PT3 + AYFX player | MSX Resource Center (Pagina 4/11)

Van ARTRAG

Enlighted (6935)

16-07-2007, 22:37

Wort to hear : SCC + SHIRU's replayer!

http://karoshi.msxgamesbox.com/index.php?topic=562.msg12172#msg12172

Van ARTRAG

Enlighted (6935)

02-08-2007, 01:25

@WYZ,
How is going you work on the PT3+FX+SCC replayer ?
You promised to release the code, but since then I had
no news from you ... In holiday time I have a bit more of spare
time for msxing. Grin
Do you need some support ?

Van ARTRAG

Enlighted (6935)

03-08-2007, 11:54

Hello
I'm finding that the SCC detection in WYZ seems to hang my code.

WYZ 's code is here:

http://karoshi.msxgamesbox.com/index.php?topic=562.0

and the SCC DETECT is this one


;DETECTA SCC **** PROVISIONAL 

DETECTSCC:      LD     	BC,$0400
                LD     	HL,$FCC1
JC3B8:          PUSH   	BC
                PUSH   	HL
                LD     	A,[HL]
                BIT    	7,A
                JR     	NZ,JC3C5
                LD     	A,C
                CALL   	JC3E5
                JR     	JC3C8
JC3C5:          CALL   	JC3D5
JC3C8:          POP    	 HL
                POP    	 BC

                RET    	 C
                INC    	 HL
                INC    	 C
                DJNZ   	 JC3B8
                LD     	 A,$FF
                LD     	 [SCCSLOT],A
                RET
JC3D5:          AND    	 $80
                OR     	 C

                LD     	 B,04
JC3DA:          PUSH   	 BC
                CALL   	 JC3E5
                POP    	 BC
                RET    	 C
                ADD    	 A,$04
                DJNZ   	 JC3DA
                RET

JC3E5:          LD     	 [SCCSLOT],A
                CALL   	 JC401
                ;PUSH  	  AF			;SOLO SI HAY DISCO
                ;LD    	  A,[$F342]
                ;LD    	  H,$80
                ;CALL  	  $0024
                ;POP   	  AF
                JR     	 NC,JC3FC
                LD     	 A,[SCCSLOT]
                SCF
                RET

JC3FC:          LD     	 A,[SCCSLOT]
                AND    	 A
                RET

JC401:          LD     	 H,$80
                CALL   	 $0024
                LD     	 A,02
                LD     	 [$9000],A
                CALL   	 JC415
                JR     	 C,JC420
                LD     	 A,$3F
                LD     	 [$9000],A

JC415:          LD     	 HL,$9800
                LD      A,[HL]
                CPL
                LD      [HL],A
                CP      [HL]
                JR      NZ,JC420
                SCF
                RET
JC420:          OR      A
                RET

Do anyone know why it does not work ?

Van jltursan

Prophet (2619)

03-08-2007, 12:40

Are you trying this on a machine/emu with diskdrives?. I'm telling you that because (looking at the comments) seems that the commented code is used when a drive is present...

Van ARTRAG

Enlighted (6935)

03-08-2007, 12:56

I use bue/openmsx and C-bios, so no diskdrive

Van ARTRAG

Enlighted (6935)

03-08-2007, 13:55

ok i think I see some light

This code (I guess) falls in the same page whee it is supposed to have the SCC registers.

A question to those worked with WYZ patch:

Doing a megarom, in order to play SCC music at each interrupt,
should I change slot to SCC slot each time i write to SCC registers
and than go back to my slot with my ROM ?

In case, it is a torture !!

should I use call 0x24 at each interrupt -twice- or there is a faster trick to
do the same (e.g. assuming no expanded slot and so on...)

Van ARTRAG

Enlighted (6935)

03-08-2007, 17:56

Hello
can anyone tell me how the SCC works wrt slots and pages?

While doing a ROM, should I keep the area around 0x9800 free from my data?
or,
should I switch slot each time I access to SCC registers ?
(in this case using freely the area at 0x9800)

Van jltursan

Prophet (2619)

04-08-2007, 00:48

As far as I understand, yes. You must first locate the slot where the SCC is contained and then, everytime you want to access it you must enable this slot and write in the SCC memory area. I've never tried with SCC programming; so I'm not 100% sure about that, maybe there're tricks to speed up a bit its management.
You can find detailed info on the BiFi pages: Konami SCC Sound Chip

Van ARTRAG

Enlighted (6935)

06-08-2007, 10:35

Ok, let me recollect.

SCC chip can be accessed using the area 9800h - 98FFh of page 3Fh of the slot where a Konami ROM with SCC is.

So, at boot time I need to locate the slot where the SCC is

Moreover, at each interrupt, I should:
1) enable the slot where the SCC is
2) set page 3Fh in Bank 3 of that Konami ROM (i.e. write 3Fh in (9000h) )
3) access to area 9800h - 98FFh
4) set back my own slot

I'm using an ASCII 8 mapper for my game, what about moving to different mapper, e.g. Konami5 ?

If I understand, using a the ROM mapper Konami with SCC means that all I need to do is to
1) set page 3Fh in Bank 3 of that Konami ROM (i.e. write 3Fh in (9000h) )
2) access access to area 9800h - 98FFh
3) set back Bank 3 to its previous value

Can anyone confirm if this is the correct way of acting ?

Van Guillian

Prophet (3517)

06-08-2007, 11:59

Moreover, at each interrupt, I should:
1) enable the slot where the SCC is
2) set page 3Fh in Bank 3 of that Konami ROM (i.e. write 3Fh in (9000h) )
3) access to area 9800h - 98FFh
4) set back my own slot

You only need to do step 2 once (i.e.: in SCC detection rutine). Next time you select the SCC slot, the SCC registers bank will be active.

I'm using an ASCII 8 mapper for my game, what about moving to different mapper, e.g. Konami5 ?

Just change ASCII8 banks register address with Konami ones (#6000, #6800, #7000, #7800 -> #5000, #7000, #9000, #B000)

If I understand, using a the ROM mapper Konami with SCC means that all I need to do is to
1) set page 3Fh in Bank 3 of that Konami ROM (i.e. write 3Fh in (9000h) )
2) access access to area 9800h - 98FFh
3) set back Bank 3 to its previous value

Can anyone confirm if this is the correct way of acting ?

Yes, it is right.