Mercurial > repos > blastem

diff runtime.S @ 137:0e7e1ccc0a81

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Implemented HV counter
author Mike Pavone <pavone@retrodev.com>
date Sun, 30 Dec 2012 22:39:41 -0800
parents 0a0743a30ca1
children aa3e1bb338c9
line wrap: on
line diff
--- a/runtime.S	Sun Dec 30 18:40:33 2012 -0800
+++ b/runtime.S	Sun Dec 30 22:39:41 2012 -0800
@@ -369,6 +369,8 @@
 	jbe cart_b
 	cmp $0xE00000, %ecx
 	jae workram_b
+	cmp $0xC00000, %ecx
+	jae vdp_psg_b
 	cmp $0xA10000, %ecx
 	jb not_io_b
 	cmp $0xA12000, %ecx
@@ -378,6 +380,17 @@
 	xor %cl, %cl
 	dec %cl
 	ret
+vdp_psg_b:
+	test $0x2700E0, %ecx
+	jnz crash
+	and $0x1F, %ecx
+	bt $0, %ecx
+	jnc vdp_swap
+	jmp do_vdp_port_read
+vdp_swap:
+	call do_vdp_port_read
+	shr $8, %cx
+	ret
 workram_b:
 	/* deal with byte swapping */
 	xor $1, %ecx