Upload

Digital Research

MPM OPERATING SYSTEMS/MPM I/MPM I SOURCE/12/mxios.asm

@@ -0,0 +1,882 @@
+;
+; Note: this module assumes that an ORG statement will be
+;   provided by concatenating either BASE0000.ASM or BASE0100.ASM
+;   to the front of this file before assembling.
+;
+;	title	'Xios for the MDS-800'
+
+;	(four drive single density version)
+;			-or-
+;	(four drive mixed double/single density)
+
+;	Version 1.1X November, 1979
+
+;	Copyright (C) 1979
+;	Digital Research
+;	Box 579, Pacific Grove
+;	California, 93950
+
+false	equ	0
+true	equ	not false
+
+asm	equ	true
+mac	equ	not asm
+
+sgl	equ	true
+dbl	equ	not sgl
+
+	if	mac
+	maclib	diskdef
+	endif
+
+numdisks equ	4	;number of drives available
+
+;	external jump table (below xios base)
+pdisp	equ	$-3
+xdos	equ	pdisp-3
+
+;	mds interrupt controller equates
+revrt	equ	0fdh	; revert port
+intc	equ	0fch	; mask port
+icon	equ	0f3h	; control port
+rtc	equ	0ffh	; real time clock
+inte	equ	1111$1101b ; enable rst 1
+
+;	mds disk controller equates
+dskbase	equ	78h	; base of disk io prts
+dstat	equ	dskbase	; disk status
+rtype	equ	dskbase+1	; result type
+rbyte	equ	dskbase+3	; result byte
+
+ilow	equ	dskbase+1	; iopb low address
+ihigh	equ	dskbase+2	; iopb high address
+
+readf	equ	4h	; read function
+writf	equ	6h	; write function
+iordy	equ	4h	; i/o finished mask
+retry	equ	10	; max retries on disk i/o
+
+;	basic i/o system jump vector
+	jmp	coldstart	;cold start
+wboot:
+	jmp	warmstart	;warm start
+	jmp	const		;console status
+	jmp	conin		;console character in
+	jmp	conout		;console character out
+	jmp	list		;list character out
+	jmp	rtnempty	;punch not implemented
+	jmp	rtnempty	;reader not implemented
+	jmp	home		;move head to home
+	jmp	seldsk		;select disk
+	jmp	settrk		;set track number
+	jmp	setsec		;set sector number
+	jmp	setdma		;set dma address
+	jmp	read		;read disk
+	jmp	write		;write disk
+	jmp	pollpt		;list status
+	jmp	sect$tran		;sector translate
+
+;	extended i/o system jump vector
+	jmp	selmemory	; select memory
+	jmp	polldevice	; poll device
+	jmp	startclock	; start clock
+	jmp	stopclock	; stop clock
+	jmp	exitregion	; exit region
+	jmp	maxconsole	; maximum console number
+	jmp	systeminit	; system initialization
+	jmp	saveZ80		; save extra Z80 registers
+	jmp	restoreZ80	; restore extra Z80 registers
+	jmp	idle		; idle procedure
+
+coldstart:
+warmstart:
+	mvi	c,0		; see system init
+				; cold & warm start included only
+				; for compatibility with cp/m
+	jmp	xdos		; system reset, terminate process
+
+;  MP/M 1.0   console handlers
+
+nmbcns	equ	2	; number of consoles
+
+poll	equ	131	; xdos poll function
+
+pllpt	equ	0	; poll printer
+pldsk	equ	1	; poll disk
+plco0	equ	2	; poll console out #0 (CRT:)
+plco1	equ	3	; poll console out #1 (TTY:)
+plci0	equ	4	; poll console in #0 (CRT:)
+plci1	equ	5	; poll console in #1 (TTY:)
+
+;
+const:			; console status
+	call	ptbljmp	; compute and jump to hndlr
+	dw	pt0st	; console #0 status routine
+	dw	pt1st	; console #1 (TTY:) status rt
+
+conin:			; console input
+	call	ptbljmp	; compute and jump to hndlr
+	dw	pt0in	; console #0 input
+	dw	pt1in	; console #1 (TTY:) input
+
+conout:			; console output
+	call	ptbljmp	; compute and jump to hndlr
+	dw	pt0out	; console #0 output
+	dw	pt1out	; console #1 (TTY:) output
+
+;
+ptbljmp:		; compute and jump to handler
+			; d = console #
+			; do not destroy <d>
+	mov	a,d
+	cpi	nmbcns
+	jc	tbljmp
+	pop	psw	; throw away table address
+rtnempty:
+	xra	a
+	ret
+tbljmp:			; compute and jump to handler
+			; a = table index
+	add	a	; double table index for adr offst
+	pop	h	; return adr points to jump tbl
+	mov	e,a
+	mvi	d,0
+	dad	d	; add table index * 2 to tbl base
+	mov	e,m	; get handler address
+	inx	h
+	mov	d,m
+	xchg
+	pchl		; jump to computed cns handler
+
+
+; ascii character equates
+
+rubout	equ	7fh
+space	equ	20h
+
+; serial i/o port address equates
+
+data0	equ	0f6h
+sts0	equ	data0+1
+data1	equ	0f4h
+sts1	equ	data1+1
+lptport	equ	0fah
+lptsts	equ	lptport+1
+
+; poll console #0 input
+
+polci0:
+pt0st:			; return 0ffh if ready,
+			;        000h if not
+	in	sts0
+	ani	2
+	rz
+	mvi	a,0ffh
+	ret
+;
+; console #0 input
+;
+pt0in:			; return character in reg a
+	mvi	c,poll
+	mvi	e,plci0
+	call	xdos		; poll console #0 input
+	in	data0		; read character
+	ani	7fh		; strip parity bit
+	ret
+;
+; console #0 output
+;
+pt0out:			; reg c = character to output
+	push	b
+	call	pt0wait		; poll console #0 output
+	pop	b
+	mov	a,c
+	out	data0		; transmit character
+	ret
+;
+; wait for console #0 output ready
+;
+pt0wait:
+	mvi	c,poll
+	mvi	e,plco0
+	jmp	xdos		; poll console #0 output
+;	ret
+
+;
+; poll console #0 output
+;
+polco0:
+			; return 0ffh if ready,
+			;        000h if not
+	in	sts0
+	ani	01h
+	rz
+	mvi	a,0ffh
+	ret
+;
+;
+; line printer driver:
+;
+list:			; list output
+	push	b
+	push	d
+	mvi	c, poll
+	mvi	e, pllpt
+	call	xdos
+	pop	d
+	pop	b
+	mov	a,c
+	cma
+	out	lptport
+	ret
+;
+; poll printer output
+;
+pollpt:
+			; return 0ffh if ready,
+			;        000h if not
+	in	lptsts
+	ani	01h
+	rz
+	mvi	a,0ffh
+	ret
+;
+; poll console #1 (TTY:) input
+;
+polci1:
+pt1st:
+			; return 0ffh if ready,
+			;        000h if not
+	in	sts1
+	ani	2
+	rz
+	mvi	a,0ffh
+	ret
+;
+; console #1 (TTY:) input
+;
+pt1in:
+			; return character in reg a
+	mvi	c,poll
+	mvi	e,plci1
+	call	xdos		; poll console #1 input
+	in	data1		; read character
+	ani	7fh		; strip parity bit
+	ret
+;
+; console #1 (TTY:) output
+;
+pt1out:
+			; reg c = character to output
+	push	b
+	call	pt1wait
+	pop	b
+	mov	a,c
+	out	data1		; transmit character
+	ret
+
+; wait for console #1 (TTY:) output ready
+
+pt1wait:
+	mvi	c,poll
+	mvi	e,plco1
+	jmp	xdos		; poll console #1 output
+;	ret
+
+; poll console #1 (TTY:) output
+
+polco1:
+			; return 0ffh if ready,
+			;        000h if not
+	in	sts1
+	ani	01h
+	rz
+	mvi	a,0ffh
+	ret
+;
+;
+;  MP/M 1.0   extended i/o system
+;
+;
+nmbdev	equ	6	; number of devices in poll tbl
+
+polldevice:
+			; reg c = device # to be polled
+			; return 0ffh if ready,
+			;        000h if not
+	mov	a,c
+	cpi	nmbdev
+	jc	devok
+	mvi	a,nmbdev; if dev # >= nmbdev,
+			; set to nmbdev
+devok:
+	call	tbljmp	; jump to dev poll code
+
+	dw	pollpt	; poll printer output
+	dw	poldsk	; poll disk ready
+	dw	polco0	; poll console #0 output
+	dw	polco1	; poll console #1 (TTY:) output
+	dw	polci0	; poll console #0 input
+	dw	polci1	; poll console #1 (TTY:) input
+	dw	rtnempty; bad device handler
+
+
+; select / protect memory
+
+selmemory:
+			; reg bc = adr of mem descriptor
+			; bc ->  base   1 byte,
+			;        size   1 byte,
+			;        attrib 1 byte,
+			;        bank   1 byte.
+
+; this hardware does not have memory protection or
+;  bank switching
+
+	ret
+
+
+; start clock
+
+startclock:
+			; will cause flag #1 to be set
+			;  at each system time unit tick
+	mvi	a,0ffh
+	sta	tickn
+	ret
+
+; stop clock
+
+stopclock:
+			; will stop flag #1 setting at
+			;  system time unit tick
+	xra	a
+	sta	tickn
+	ret
+
+; exit region
+
+exitregion:
+			; ei if not preempted
+	lda	preemp
+	ora	a
+	rnz
+	ei
+	ret
+
+; maximum console number
+
+maxconsole:
+	mvi	a,nmbcns
+	ret
+
+; system initialization
+
+systeminit:
+;	note: this system init assumes that the usarts
+;	have been initialized by the coldstart boot
+
+;	setup restart jump vectors
+	mvi	a,0c3h
+	sta	1*8
+	lxi	h,int1hnd
+	shld	1*8+1		; jmp int1hnd at restart 1
+
+;	setup interrupt controller & real time clock
+	mvi	a,inte
+	out	intc		; enable int 0,1,7
+	xra	a
+	out	icon		; clear int mask
+	out	rtc		; enable real time clock
+	ret
+
+;
+; Z80 extra register save and restore
+;
+saveZ80:
+	pop	h		; return address to HL
+	; push IX, IY, etc.
+	pchl
+
+restoreZ80:
+	; pop IX, IY, etc.
+	ret
+
+;
+; Idle procedure
+;
+idle:
+	mvi	c,dsptch
+	jmp	xdos		; perform a dispatch, this form
+				;  of idle must be used in systems
+				;  without interrupts, i.e. all polled
+
+;	-or-
+
+;	ei			; simply halt until awaken by an
+;	hlt			;  interrupt
+;	ret
+
+
+;  MP/M 1.0   interrupt handlers
+
+flagset	equ	133
+dsptch	equ	142
+
+int1hnd:
+			; interrupt 1 handler entry point
+			;  
+			;  location 0008h contains a jmp
+			;  to int1hnd.
+	push	psw
+	mvi	a,2h
+	out	rtc	; reset real time clock
+	out	revrt	; revert intr cntlr
+	lda	slice
+	dcr	a	; only service every 32nd slice
+	sta	slice
+	jz	t32ms	; jump if 32ms elapsed
+	pop	psw
+	ei
+	ret
+
+t32ms:
+	mvi	a,32
+	sta	slice	; reset slice counter
+	pop	psw
+	shld	svdhl
+	pop	h
+	shld	svdret
+	push	psw
+	lxi	h,0
+	dad	sp
+	shld	svdsp		; save users stk ptr
+	lxi	sp,intstk+48	; lcl stk for intr hndl
+	push	d
+	push	b
+
+	mvi	a,0ffh
+	sta	preemp	; set preempted flag
+
+	lda	tickn
+	ora	a		; test tickn, indicates
+				;  delayed process(es)
+	jz	notickn
+	mvi	c,flagset
+	mvi	e,1
+	call	xdos		; set flag #1 each tick
+notickn:
+	lxi	h,cnt32
+	dcr	m		; dec 32 tick cntr
+	jnz	not1sec
+	mvi	m,32
+	mvi	c,flagset
+	mvi	e,2
+	call	xdos		; set flag #2 @ 1 sec
+not1sec:
+	xra	a
+	sta	preemp	; clear preempted flag
+	pop	b
+	pop	d
+	lhld	svdsp
+	sphl			; restore stk ptr
+	pop	psw
+	lhld	svdret
+	push	h
+	lhld	svdhl
+
+; the following dispatch call will force round robin
+;  scheduling of processes executing at the same priority
+;  each 1/32nd of a second.
+; note: interrupts are not enabled until the dispatcher
+;  resumes the next process.  this prevents interrupt
+;  over-run of the stacks when stuck or high frequency
+;  interrupts are encountered.
+
+	jmp	pdisp		; MP/M dispatch
+
+;
+; bios data segment
+;
+slice:	db	32	; 32 slices = 32ms = 1 tick
+cnt32:	db	32	; 32 tick cntr = 1 sec
+intstk:	ds	48	; local intrpt stk
+svdhl:	dw	0	; saved regs hl during int hndl
+svdsp:	dw	0	; saved sp during int hndl
+svdret:	dw	0	; saved return during int hndl
+tickn:	db	0	; ticking boolean,true = delayed
+preemp:	db	0	; preempted boolean
+;
+
+* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+*								*
+*	Intel MDS-800 diskette interface routines		*
+*								*
+* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+
+seldsk:	;select disk given by register c
+	lxi 	h, 0 
+	mov 	a,c
+	cpi 	numdisks 
+	rnc  		; first, insure good select
+	ani 	2 	
+	sta 	dbank	; then save it
+	lxi 	h,sel$table 
+	mvi 	b,0 
+	dad 	b 
+	mov 	a,m 
+	sta 	iof
+	mov 	h,b 
+	mov 	l,c
+	dad 	h 
+	dad 	h 
+	dad 	h 
+	dad 	h	; times 16
+	lxi 	d,dpbase 
+	dad 	d
+	ret
+
+home:	;move to home position
+;	treat as track 00 seek
+	mvi	c,0
+;
+settrk:	;set track address given by c
+	lxi	h,iot
+	mov	m,c
+	ret
+;
+setsec:	;set sector number given by c
+	mov	a,c	;sector number to accum
+	sta	ios	;store sector number to iopb
+	ret
+;
+setdma:	;set dma address given by regs b,c
+	mov	l,c
+	mov	h,b
+	shld	iod
+	ret
+
+sect$tran:		; translate the sector # in <c> if needed
+	mov 	h,b 
+	mov 	l,c 
+	inx 	h  ; in case of no translation
+	mov 	a, d 
+	ora 	e 
+	rz	
+	xchg 
+	dad 	b	; point to physical sector
+	mov 	l,m 
+	mvi 	h,0
+	ret
+
+
+read:	;read next disk record (assuming disk/trk/sec/dma set)
+	mvi	c,readf	;set to read function
+	jmp	setfunc
+;
+write:	;disk write function
+	mvi	c,writf
+;
+setfunc:
+;	set function for next i/o (command in reg-c)
+	lxi	h,iof	;io function address
+	mov	a,m	;get it to accumulator for masking
+	ani	1111$1000b	;remove previous command
+	ora	c	;set to new command
+	mov	m,a	;replaced in iopb
+;	single density drive 1 requires bit 5 on in sector #
+;	mask the bit from the current i/o function
+	ani	0010$0000b	;mask the disk select bit
+	lxi	h,ios		;address the sector select byte
+	ora	m		;select proper disk bank
+	mov	m,a		;set disk select bit on/off
+;
+waitio:
+	mvi	c,retry	;max retries before perm error
+rewait:
+;	start the i/o function and wait for completion
+	call	intype	;in rtype
+	call	inbyte	;clears the controller
+
+	lda	dbank		;set bank flags
+	ora	a		;zero if drive 0,1 and nz if 2,3
+	mvi	a,iopb and 0ffh	;low address for iopb
+	mvi	b,iopb shr 8	;high address for iopb
+	jnz	iodr1	;drive bank 1?
+	out	ilow		;low address to controller
+	mov	a,b
+	out	ihigh	;high address
+	jmp	wait0		;to wait for complete
+
+iodr1:	;drive bank 1
+	out	ilow+10h	;88 for drive bank 10
+	mov	a,b
+	out	ihigh+10h
+wait0:
+	push	b		; save retry count
+	mvi	c, poll		; function poll
+	mvi	e, pldsk	; device is disk
+	call	xdos
+	pop	b		; restore retry counter in <c>
+
+
+;	check io completion ok
+	call	intype		;must be io complete (00) unlinked
+;	00 unlinked i/o complete,    01 linked i/o complete (not used)
+;	10 disk status changed       11 (not used)
+	cpi	10b		;ready status change?
+	jz	wready
+
+;	must be 00 in the accumulator
+	ora	a
+	jnz	werror		;some other condition, retry
+
+;	check i/o error bits
+	call	inbyte
+	ral
+	jc	wready		;unit not ready
+	rar
+	ani	11111110b	;any other errors?  (deleted data ok)
+	jnz	werror
+
+;	read or write is ok, accumulator contains zero
+	ret
+
+poldsk:
+	call	instat			; get current controller status
+	ani	iordy			; operation complete ?
+	rz				; not done
+	mvi	a,0ffh			; done flag
+	ret				; to xdos
+
+
+wready:	;not ready, treat as error for now
+	call	inbyte		;clear result byte
+	jmp	trycount
+
+werror:	;return hardware malfunction (crc, track, seek, etc.)
+;	the mds controller has returned a bit in each position
+;	of the accumulator, corresponding to the conditions:
+;	0	- deleted data (accepted as ok above)
+;	1	- crc error
+;	2	- seek error
+;	3	- address error (hardware malfunction)
+;	4	- data over/under flow (hardware malfunction)
+;	5	- write protect (treated as not ready)
+;	6	- write error (hardware malfunction)
+;	7	- not ready
+;	(accumulator bits are numbered 7 6 5 4 3 2 1 0)
+
+trycount:
+;	register c contains retry count, decrement 'til zero
+	dcr	c
+	jnz	rewait	;for another try
+
+;	cannot recover from error
+	mvi	a,1	;error code
+	ret
+
+;	intype, inbyte, instat read drive bank 00 or 10
+intype:	lda	dbank
+	ora	a
+	jnz	intyp1	;skip to bank 10
+	in	rtype
+	ret
+intyp1:	in	rtype+10h	;78 for 0,1  88 for 2,3
+	ret
+
+inbyte:	lda	dbank
+	ora	a
+	jnz	inbyt1
+	in	rbyte
+	ret
+inbyt1:	in	rbyte+10h
+	ret
+
+instat:	lda	dbank
+	ora	a
+	jnz	insta1
+	in	dstat
+	ret
+insta1:	in	dstat+10h
+	ret
+
+
+
+;	data areas (must be in ram)
+
+dbank:	db	0	;disk bank 00 if drive 0,1
+			;	   10 if drive 2,3
+
+iopb:			;io parameter block
+	db	80h	;normal i/o operation
+iof:	db	readf	;io function, initial read
+ion:	db	1	;number of sectors to read
+iot:	db	2	;track number
+ios:	db	1	;sector number
+iod:	dw	$-$	;io address
+
+
+sel$table:
+	if	sgl
+	db	00h, 30h, 00h, 30h	; drive select bits
+	endif
+	if	dbl
+	db	00h, 10h, 00h, 30h	; drive select bits
+	endif
+
+	if	mac and sgl
+	disks	numdisks		; generate drive tables
+	diskdef	0,1,26,6,1024,243,64,64,2
+	diskdef	1,0
+	diskdef	2,0
+	diskdef	3,0
+	endef
+	endif
+
+	if	mac and dbl
+	disks	numdisks		; generate drive tables
+	diskdef 0,1,52,,2048,243,128,128,2,0
+	diskdef	1,0
+	diskdef	2,1,26,6,1024,243,64,64,2
+	diskdef	3,2
+	endef
+	endif
+
+	if	asm
+dpbase	equ	$		;base of disk param blks
+dpe0:	dw	xlt0,0000h	;translate table
+	dw	0000h,0000h	;scratch area
+	dw	dirbuf,dpb0	;dir buff, parm block
+	dw	csv0,alv0	;check, alloc vectors
+dpe1:	dw	xlt1,0000h	;translate table
+	dw	0000h,0000h	;scratch area
+	dw	dirbuf,dpb1	;dir buff, parm block
+	dw	csv1,alv1	;check, alloc vectors
+dpe2:	dw	xlt2,0000h	;translate table
+	dw	0000h,0000h	;scratch area
+	dw	dirbuf,dpb2	;dir buff, parm block
+	dw	csv2,alv2	;check, alloc vectors
+dpe3:	dw	xlt3,0000h	;translate table
+	dw	0000h,0000h	;scratch area
+	dw	dirbuf,dpb3	;dir buff, parm block
+	dw	csv3,alv3	;check, alloc vectors
+dpb0	equ	$		;disk param block
+	endif
+
+	if	asm and dbl
+	dw	52		;sec per track
+	db	4		;block shift
+	db	15		;block mask
+	db	0		;extnt mask
+	dw	242		;disk size-1
+	dw	127		;directory max
+	db	192		;alloc0
+	db	0		;alloc1
+	dw	32		;check size
+	dw	2		;offset
+xlt0	equ	0		;translate table
+dpb1	equ	dpb0
+xlt1	equ	xlt0
+dpb2	equ	$
+	endif
+
+	if	asm
+	dw	26		;sec per track
+	db	3		;block shift
+	db	7		;block mask
+	db	0		;extnt mask
+	dw	242		;disk size-1
+	dw	63		;directory max
+	db	192		;alloc0
+	db	0		;alloc1
+	dw	16		;check size
+	dw	2		;offset
+	endif
+
+	if	asm and sgl
+xlt0	equ	$
+	endif
+
+	if	asm and dbl
+xlt2	equ	$
+	endif
+
+	if	asm
+	db	1
+	db	7
+	db	13
+	db	19
+	db	25
+	db	5
+	db	11
+	db	17
+	db	23
+	db	3
+	db	9
+	db	15
+	db	21
+	db	2
+	db	8
+	db	14
+	db	20
+	db	26
+	db	6
+	db	12
+	db	18
+	db	24
+	db	4
+	db	10
+	db	16
+	db	22
+	endif
+
+	if	asm and sgl
+dpb1	equ	dpb0
+xlt1	equ	xlt0
+dpb2	equ	dpb0
+xlt2	equ	xlt0
+dpb3	equ	dpb0
+xlt3	equ	xlt0
+	endif
+
+	if	asm and dbl
+dpb3	equ	dpb2
+xlt3	equ	xlt2
+	endif
+
+	if	asm
+begdat	equ	$
+dirbuf:	ds	128		;directory access buffer
+	endif
+
+	if	asm and sgl
+alv0:	ds	31
+csv0:	ds	16
+alv1:	ds	31
+csv1:	ds	16
+	endif
+
+	if	asm and dbl
+alv0:	ds	31
+csv0:	ds	32
+alv1:	ds	31
+csv1:	ds	32
+	endif
+
+	if	asm
+alv2:	ds	31
+csv2:	ds	16
+alv3:	ds	31
+csv3:	ds	16
+enddat	equ	$
+datsiz	equ	$-begdat
+	endif
+
+	db	0	; this last db is req'd to
+			; ensure that the hex file
+			; output includes the entire
+			; diskdef
+
+	end
+