_out, NULL, NULL, ogc);
+    
+    overscan_x = overscan_y = 16;
+    ogc->cga.rgb_type = device_get_config_int("rgb_type");
+    cga_palette = (ogc->cga.rgb_type << 1);
+    cgapal_rebuild();
+	ogc_mdaattr_rebuild();
+	    
+	/* color display */
+	if (device_get_config_int("rgb_type")==0 || device_get_config_int("rgb_type") == 4) 
+		ogc->mono_display = 0;
+	else
+		ogc->mono_display = 1;    
+
+    return ogc;
+}
+
+
+const device_config_t ogc_m24_config[] =
+{
+        {
+                /* Olivetti / ATT compatible displays */
+				"rgb_type", "RGB type", CONFIG_SELECTION, "", CGA_RGB, "", { 0 },
+                {
+                        {
+                                "Color", 0
+                        },
+                        {
+                                "Green Monochrome", 1
+                        },
+                        {
+                                "Amber Monochrome", 2
+                        },
+                        {
+                                "Gray Monochrome", 3
+                        },
+                        {
+                                ""
+                        }
+                }
+        },
+        {
+                "snow_enabled", "Snow emulation", CONFIG_BINARY, "", 1,
+        },
+        {
+                "", "", -1
+        }
+};
+
+const device_t ogc_m24_device =
+{
+	"Olivetti M21/M24/M28 (GO317/318/380/709) video card",
+	DEVICE_ISA, 0,
+	ogc_init,
+	ogc_close,
+	NULL,
+	{ NULL },
+	ogc_speed_changed,
+	NULL,
+	ogc_m24_config
+};
+
+const device_t ogc_device =
+{
+	"Olivetti OGC (GO708)",
+	DEVICE_ISA, 0,
+	ogc_init,
+	ogc_close,
+	NULL,
+	{ NULL },
+	ogc_speed_changed,
+	NULL,
+	cga_config
+};
--- a/src/video/vid_table.c
+++ b/src/video/vid_table.c
@@ -177,6 +177,7 @@ video_cards[] = {
    { "virge375_vbe20_vlb",	&s3_virge_375_4_vlb_device		},
    { "tgui9400cxi_vlb",	&tgui9400cxi_device			},
    { "tgui9440_vlb",		&tgui9440_vlb_device			},
+    { "ogc",        		&ogc_device				},
    { "",			NULL                        		}
 };

--- a/src/video/video.c
+++ b/src/video/video.c
@@ -1038,7 +1038,21 @@ loadfont(wchar_t *s, int format)
 		for (c = 0; c < 256; c++)
 			fread(&fontdat12x18[c][0], 1, 36, f);
 		break;
-    }
+
+    case 10:		/* Olivetti M19 */
+		fseek(f, 90, SEEK_SET);
+		for (d = 0; d < 4; d++) {
+			/* There are 4 fonts in the ROM */
+			for (c = 0; c < 256; c++)	/* 8x14 MDA in 8x16 cell */
+				fread(&fontdatm[256*d + c][0], 1, 16, f);
+			for (c = 0; c < 256; c++) {	/* 8x8 CGA in 8x16 cell */
+				fread(&fontdat[256*d + c][0], 1, 8, f);
+				fseek(f, 8, SEEK_CUR);
+			}
+		}
+		break;
+
+	}

    (void)fclose(f);
 }