*****************************************************************
*								*
* Cbios for CP/M Ver 2.2 for Disk Jockey 2D controller (all	*
* revs). Handles diskettes with sector sizes of 128 bytes	*
* single density, 256, 512, 1024 bytes double density.		*
*								*
* Written by Bobby Dale Gifford.				*
* 9/1/79							*
*								*
* Disk Map of sectors used by Cold Boot, Warm Boot, Firmware,	*
* and CP/M:							*
*								*
* trk 0 sec  1 = First sector of cold boot.		e700h	*
*     0      2 = Cold boot 256.				  80h	*
*     0      3 = Cold boot 512.				  80h	*
*     0      4 = Cold boot 1024.			  80h	*
*     0      5 = Warm boot 256.				  80h	*
*     0      6 = Warm boot 512.				  80h	*
*     0      7 = Warm boot 1024.			  80h	*
*     0      8 = Cold/Warm boot.			3200h	*
*     0      9 = Firmware.				e400h	*
*     0     10 = Firmware+80h.				e480h	*
*     0     11 = Firmware+100h				e500h	*
*     0     12 = Firmware+180h.				e580h	*
*     0     13 = Firmware+200h.				e600h	*
*     0     14 = Firmware+280h.				e680h	*
*     0     15 = Firmware+300h.				e700h	*
*     0     16 = Firmware+380h.				e780h	*
*     0     17 = CCP.					2d00h	*
*     0     10 = CCP+80h.				2d80h	*
*     0     12 = CCP+100h.				2e00h	*
*     0     14 = CCP+180h.				2e80h	*
*     0     16 = CCP+200h.				2f00h	*
*     0     18 = CCP+280h.				2f80h	*
*     0     20 = CCP+300h.				3000h	*
*     0     22 = CCP+380h.				3080h	*
*     0     24 = CCP+400h.				3100h	*
*     0     26 = CCP+480h.				3180h	*
*     1        = Rest of CP/M.			  3200h-4fffh	*
*								*
*****************************************************************

	title	'*** Cbios For CP/M Ver. 2.2 ***'

*****************************************************************
*								*
* The following revision number is in reference to the CP/M	*
* 2.0 Cbios. 							*
*								*
*****************************************************************

revnum	equ	31		;Cbios revision number
cpmrev	equ	22		;CP/M revision number

*****************************************************************
*								*
* The following equates relate the Thinker Toys 2D controller.	*
* If the controller is non standard (0E000H) only the ORIGIN	*
* equate need be changed. This version of the Cbios will work	*
* with 2D controller boards rev 0, 1, 3, 3.1, 4.		*
*								*
*****************************************************************

origin	equ	0E000H
djram	equ	origin+400h	;Disk Jockey 2D RAM address
djcin	equ	djram+3h	;Disk Jockey 2D character input routine
djcout	equ	djram+6h	;Disk Jockey 2D character output routine
djhome	equ	djram+9h	;Disk Jockey 2D track zero seek
djtrk	equ	djram+0ch	;Disk Jockey 2D track seek routine
djsec	equ	djram+0fh	;Disk Jockey 2D set sector routine
djdma	equ	djram+012h	;Disk Jockey 2D set DMA address
djread	equ	djram+15h	;Disk Jockey 2D read routine
djwrite	equ	djram+18h	;Disk Jockey 2D write routine
djsel	equ	djram+1bh	;Disk Jockey 2D select drive routine
djtstat	equ	djram+21h	;Disk Jockey 2D terminal status routine
djstat	equ	djram+27h	;Disk Jockey 2D status routine
djerr	equ	djram+2ah	;Disk Jockey 2D error, flash led
djden	equ	djram+2dh	;Disk Jockey 2D set density routine
djside	equ	djram+30h	;Disk Jockey 2D set side routine

*****************************************************************
*								*
* CP/M system equates. If reconfiguration of the CP/M system	*
* is being done, the changes can be made to the following	*
* equates.							*
*								*
*****************************************************************

msize	equ	24		;Memory size of target CP/M
bias	equ	(msize-20)*1024	;Memory offset from 20k system
ccp	equ	2d00h+bias	;Console command processor
bdos	equ	ccp+800h	;BDOS address
bios	equ	ccp+1600h	;CBIOS address
cdisk	equ	4		;Address of last logged disk
buff	equ	80h		;Default buffer address
tpa	equ	100h		;Transient memory
intioby	equ	0		;Initial IOBYTE
iobyte	equ	3		;IOBYTE location
wbot	equ	0		;Warm boot jump address
entry	equ	5		;BDOS entry jump address

*****************************************************************
*								*
* The following are internal Cbios equates. Most are misc. 	*
* constants.							*
*								*
*****************************************************************

retries	equ	10		;Max retries on disk i/o before error
acr	equ	0dh		;A carriage return
alf	equ	0ah		;A line feed
aetx	equ	3		;A ETX char
aack	equ	6		;A ACK char
clear	equ	1ah		;Clear screen char on ADM3 terminal
maxdisk	equ	4		;Maximum # of disk drives
dblsid	equ	8		;Side bit from controller

*****************************************************************
*								*
* The jump table below must remain in the same order, the 	*
* routines may be changed, but the function executed must be	*
* the same.							*
*								*
*****************************************************************

	org	bios		;CBIOS starting address

	jmp	cboot		;Cold boot entry point
wboote	jmp	wboot		;Warm boot entry point
	jmp	const		;Console status routine
	jmp	conin		;Console input
cout	jmp	conout		;Console output
	jmp	list		;List device output
	jmp	punch		;Punch device output
	jmp	reader		;Reader device input
	jmp	home		;Home drive
	jmp	setdrv		;Select disk
	jmp	settrk		;Set track
	jmp	setsec		;Set sector
	jmp	setdma		;Set DMA address
	jmp	read		;Read the disk
	jmp	write		;Write the disk
	jmp	listst		;List device status
	jmp	sectran		;Sector translation
djdrv	jmp	djsel		;Hook for SINGLE.COM program

*****************************************************************
*								*
* Signon message output during cold boot.			*
*								*
*****************************************************************

prompt	db	acr,alf,alf
	db	'0'+msize/10		;CP/M memory size
	db	'0'+(msize mod 10)
	db	'K CP/M Vers. '		;CP/M version number
	db	cpmrev/10+'0'
	db	'.'
	db	(cpmrev mod 10)+'0'
	db	', Cbios rev '
	db	revnum/10+'0','.'	;Cbios revision number
	db	revnum mod 10+'0'
	db	acr,alf
	db	'For Thinker Toys Disk Jockey 2D Controller '
	db	'@ 0'

	if	origin/4096 > 10	;Controller origin (HEX)
	db	origin/4096+'A'-10
	else
	db	origin/4096+'0'
	endif

	if	(origin/256 and 0fh) > 10
	db	(origin/256 and 0fh)+'A'-10
	else
	db	(origin/256 and 0fh)+'0'
	endif
	db	'00H.'
	db	acr,alf,0

*****************************************************************
*								*
* Utility routine to output the message pointed at by H&L,	*
* terminated with a null.					*
*								*
*****************************************************************

message	mov	a,m		;Get a character of the message
	inx	h		;Bump text pointer
	ana	a		;Test for end
	rz			;Return if done
	push	h		;Save pointer to text
	mov	c,a		;Output character in C
	call	cout		;Output the character
	pop	h		;Restore the pointer
	jmp	message		;Continue until null reached

*****************************************************************
*								*
* Cboot is the cold boot loader. All of CP/M has been loaded in	*
* when control is passed here.					*
*								*
*****************************************************************

cboot	lxi	sp,tpa		;Set up stack
	call	tinit		;Initialize the terminal
	lxi	h,prompt	;Prep for sending signon message
	call	message		;Send the prompt
	xra	a		;Select disk A
	sta	cpmdrv
	sta	cdisk

*****************************************************************
*								*
* Gocpm is the entry point from cold boots, and warm boots. It	*
* initializes some of the locations in page 0, and sets up the	*
* initial DMA address (80h).					*
*								*
*****************************************************************

gocpm	lxi	h,buff		;Set up initial DMA address
	call	setdma
	mvi	a,(jmp)		;Initialize jump to warm boot
	sta	wbot
	sta	entry		;Initialize jump to BDOS
	lxi	h,wboote	;Address in warm boot jump
	shld	wbot+1
	lxi	h,bdos+6	;Address in BDOS jump
	shld	entry+1
	xra	a		;A <- 0
	sta	bufsec		;Disk Jockey buffer empty
	sta	bufwrtn		;Set buffer not dirty flag
	lda	cdisk		;Jump to CP/M with currently selected disk in C
	mov	c,a
	lxi	d,cmndbeg	;Beginning of initial command
	lxi	h,ccp+8		;Command buffer
	mvi	a,cmndend-cmndbeg+1 ;Length of command
	sta	ccp+7
	mov	b,a
	call	movlop
	lda	cwflg
	ana	a
	lda	autoflg
	jz	cldbot
	rar
cldbot	rar
	jc	ccp
	jmp	ccp+3		;Enter CP/M

cwflg	db	0		;Cold/warm boot flag

*****************************************************************
*								*
* The following byte determines if an initial command is to be	*
* given to CP/M on warm or cold boots. The value of the byte is	*
* used to give the command to CP/M:				*
*								*
* 0 = never give command.					*
* 1 = give command on cold boots only.				*
* 2 = give the command on warm boots only.			*
* 3 = give the command on warm and cold boots.			*
*								*
*****************************************************************

autoflg	db	1		;Auto command feature

*****************************************************************
*								*
* If there is a command inserted here, it will be given if the	*
* auto feature is enabled.					*
*	For Example:						*
*								*
*	cmndbeg	db	'MBASIC MYPROG'				*
*	cmndend	db	0					*
*								*
* will execute microsoft basic, and mbasic will execute the	*
* "MYPROG" basic program.					*
*								*
*****************************************************************

cmndbeg	db	''		;Initial command goes here
cmndend	db	0

*****************************************************************
*								*
* Wboot loads in all of CP/M except the CBIOS, then initializes	*
* system parameters as in cold boot. See the Cold Boot Loader	*
* listing for exactly what happens during warm and cold boots.	*
*								*
*****************************************************************

wboot	lxi	sp,tpa		;Set up stack pointer
	mvi	a,1
wflg	equ	$-1		;Test if beginning or
	ana	a		;	ending a warm boot
	mvi	a,1
	sta	wflg
	sta	cwflg		;Set cold/warm boot flag
	jz	gocpm		
	xra	a
	sta	wflg		
	mov	c,a
	call	djdrv		;Select drive A
	mvi	c,0		;Select single density
	call	djden
	mvi	c,0		;Select side 0
	call	djside
	mvi	a,15		;Initialize the sector to read
	sta	newsec
	lxi	h,ccp-100h	;And the DMA address
	shld	newdma
	call	warmlod		;Read in CP/M
	lxi	b,ccp+500h	;Load address for rest of warm boot
	call	djdma
	mvi	c,8
	call	djsec
	call	warmrd
	jmp	ccp+503h

warmlod	mvi	a,15		;Previous sector
newsec	equ	$-1
	inr	a		;Update the previous sector
	inr	a
	cpi	27		;Was it the last ?
	jc	nowrap
	sui	9		;Yes
	cpi	19
	rz
	lhld	newdma
	lxi	d,-480h
	dad	d
	shld	newdma
nowrap	sta	newsec		;Save the new sector to read
	mov	c,a
	call	djsec
	lxi	h,ccp-100h	;Get the previous DMA address
newdma	equ	$-2
	lxi	d,100h		;Update the DMA address
	dad	d
	shld	newdma		;Save the DMA address
	mov	b,h
	mov	c,l
	call	djdma		;Set the DMA address
	call	warmrd
	jmp	warmlod

warmrd	lxi	b,retries*100h+0;Maximum # of errors
wrmread	push	b
	call	djtrk		;Set the track
	call	djread		;Read the sector
	pop	b
	rnc			;Continue if successful
	dcr	b
	jnz	wrmread		;Keep trying
	jmp	djerr

*****************************************************************
*								*
* Setsec just saves the desired sector to seek to until an	*
* actual read or write is attempted.				*
*								*
*****************************************************************

setsec	mov	a,c		;Save the sector number
	sta	cpmsec		;CP/M sector #
	ret

*****************************************************************
*								*
* Setdma saves the DMA address for the data transfer.		*
*								*
*****************************************************************

setdma	mov	h,b		;hl <- bc
	mov	l,c
	shld	cpmdma		;CP/M dma address
	ret

*****************************************************************
*								*
* Home is translated into a seek to track zero.			*
*								*
*****************************************************************

home	mvi	c,0		;Track to seek to

*****************************************************************
*								*
* Settrk saves the track # to seek to. Nothing is done at this	*
* point, everything is deffered until a read or write.		*
*								*
*****************************************************************

settrk	mov	a,c		;A <- track #
	sta	cpmtrk		;CP/M track #
	ret

*****************************************************************
*								*
* Sectran translates a logical sector # into a physical sector	*
* #.								*
*								*
*****************************************************************

sectran	inx	b
	push	d		;Save table address
	push	b		;Save sector #
	call	getdpb		;Get DPB address into HL
	mov	a,m		;Get # of CP/M sectors/track
	ora	a		;Clear cary
	rar			;Divide by two
	sub	c
	push	psw		;Save adjusted sector
	jm	sidetwo
sidea	pop	psw		;Discard adjusted sector
	pop	b		;Restore sector requested
	pop	d		;Restor address of xlt table
sideone	xchg			;hl <- &(translation table)
	dad	b		;bc = offset into table
	mov	l,m		;hl <- physical sector
	mvi	h,0
	ret

sidetwo	lxi	b,15		;Offset to side bit
	dad	b
	mov	a,m
	ani	8		;Test for double sided
	jz	sidea		;Media is only single sided
	pop	psw		;Retrieve adjusted sector
	pop	b
	cma			;Make sector request positive
	inr	a
	mov	c,a		;Make new sector the requested sector
	pop	d
	call	sideone
	mvi	a,80h		;Side two bit
	ora	l		;	and sector
	mov	l,a
	ret

*****************************************************************
*								*
* Setdrv selects the next drive to be used in read/write	*
* operations. If the drive has never been selected before, a	*
* parameter table is created which correctly describes the 	*
* diskette currently in the drive. Diskettes can be of four	*
* different sector sizes:					*
*	1) 128 bytes single density.				*
*	2) 256 bytes double density.				*
*	3) 512 bytes double density.				*
*	4) 1024 bytes double density.				*
*								*
*****************************************************************

setdrv	mov	a,c		;Save the drive #
	sta	cpmdrv
	cpi	maxdisk		;Check for a valid drive #
	jnc	zret		;Illegal drive #
	mov	a,e		;Test if drive ever logged in before
	ani	1
	jnz	setdrv1		;Bit 0 of E = 0 -> Never selected before
	mvi	a,1		;Select sector 1 of track 1
	sta	truesec
	sta	cpmtrk
	call	fill		;Flush buffer and refill
	jc	zret		;Test for error return
	call	djstat		;Get status on current drive
	ani	0ch		;Strip off unwanted bits
	push	psw		;Used to select a DPB
	rar
	lxi	h,xlts		;Table of XLT addresses
	mov	e,a
	mvi	d,0
	dad	d
	push	h		;Save pointer to proper XLT
	call	getdpb		;Get DPH pointer into DE
	xchg			;
	pop	d
	mvi	b,2		;Number of bytes to move
	call	movlop		;Move the address of XLT
	lxi	d,8		;Offset to DPB pointer
	dad	d		;HL <- &DPH.DPB
	push	h
	lhld	origin+7	;Get address of DJ terminal out routine
	inx	h		;Bump to look at address of
				;	uart status location
	mov	a,m		
	xri	3		;Adjust for proper rev DJ
	mov	l,a
	mvi	h,(origin+300h)/100h
	mov	a,m
	ani	dblsid		;Check double sided bit
	lxi	d,dpb128s	;Base for single sided DPB's
	jnz	sideok
	lxi	d,dpb128d	;Base of double sided DPB's
sideok	xchg			;HL <- DBP base, DE <- &DPH.DPB
	pop	d		;Restore DE (pointer into DPH)
	pop	psw		;Offset to correct DPB
	ral
	ral
	mov	c,a
	mvi	b,0
	dad	b
	xchg			;Put DPB address in DPH
	mov	m,e
	inx	h
	mov	m,d
setdrv1	call	getdpb		;Get address of DPB in HL
	lxi	b,15		;Offset to sector size
	dad	b
	mov	a,m		;Get sector size
	ani	7h
	sta	secsiz
	mov	a,m
	rar
	rar
	rar
	rar
	ani	0fh
	sta	secpsec
	xchg			;HL <- DPH
	ret

zret	lxi	h,0		;Seldrv error exit
	ret

*****************************************************************
*								*
* Getdpb returns HL pointing to the DPB of the currently	*
* selected drive, DE pointing to DPH.				*
*								*
*****************************************************************

getdpb	lda	cpmdrv		;Get drive #
	mov	l,a		;Form offset
	mvi	h,0
	dad	h
	dad	h
	dad	h
	dad	h
	lxi	d,dpzero	;Base of DPH's 
	dad	d
	push	h		;Save address of DPH
	lxi	d,10		;Offset to DPB
	dad	d
	mov	a,m		;Get low byte of DPB address
	inx	h
	mov	h,m		;Get low byte of DPB
	mov	l,a
	pop	d
	ret

*****************************************