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|
;
; Christian Groessler, October 2000
;
; This file provides the __sio_call function
; The function does a SIO call, it's not completely
; generic (e.g. transfer size is fixed), it's used
; to save space with _dio_read and _dio_write functions.
;
; unsigned char __fastcall__ _sio_call(dhandle_t handle,
; unsigned sect_num,
; void *buffer,
; unsigned sio_val);
; dhandle_t - 16bit (ptr)
; sio_val is (sio_command | sio_direction << 8)
;
.export __sio_call
.include "atari.inc"
.import popa,popax,popptr1
.import sectsizetab,__oserror
.importzp ptr1
.proc __sio_call
sta DCOMND ; set command into DCB
stx DSTATS ; set data flow directon
jsr popax ; get buffer address
sta DBUFLO ; set buffer address into DCB
stx DBUFHI
jsr popax
sta DAUX1 ; set sector #
stx DAUX2
jsr popptr1
ldy #sst_flag
lda (ptr1),y
and #128
beq _inv_hand ; handle not open or invalid
ldy #sst_driveno
lda (ptr1),y
clc
adc #1
sta DUNIT ; unit number (d1,d2,d3,...)
lda DAUX2 ; high byte sector #
bne _realsz
lda DAUX1
cmp #4 ; sectors 1 to 3 are special (always 128 bytes)
bcs _realsz
lda #$80
sta DBYTLO
asl a
sta DBYTHI
beq _cont
_realsz:ldy #sst_sectsize
lda (ptr1),y
sta DBYTLO
iny
lda (ptr1),y
sta DBYTHI
_cont: lda #DISKID ; SIO bus ID of diskette drive
sta DDEVIC
lda #15
sta DTIMLO ; value got from DOS source
jsr SIOV ; execute
ldx #0
lda DSTATS
bmi _req_err ; error occurred
txa ; no error occurred
_req_err:
sta __oserror
rts
_inv_hand:
ldx #0
lda #BADIOC
bne _req_err
.endproc
|
