mirror of
https://github.com/A2osX/A2osX.git
synced 2024-11-05 10:04:48 +00:00
86 lines
1.7 KiB
Plaintext
86 lines
1.7 KiB
Plaintext
NEW
|
||
AUTO 3,1
|
||
*--------------------------------------
|
||
* this routine handles interrupts and is coded to reach 'lreset' precisely at
|
||
* address $FFCB (ROM rts opcode) for rom switching to function.
|
||
* $2D9B-2DFF moved to $FF9B-FFFF
|
||
*--------------------------------------
|
||
IRQ.START
|
||
XDOS.IRQV ldx #$FA save 6 bytes of page 0
|
||
|
||
.2 lda $00,x
|
||
sta svzerop-$FA,x
|
||
inx
|
||
bne .2
|
||
|
||
ldx #0
|
||
|
||
.3 stx irqXindex
|
||
|
||
lda inttbl+1,x test for a valid routine.
|
||
beq .4 branch if no routine.
|
||
|
||
jsr gointX execute
|
||
|
||
bcc irqdone
|
||
|
||
.4 ldx irqXindex
|
||
inx
|
||
inx
|
||
cpx #10
|
||
bne .3
|
||
|
||
inc irqcount allow 255 unclaimed interrupts
|
||
bne irqdone before system death.
|
||
|
||
lda #$01 bad irq so
|
||
jsr GP.SysDeath kill the system.
|
||
|
||
.LIST ON
|
||
IRQ.FREE1 .EQ $ffc8-*
|
||
.LIST OFF
|
||
|
||
.BS IRQ.FREE1
|
||
|
||
gorom sta RROMBNK2 hits ROM rts at $FFCB
|
||
|
||
* 'lreset' address must = $FFCB for rom switch i/o to work
|
||
|
||
lreset lda /resetv-1
|
||
pha
|
||
lda #resetv-1
|
||
pha
|
||
jmp gorom
|
||
|
||
irqdone ldx #$FA
|
||
|
||
.1 lda svzerop-$FA,x restore the zero page
|
||
sta $00,x
|
||
inx
|
||
bne .1
|
||
|
||
rti
|
||
|
||
gointX jmp (inttbl,x) interrupt routine x
|
||
|
||
irqcount .HS 00 # of unclaimed interrupts.
|
||
irqXindex .HS 00
|
||
svzerop .HS 000000000000
|
||
|
||
.LIST ON
|
||
IRQ.FREE2 .EQ $fffa-*
|
||
.LIST OFF
|
||
|
||
.BS IRQ.FREE2
|
||
|
||
.DA nmivect nmi handler
|
||
.DA lreset reset handler
|
||
irqv .DA * PATCHED with ROM vector by LDR
|
||
.LIST OFF
|
||
*--------------------------------------
|
||
IRQ.LEN .EQ *-IRQ.START
|
||
MAN
|
||
SAVE USR/SRC/PRODOS.FX/PRODOS.S.IRQ
|
||
LOAD USR/SRC/PRODOS.FX/PRODOS.S
|
||
ASM
|