mirror of
https://github.com/A2osX/A2osX.git
synced 2024-11-22 00:32:44 +00:00
323 lines
9.6 KiB
Plaintext
323 lines
9.6 KiB
Plaintext
NEW
|
||
AUTO 3,1
|
||
* object code = ram_0
|
||
* /RAM driver (aux bank portion)
|
||
* this code is packed into $200 length with no room for expansion !!
|
||
* (see note at end of this obj)
|
||
|
||
* after the main /RAM routine has determined that the command is ok and the
|
||
* block to be read/written is within range, it transfers control to this
|
||
* aux /RAM routine which remaps the block requested as follows:
|
||
* request blocks 0,1: invalid
|
||
* 2: returns VDIR (card block 3)
|
||
* 3: returns BITMAP (synthesized)
|
||
* 4: returns card block 0
|
||
* $05-$5F: returns card blocks $05-$5F
|
||
* $60-$67: returns blocks $68-$7F in bank 1 of language card
|
||
* $68-$7F: returns blocks $68-$7F in bank 2 of language card
|
||
|
||
H5100 lda RD80STORE read 80 store
|
||
pha save for later
|
||
sta CLR80STORE turn off 80 store
|
||
ldx #$04 move the parameters for use:
|
||
L5109 lda A4L,x cmd, unit, bufptr and block (lo)
|
||
sta tcmd,x -> tcmd, tunit, R2L, R2H, R01
|
||
dex
|
||
bpl L5109
|
||
and formatflg format the volume first time
|
||
bne L514F thru, or when requested.
|
||
ldx bloknml save R01 during format.
|
||
lda /vblock1 block to be cleared.
|
||
jsr clrbuf1 clears all buffers.
|
||
ldy #$03 format volume in 2 chunks.
|
||
L511F lda VDIR,y
|
||
sta vblock1+4,y
|
||
dey
|
||
bpl L511F
|
||
lda #$FE set last block as unusable
|
||
sta BITMAP+15 to protect vectors.
|
||
tya set bitmap bits to $FF.
|
||
ldy #$0E 15 bytes to set
|
||
L5130 sta BITMAP,y
|
||
dey
|
||
bne L5130
|
||
sty BITMAP first byte = 0.
|
||
ldy #$07 do other chunk
|
||
L513B lda access,y
|
||
sta vblock1+34,y
|
||
dey
|
||
bpl L513B
|
||
lda formatflg if 0, set to $FF
|
||
bne L51AA else exitcard.
|
||
sty formatflg y = $FF, won't format next time.
|
||
stx R01 restore R01
|
||
|
||
* use the requested block number to determine
|
||
* which routine performs the transfer
|
||
|
||
L514F asl R01 block requested -> page requested.
|
||
lda R01 get page requested.
|
||
cmp #$BF in language card ?
|
||
bcs L5163 yes, do it.
|
||
cmp #$06 bitmap ?
|
||
bne L5160
|
||
jmp tbmap yes, transfer bitmap
|
||
L5160 jmp treg else normal transfer.
|
||
|
||
* when a block between $60 and $7F is requested, it must be spirited into/from
|
||
* the language card area of the 64k card. this requires a 2 stage move:
|
||
* into the temp buffer and then to it's real destination.
|
||
|
||
L5163 tax save R1 for later.
|
||
jsr setptr get direction
|
||
php and save it.
|
||
bcs L51B8 if it's a write.
|
||
lcrd txa get R1 back
|
||
cmp #$CF which bank is it in ?
|
||
bcs L5173 in main bank.
|
||
ora #$10 in secondary bank.
|
||
bne L5179 branch always.
|
||
L5173 sta RRAMWRAMBNK2 turn on main $D000
|
||
sta RRAMWRAMBNK2
|
||
L5179 sta R01 restore R1.
|
||
lda R2H save R2 for later
|
||
pha
|
||
ldx R2L
|
||
sta SETALTZP use alternate zero page/stack
|
||
lda /dbuf set R2 to dbuf
|
||
sta R2H
|
||
lda #dbuf
|
||
sta R2L
|
||
jsr setptr set pointers
|
||
tay A > 0 from setptr
|
||
L5194 lda (A1L),y move A1,A2 to A4,A3
|
||
sta (A4L),y
|
||
lda (A2L),y
|
||
sta (A3L),y
|
||
dey
|
||
bne L5194
|
||
sta CLRALTZP use main zero page/stack
|
||
L51A2 stx R2L
|
||
pla restore R2
|
||
sta R2H
|
||
plp get direction.
|
||
L51AA bcs L51B5 write, done with move.
|
||
sta RRAMWRAMBNK1 switch in MLI part of LC
|
||
sta RRAMWRAMBNK1
|
||
jsr blockdo0 read, transfer dbuf to main
|
||
L51B5 jmp exitcard
|
||
L51B8 jsr blockdo0 transfer main to dbuf.
|
||
jmp lcrd transfer dbuf to language card
|
||
|
||
* blockdo0 transfers a block between main memory and the 64k card. R1 contains
|
||
* the page address of the block in the card; R2 contains the page address of
|
||
* the block in main memory. the address in main memory is always in the
|
||
* language card, so the language card is always switched in. if cmd is 2, a
|
||
* write is done (R2->R1); if cmd is 1, a read is done (R1->R2).
|
||
|
||
blockdo0 lda /dbuf set up R1 = dbuf
|
||
blockdo1 sta R01
|
||
blockdo jsr setptr set pointers.
|
||
bcs L51DB it's a write.
|
||
sta CLRWRITEAUX transfer buffer directly to main.
|
||
tay 0 left from setptr.
|
||
L51CC lda (A1L),y transfer A1,A2 to A4,A3
|
||
sta (A4L),y
|
||
lda (A2L),y
|
||
sta (A3L),y
|
||
dey
|
||
bne L51CC
|
||
sta SETWRITEAUX back the way it was.
|
||
donewrt rts mainwrt returns here
|
||
|
||
L51DB lda #mainwrt pointers set up,
|
||
sta passit pass control to main ram
|
||
lda /mainwrt
|
||
jmp ex1 set passit+1 and transfer
|
||
|
||
* setptr is used by other routines to set up pointers and dtect read or write
|
||
|
||
setptr lda tcmd is it read or write ?
|
||
lsr
|
||
bcs L5208 taken if write.
|
||
lda R2H destination page
|
||
sta A4L+1
|
||
sta A3L+1
|
||
lda R2L
|
||
sta A4L
|
||
sta A3L
|
||
lda R01 source page
|
||
sta A1L+1
|
||
sta A2L+1
|
||
lda #$00 source page aligned
|
||
sta A1L
|
||
sta A2L
|
||
beq L5223
|
||
L5208 lda R2H source page
|
||
sta A1L+1
|
||
sta A2L+1
|
||
lda R2L
|
||
sta A1L
|
||
sta A2L
|
||
lda R01 destination page
|
||
sta A4L+1
|
||
sta A3L+1
|
||
lda #$00 destination page aligned
|
||
sta A4L
|
||
sta A3L
|
||
L5223 inc A2L+1
|
||
inc A3L+1
|
||
rts
|
||
|
||
* tzip is called if blocks 0,1,4,5 are requested.
|
||
* on write it does nothing, on read it returns 0's.
|
||
|
||
tzip jsr clrbuf0 fill dbuf with 0's
|
||
jsr blockdo transfer the 0's
|
||
jmp exitcard and return
|
||
|
||
* clrbuf fills the buffer indicated by R01 to 0's.
|
||
* should only be called on a read or format.
|
||
|
||
clrbuf0 lda /dbuf dbuf is temp buffer.
|
||
clrbuf1 sta R01 assign to block.
|
||
clrbuf2 jsr setptr set pointers
|
||
tay acc = 0
|
||
L523A sta (A1L),y
|
||
sta (A2L),y
|
||
dey
|
||
bne L523A
|
||
rts
|
||
|
||
* treg maps the requested block into the aux card
|
||
* so that 8k data files will be contiguous (the index
|
||
* blocks will not be placed within data).
|
||
|
||
treg cmp #$04 page 4 = vdir
|
||
bne L524A not vdir, continue
|
||
lda #$07 else transfer block 7
|
||
bne L5258
|
||
L524A cmp #$0F if any page < $F (block 8) requested,
|
||
bcc tzip it is invalid.
|
||
ldx #$00 x = # of iterations.
|
||
lda bloknml use true block #.
|
||
cmp #$5D beyond 8k blocks ?
|
||
bcc L525B no, do normal
|
||
sbc #$50 else subtract offset
|
||
L5258 jmp times2 and multiply by 2
|
||
|
||
* determine which 8k chunk it is in, place in x;
|
||
* block offset into chunk goes into y.
|
||
|
||
L525B sec
|
||
sbc #$08 block=block-6
|
||
L525E cmp #$11 if <=17 then done
|
||
bcc L5268
|
||
sbc #$11 else block=block-17.
|
||
inx iteration count.
|
||
bpl L525E should branch always
|
||
brk otherwise crash !!!
|
||
L5268 tay remainder in y
|
||
|
||
* if remainder is 1 then it's an index block:
|
||
* start index blocks at $1000,$2000...$19FF.
|
||
* if remainder is 0 then it is first data block
|
||
* in 8k chunk. page is 32 + (16 * x).
|
||
* otherwise, it is some other data block.
|
||
* page is 32 + (16 * x) + (2 * y)
|
||
|
||
cpy #$01 is it index block ?
|
||
bne L5273 no.
|
||
txa index = 2 * (8 + x)
|
||
clc
|
||
adc #$08
|
||
bne times2 multiply by 2.
|
||
L5273 inx iteration + 1.
|
||
txa page = 2 * (16 + 8x)
|
||
asl
|
||
asl
|
||
asl
|
||
asl
|
||
sta R01
|
||
tya get offset into 8k chunk
|
||
beq L5281 if 0, no offset
|
||
dey else offset = 2 * y
|
||
tya
|
||
L5281 clc
|
||
adc R01
|
||
times2 asl acc = 2 * acc
|
||
jsr blockdo1 store in R01 and transfer
|
||
jmp exitcard and return
|
||
|
||
* when block 3 is requested, the bitmap is returned. the real bitmap is only
|
||
* 16 bytes long; the rest of the block is synthesized. the temporary buffer
|
||
* at $800 is used to build/read a full size bitmap block.
|
||
|
||
tbmap lda /dbuf use temp buffer as block
|
||
sta R01
|
||
jsr setptr set pointers, test read/write.
|
||
bcs L52A9 branch if it's write.
|
||
jsr clrbuf2
|
||
ldy #$0F put real bitmap there
|
||
L529B lda BITMAP,y
|
||
sta (A1L),y
|
||
dey
|
||
bpl L529B
|
||
jsr blockdo move temp buf to user buf
|
||
jmp exitcard
|
||
L52A9 jsr blockdo move user buf to temp buf
|
||
jsr setptr
|
||
ldy #$0F move temp buf to bitmap.
|
||
L52B1 lda (A4L),y (pointer set by setptr)
|
||
sta BITMAP,y
|
||
dey
|
||
bpl L52B1
|
||
jmp exitcard
|
||
|
||
formatflg .HS 00 not formatted yet
|
||
tcmd .HS 00 command
|
||
.HS 00 unit (not used)
|
||
R2L .HS 00 R2 = user buffer
|
||
R2H .HS 00
|
||
R01 .HS 00 page requested
|
||
BITMAP .HS 00FFFFFF blocks 0-7 used
|
||
.HS FFFFFFFF
|
||
.HS FFFFFFFF
|
||
.HS FFFFFFFE
|
||
VDIR .HS F3 storage type = F, name length = 3
|
||
.AS "RAM"
|
||
access .DA #$C3 destroy, rename, read enabled
|
||
.HS 27 entry length
|
||
.HS 0D
|
||
.HS 0000
|
||
.HS 0300 block 3
|
||
.HS 7F 128 blocks
|
||
|
||
exitcard lda RRAMWRAMBNK1 restore language card
|
||
lda RRAMWRAMBNK1
|
||
pla get 80store
|
||
bpl L52EA 80store wasn't on
|
||
sta SET80STORE enable 80store
|
||
L52EA jmp bypass jump around passit
|
||
passit .HS 0000
|
||
bypass lda #noerr set up return to noerr
|
||
sta passit
|
||
lda /noerr
|
||
ex1 sta passit+1 also used by blockwrite
|
||
clc transfer card to main
|
||
clv use standard zeropage/stack
|
||
jmp xfer jmp back from language card.
|
||
|
||
* NOTE: the previous section of code MUST NOT use $3FE or $3FF
|
||
* since the interrupt vector must go there if aux interrupts
|
||
* are to be used. no room for expansion here !!
|
||
|
||
.HS 0000 $3FE-$3FF
|
||
|
||
* end of obj ram_0
|
||
*--------------------------------------
|
||
MAN
|
||
SAVE USR/SRC/PRODOS.203/PRODOS.S.RAMX
|
||
LOAD USR/SRC/PRODOS.203/PRODOS.S
|
||
ASM
|