<![CDATA[ChipMusic.org - Gameboy Camera - Force Trippy H]]> 2016-06-23T22:27:09Z PunBB https://chipmusic.org/forums/topic/17587/gameboy-camera-force-trippy-h/ <![CDATA[Re: Gameboy Camera - Force Trippy H]]> Sorry guys! Super busy. Here is what I have on my work PC

Known Routines:

$097D - "Delay_1" This is a delay routine, value passed via BC
$03AD - "LCD_Turn_Off" No variables passed
$0462 - "Zero_RAM"    Start location passed in HL, number of bytes to zero in BC
$03E2 - "DMA_Routine_2_HRAM" , No Variables, moves a 10 byte program into HRAM, the DMA routine.
$092A - "Init_OAM_Buffer"    ;Sets the OAM buffer ($D400) to 0xF0
$0914 - "Clear_Tile_Map0"    ;sets $9800-9BFF to $FF
$091F - "Clear_Tile_Map1"     ;sets $9C00-9FFF to $FF
$2B25 - "Init_Snd"        ;Turns sound registers on, volume, channels, clears DD00-DF00
$1DEC -
$1DE0 - "Delay_2" , No variables Passed.

Known Memory Locations:
$FF9B - Current Memory Bank selected
$D400 - D49F - DMA Start address (Buffer?)
$DD00-DF00 - Suspected Sound buffers?




$0101: Jp Main

Main:
    Ld sp, $FFFE         ;Initialise Stack
    Di            ;disable interrupts
    Xor a            ;clear a
    Ldh [$FF0F], a    ;Dissable all IRQ’s
    Ldh a,[$FF40]        ;Get LCDC
    Bit 7,a            ;Test bit 7 – Display Enabled?
    Jr zn, LCD_Enabled    ;Conditional Jump ()
    Set 7,a            ;set bit 7
    Ldh [$FF40],a        ;Store LCDC

LCD_Enabled:
    Ld bc, $0002        ;pass $0002 to Function $097D
    Call Delay_1         ;Jazz, Please watch this in the emulator to find the delay length?
                ;Best guess is the delay is necessary to initialise the cart MCU

VblankWait:
    Ldh a,[FF44]        ;Waiting for a V-Blank…
    Cp a,$91
    Jr c,VblankWait

    Ld a,$80
    Ldh [$FF40],a ;Enable LCD – Did I make a mistake with the above routines? Jazz?
    Xor a         ;Clear A
    Ldh [$FF47],a     ;Clear Pallete Data
    Ldh [$FF48],a     ;Clear Pallete Data
    Ldh [$FF49],a     ;Clear Pallete Data

    Ld bc, $0002        ;pass $0002 to Function $097D
    Call Delay_1         ;Jazz, Please watch this in the emulator to find the delay length?
       
    Call  Turn_LCD_Off   

    ld hl,$C000        ;Load HL with Work RAM location
    ld BC,$1FFF        ;Load BC with 1FFF
    Call Zero_RAM        ;Zero BC number of bytes, from location HL

   

    ld   a,$00        ;Why do they zero A this way, and not XOR A like other routines???
    ld   [$0000],a        ;Disable Cartridge Save RAM
    ld   a,$01        ;
    ld   [$2000],a        ;Set ROM bank 1
    ld   a,$00       
    ld   [$4000],a        ;Set Ram bank 0
    ld   a,$01
    ldh  [$FF9B],a        ;Store 1 into FF9B - Perhaps a buffer to keep track of bank numbers?
    ld   sp,$DFFF        ;Move stack pointer to $DFFF
    ld   hl,$FF80        ;Load $FF80 into HL
    ld   bc,$007E        ;Load $007E into BC
    Call Zero_RAM        ;Clear the HRAM

   
    Call DMA_Routine_2_HRAM ;move the DMA routine to HRAM

    Call Init_OAM_Buffer    ;Sets the OAM buffer ($D400) to 0xF0

    Call Clear_Tile_Map0

    Call Clear_Tile_Map1

    xor a    ;Clear A
   
    ld   [$D520],a    ;Zero all these important registers...
    ld   [$D521],a
    ld   [$D522],a
    ldh  [$FFC5],a
    ldh  [$FFC6],a
    ldh  [$FFD0],a
    ldh  [$FFD4],a
    ld   [$DC41],a
    ld   [$D523],a
    ldh  [$FFC4],a

    ld   hl,$FFAB
    xor  a
    ldi  [hl],a    ;Zero from  FFAB - FFB2
    ldi  [hl],a
    ldi  [hl],a
    ldi  [hl],a
    ldi  [hl],a
    ldi  [hl],a
    ldi  [hl],a
    ldi  [hl],a
    ld   a,$8F
    ldi  [hl],a    ;$8F into FFB3
    ld   a,$A6
    ldi  [hl],    ;$A6 into FFB4

    Call Init_Snd    ;

    Call $1DEC    ;






$1DEC:
    ld   a,$0B
    ld   hl,$4010
    call $1D95

    call Delay_2

    ldh  a,[$FF00]
    and  a,$03
    cp   a,$03
    jr   nz,$1E3A
    ld   a,$20
    ldh  [$FF00],a
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    ld   a,$30
    ldh  [$FF00],a
    ld   a,$10
    ldh  [$FF00],a
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    ld   a,$30
    ldh  [$FF00],a
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    ldh  a,[$FF00]
    and  a,$03
    cp   a,$03
    jr   nz,$1E3A
    ld   a,$0B
    ld   hl,$4000
    call $1D95
    call $1DE0
    and  a
    ret 
    ld   a,$0B
    ld   hl,$4000
    call $1D95
    call Delay_2
    scf 
    ret 




$1D95:    ;Variables passed, A and HL

    ldh  [$FF9D],a        ;put variable A into FF9D - Temp bank buffer 2?
    ldh  a,[BankBuffer]    ;Get current bank
    push af            ;Store it on the stack
    ldh  a,[$FF9D]        ;Get that variable buffer
    ldh  [BankBuffer],a    ;Update the current bank register
    ld   [$2000],a        ;Set the bank
    ld   a,[hl]        ;Load first byte of passed variable HL
    and  a,$07        ;cmp with $07
    jr   z,Label1        ;if something, then end routine.....

    ld   b,a        ;otherwise,  multiply it by 0xFF, and put it in BC
    ld   c,$00
    push bc            ;push BC onto the stack
    ld   a,$00       
    ld   [$ff00+c],a    ;Clear keypad latch
    ld   a,$30
    ld   [$ff00+c],a    ;Set P14+15 high
    ld   b,$10        ;load B with $10
Label4:    ld   e,$08        ;Load E with $08
    ldi  a,[hl]       
    ld   d,a
Label3:    bit  0,d
    ld   a,$10
    jr   nz,Label2
    ld   a,$20
Label2:    ld   [$ff00+c],a
    ld   a,$30
    ld   [$ff00+c],a
    rr   d
    dec  e
    jr   nz,Label3
    dec  b
    jr   nz,Label4
    ld   a,$20
    ld   [$ff00+c],a
    ld   a,$30
    ld   [$ff00+c],a
    pop  bc
    dec  b
    jr   z,Label1
    call Delay_2
    jr   $1DA9
Label1:    pop  af
    ldh  [BankBuffer],a
    ld   [$2000],a
    ret 

Delay_2:
    ld   de,$1B58
.Loop    nop 
    nop 
    nop 
    dec  de
    ld   a,d
    or   e
    jr   nz,.Loop
    ret 





Init_Snd: ;Set bank 1F, execute code at $7FF6, Restore previous bank.
    ldh  a,[$FF9B] ;Store the current ROM bank
    push af
    ld   a,$1F    ;Change to ROM Bank 1F
    ldh  [$FF9B],a    ;Update the bank buffer
    ld   [$2000],a    ;Switch bank 1F
    call $7FF6    ;Turn on Sound registers, Zero DD00-DF00 - Sound buffers???
    pop  af        ;Restore the current rom bank
    ldh  [$FF9B],a    ;
    d   [$2000],a    ;Set the current rom bank.
    ret     

        1F:7FF6 > jumps to :5343
        1F:5343:
            ld   a,$80
            ldh  [$FF26],a    ;Enable all sound channels
            ld   a,$77
            ldh  [$FF24],a  ;Max volume
            ld   a,$FF
            ldh  [$FF25],a    ;Sound output to all terminals
            ld   hl,$DD00
        .Loop    ld   [hl],$00    ;Zero DD00-DF00
            inc  l
            jr   nz,.Loop
            inc  h
            ld   a,h
            cp   a,$DF
            jr   nz,.Loop
            ret 

Clear_Tile_Map0:
    ld   a,$FF
    ld   hl,$9800
    ldi  [hl],a
    bit  2,h
    jr   z,$0919
    ret 


Clear_Tile_Map1:
    ld   a,$FF
    ld   hl,$9C00
    ldi  [hl],a
    bit  5,h
    jr   z,$0924
    ret 
   


Init_OAM_Buffer: ;Set OAM buffer to 0xF0, all of it.
    ld   hl,$D400
    ld   b,$A0
    ld   a,$F0
    ldi  [hl],a
    dec  b
    jr   nz,$0931
    xor  a
    ldh  [$FF9A],a
    ret 



DMA_Routine_2_HRAM: ;Move the DMA transfer routine into HRAM
    ld   c,$80
    ld   b,$0A
    ld   hl,DMA_Routine   
    ldi  a,[hl]    ;
    ld   [$ff00+c],a
    inc  c
    dec  b
    jr   nz,$03E9
    ret     

DMA_Routine:    ;This routine is placed into HRAM via DMA_Routine_2_HRAM
    ld a,$D4        ;Start address = $D400, Destination is FE00
    ldh [$FF46],a
    ld a,$28
    dec a
    jr nz,$03F6
    Ret

Zero_RAM:
    xor  a
    ldi  [hl],a
    dec  bc
    ld   a,c
    or   b
    jr   nz,$0462
    ret    



Turn_LCD_Off:
    Ldh a,[$FF40]     ; get LCDC
    Bit 7,a        ;Disabled?
    Ret z        ;return with zero flag carried
    Ldh a,[$FFFF]    ;Get Interrupt Status
    Push AF        ;push it to the stack
    And A,$FC    ;Clear bits 0+1 – Vblank int, and LCD Stat int.
    Ldh [$FFFF],A    ;Update the interrupt status

.Wait4V:
    Ld a,[FF44]
    Cp a,$91
Jr nz, .Wait4V
   
    Ldh a,[$FFAB]    ;FFAB is a buffer register of LCDC
    Res 7,a
    ldh [$FF40],a    ;store in LCDC
    ldh [$FFAB],a   ;Update LCDC buffer register   
    pop af
    ldh [$FFFF],a    ;restore the Interupt register
    RET



Delay_1 : ;Data passed in via Register BC
    Ld de,$06D6        ;Delay loop pre-set
Delay_Inner_Loop:
    Nop
    Nop
    Nop
    Dec de            ;
    Ld a,d            ;
    Or e            ;
    Jr nz, Delay_Inner_Loop: ;Loop $06D6 times
    Dec BC
    Ld a,b
    Or c
    Jr nz, Delay_1: ;Loop the above loop, BC times.
    Ret


There is more on my home PC

]]> https://chipmusic.org/BennVenn 2016-06-23T22:27:09Z https://chipmusic.org/forums/post/245392/#p245392 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> this would save me so much time. patiently waiting :3

]]> https://chipmusic.org/unicorn+wizard 2016-06-23T05:47:22Z https://chipmusic.org/forums/post/245345/#p245345 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> this would save me so much time. patiently waiting :3

]]> https://chipmusic.org/unicorn+wizard 2016-06-23T05:47:03Z https://chipmusic.org/forums/post/245344/#p245344 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> Unfortunately Ben never got around sending me what he has so far... sad

]]> https://chipmusic.org/zemzelett 2016-06-15T08:53:07Z https://chipmusic.org/forums/post/245045/#p245045 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> Any updates? smile

]]> https://chipmusic.org/nordloef 2016-06-13T17:10:32Z https://chipmusic.org/forums/post/244987/#p244987 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> It's on hold while I finish up a few other projects. I'm happy to pass what I've done on to you. PM me?

]]> https://chipmusic.org/BennVenn 2016-04-17T23:09:39Z https://chipmusic.org/forums/post/242872/#p242872 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> May i ask if you are still working on this?

I wanted to do the same a few months back but didn't get around doing it and then i saw your post. That's why i'm asking.

]]> https://chipmusic.org/zemzelett 2016-04-17T22:21:03Z https://chipmusic.org/forums/post/242869/#p242869 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> Jazzmarazz wrote:

[
I found what you are talking about. That is a pretty ugly side-effect of disabling interrupts, loading too much stuff and the enabling interrupts again. I can definitely look into it.

Ah cool, would be amazing, good luck! smile

]]> https://chipmusic.org/Cementimental 2016-03-03T18:52:44Z https://chipmusic.org/forums/post/240938/#p240938 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> No, there is a substantial amount to weed through. And yeah, the code should be available once we're finished with it.

]]> https://chipmusic.org/Jazzmarazz 2016-02-02T00:02:51Z https://chipmusic.org/forums/post/239142/#p239142 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> Oh, sorry I thought you meant you had already reversed the whole thing.

]]> https://chipmusic.org/catskull 2016-02-01T23:32:31Z https://chipmusic.org/forums/post/239139/#p239139 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> Not at this time. Besides, we only have a few routines reversed. I'll talk with Benn and see what he plans.
I have no issue.

]]> https://chipmusic.org/Jazzmarazz 2016-02-01T23:13:34Z https://chipmusic.org/forums/post/239138/#p239138 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> Sweet! Open source Trippy-H. Are you posting the code anywhere?

]]> https://chipmusic.org/catskull 2016-02-01T23:08:57Z https://chipmusic.org/forums/post/239137/#p239137 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> Update:
Benn and I (mostly Benn) have decided to hand-disassemble the machine code of the Gameboy Camera ROM. With this, the ROM can be rewritten and recompiled to reflect whatever changes, updates or exclusions we choose. It makes for any changes to be much more simple and to some extent, more plausible. Modifying the routines will make any releases less wasteful with resources. There is no need for a dedicated Trippy-H game to be 1MByte.

]]> https://chipmusic.org/Jazzmarazz 2016-02-01T22:21:46Z https://chipmusic.org/forums/post/239135/#p239135 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> PM'd

]]> https://chipmusic.org/BennVenn 2016-01-28T21:21:31Z https://chipmusic.org/forums/post/238982/#p238982 <![CDATA[Re: Gameboy Camera - Force Trippy H]]> pselodux wrote:
Jazzmarazz wrote:

That would probably be one of the last updates I add if at all. I can imagine that being one of the most difficult.
If I had a source code, I would say no problem. Bu ti am just editing the hex file, one bit at a time. tongue

Yeah, understood, it's a bit of a dream big_smile great work so far though!

There is so much extra space in ROM and WRAM that it would be feasible. I would just need to figure out how to intercept the button-detect routine and add a few more two-button jumps.

]]> https://chipmusic.org/Jazzmarazz 2016-01-28T20:38:17Z https://chipmusic.org/forums/post/238980/#p238980