mirror of
https://github.com/cc65/cc65.git
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intermediate check-in -- added handling of read requests
This commit is contained in:
Christian Groessler
parent
85dc09fd9f
commit
e5f409e357
@ -9,6 +9,7 @@
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.include "atari.inc"
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.include "save_area.inc"
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.include "zeropage.inc"
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.import __CHARGEN_START__
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.export sram_init
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@ -19,19 +20,14 @@ BUFSZ_CIO = BUFSZ
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BUFSZ_SIO = BUFSZ
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.macro disable_rom
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.local cont
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;dec enable_count
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;bne cont
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lda PORTB
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and #$fe
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sta PORTB
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lda #>__CHARGEN_START__
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sta CHBAS
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sta CHBASE
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cont:
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.endmacro
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.macro enable_rom
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;inc enable_count
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lda PORTB
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ora #1
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sta PORTB
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@ -42,7 +38,7 @@ cont:
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.segment "INIT"
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enable_count: .res 1
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;enable_count: .res 1
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; Turn off ROMs, install system and interrupt wrappers, set new chargen pointer
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@ -55,7 +51,7 @@ sram_init:
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; disable ROMs
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;inx
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stx enable_count
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;stx enable_count
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disable_rom
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; setup interrupt vectors
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@ -95,16 +91,22 @@ sram_init:
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rts
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.segment "EXTZP" : zeropage
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zpptr1: .res 2
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zpptr2: .res 2
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.segment "LOWBUFS"
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; bounce buffers for CIO and SIO calls
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CIOV_buffer: .res BUFSZ_CIO
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SIOV_buffer: .res BUFSZ_SIO
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CIO_buffer: .res BUFSZ_CIO
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SIO_buffer: .res BUFSZ_SIO
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.segment "LOWCODE"
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; Interrupt handlers
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; ------------------
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@ -142,95 +144,40 @@ my_RESET_han:
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; System request handlers
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; -----------------------
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; CIO handler
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; We have buffer pointer and length entries in the IOCB, but their
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; usage depends on the function.
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; Some functions don't care about both (pointer and length), and some
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; only use the pointer (like e.g. OPEN), and some use both.
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; So we need function specific handlers to correctly deal with
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; buffers which are overlapping with the ROM area.
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; All input and output registers need to be preserved (I'm not 100%
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; sure about Y, but let's preserve it for now.)
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;
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; FIXME: Currently only the requests used by the runtime lib are handled.
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my_CIOV:
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; for filenames we assume they will fit into our bounce buffer
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; @@@ TODO: check X for valid IOCB index ((X < $80) and ((X & $F) == 0))
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sta CIO_a
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sty CIO_y
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stx CIO_x
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lda ICCOM,x ; get function
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cmp #OPEN
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beq CIO_filename ; filename as input parameter in buffer, length not used
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cmp #PUTREC
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bcc CIO_read ; input (GETREC or GETCHR)
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cmp #CLOSE
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bcc CIO_write ; output (PUTREC or PUTCHR)
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beq CIO_pass ; pass through, buffer not used
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cmp #RENAME ; 2 filenames as input parameters in buffer, length not used
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beq CIO_filename2
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cmp GETCWD
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bcc CIO_filename ; filename as parameter in buffer, length not used
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beq CIO_read ; input
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bcs CIO_pass ; other command: assume no buffers
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.if 0 ; all crap
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; check if buffer is potentially used (buffer length != 0)
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; one filename, terminated by "invalid character", located at ICBAL/ICBAH
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CIO_filename:
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jsr setup_zpptr1_y0
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jsr copy_filename
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CIO_fn_cont:
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jsr ciobuf_to_iocb
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ldy CIO_y
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jsr CIO_call_a ; call CIO (maybe A isn't needed, then we could call CIO_call)
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php
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pha
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lda ICBLL,x
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ora ICBLH,x
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bne could_be
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;@@@ check if X is preserved over CIO call
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jsr restore_icba ; restore original ICBAL/ICBAH
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pla
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jmp CIOV_call
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plp
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rts ; back to application
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; buffer might be used by the request
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could_be:
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; two filenames, terminated and separated by "invalid character", located at ICBAL/ICBAH
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; check if buffer is inside ROM area
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lda ICBAH,x
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cmp #$C0 ; if buffer is above $C000, it's definitely inside ROM area
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bcs need_work
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lda ICBAL,x ; low byte of buffer address
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adc ICBLL,x ; low byte of buffer length
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lda ICBAH,x ; high byte (address)
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adc ICBLH,x ; high byte (length)
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cmp #$C0
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bcc CIOV_call ; no need to use bounce buffers, just forward call to CIO
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need_work:
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; Check if length is bigger than the size of our bounce buffer.
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; If yes, we need to split the call into multiple calls.
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; @@@ FIXME: currently only supports bounce buffers < 256 bytes
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lda ICBLH,x ; high byte of length
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bne hard_work
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lda ICBLL,x ; low byte of length
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cmp #<BUFSZ_CIO
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beq little_work
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bcs hard_work
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; Request buffer is smaller or equal to our bounce buffer.
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; Copy the data into the bounce buffer, set bounce buffer address
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; in the IOCB, call CIO, and copy the output data back.
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; @@@ TODO: check for read/write and do only one of the copy operations
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little_work:
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CIO_filename2:
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jsr setup_zpptr1_y0
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jsr copy_filename
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iny
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jsr copy_filename
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jmp CIO_fn_cont
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; Request buffer is larger than our bounce buffer.
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hard_work:
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.endif ; crap alert
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CIO_call_a:
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lda CIO_a
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CIOV_call:
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pha
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@ -248,6 +195,321 @@ CIOV_call:
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rts
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CIO_write:
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lda ICBLL,x
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ora ICBLH,x
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beq CIO_call_a ; special I/O through A register in case buffer length is 0
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;...
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bne CIO_call_a
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; CIO handler
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; We have buffer pointer and length entries in the IOCB, but their
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; usage depends on the function.
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; Some functions don't care about any of them (pointer and length),
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; and some only use the pointer (like e.g. OPEN), and some use both.
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; So we need function specific handlers to correctly deal with
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; buffers which are overlapping with the ROM area.
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; All input and output registers need to be preserved (I'm not 100%
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; sure about Y as input, but let's preserve it for now.)
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;
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; FIXME: Currently only the requests used by the runtime lib are handled.
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my_CIOV:
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;jmp CIOV_call
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;brk
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; @@@ TODO: check X for valid IOCB index ((X < $80) and ((X & $F) == 0))
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sta CIO_a
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sty CIO_y
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stx CIO_x
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lda ICCOM,x ; get function
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cmp #OPEN
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beq CIO_filename ; filename as input parameter in buffer, length not used
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cmp #PUTREC
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bcc CIO_read ; input (GETREC or GETCHR)
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cmp #CLOSE
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bcc CIO_write ; output (PUTREC or PUTCHR)
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beq CIO_call_a ; pass through, buffer not used
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cmp #RENAME ; 2 filenames as input parameters in buffer, length not used
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beq CIO_filename2
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cmp #GETCWD
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bcc CIO_filename ; filename as input parameter in buffer, length not used
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beq CIO_read ; input
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bcs CIO_call_a ; other commands: assume no buffer
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; not reached
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CIO_read:
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lda ICBLL,x
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ora ICBLH,x
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beq CIO_call_a ; special I/O through A register in case buffer length is 0
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; If the data length is larger than our bounce buffer, we have to split the request into smaller ones.
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; Otherwise we can get away with one call and a copy to the final destination afterwards.
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lda ICBLH,x ; get high byte of length
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bne big_read ; not zero -> data too large for our buffers
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; CHANGE HERE TO SUPPORT BOUNCE BUFFERS > 255 BYTES
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lda #<BUFSZ_CIO
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cmp ICBLL,x
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bcc big_read
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; Data size fits into bounce buffer
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jsr setup_zpptr1
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jsr ciobuf_to_iocb
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jsr CIO_call_a ; call CIO
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php
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bpl no_err
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cpy #EOFERR
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beq no_err
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pha
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jsr restore_icba
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pla
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plp
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rts ; return with error
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no_err:
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sta CIO_a
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sty CIO_y
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jsr copy_to_user ; copy data into user buffer
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jsr restore_icba
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lda CIO_a
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ldy CIO_y
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plp
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rts ; return with success
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; Data size does not fit into bounce buffer
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big_read:
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lda #0
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sta retlen ; initialize return length
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sta retlen+1
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jsr iocblen_to_orig_len
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jsr iocbptr_to_orig_ptr
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jsr setup_zpptr1
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jsr ciobuf_to_iocb ; let ICBAL/ICBAH point to bounce buffer
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br_loop:
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jsr cmp_orig_len_cio_bufsz ; is transfer length > bounce buffer size?
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bcs br_last ; no, last transfer, use remaining size
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lda #>BUFSZ_CIO
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sta ICBLH,x ; set data length
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lda #<BUFSZ_CIO
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sta ICBLL,x
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bne br_cont
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br_last:
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lda orig_len+1
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sta ICBLH,x ; set data length
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lda orig_len
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sta ICBLL,x
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br_cont:
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sta req_len ; remember length of this request
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lda ICBLH,x
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sta req_len+1
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jsr CIO_call_a ; do the request
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php
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bpl br_no_err
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cpy #EOFERR
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beq br_no_err
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pha
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jsr restore_icba
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pla
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plp
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rts ; return with error
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br_no_err:
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sta CIO_a
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sty CIO_y
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pla
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sta CIO_p
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jsr copy_to_user
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; update retlen
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clc
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lda retlen
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adc ICBLL,x
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sta retlen
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lda retlen+1
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adc #0
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sta retlen+1
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; if the request read less bytes than requested, we're done
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lda ICBLL,x
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cmp req_len
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bne br_done
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lda ICBLH,x
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cmp req_len+1
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bne br_done
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; update user buffer pointer (zpptr1)
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lda zpptr1
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adc ICBLL,x
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sta zpptr1
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lda zpptr1+1
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adc #0
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sta zpptr1+1
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; update remaining length
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sec
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lda orig_len
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sbc ICBLL,x
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sta orig_len
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lda orig_len+1
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sbc #0
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sta orig_len+1
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; still something left to do (remaining length != 0)?
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lda orig_len
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ora orig_len+1
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beq br_done
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jmp br_loop
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; done, write original buffer pointer and total transfer length to IOCB and return to application
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br_done:
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lda retlen
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sta ICBLL,x
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lda retlen+1
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sta ICBLH,x
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jsr orig_ptr_to_iocbptr
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lda CIO_p
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pha
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lda CIO_a
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ldy CIO_y
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plp
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rts ; return with success
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; check if length is larger than bounce buffer size
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; input: orig_len - length
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; output: A - destroyed
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; CF - 0/1 for larger/not larger
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cmp_orig_len_cio_bufsz:
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sec
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lda #<BUFSZ_CIO
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sbc orig_len
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lda #>BUFSZ_CIO
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sbc orig_len+1
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rts
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; copy data from bounce buffer into user buffer
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; input: X - IOCB index
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; zpptr1 - pointer to user buffer
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; output: A - destroyed
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; Y - 0
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copy_to_user:
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ldy ICBLL,x ; get # of bytes read (CHANGE HERE TO SUPPORT BOUNCE BUFFERS > 255 BYTES)
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beq copy_done
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copy: dey
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lda CIO_buffer,y
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sta (zpptr1),y
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cpy #0
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bne copy
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copy_done:
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rts
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; copy ICBLL/ICBLH to 'orig_len'
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; input: X - IOCB index
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; output: A - destroyed
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iocblen_to_orig_len:
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lda ICBLL,x
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sta orig_len
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lda ICBLH,x
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sta orig_len+1
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rts
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; copy ICBAL/ICBAH to 'orig_ptr'
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; input: X - IOCB index
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; output: A - destroyed
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iocbptr_to_orig_ptr:
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lda ICBAL,x
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sta orig_ptr
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lda ICBAH,x
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sta orig_ptr+1
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rts
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; copy 'orig_ptr' to ICBAL/ICBAH
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; input: X - IOCB index
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; output: A - destroyed
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orig_ptr_to_iocbptr:
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lda orig_ptr
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sta ICBAL,x
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lda orig_ptr+1
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sta ICBAH,x
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rts
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; restore original contents of ICBAL/ICBAH from 'zpptr1'
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; input: X - IOCB index
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; output: A - destroyed
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restore_icba:
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lda zpptr1
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sta ICBAL,x
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lda zpptr1+1
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sta ICBAH,x
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rts
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; put bounce buffer address into ICBAL/ICBAH
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; input: X - IOCB index
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; output: A - destroyed
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ciobuf_to_iocb:
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lda #<CIO_buffer
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sta ICBAL,x
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lda #>CIO_buffer
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sta ICBAH,x
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rts
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; copy file name pointed to by 'zpptr1' to bounce buffer 'CIO_buffer'
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; input: Y - index into file name buffer and CIO_buffer
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; output: Y - points to first invalid byte after file name
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; A - destroyed
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copy_filename:
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lda (zpptr1),y
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sta CIO_buffer,y
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beq copy_fn_done
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iny
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cmp #ATEOL
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bne copy_filename
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dey
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copy_fn_done:
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rts
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; write IOCB buffer address into zpptr1
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; input: X - IOCB index
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; output: Y - 0 (for setup_zpptr1_y0, else unchanged)
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; A - destroyed
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setup_zpptr1_y0:
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ldy #0
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setup_zpptr1:
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lda ICBAL,x ; put buffer address into zp pointer
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sta zpptr1
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lda ICBAH,x
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sta zpptr1+1
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rts
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;---------------------------------------------------------
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my_SIOV:
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pha
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lda PORTB
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@ -263,6 +525,7 @@ my_SIOV:
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plp
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rts
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;---------------------------------------------------------
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KEYBDV_wrapper:
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@ -284,8 +547,16 @@ kret: pha
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pla
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rts
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CIO_a: .res 1
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CIO_x: .res 1
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CIO_y: .res 1
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CIO_p: .res 1
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cur_CIOV_PORTB: .res 1
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cur_SIOV_PORTB: .res 1
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cur_KEYBDV_PORTB: .res 1
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orig_ptr: .res 2
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orig_len: .res 2
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req_len: .res 2
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retlen: .res 2
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.endif ; .if .defined(__ATARIXL__)
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