video/pc_vga_s3: fix start address shift in extended video mode, fix …

…heavy przonegd flicker and SDD scroll tests
mamedev · Mar 5, 2024 · 38b78c0 · 38b78c0
1 parent 84f5fb0
commit 38b78c0
Show file tree

Hide file tree

Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/src/devices/video/pc_vga_s3.cpp b/src/devices/video/pc_vga_s3.cpp
@@ -45,9 +45,13 @@ void s3vision864_vga_device::device_add_mconfig(machine_config &config)
 
 TIMER_CALLBACK_MEMBER(s3vision864_vga_device::vblank_timer_cb)
 {
-	// not sure if this is correct, but XF86_S3 seems to expect the viewport scrolling to be faster
 	if(s3.memory_config & 0x08)
-		vga.crtc.start_addr = vga.crtc.start_addr_latch << 2;
+	{
+		// - SDD scrolling test expects a << 2 for 8bpp and no shift for anything else
+		// - Slackware 3.x XF86_S3 expect a << 2 shift (to be confirmed)
+		// - przonegd expect no shift (RGB16)
+		vga.crtc.start_addr = vga.crtc.start_addr_latch << (svga.rgb8_en ? 2 : 0);
+	}
 	else
 		vga.crtc.start_addr = vga.crtc.start_addr_latch;
 	vga.attribute.pel_shift = vga.attribute.pel_shift_latch;

diff --git a/src/mame/pc/przone.cpp b/src/mame/pc/przone.cpp
@@ -7,8 +7,12 @@ Prize Zone (c) 199? Lazer-Tron
 TODO:
 - identify proper motherboard/BIOS;
 - hookup vibra16 ISA card in place of sblaster_16;
-- Trackball in place of PS/2 mouse;
 - Printer error B0 keeps popping in attract/game select (disable in service mode as workaround);
+- Trackball in place of PS/2 mouse (may run thru a COM? autoexec.bat logs hint that the driver is
+loaded at CD time);
+- CD-ROM reading test is too fast (739% of what is reported as 8X);
+- Tri-Scraper / Super Solitaire / Super 11's: timer doesn't count down (goes only up),
+  it does with mouse click, likely bug for wrong input device?
 
 ===================================================================================================