diff options
Diffstat (limited to 'system/shard-x86-at/7/src/FDISK.ASM')
| -rw-r--r-- | system/shard-x86-at/7/src/FDISK.ASM | 839 |
1 files changed, 839 insertions, 0 deletions
diff --git a/system/shard-x86-at/7/src/FDISK.ASM b/system/shard-x86-at/7/src/FDISK.ASM new file mode 100644 index 0000000..1ada045 --- /dev/null +++ b/system/shard-x86-at/7/src/FDISK.ASM @@ -0,0 +1,839 @@ +;-----------------------------------------------------------------------
+; Disketten I/O
+; Input:
+; (ah)=0 Reset Diskette System
+; hard reset to nec, prepare command, recal rquired
+; on all drives
+; (ah)=1 read the status of the system into (al)
+; diskette_status from last operation is used
+;
+; Registers for read/write/verify/format
+; (dl) drive number (0-3 allowed, vlue checked)
+; (dh) head number (0-1 allowed, not value checked)
+; (ch) track number (0-39, not value checked)
+; (cl) sektor number (1-8, not value checked,
+; not used for format)
+; (al) number of sektors ( max = 8, not value checked,
+; not used for format
+; (es:bx) address of buffer (not required for verify)
+; (ah)=2 read the desired sektors into memory
+; =3 write
+; =4 verify
+; =5 format
+; for the format operation, the buffer pointer (es,bx)
+; must point to the collektion of desired address fields
+; for the track. Each field is composed of 4 Bytes,
+; (c,h,r,n) where c = track number, h=head number,
+; r = sektor number, n = number of bytes per sektor
+; (00=128, 01=256, 02=512, 03=1024). There must be one
+; entry for every sektor on the track. This information
+; is used to find the requested sektor during read/write
+; access.
+;
+; Data Variable -- disk_pointer
+; double word pointer to the current set of diskette parameters
+; Output
+; ah = status of Operation
+; Status bits are defined in the equates for
+; Diskette_status variable in the data segment of this
+; module.
+; cy = 0 successful operation (ah = 0 on return)
+; cy = 1 failed operation (ah has error reason)
+; for read/write/verify
+; ds,bx,dx,ch,cl reserved
+; al = number of sektors actually read
+; ***** al may not be correkt if time out error occurs
+; note: if an error is reported by the diskette code, the
+; appropriate action is to reset the diskette, then retry
+; the operation, on read access, no motor start delay
+; is taken, so that three retries are required on reads
+; to ensure that the problem is not due to motor
+; start-up.
+;-----------------------------------------------------------------------
+
+ data segment at 40h
+ org 3eh
+seek_status db ?
+int_flag equ 80h
+motor_status db ?
+motor_count db ?
+motor_wait equ 37
+diskette_status db ?
+nec_status db 7 dup(?)
+
+ data ends
+
+ assume ds:data
+
+ ife withhd
+dma equ 0 ; dma address
+dma_high equ 82h ; port for high 4 bits of dma
+ endif
+
+
+diskette_io proc near
+ sti
+ push bx
+ push cx
+ push ds
+ push si
+ push di
+ push bp
+ push dx
+ mov bp,sp ; set up pointer to head parm
+ mov si,data
+ mov ds,si
+ call j1 ; call the rest to ensure ds restored
+ mov bx,4 ; get the motor wait parameter
+ call get_parm
+ mov motor_count,ah ; set the timer count for the motor
+ mov ah,diskette_status ; get status of operation
+ cmp ah,1 ; set the carry flag to indicate
+ cmc ; success or failure
+ pop dx
+ pop bp
+ pop di
+ pop si
+ pop ds
+ pop cx
+ pop bx
+ ret
+diskette_io endp
+
+j1 proc near
+ mov dh,al
+ and motor_status,07fh
+ or ah,ah
+ jz disk_reset
+ dec ah
+ jz fdisk_status
+ mov diskette_status,0
+ cmp dl,4
+ jae j3
+ dec ah
+ jz fdisk_read
+ dec ah
+ jnz j2
+ jmp fdisk_write
+j2:
+ dec ah
+ jz disk_verf
+ dec ah
+ jz disk_format
+j3:
+ mov diskette_status,bad_cmd
+ ret
+j1 endp
+
+;----- reset the diskette system
+
+disk_reset proc near
+ mov dx,03f2h
+ cli
+ mov al,motor_status
+ mov cl,4
+ sal al,cl
+ test al,20h
+ jnz j5
+ test al,40h
+ jnz j4
+ test al,80h
+ jz j6
+ inc al
+j4:
+ inc al
+j5:
+ inc al
+j6:
+ or al,8
+ out dx,al
+ mov seek_status,0
+ mov diskette_status,0
+ or al,4
+ out dx,al
+ sti
+ call chk_stat_2
+
+ mov al,nec_status
+ cmp al,0c0h
+ jz j7
+ or diskette_status,bad_cntlr
+ ret
+
+;----- send specific command to nec
+
+j7:
+ mov ah,3
+ call nec_output
+ mov bx,1
+ call get_parm
+ mov bx,3
+ call get_parm
+j8:
+ ret
+disk_reset endp
+
+
+;-----diskette status routine
+
+fdisk_status proc near
+ mov al,diskette_status
+ ret
+fdisk_status endp
+
+
+;-----diskette read
+
+fdisk_read proc near
+ mov al,046h
+j9:
+ call dma_setup
+ mov ah,0e6h
+ jmp short rw_opn
+fdisk_read endp
+
+
+;----- diskette verify
+
+disk_verf proc near
+ mov al,042h
+ jmp j9
+disk_verf endp
+
+
+;----- diskette format
+
+disk_format proc near
+ or motor_status,80h
+ mov al,04ah
+ call dma_setup
+ mov ah,04dh
+ jmp short rw_opn
+j10:
+ mov bx,7
+ call get_parm
+ mov bx,9
+ call get_parm
+ mov bx,15
+ call get_parm
+ mov bx,17
+ jmp j16
+disk_format endp
+
+
+;-----diskette write routine
+
+fdisk_write proc near
+ or motor_status,80h
+ mov al,04ah
+ call dma_setup
+ mov ah,0c5h
+fdisk_write endp
+
+;-----allow write routine to fall into rw_opn
+
+;-----------------------------------------------------------------------
+; rw_opn
+; this routine performs the read/write/verify operation
+;-----------------------------------------------------------------------
+
+rw_opn proc near
+ jnc j11
+ mov diskette_status,dma_boundary
+ mov al,0
+ ret
+j11:
+ push ax
+
+;----- turn on the motor and select the drive
+
+ push cx
+ mov cl,dl
+ mov al,1
+ sal al,cl
+ cli
+
+ mov motor_count,0ffh
+ test al,motor_status
+ jnz j14
+ and motor_status,0f0h
+ or motor_status,al
+ sti
+ mov al,10h
+ sal al,cl
+ or al,dl
+ or al,0ch
+ push dx
+ mov dx,03f2h
+ out dx,al
+ pop dx
+
+;----- wait for motor if write operation
+
+ test motor_status,80h
+ jz j14
+
+ clc
+ mov ax,090fdh
+ int 15h
+ jc j14
+
+
+ mov bx,20
+ call get_parm
+ or ah,ah
+j12:
+ jz j14
+ sub cx,cx
+j13:
+ loop j13
+ dec ah
+ jmp j12
+j14:
+ sti
+ pop cx
+
+;----- do the seek operation
+
+ call seek
+ pop ax
+ mov bh,ah
+ mov dh,0
+ jc j17
+ mov si,offset j17
+ push si
+
+;----- send out the parameters to the controller
+
+ call nec_output
+ mov ah,[bp+1]
+ sal ah,1
+ sal ah,1
+ and ah,4
+ or ah,dl
+ call nec_output
+
+;----- test for format command
+
+ cmp bh,04dh
+ jne j15
+ jmp j10
+j15:
+ mov ah,ch
+ call nec_output
+ mov ah,[bp+1]
+ call nec_output
+ mov ah,cl
+ call nec_output
+ mov bx,7
+ call get_parm
+ mov bx,9
+ call get_parm
+ mov bx,11
+ call get_parm
+ mov bx,13
+j16:
+ call get_parm
+ pop si
+
+;----- let the operation happen
+
+ call wait_int
+j17:
+ jc j21
+ call results
+ jc j20
+
+;----- check the results returned by the controller
+
+ cld
+ mov si,offset nec_status
+ lods nec_status
+ and al,0c0h
+ jz j22
+ cmp al,040h
+ jnz j18
+
+;----- abnormal termination, find out wy
+
+ lods nec_status
+ sal al,1
+ mov ah,record_not_fnd
+ jc j19
+ sal al,1
+ sal al,1
+ mov ah,bad_crc
+ jc j19
+ sal al,1
+ mov ah,bad_dma
+ jc j19
+ sal al,1
+ sal al,1
+ mov ah,record_not_fnd
+ jc j19
+ sal al,1
+ mov ah,write_protect
+ jc j19
+ sal al,1
+ mov ah,bad_addr_mark
+ jc j19
+
+;----- nec must have failed
+
+j18:
+ mov ah,bad_cntlr
+j19:
+ or diskette_status,ah
+ call num_trans ; how many were really transferred
+j20:
+ ret
+j21:
+ call results
+ ret
+
+;----- operation was successfull
+
+j22:
+ call num_trans
+ xor ah,ah
+ ret
+rw_opn endp
+
+;-----------------------------------------------------------------------
+; nec_output
+; This routine sends a byte to the nec controller after testing
+; for correct direction and controller ready. This routine will
+; time out if the byte is not accepted within a reasonable
+; amount of time, setting the diskette status on completion.
+; Input
+; (ah) byte to be output
+; Output
+; cy=0 success
+; cy=1 failure -- diskette status updated
+; If a failure has occured, the return is made one level
+; higher than the caller of nec_output. (!Schweinkram)
+; This removes the requirement of testing after every
+; call of nec_output
+; (al) destroyed
+;-----------------------------------------------------------------------
+
+nec_output proc near
+ push dx
+ push cx
+ mov dx,03f4h
+ xor cx,cx
+j23:
+ in al,dx
+ test al,040h
+ jz j25
+ loop j23
+j24:
+ or diskette_status,time_out
+ pop cx
+ pop dx
+ pop ax ; discard the return address
+ stc
+ ret
+j25:
+ xor cx,cx
+j26:
+ in al,dx
+ test al,080h
+ jnz j27
+ loop j26
+ jmp j24
+j27:
+ mov al,ah
+ mov dl,0f5h
+ out dx,al
+ pop cx
+ pop dx
+ ret
+nec_output endp
+
+;-----------------------------------------------------------------------
+; get_parm
+; This routine fetches the indext pointer from the disk_bas
+; block pointed at by the data variable disk_pointer. A byte from
+; that table is then moved into ah, the index of that byte being
+; the parm in bx
+; Input:
+; bx index of byte to be fetched *2
+; if the low bit of bx is on, the byte is immediately output
+; to the nec controller
+; Exit
+; am that byte from block
+;-----------------------------------------------------------------------
+
+disk_pointer equ 1eh * 4
+
+get_parm proc near
+ push ds
+ push si
+ sub ax,ax
+ mov ds,ax
+
+ lds si,dword ptr ds:disk_pointer
+ shr bx,1
+
+ mov ah,[si+bx]
+ pop si
+ pop ds
+ jc nec_output
+ ret
+get_parm endp
+
+;-----------------------------------------------------------------------
+; seek
+; Thi routine will move the head on the named drive to the
+; named track. If the drive has not been accessed since the
+; drive reset command was issued, the drive will be recalibrated.
+; Input:
+; (dl) = Drive to seek on
+; (ch) = track t seek to
+; Output:
+; cy = 0 success
+; cy = 1 failure -- diskette_status set accordingly
+; (ax) destroyed
+;-----------------------------------------------------------------------
+
+seek proc near
+ mov al,1
+ push cx
+ mov cl,dl
+ rol al,cl
+ pop cx
+ test al,seek_status
+ jnz j28
+ or seek_status,al
+ mov ah,07h
+ call nec_output
+ mov ah,dl
+ call nec_output
+ call chk_stat_2
+ jc j32
+
+;----- drive is in synch with controller, seek to track
+
+j28:
+ mov ah,0fh
+ call nec_output
+ mov ah,dl
+ call nec_output
+ mov ah,ch
+ call nec_output
+ call chk_stat_2
+
+;----- wait for head settle
+
+ pushf
+ mov bx,18
+ call get_parm
+ push cx
+j29:
+ mov cx,550
+ or ah,ah
+ jz j31
+j30:
+ loop j30
+ dec ah
+ jmp j29
+j31:
+ pop cx
+ popf
+j32:
+ ret
+seek endp
+
+;-----------------------------------------------------------------------
+; dma_setup
+; this routine sets up the dma for read/write/verify operations
+; input:
+; (al) = mode byte for the dma
+; (es:bx) - address to read/write the data
+; output:
+; (ax) destroyed
+;-----------------------------------------------------------------------
+
+dma_setup proc near
+ push cx
+ cli
+ out dma+12,al
+ push ax
+ pop ax
+ out dma+11,al
+ mov ax,es
+ mov cl,4
+ rol ax,cl
+ mov ch,al
+ and al,0f0h
+ add ax,bx
+ jnc jj33
+ inc ch
+jj33:
+ push ax
+ out dma+4,al
+ mov al,ah
+ out dma+4,al
+ mov al,ch
+ and al,0fh
+ out 081h,al
+
+;----- determine count
+
+ mov ah,dh
+ sub al,al
+ shr ax,1
+ push ax
+ mov bx,6
+ call get_parm
+ mov cl,ah
+ pop ax
+ shl ax,cl
+ dec ax
+ push ax
+ out dma+5,al
+ mov al,ah
+ out dma+5,al
+ sti
+ pop cx
+ pop ax
+ add ax,cx
+ pop cx
+ mov al,2
+ out dma+10,al
+ ret
+dma_setup endp
+
+;-----------------------------------------------------------------------
+; chk_stat_2
+; This routine handles the interrupt received after a
+; recalibrate, seek, or reset to the adapter.
+; The interrupt is waited for, the interrupt sensed,
+; and the result returned to the caller.
+; input:
+; none
+; output:
+; cy = 0 success
+; cy = 1 failure -- error is in diskette_status
+; (ax) destroyed
+;-----------------------------------------------------------------------
+
+chk_stat_2 proc near
+ call wait_int
+ jc j34
+ mov ah,08h
+ call nec_output
+ call results
+ jc j34
+ mov al,nec_status
+ and al,060h
+ cmp al,060h
+ jz j35
+ clc
+j34:
+ ret
+j35:
+ or diskette_status,bad_seek
+ stc
+ ret
+chk_stat_2 endp
+
+;-----------------------------------------------------------------------
+; wait_int
+; This routine waits for an interrupt to occur. A time out
+; routine takes place during the wait, so that an error may be
+; returned if the drive is not ready.
+; input:
+; none
+; output:
+; cy = 0 success
+; cy = 1 failure -- diskette_status is set accordingly
+; (ax) destroyed
+;-----------------------------------------------------------------------
+
+wait_int proc near
+ sti
+ push ax
+ push bx
+ push cx
+ clc
+ mov ax,09001h
+ int 15h
+ sti
+ jc j36a
+;
+ mov bl,2
+ xor cx,cx
+j36:
+ test seek_status,int_flag
+ jnz j37
+; push cx
+; push bx
+; push ds
+; push es
+; push ax
+; push dx
+; push si
+; push di
+; push bp
+; call cs:warte
+; pop bp
+; pop di
+; pop si
+; pop dx
+; pop ax
+; pop es
+; pop ds
+; pop bx
+; pop cx
+ loop j36
+ dec bl
+ jnz j36
+
+j36a: or diskette_status, time_out
+ stc
+j37:
+ pushf
+ and seek_status, not int_flag
+ popf
+ pop cx
+ pop bx
+ pop ax
+ ret
+wait_int endp
+
+;-----------------------------------------------------------------------
+; disk_int
+; This routine handles the diskette interrupt
+; Input
+; none
+; output:
+; The interrupt flag is set is seek_status
+;-----------------------------------------------------------------------
+
+;**************
+;org 0ef57h
+;**************
+disk_int proc far
+ sti
+ push ds
+ push ax
+ push si
+ mov si,data
+ mov ds,si
+ or seek_status, int_flag
+ mov al,20h
+ out 20h,al
+ mov ax,09101h
+ int 15h
+ pop si
+ pop ax
+ pop ds
+ iret
+disk_int endp
+
+;-----------------------------------------------------------------------
+; results
+; This routine will read anything that the nec controller has
+; to say following an interrupt.
+; input:
+; none
+; output:
+; cy = 0 successful transfer
+; cy = 1 failure -- time out in waiting for status
+; nec_status area has status byte loaded into it
+; (ah) destroyed
+;-----------------------------------------------------------------------
+
+results proc near
+ cld
+ mov di,offset nec_status
+ push cx
+ push dx
+ push bx
+ mov bl,7
+
+;-----wait for request for master
+
+j38:
+ xor cx,cx
+ mov dx,03f4h
+j39:
+ in al,dx
+ test al,80h
+ jnz j40a
+ loop j39
+ or diskette_status, time_out
+j40:
+ stc
+ pop bx
+ pop dx
+ pop cx
+ ret
+
+;----- test the direction bit
+
+j40a:
+ in al,dx
+ test al,40h
+ jnz j42
+j41:
+ or diskette_status,bad_cntlr
+ jmp j40
+
+;-----read in the status
+
+j42:
+ inc dx
+ in al,dx
+ mov [di],al
+ inc di
+ mov cx,10
+j43: loop j43
+ dec dx
+ in al,dx
+ test al,10h
+ jz j44
+ dec bl
+ jnz j38
+ jmp j41
+
+;----- result operation is done
+
+j44:
+ pop bx
+ pop dx
+ pop cx
+ ret
+
+;-----------------------------------------------------------------------
+; num_trans
+; This routine calculates the number of sectors that were
+; actually transferred to/from the diskette
+; input
+; (ch) = cylinder of operation
+; (cl) = start sector of operation
+; output
+; (al) = number actually transferred
+; no other registers modified
+;-----------------------------------------------------------------------
+
+num_trans proc near
+ mov al,nec_status+3
+ cmp al,ch
+ mov al,nec_status+5
+ jz j45
+ mov bx,8
+ call get_parm
+ mov al,ah
+ inc al
+j45:
+ sub al,cl
+ ret
+num_trans endp
+results endp
+
+ assume ds:shard
+
+
\ No newline at end of file |