[atari7800] Reading both fire buttons ?

Erm, okay :) I can't seem to read the joystick buttons independently in
Mess, well I can if I remove support for single button devices, but the
problem seems to be that Mess pretends that any button press from the two
button device is also a fire input on the single input device, erm I think..

I gave up, and just borrowed the ReadJoystick function from Falcon, and this
seems to confirm this..

Any press from a dual button pad, also triggers the single button ?

Which in this code, will stop the dual mode ever trying to read again ?

I wouldn't normally worry about this, I'd just go off and code it up for 2
buttons only, but it'd be nice to be able to discern the joystick type
currently plugged in, and this comment worry me.. A lot :\

                lda ONEBUT                 ;SET ONE-BUTTON MODE IMMEDIATELY
                ora .jbits,X               ; TO AVOID DESTROYING HARDWARE!

Which makes it seem important, that if we've a one button joystick we stop
buggering about with the 2 button ports..

Anyone tell me what's going on here ? Is it Mess ?

I've initialised the ports for the paddle inputs as in the docs, yet
lda #$14                   ;IO HARDWARE
                sta SWBCNT
                lda #0                     ;SELECT TWO BUTTON MODE
                sta SWCHB

There's definitely 2 button input happening, but it's masked by the single
button input occurring as well ?

I'm puzzled.. (again)

I can see the simple solution, just to read the triggers independently, but
I don't like that, at all, because that's not going to tell me why this
doesn't work as expected ?

Btw: Is anybody else actually doing anything on the 7800 at the moment ? I'm
currently mucking about with some 3D filled polygon stuff, which is actually
really nice and fast on the 7800, of which I'll post a little demo to the
list in a day or so, well as soon as I can get the bloody fire button inputs
to work on one button and two button devices >:(

Andym00






        ; * READJOY: READ JOYSTICK/BUTTONS.  ON ENTRY X = PLAYER.  Y GETS
TRASHED
ReadJoystick:   subroutine
                ldy INPT4,X
                bpl .gotone             ; IF BIT 7 IS LO, OLD-STYLE BUTTON
HIT

                lda ONEBUT              ; ARE WE ALREADY IN OLD-STYLE MODE?
                and .jbits,X
                bne .gotone2    ; YES.  GO RIGHT TO ONE-BUTTON HANDLER.

                txa                     ; OTHERWISE, COMPUTE INDEX INTO
                asl                     ; PADDLE PORTS, FOR PLAYER X,
                tay                     ; IN Y (X * 2)

                lda INPT4L,Y    ;READ LEFT BUTTON
                eor #$FF                ; INVERT SENSE
                sta LeftButton,X
                lda INPT4R,Y    ; RIGHT BUTTON
                eor #$FF                ; INVERT SENSE
                sta RightButton,X

                rts

                ;HERE ON OLD-STYLE SINGLE BUTTON JOYSTICK PRESS.
.gotone
                lda ONEBUT         ;SET ONE-BUTTON MODE IMMEDIATELY
                ora .jbits,X       ; TO AVOID DESTROYING HARDWARE!
                sta SWCHB
                sta ONEBUT         ;UPDATE ONE BUTTON FLAG BYTE

                ;HERE ON ANY OLD-STYLE JOYSTICK, WHETHER PRESSED OR NOT
.gotone2:
                tya
                sta LeftButton,X   ; (Y CONTAINS CURRENT VALUE OF INPT4)
                sta RightButton,X  ;CLEAR RIGHT BUTTON COPY

                rts

.jbits          BYTE $04,$10 ;MASK OF "ONE-BUTTON" BITS PER PLAYER

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