X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=hexed%2Fhexed.s;h=2152aa8e859e5e1cc1324b98abc336eb76fcd4f4;hb=ff17c043cedcaa32e6559677cb4670ac910d7255;hp=6ecbab2a122c6fc94221c4a5e910ced94b5a54dd;hpb=d4279640e3739ee58fade392f9c442cae0dfc71f;p=megadrive.git

diff --git a/hexed/hexed.s b/hexed/hexed.s
index 6ecbab2..2152aa8 100644
--- a/hexed/hexed.s
+++ b/hexed/hexed.s
@@ -1,9 +1,37 @@
-##################################################
-#                                                #
-# Assemble with gas                              #
-#   --register-prefix-optional --bitwise-or      #
-#                                                #
-##################################################
+###############################################################################
+#
+# Copyright (c) 2009, Gražvydas Ignotas
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in the
+#       documentation and/or other materials provided with the distribution.
+#     * Neither the name of the organization nor the
+#       names of its contributors may be used to endorse or promote products
+#       derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL <copyright holder> BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Assemble with gas
+#   --register-prefix-optional --bitwise-or
+#
+
+.equ USE_VINT,        0
+.equ COPY_TO_EXP,     1
+.equ RELOCATE_TO_RAM, 1
 
 .text
 .globl main
@@ -29,7 +57,7 @@
 .equ VDP1_E_DMA,	0x10
 .equ VDP1_NTSC,		0x00
 .equ VDP1_PAL,		0x08
-.equ VDP1_RESERVED,	0x04
+.equ VDP1_MODE5,	0x04
 
 .equ VDP12_STE,		0x08
 .equ VDP12_SCREEN_V224,	0x00
@@ -52,6 +80,8 @@
 .equ MMODE_GOTO,	3
 .equ MMODE_START_MENU,	4
 .equ MMODE_GOTO_PREDEF,	5
+.equ MMODE_JMP_ADDR,	6
+.equ MMODE_DUMP,	7
 
 .equ predef_addr_cnt,	((predef_addrs_end-predef_addrs)/4)
 
@@ -72,13 +102,13 @@
 	write_vdp_r_dst \reg, \val, (a3)
 .endm
 
-/* For immediate addresses */
-.macro VRAM_ADDR reg adr
-	move.l #(((0x4000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
+# Set up address in VDP, control port in dst
+.macro VRAM_ADDR adr dst
+	move.l #(0x40000000 | ((\adr & 0x3fff) << 16) | (\adr >> 14)),\dst
 .endm
 
-.macro CRAM_ADDR reg adr
-	move.l	#(((0xc000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
+.macro VSRAM_ADDR adr dst
+	move.l #(0x40000010 | ((\adr & 0x3fff) << 16) | (\adr >> 14)),\dst
 .endm
 
 
@@ -105,16 +135,6 @@
 .endm
 
 
-.macro VSCROLL_ADDR reg adr
-	move.l	#(((0x4000 + (\adr & 0x3fff)) << 16) + ((\adr >> 14) | 0x10)),\reg
-.endm
-
-
-.macro HSCROLL_ADDR reg adr
-	move.l #(((0x4000 + (\adr & 0x3fff)) << 16) + (\adr >> 14)),\reg
-.endm
-
-
 # convert tile coords in d0, d1 to nametable addr to a0
 .macro XY2NT
 	lsl.w		#6,d1
@@ -148,8 +168,9 @@
 	or.w		#(\mode_back<<11)|(\mode_new<<8),d7
 .endm
 
+#  destroys a0,d0-d2
 .macro menu_text str x y pal
-	lea		\str,a0
+	lea		(\str,pc),a0
 	move.l		#\x,d0
 	move.l		#\y,d1
 	move.l		#0x8000|(\pal<<13),d2
@@ -193,18 +214,35 @@ safe_addrs:
 	dc.l 0xa13000, 0xa130ff
 safe_addrs_end:
 
+transfer_mode:
+	dc.l 0x000000		/* 1 for recv */
+transfer_addr:
+	dc.l 0x000000
+transfer_len:
+	dc.l 0x000800
+
 txt_edit:
 	.ascii	"- edit -\0"
 txt_a_confirm:
 	.ascii	"A-confirm\0"
 txt_about:
-	.ascii	"hexed r1\0"
+	.ascii	"hexed r2\0"
 txt_goto:
 	.ascii	"Go to address\0"
 txt_goto_predef:
 	.ascii	"Go to (predef)\0"
+txt_jmp_addr:
+	.ascii	"Jump to address\0"
+txt_dump:
+	.ascii	"Transfer\0"
 txt_dtack:
 	.ascii	"DTACK safety\0"
+txt_ready_send:
+	.ascii	"Ready to send\0"
+txt_ready_recv:
+	.ascii	"Ready to recv\0"
+txt_working:
+	.ascii	"Working..    \0"
 txt_dtack_err:
 	.ascii	"DTACK err?\0"
 txt_exc:
@@ -230,22 +268,56 @@ main:
 	/* mask irqs during init */
 	move.w		#0x2700,sr
 
-.if 0
-	/* copy */
-	lea		(0,pc),a0
-	move.l		a0,d0
-	swap		d0
-	lsr.l		#4,d0
-	and.b		#0x0f,d0
-	cmp.b		#0,d0
+.if COPY_TO_EXP
+	/* copy to expansion device if magic number is set */
+	move.l		#0x400000,a1
+	cmp.w		#0x1234,(a1)
 	bne		0f
 
-	move.w		#8000/2,d0
 	move.l		#0,a0
-	move.l		#0x400000,a1
+	move.w		#0x2000/8-1,d0
+1:
+	move.l		(a0)+,(a1)+
+	move.l		(a0)+,(a1)+
+	dbra		d0,1b
+0:
+.endif
+
+.if RELOCATE_TO_RAM
+	/* we could be relocated by 32x or something else, adjust start addr */
+	lea		(pc),a0
+	move.l		a0,d0
+	and.l		#0xff0000,d0
+	move.l		d0,a0
+
+	/* copy, assume 8K size */
+	move.l		#0xFF0100,a1
+	move.w		#0x2000/8-1,d0
+1:
+	move.l		(a0)+,(a1)+
+	move.l		(a0)+,(a1)+
+	dbra		d0,1b
+
+	/* copy test code */
+	lea             (test_code,pc),a0
+	move.l		#0xffc000,a1
+	move.w		#(test_code_end - test_code)/2-1,d0
 1:
 	move.w		(a0)+,(a1)+
 	dbra		d0,1b
+
+	lea		(0f,pc),a0
+	move.l		a0,d0
+	and.l		#0x00ffff,d0
+	add.l		#0xFF0100,d0
+	move.l		d0,a0
+
+	/* patch test code */
+	move.l		#0xffc000,a1
+	add.w		#(test_code_ret_op-test_code+2),a1
+	move.l		a0,(a1)
+
+	jmp		(a0)
 0:
 .endif
 
@@ -260,17 +332,37 @@ main:
 	/* Initialize VDP */
 	jsr 		init_gfx
 
+	/* Clear h/v scroll */
+	movea.l		#GFXDATA,a0
+	VRAM_ADDR	0x8000,(GFXCNTL)
+	move.l		#0,(a0)
+	VSRAM_ADDR	0,(GFXCNTL)
+	move.l		#0,(a0)
+
 	/* Load color data */
 	movea.l		#0,a0
-	movea.l		#colors,a1
+	lea		(colors,pc),a1
 	moveq.l		#(colors_end-colors)/2,d0
 	jsr		load_colors
 
-	/* load patterns */
-	movea.l		#0,a0
-	movea.l		#font,a1
-	move.l		#128,d0
-	jsr		load_tiles
+	/* load font patterns */
+	movea.l		#GFXDATA,a0
+	lea		(font,pc),a1
+	VRAM_ADDR	0,(GFXCNTL)
+	move.w		#128*8,d3
+font_loop:
+	moveq.l		#8-1,d2
+	moveq.l		#0,d1
+	move.b		(a1)+,d0
+0:
+	lsr.b		#1,d0
+	roxl.l		#1,d1
+	ror.l		#5,d1
+	dbra		d2,0b
+
+	rol.l		#1,d1		/* fixup */
+	move.l		d1,(a0)
+	dbra		d3,font_loop
 
 	/* generate A layer map */
 	movea.l		#0xe000,a1
@@ -297,33 +389,41 @@ lmaploop0:
 	/* upload sprite data */
 	movea.l		#0xfc00,a0
 	jsr		load_prepare
-	movea.l		#sprite_data,a1
+	lea		(sprite_data,pc),a1
 
 	move.l		#(sprite_data_end-sprite_data)/2-1,d3
 0:	move.l		(a1)+,(a0)
 	dbra		d3,0b
 
+.if USE_VINT
 	/* wait for vsync before unmask */
-	move.l 		#GFXCNTL,a3
+	jsr		wait_vsync_poll
+
+	/* wait a bit to avoid nested vint */
+	move.w		#20,d0
 0:
-	move.w		(a3),d0
-	and.b		#8,d0
-	nop
-	nop
-	beq		0b
+	dbra		d0,0b		/* 10 cycles to go back */
 
-        move.w		#0x2000,sr
+	/* enable and unmask vint */
+	write_vdp_r_dst 1,(VDP1_E_VBI | VDP1_E_DISPLAY | VDP1_MODE5),(GFXCNTL)
+	move.w		#0x2000,sr
+.endif
 
 ##################################################
 
 forever:
+.if USE_VINT
 	jsr		wait_vsync
+.else
+	jsr		wait_vsync_poll
+	jsr		VBL
+.endif
 	bra 		forever
 
 
 INT:
 	/* let's hope VRAM is already set up.. */
-	lea		txt_exc,a0
+	lea		(txt_exc,pc),a0
 	move.l		#9,d0
 	move.l		#27,d1
 	move.l		#0xe000,d2
@@ -334,29 +434,29 @@ INT:
 
 VBL:
 	addq.b		#1,d7
-	movem.l		d0-d4/a0-a5,-(a7)
+#	movem.l		d0-d4/a0-a5,-(a7)
 
 	moveq.l		#0,d0
 	move.w		d7,d0
 	lsr.w		#6,d0
 	and.w		#0x1c,d0
-	move.l		(jumptab,pc,d0),a0
+	lea		(jumptab,pc,d0),a0
 	jmp		(a0)
 jumptab:
-	dc.l		mode_main
-	dc.l		mode_val_input
-	dc.l		mode_edit_val	/* edit val in editor */
-	dc.l		mode_goto
-	dc.l		mode_start_menu
-	dc.l		mode_goto_predef
-	dc.l		mode_main
-	dc.l		mode_main
+	bra		mode_main
+	bra		mode_val_input
+	bra		mode_edit_val	/* edit val in editor */
+	bra		mode_goto
+	bra		mode_start_menu
+	bra		mode_goto_predef
+	bra		mode_jmp_addr
+	bra		mode_transfer
 
 ##################### main #######################
 
 mode_main:
 	/* assume we will hang */
-	lea		txt_dtack_err,a0
+	lea		(txt_dtack_err,pc),a0
 	move.l		#9,d0
 	move.l		#27,d1
 	move.l		#0xe000,d2
@@ -660,8 +760,12 @@ input_noc:
 
 input_nos:
 vbl_end:
-	movem.l		(a7)+,d0-d4/a0-a5
+#	movem.l		(a7)+,d0-d4/a0-a5
+.if USE_VINT
 	rte
+.else
+	rts
+.endif
 
 
 draw_cursor_unsafe_byte:
@@ -678,7 +782,7 @@ draw_cursor_unsafe_byte:
 	move.l		a2,a0
 	add.w		#31*2,a0
 	jsr		load_prepare	/* restore a0 */
-	jmp		draw_chars_hsafe_pre
+	bra		draw_chars_hsafe_pre
 
 draw_cursor_unsafe_word:
 	move.l		a6,d0
@@ -699,7 +803,7 @@ draw_cursor_unsafe_word:
 	move.l		a2,a0
 	add.w		#29*2,a0
 	jsr		load_prepare	/* restore a0 */
-	jmp		draw_chars_hsafe_pre
+	bra		draw_chars_hsafe_pre
 
 
 draw_cursor_byte:
@@ -720,7 +824,7 @@ draw_cursor_byte:
 	add.w		#31*2,a0
 	jsr		load_prepare	/* restore a0 */
 
-	jmp		draw_chars_pre
+	bra		draw_chars_pre
 
 draw_cursor_word:
 	move.l		a6,d0
@@ -742,7 +846,7 @@ draw_cursor_word:
 	add.w		#29*2,a0
 	jsr		load_prepare	/* restore a0 */
 
-	jmp		draw_chars_pre
+	bra		draw_chars_pre
 
 
 #################### hedit #######################
@@ -768,7 +872,7 @@ mode_edit_val:
 1:
 
 	change_mode	MMODE_VAL_INPUT, MMODE_EDIT_VAL
-	jmp		vbl_end
+	bra		vbl_end
 
 mode_hedit_finish:
 	/* write the val */
@@ -800,7 +904,7 @@ mode_goto:
 	or.b		#3,d5		/* 3 bytes */
 	bclr.l		#7,d6
 	change_mode	MMODE_VAL_INPUT, MMODE_GOTO
-	jmp		vbl_end
+	bra		vbl_end
 
 mode_goto_finish:
 	lsr.l		#8,d5
@@ -837,13 +941,13 @@ mode_val_input:
 	dbra		d1,0b
 
 	/* text */
-	lea		txt_edit,a0
+	lea		(txt_edit,pc),a0
 	move.l		#15,d0
 	move.l		#11,d1
 	move.l		#0xc000,d2
 	jsr		print
 
-	lea		txt_a_confirm,a0
+	lea		(txt_a_confirm,pc),a0
 	move.l		#15,d0
 	move.l		#15,d1
 	move.l		#0xc000,d2
@@ -929,7 +1033,7 @@ mode_val_input:
 	eor.l		#0xffffffff,d3
 	and.l		d3,d5
 	or.l		d1,d5
-	jmp		vbl_end
+	bra		vbl_end
 
 ai_no_ud:
 	btst.l		#10,d0
@@ -950,7 +1054,7 @@ ai_no_ud:
 	and.b		#0xe3,d5
 	lsl.b		#2,d2
 	or.b		d2,d5
-	jmp		vbl_end
+	bra		vbl_end
 
 ai_no_dpad:
 	move.w		d0,d1
@@ -970,7 +1074,7 @@ ai_no_sb:
 	or.w		d1,d7
 
 ai_no_input:
-	jmp		vbl_end
+	bra		vbl_end
 
 
 ################### start menu ###################
@@ -983,11 +1087,13 @@ mode_start_menu:
 	menu_text	txt_about,       13,  9, 1
 	menu_text	txt_goto,        13, 11, 0
 	menu_text	txt_goto_predef, 13, 12, 0
-	menu_text	txt_dtack,       13, 13, 0
-	menu_text	txt_a_confirm,   13, 15, 2
+	menu_text	txt_jmp_addr,    13, 13, 0
+	menu_text	txt_dump,        13, 14, 0
+	menu_text	txt_dtack,       13, 15, 0
+	menu_text	txt_a_confirm,   13, 17, 2
 
 	/* dtack safety on/off */
-	movea.l		#0xe000+26*2+13*64*2,a0
+	movea.l		#0xe000+26*2+15*64*2,a0
 	jsr		load_prepare
 	move.w		#0x8000|'O',(a0)
 	btst.l		#4,d6
@@ -1003,7 +1109,7 @@ mode_start_menu:
 	movea.l		#0xe000+11*2+11*64*2,a0
 	moveq.l		#0,d0
 	move.b		d5,d0
-	and.b		#3,d0
+	and.b		#7,d0
 	lsl.w		#7,d0
 	add.w		d0,a0
 	jsr		load_prepare
@@ -1016,44 +1122,56 @@ mode_start_menu:
 	and.w		#3,d1
 	beq		msm_no_ud
 	move.b		d5,d1
-	and.b		#3,d1
+	and.b		#7,d1
 	btst.l		#0,d0
 	sne		d2
 	or.b		#1,d2		/* up -1, down 1 */
 	add.b		d2,d1
 	cmp.b		#0,d1
 	bge		0f
-	move.b		#2,d1
+	move.b		#4,d1
 0:
-	cmp.b		#2,d1
+	cmp.b		#4,d1
 	ble		0f
 	move.b		#0,d1
 0:
-	and.b		#0xfc,d5
+	and.b		#0xf8,d5
 	or.b		d1,d5
-	jmp		vbl_end
+	bra		vbl_end
 
 msm_no_ud:
 	btst.l		#4,d0		/* A - confirm */
 	beq		msm_no_a
 	move.b		d5,d1
-	and.b		#3,d1
+	and.b		#7,d1
 	bne		0f
 	change_mode	MMODE_GOTO, MMODE_MAIN
 	bsr		start_menu_box
-	jmp		vbl_end
+	bra		vbl_end
 0:
 	cmp.b		#1,d1
 	bne		0f
 	moveq.l		#0,d5
 	change_mode	MMODE_GOTO_PREDEF, MMODE_MAIN
 	bsr		start_menu_box
-	jmp		vbl_end
+	bra		vbl_end
 0:
 	cmp.b		#2,d1
 	bne		0f
+	change_mode	MMODE_JMP_ADDR, MMODE_MAIN
+	bsr		start_menu_box
+	bra		vbl_end
+0:
+	cmp.b		#3,d1
+	bne		0f
+	change_mode	MMODE_DUMP, MMODE_MAIN
+	bsr		start_menu_box
+	bra		vbl_end
+0:
+	cmp.b		#4,d1
+	bne		0f
 	bchg.l		#4,d6
-	jmp		vbl_end
+	bra		vbl_end
 0:
 
 msm_no_a:
@@ -1063,11 +1181,11 @@ msm_no_a:
 	bra		return_to_main
 
 msm_no_bc:
-	jmp		vbl_end
+	bra		vbl_end
 
 start_menu_box:
 	movea.l		#0xe000+10*2+8*64*2,a1
-	move.w		#9-1,d1
+	move.w		#11-1,d1
 0:
 	move.w		a1,a0
 	jsr		load_prepare
@@ -1099,7 +1217,7 @@ mode_goto_predef:
 
 	/* draw addresses */
 	movea.l		#0xe000+17*2+9*64*2,a1
-	lea		predef_addrs,a2
+	lea		(predef_addrs,pc),a2
 	move.w		#predef_addr_cnt-1,d4
 	move.l		#0x8006,d3
 mgp_da_loop:
@@ -1137,7 +1255,7 @@ mgp_da_loop:
 	ble		0f
 	move.b		#0,d5
 0:
-	jmp		vbl_end
+	bra		vbl_end
 
 mgp_no_ud:
 	btst.l		#4,d0		/* A - confirm */
@@ -1145,10 +1263,10 @@ mgp_no_ud:
 	moveq.l		#0,d0
 	move.b		d5,d0
 	lsl.w		#2,d0
-	lea		predef_addrs,a0
+	lea		(predef_addrs,pc),a0
 	move.l		(a0,d0),d5
 	lsl.l		#8,d5
-	jmp		mode_goto_finish
+	bra		mode_goto_finish
 
 mgp_no_a:
 	move.w		d0,d1
@@ -1157,7 +1275,118 @@ mgp_no_a:
 	bra		return_to_main
 
 mgp_no_bc:
-	jmp		vbl_end
+	bra		vbl_end
+
+##################### jmp ########################
+
+mode_jmp_addr:
+	btst.l		#7,d6
+	bne		mode_jmp_finish
+
+	moveq.l		#0,d5
+	or.b		#3,d5		/* 3 bytes */
+	bclr.l		#7,d6
+	change_mode	MMODE_VAL_INPUT, MMODE_JMP_ADDR
+	bra		vbl_end
+
+mode_jmp_finish:
+	lsr.l		#8,d5
+	write_vdp_r_dst	1,(VDP1_E_DISPLAY | VDP1_MODE5),(GFXCNTL)	/* disable vint */
+	move.l		d5,a0
+	jmp		(a0)
+
+################### transfer #####################
+
+mode_transfer:
+	move.b		#0x40,(0xa1000b).l
+	move.b		#0x40,(0xa10005).l
+
+	move.l		(transfer_mode,pc),d0
+	tst.l		d0
+	bne		0f
+	lea		(txt_ready_send,pc),a0
+	bra		1f
+0:
+	lea		(txt_ready_recv,pc),a0
+1:
+	move.l		#13,d0
+	move.l		#13,d1
+	move.l		#0x8000,d2
+	jsr		print
+
+wait_tl_low0:
+	move.b		(0xa10005),d0
+	btst.b		#4,d0
+	bne		wait_tl_low0
+
+	menu_text	txt_working, 13, 13, 0
+
+	lea		0xa10005,a1
+	move.l		(transfer_addr,pc),a0
+	move.l		(transfer_len,pc),d2
+
+	move.l		(transfer_mode,pc),d0
+	tst.l		d0
+	bne		transfer_recv
+
+transfer_send:
+	move.b		#0x4f,(0xa1000b).l
+
+tr_send_loop:
+	move.b		(a0),d1
+	and.b		#0x0f,d1
+
+wait_tl_low1:
+	move.b		(a1),d0
+	btst.b		#4,d0
+	bne		wait_tl_low1
+
+	move.b		d1,(a1)		/* clears TH and writes data */
+
+	move.b		(a0)+,d1
+	lsr.b		#4,d1
+	bset.b		#6,d1		/* prepare TH */
+
+wait_tl_hi1:
+	move.b		(a1),d0
+	btst.b		#4,d0
+	beq		wait_tl_hi1
+
+	move.b		d1,(a1)
+	subq.l		#1,d2
+	bne		tr_send_loop
+
+	move.b		#0,(0xa1000b).l
+	bra		return_to_main
+
+transfer_recv:
+	move.b		#0,(a1)		/* clear TH */
+
+tr_recv_loop:
+wait_tl_low2:
+	move.b		(a1),d0
+	btst.b		#4,d0
+	bne		wait_tl_low2
+
+	move.b		#0x40,(a1)	/* set TH */
+	move.b		d0,d1
+	and.b		#0x0f,d1
+
+wait_tl_hi2:
+	move.b		(a1),d0
+	btst.b		#4,d0
+	beq		wait_tl_hi2
+
+	move.b		#0,(a1)		/* clear TH */
+	lsl.b		#4,d0
+	or.b		d0,d1
+	move.b		d1,(a0)+
+
+	subq.l		#1,d2
+	bne		tr_recv_loop
+
+	move.b		#0,(0xa1000b).l
+	bra		return_to_main
 
 
 # go back to main mode
@@ -1165,7 +1394,7 @@ return_to_main:
 	bclr.l		#7,d6		/* not edited */
 	change_mode	MMODE_MAIN, MMODE_MAIN
 	write_vdp_r_dst	12,(VDP12_SCREEN_V224 | VDP12_SCREEN_H320),(GFXCNTL)
-	jmp		vbl_end
+	bra		vbl_end
 
 
 #################################################
@@ -1177,21 +1406,22 @@ return_to_main:
 init_gfx:
 	move.l 		#GFXCNTL,a3
 	write_vdp_reg 	0,(VDP0_E_DISPLAY | VDP0_PLTT_FULL)
-	write_vdp_reg 	1,(VDP1_E_VBI | VDP1_E_DISPLAY | VDP1_E_DMA | VDP1_RESERVED)
+	write_vdp_reg 	1,(VDP1_E_DISPLAY | VDP1_MODE5)
 	write_vdp_reg 	2,(0xe000 >> 10)	/* Screen map a adress */
 	write_vdp_reg 	3,(0xe000 >> 10)	/* Window address */
 	write_vdp_reg 	4,(0xc000 >> 13)	/* Screen map b address */
 	write_vdp_reg 	5,(0xfc00 >>  9)	/* Sprite address */
 	write_vdp_reg 	6,0	
 	write_vdp_reg	7,0			/* Backdrop color */
-	write_vdp_reg	10,1			/* Lines per hblank interrupt */
-	write_vdp_reg	11,0			/* 2-cell vertical scrolling */
-	write_vdp_reg	12,(VDP12_SCREEN_V224 | VDP12_SCREEN_H320)
-	write_vdp_reg	13,(0x8000 >> 10)	/* Horizontal scroll address */
-	write_vdp_reg	15,2
-	write_vdp_reg	16,(VDP16_MAP_V32 | VDP16_MAP_H64)	/* layer size */
-	write_vdp_reg	17,0
-	write_vdp_reg	18,0xff
+	write_vdp_reg	0x0a,1			/* Lines per hblank interrupt */
+	write_vdp_reg	0x0b,0			/* 2-cell vertical scrolling */
+	write_vdp_reg	0x0c,(VDP12_SCREEN_V224 | VDP12_SCREEN_H320)
+	write_vdp_reg	0x0d,(0x8000 >> 10)	/* Horizontal scroll address */
+	write_vdp_reg	0x0e,0
+	write_vdp_reg	0x0f,2
+	write_vdp_reg	0x10,(VDP16_MAP_V32 | VDP16_MAP_H64)	/* layer size */
+	write_vdp_reg	0x11,0
+	write_vdp_reg	0x12,0
 	rts
 
 
@@ -1202,7 +1432,7 @@ get_safety_mask:
 	move.l		a1,d1
 	lsl.l		#8,d1
 	lsr.l		#8,d1
-	lea		safe_addrs,a1
+	lea		(safe_addrs,pc),a1
 	move.w		#(safe_addrs_end - safe_addrs)/8-1,d2
 0:
 	move.l		(a1)+,d0
@@ -1297,27 +1527,6 @@ get_input:
 	move.w		d1,d0
 	rts
 
-# Load tile data from ROM
-#  a0: VRAM base
-#  a1: pattern address
-#  d0: number of tiles to load
-#  destroys d1
-
-load_tiles:
-	move.l		d0,d1
-	VRAM_ADDR_var 	a0
-	move.l 		d0,(GFXCNTL).l
-	
-	move.l 		#GFXDATA,a0
-	lsl.w		#3,d1
-	subq.l 		#1,d1
-0:
-	move.l 		(a1)+,(a0)
-	dbra 		d1,0b
-
-	rts
-
-
 # Prepare to write to VDP RAM @a0
 # sets a0 to VDP data port for convenience
 #  a0: VRAM base
@@ -1369,7 +1578,7 @@ _print_loop:
 	beq		_print_end
 
 	move.w		d0,(a0)
-	jmp		_print_loop
+	bra		_print_loop
 
 _print_end:
 	rts
@@ -1412,11 +1621,7 @@ _print_hex_loop:
 	rts
 
 
-#################################################
-#                                               #
-#       Wait for next VBlank interrupt          #
-#                                               #
-#################################################
+# wait vertical sync interrupt
 
 wait_vsync:
 	move.b		d7,d0
@@ -1427,6 +1632,42 @@ _wait_change:
 	rts
 
 
+# wait vsync start (polling)
+#  destroys a0,d0
+
+wait_vsync_poll:
+	move.l 		#GFXCNTL,a0
+0:
+	move.w		(a0),d0
+	and.b		#8,d0
+	nop
+	nop
+	bne		0b
+0:
+	move.w		(a0),d0
+	and.b		#8,d0
+	nop
+	nop
+	beq		0b
+	rts
+
+
+test_code:
+	move.w		#3, (0xa15100)  /* adapter enable, reset off */
+	nop
+	nop
+	move.w		#1, (0xa15180)  /* mode 1 */
+	movea.l		#0xa15200, a0
+	move.l		#256-1, d0
+0:
+	move.w		#0,(a0)+
+	dbra		d0,0b
+	move.w		#0x83e0, (0xa15200) /* color 0 */
+
+test_code_ret_op:
+	jmp	0x123456        /* will be patched */
+test_code_end:
+
 #################################################
 #                                               #
 #                 RAM DATA                      #