The HUD code in Sonic 1 has it where it's part of the normal object system whereas in Sonic 2, 3 and Knuckles, it's manually written into the priority table and gets called from the sprite rendering routine. To port this over to Sonic 1 (Hivebrain), the old HUD code needs to be removed and to do that, go to Obj21 and you should see something like this: Code: Obj21: ; XREF: Obj_Index moveq #0,d0 move.b $24(a0),d0 move.w Obj21_Index(pc,d0.w),d1 jmp Obj21_Index(pc,d1.w) ; =========================================================================== Obj21_Index: dc.w Obj21_Main-Obj21_Index dc.w Obj21_Flash-Obj21_Index ; =========================================================================== Obj21_Main: ; XREF: Obj21_Main addq.b #2,$24(a0) move.w #$90,8(a0) move.w #$108,$A(a0) move.l #Map_obj21,4(a0) move.w #$6CA,2(a0) move.b #0,1(a0) move.b #0,$18(a0) Obj21_Flash: ; XREF: Obj21_Main tst.w ($FFFFFE20).w ; do you have any rings? beq.s Obj21_Flash2 ; if not, branch clr.b $1A(a0) ; make all counters yellow jmp DisplaySprite ; =========================================================================== Obj21_Flash2: moveq #0,d0 btst #3,($FFFFFE05).w bne.s Obj21_Display addq.w #1,d0 ; make ring counter flash red cmpi.b #9,($FFFFFE23).w ; have 9 minutes elapsed? bne.s Obj21_Display ; if not, branch addq.w #2,d0 ; make time counter flash red Obj21_Display: move.b d0,$1A(a0) jmp DisplaySprite ; =========================================================================== change it to look like this: Code: Obj21: ; XREF: Obj_Index rts ; =========================================================================== You won't need the old HUD code anymore because it's handled by this new routine which I will post below. Now for the new HUD code, add this below the rts in the block of code posted above: Code: ; --------------------------------------------------------------------------- ; HUD Object code - SCORE, TIME, RINGS ; --------------------------------------------------------------------------- loc_40804: tst.w ($FFFFFE20).w beq.s loc_40820 moveq #0,d1 btst #3,($FFFFFE05).w bne.s BranchTo_loc_40836 cmpi.b #9,($FFFFFE23).w bne.s BranchTo_loc_40836 addq.w #2,d1 BranchTo_loc_40836 bra.s loc_40836 ; =========================================================================== loc_40820: moveq #0,d1 btst #3,($FFFFFE05).w bne.s loc_40836 addq.w #1,d1 cmpi.b #9,($FFFFFE23).w bne.s loc_40836 addq.w #2,d1 loc_40836: move.w #$90,d3 move.w #$108,d2 lea (Map_Obj21).l,a1 movea.w #$6CA,a3 add.w d1,d1 adda.w (a1,d1.w),a1 moveq #0,d1 move.b (a1)+,d1 subq.b #1,d1 bmi.s return_40858 jsr sub_D762 return_40858: rts ; End of function h This is the HUD code from S2 slightly modified to work with Sonic 1's mapping system. For the rest of the code, go to BuildSprites and change this part: Code: BuildSprites: ; XREF: TitleScreen; et al lea ($FFFFF800).w,a2 ; set address for sprite table moveq #0,d5 lea ($FFFFAC00).w,a4 moveq #7,d7 to this: Code: BuildSprites: ; XREF: TitleScreen; et al lea ($FFFFF800).w,a2 ; set address for sprite table moveq #0,d5 moveq #0,d4 tst.b ($FFFFFFD0).w ; this was level_started_flag beq.s BuildSprites_2 jsr loc_40804 BuildSprites_2: lea ($FFFFAC00).w,a4 moveq #7,d7 For the level_started_flag you can use any unused RAM address for it. I used $FFFFFFD0 for this guide. Go to SegaScreen and then scroll down until you see this line: Code: move.w #0,($FFFFF660).w add this below it: Code: move.b #0,($FFFFFFD0).w Go to Title_ClrPallet and you should see this line somewhere below it: Code: move.b #$8A,($FFFFD080).w ; load "SONIC TEAM PRESENTS" object add this below it: Code: move.b #0,($FFFFFFD0).w Go to Level and you should see this somewhere below it: Code: bset #7,($FFFFF600).w ; add $80 to screen mode (for pre level sequence) add this below it: Code: move.b #0,($FFFFFFD0).w Further down at loc_3946 you should see this somewhere below the label: Code: move.b #$21,($FFFFD040).w ; load HUD object replace that with this: Code: move.b #1,($FFFFFFD0).w Go to SS_ClrNemRam and find this line below it: Code: move.b #9,($FFFFD000).w ; load special stage Sonic object add this below it: Code: move.b #0,($FFFFFFD0).w Go to End_LoadSonic and find this line below it: Code: move.b #$21,($FFFFD040).w ; load HUD object replace it with this: Code: move.b #1,($FFFFFFD0).w Then go to Cred_ClrPallet and find this line below it: Code: move.b #$8A,($FFFFD080).w ; load credits object and add this below it: Code: move.b #0,($FFFFFFD0).w And for the last step (thanks Iso) go to Cont_ClrObjRam and find this line: Code: move.b #4,($FFFFD0E4).w then add this below it: Code: move.b #0,($FFFFFFD0).w You're now done and should have a near perfect port of S2's HUD code to Sonic 1. It also fixes the bug where "Time" does not flash if you have 9 minutes on the timer and have rings. The source code with all steps applied is provided below.
Seems you forgot a step! The fix is easy enough, simply go to Cont_ClrObjRam:, and under Code: move.b #4,($FFFFD0E4).w Clear the HUD draw flag Code: move.b #0,($FFFFFFD0).w
