From b9dbe823c982d5dcdbee8fbc3b0fb2056057160c Mon Sep 17 00:00:00 2001 From: "R. Belmont" Date: Thu, 4 Sep 2014 02:37:23 +0000 Subject: [PATCH] (MESS) pc_vga: correct access to attribute register when PAS bit is set, allows XFree86 to detect ISA VGA. [Peter Ferrie] --- src/emu/video/pc_vga.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/src/emu/video/pc_vga.c b/src/emu/video/pc_vga.c index 062df99af88..7fa0a5b33f6 100644 --- a/src/emu/video/pc_vga.c +++ b/src/emu/video/pc_vga.c @@ -1677,8 +1677,9 @@ READ8_MEMBER(vga_device::port_03c0_r) data = vga.attribute.index; break; case 1: - if(vga.attribute.index&0x20) - data = vga.attribute.index; // TODO: open bus + if((vga.attribute.index&0x20) + && ((vga.attribute.index&0x1f)<0x10)) + data = 0; // palette access is disabled in this mode else if ((vga.attribute.index&0x1f)