1 line
6.1 KiB
Plaintext
1 line
6.1 KiB
Plaintext
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;*******************************************************
;
; SCSI Driver 'Open' Filter
;
; Written by Matt Gulick. Started June 8,1988
;
; Copyright Apple Computer, Inc. 1988,89
;
;*******************************************************
;*******************************************************
;
; This file contains the subroutines needed by the
; SCSI Driver to respond to the Open call number
; $0001. In a Block Device Driver this will return no
; error and perform no function. In the case of a
; Character device however, this will need to prepare
; the target device for Data I/O that may be sent to
; it.
;
;*******************************************************
;*******************************************************
;
; Revision History:
;
;*******************************************************
; June 8, 1988 File started.
; June 20 1988 Registers in and out are
;
; April 11 1989 Added Character Device Code.
STRING PASCAL
BLANKS OFF
PAGESIZE 70
PRINT NOGEN
PRINT NOMDIR
MACHINE M65816
IMPORT test_unit_rdy
IMPORT auto_sense_data
IMPORT reserve_unit
PRINT OFF
INCLUDE 'scsihd.equates'
INCLUDE 'M16.MEMORY'
INCLUDE 'M16.UTIL'
PRINT ON
EJECT
IF block_dvc = true\
AND character_dvc = false THEN
;*******************************************************
;
; This routine is used as the Open code for a Block
; Device Driver.
;
; Inputs: None.
;
; Outputs: Acc = 0
; Carry = 0
; Y register = Unspecified
; X register = Unspecified
; P register = 0=M=X=e
; Direct Page = GS/OS Direct Page
; Data Bank = Ours
;
; Errors: None.
;
;*******************************************************
ENDIF
;-------------------------------------------------------------------------------
IF character_dvc = true\
AND block_dvc = false THEN
;*******************************************************
;
; This routine is used as the Open code for a
; Character Device Driver. This code is commented out
; so that is available to any one who uses this SCSI
; Driver Skeleton.
;
; Inputs: None.
;
; Outputs: Acc = Error
; Carry = Set or Clear
; Y register = Unspecified
; X register = Unspecified
; P register = 0=M=X=e
; Direct Page = GS/OS Direct Page
; Data Bank = Ours
;
; Errors: Already Open Error $0024
; For other errors see Spec.
;
;*******************************************************
ENDIF
;-------------------------------------------------------------------------------
EXPORT open
open PROC
;-------------------------------------------------------------------------------
IF block_dvc = true\
AND character_dvc = false THEN
;
; Is the device online?
;
ldy #dib.dvcflag
lda [dib_ptr],y
and #dvc_online
bne @open ;Yes.
;
; Device is currently offline.
;
lda #drvr_off_line
sec
rts
;
; Return ok.
;
@open lda #$0000
clc
rts
ENDIF
;-------------------------------------------------------------------------------
IF character_dvc = true\
AND block_dvc = false THEN
;
; Is the device online?
;
ldy #dib.dvcflag
lda [dib_ptr],y
and #dvc_online
bne @open ;Yes.
;
; Device is currently offline.
;
lda #drvr_off_line
sec
rts
;
; Check if Open.
;
@open lda |open_flag
bne @alrdy_opn
;-------------------------------------------------------------------------------
IF scsi_dtype = scanner\
OR scsi_dtype = appl_laser THEN
;
; It's a character device. Prepare it
; for operation.
;
; Set flag so that we will do this
; at most 2 times for this call.
;
@try_again lda #$ffff
sta @loop_cnt
;
; Is the Unit Ready for
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