chibi-pc09/cpm/pcpm/CCP.MAC

	title	Console Command Processor (ccp), ver 2.0
;	assembly language version of the cp/m console command processor
;
;	Personal CP/M version 1.0 May 1984
;
;	COPYRIGHT (C) 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984
;	Digital Research
;	Box 579, Pacific Grove,
;	California, 93950
;
false	equ	0000h
true	equ	not false
;
;

	cseg

BASE	equ	$
BDOSL	equ	BASE+800H
SUBADDR	equ	BDOSL+09H
ZEROADD	equ	BDOSL+0BH
tran	equ	100h
tranm	equ	$
ccploc	equ	$


;	********************************************************
;	*	base of ccp contains the following code/data   *
;	*	ccp:	jmp ccpstart	(start with command)   *
;	*		jmp ccpclear    (start, clear command) *
;	*	ccp+6	127		(max command length)   *
;	*	ccp+7	comlen		(command length = 00)  *
;	*	ccp+8	' ... '		(16 blanks)	       *
;	********************************************************
;	* normal entry is at ccp, where the command line given *
;	* at ccp+8 is executed automatically (normally a null  *
;	* command with comlen = 00).  an initializing program  *
;	* can be automatically loaded by storing the command   *
;	* at ccp+8, with the command length at ccp+7.  in this *
;	* case, the ccp executes the command before prompting  *
;	* the console for input.  note that the command is exe-*
;	* cuted on both warm and cold starts.  when the command*
;	* line is initialized, a jump to "jmp ccpclear" dis-   *
;	* ables the automatic command execution.               *
;	********************************************************

	jp	ccpstart	;start ccp with possible initial command

	jp	ccpclear	;clear the command buffer

maxlen:	defb	127	;max buffer length
comlen:	defb	6	;command length

combuf:

	defb	'VCCPLD  '	;8 character fill
	defb	'        '	;8 character fill
	defb	'COPYRIGHT (C) 1984, DIGITAL RESEARCH  '	; 38
	defs	128-($-combuf)
				;total buffer length is 128 characters

comaddr:	defw	combuf	;address of next to char to scan
staddr:		defs	2	;starting address of current fillfcb request

diska	equ	0004h	;disk address for current disk
bdos	equ	0005h	;primary bdos entry point
buff	equ	0080h	;default buffer
fcb	equ	005ch	;default file control block

rcharf	equ	1	;read character function
pcharf	equ	2	;print character function
pbuff	equ	9	;print buffer function
rbuff	equ	10	;read buffer function
breakf	equ	11	;break key function
liftf	equ	12	;lift head function (no operation)
initf	equ	13	;initialize bdos function
self	equ	14	;select disk function
openf	equ	15	;open file function
closef	equ	16	;close file function
searf	equ	17	;search for file function
searnf	equ	18	;search for next file function
delf	equ	19	;delete file function
dreadf	equ	20	;disk read function
dwritf	equ	21	;disk write function
makef	equ	22	;file make function
renf	equ	23	;rename file function
logf	equ	24	;return login vector
cself	equ	25	;return currently selected drive number
dmaf	equ	26	;set dma address
userf	equ	32	;set user number

;
;	special fcb flags
;

rofile	equ	9	;read only file
sysfile	equ	10	;system file flag

;
;	special characters
;

cr	equ	13	;carriage return
lf	equ	10	;line feed
la	equ	5fh	;left arrow
eofile	equ	1ah	;end of file

;
;	utility procedures
;

printchar:

	ld	E,A
	ld	C,pcharf
	jp	bdos

printbc:
;print character, but save b,c registers

	push	bc
	call	printchar
	pop	bc
	ret

crlf:

	ld	A,cr
	call	printbc
	ld	A,lf
	jr	printbc

blank:

	ld	A,' '
	jr	printbc
<EFBFBD>print:	
;print string starting at b,c until next 00 entry

	push	bc
	call	crlf
	pop	hl		;now print the string

prin0:	

	ld	A,(hl)
	or	A
	ret	z		;stop on 00
	inc	hl
	push	hl		;ready for next
	call	printchar
	pop	hl		;character printed
	jr	prin0		;for another character

initialize:

	ld	C,initf
	jp	bdos

select:

	ld	E,A
	ld	C,self
	jp	bdos

openc:	
;open comfcb

	xor	A
	ld	(comrec),a	;clear next record to read
	ld	de,comfcb

open:	
;open the file given by d,e

	ld	C,openf

bdos$inr:

	call	bdos
	ld	(dcnt),a
	inc	A
	ret

close:	
;close the file given by d,e

	ld	C,closef
	jr	bdos$inr

search:	
;search for the file given by d,e

	ld	C,searf
	jr	bdos$inr

searchn:
;search for the next occurrence of the file given by d,e

	ld	C,searnf
	jr	bdos$inr

searchcom:
;search for comfcb file

	ld	de,comfcb
	jr	search

delete:	
;delete the file given by d,e
	
	ld	C,delf
	jp	bdos

bdos$cond:

	call	bdos
	or	A
	ret

diskread:
;read the next record from the file given by d,e

	ld	C,dreadf
	jr	bdos$cond

diskreadc:
;read the comfcb file

	ld	de,comfcb
	jr	diskread

diskwrite:
;write the next record to the file given by d,e

	ld	C,dwritf
	jr	bdos$cond
<EFBFBD>make:	
;create the file given by d,e

	ld	C,makef
	jr	bdos$inr

renam:	
;rename the file given by d,e

	ld	C,renf
	jp	bdos

getuser:
;return current user code in a

	ld	E,0ffh		;drop through to setuser

setuser:

	ld	(USERNO),a
	ld	C,userf
	jp	bdos		;sets user number

saveuser:
;save user#/disk# before possible ^c or transient

	call	GETUSER
	ld	(USERNO),a
	add	a,A
	add	a,A
	add	a,A
	add	a,A		;rot left
	ld	hl,cdisk
	or	(hl)		;4b=user, 4b=disk
	ld	(diska),a	;stored away in memory for later
	ret

translate:
;translate character in register a to upper case

	cp	61h
	ret	c		;return if below lower case a
	cp	7bh
	ret	nc		;return if above lower case z
	and	5fh
	ret			;translated to upper case

COPY$SUBFCB:

	ld	hl,(SUBADDR)
	inc	hl
	ld	de,SUB$S1
	ld	B,21
	or	A
	jr	nz,COPY$SF1
	ex	de,hl

COPY$SF1:

	dec	B
	ret	z
	ld	A,(hl)
	ld	(de),a
	inc	hl
	inc	de
	jr	COPY$SF1

readcom:
;read the next command into the command buffer
;check for submit file

	ld	hl,(SUBADDR)
	ld	A,(hl)
	or	A
	jr	z,NOSUB
	inc	A
	jr	z,OPEN$SUB
	call	COPY$SUBFCB
	jr	READ$SUB

OPEN$SUB:

	push	hl
	ld	de,SUBFCB
	call	OPEN
	pop	hl
	ld	(hl),0
	jr	z,NOSUB
	inc	(hl)

READ$SUB:

	call	SETDMABUFF

;change drives to open and read the file

	ld	a,(subrc)
	dec	A		;read last record(s) first
	ld	(subcr),a	;current record to read
	ld	de,subfcb
	call	diskread	;end of file if last record
	jr	nz,nosub
<EFBFBD>;disk read is ok, transfer to combuf

	ld	de,comlen
	ld	hl,buff
	ld	B,128
	call	move0

;line is transferred, close the file with a
;deleted record

	ld	hl,SUBRC
	dec	(hl)		; ONE LESS RECORD
	xor	A
	call	COPY$SUBFCB

;print to the 00

	ld	hl,combuf
	call	prin0
	call	break$key
	jr	z,noread
	call	del$sub
	jp	ccp		;break key depressed

nosub:	
;no submit file

	call	del$sub

;translate to upper case, store zero at end

	call	saveuser	;user # save in case control c
	ld	hl,(SUBADDR)
	dec	hl
	ld	(hl),0FFH
	push	hl
	ld	C,rbuff
	ld	de,maxlen
	call	bdos
	pop	hl
	ld	(hl),0

noread:	
;enter here from submit file
;set the last character to zero for later scans

	ld	hl,comlen
	ld	B,(hl)		;length is in b

readcom0:	

	inc	hl
	ld	A,B
	or	A		;end of scan?
	jr	z,readcom1
	ld	A,(hl)		;get character and translate
	call	translate
	ld	(hl),A
	dec	B
	jr	readcom0

readcom1:	
;end of scan, h,l address end of command

	ld	(hl),A		;store a zero
	ld	hl,combuf
	ld	(comaddr),hl	;ready to scan to zero
	ret

break$key:
;check for a character ready at the console

	ld	C,breakf
	call	bdos
	or	A
	ret	z
	ld	C,rcharf
	call	bdos		;character cleared
	or	A
	ret

cselect:
;get the currently selected drive number to reg-a

	ld	C,cself
	jp	bdos

setdmabuff:
;set default buffer dma address

	ld	de,buff		;(drop through)

setdma:
;set dma address to d,e

	ld	C,dmaf
	jp	bdos

del$sub:
;delete the submit file, and set submit flag to false

	ld	hl,(SUBADDR)
	ld	A,(hl)
	or	A
	ret	z		;return if no sub file
	ld	(hl),0		;submit flag is set to false
	ld	de,subfcb
	jp	delete

comerr:
;error in command string starting at position
;'staddr' and ending with first delimiter

	call	crlf		;space to next line
	ld	hl,(staddr)	;h,l address first to print
comerr0:	
;print characters until blank or zero

	ld	A,(hl)
	cp	' '
	jr	z,comerr1	; not blank
	or	A
	jr	z,comerr1	; not zero, so print it
	push	hl
	call	printchar
	pop	hl
	inc	hl
	jr	comerr0		; for another character

comerr1:	
;print question mark,and delete sub file

	ld	A,'?'
	call	printchar
	call	crlf
	call	del$sub
	jp	ccp	;restart with next command

;
; fcb scan and fill subroutine (entry is at fillfcb below)
;fill the comfcb, indexed by a (0 or 16)
;subroutines
;

delim:	
;look for a delimiter

	ld	a,(de)
	or	A
	ret	z	;not the last element
	cp	' '
	jr	c,comerr	;non graphic
	ret	z	;treat blank as delimiter
	cp	'='
	ret	z
	cp	la
	ret	z		;left arrow
	cp	'.'
	ret	z
	cp	':'
	ret	z
	cp	';'
	ret	z
	cp	'<'
	ret	z
	cp	'>'
	ret	z
	ret			;delimiter not found

deblank:	
;deblank the input line

	ld	a,(de)
	or	A
	ret	z		;treat end of line as blank
	cp	' '
	ret	nz
	inc	de
	jr	deblank

addh:	
;add a to h,l

	add	a,L
	ld	L,A
	ret	nc
	inc	H
	ret

fillfcb0:
;equivalent to fillfcb(0)

	ld	A,0

fillfcb:

	ld	hl,comfcb
	call	addh
	push	hl
	push	hl		;fcb rescanned at end
	xor	A
	ld	(sdisk),a	;clear selected disk (in case a:...)
	ld	hl,(comaddr)
	ex	de,hl		;command address in d,e
	call	deblank		;to first non-blank character
	ex	de,hl
	ld	(staddr),hl	;in case of errors
	ex	de,hl
	pop	hl		;d,e has command, h,l has fcb address

;look for preceding file name a: b: ...

	ld	a,(de)
	or	A
	jr	z,setcur0	;use current disk if empty command
	sbc	a,'A'-1
	ld	B,A		;disk name held in b if : follows
	inc	de
	ld	a,(de)
	cp	':'
	jr	z,setdsk	;set disk name if :

setcur:	
;set current disk
<EFBFBD>	dec	de		;back to first character of command

setcur0:

	ld	a,(cdisk)
	ld	(hl),A
	jr	setname

setdsk:	
;set disk to name in register b

	ld	A,B
	ld	(sdisk),a	;mark as disk selected
	ld	(hl),B
	inc	de		;past the :

setname:	
;set the file name field

	ld	B,8		;file name length (max)

setnam0:	

	call	delim
	jr	z,padname	;not a delimiter
	inc	hl
	cp	'*'
	jr	nz,setnam1	;must be ?'s
	ld	(hl),'?'
	jr	setnam2		;to dec count

setnam1:	

	ld	(hl),A		;store character to fcb
	inc	de

setnam2:	

	dec	B		;count down length
	jr	nz,setnam0

;end of name, truncate remainder

trname:	

	call	delim
	jr	z,setty		;set type field if delimiter
	inc	de
	jr	trname

padname:	

	inc	hl
	ld	(hl),' '
	dec	B
	jr	nz,padname

setty:	
;set the type field

	ld	B,3
	cp	'.'
	jr	nz,padty	;skip the type field if no .
	inc	de		;past the ., to the file type field

setty0:	
;set the field from the command buffer

	call	delim
	jr	z,padty
	inc	hl
	cp	'*'
	jr	nz,setty1
	ld	(hl),'?'	;since * specified
	jr	setty2

setty1:	
;not a *, so copy to type field

	ld	(hl),A
	inc	de

setty2:	
;decrement count and go again

	dec	B
	jr	nz,setty0

;end of type field, truncate

trtyp:	
;truncate type field

	call	delim
	jr	z,efill
	inc	de
	jr	trtyp

padty:	
;pad the type field with blanks

	inc	hl
	ld	(hl),' '
	dec	B
	jr	nz,padty

efill:	
;end of the filename/filetype fill, save command address
;fill the remaining fields for the fcb

	ld	B,3

efill0:	

	inc	hl
	ld	(hl),0
	dec	B
	jr	nz,efill0
	ex	de,hl
	ld	(comaddr),hl	;set new starting point

;recover the start address of the fcb and count ?'s

	pop	hl
	ld	bc,11		;b=0, c=8+3

scnq:	

	inc	hl
	ld	A,(hl)
	cp	'?'
	jr	nz,scnq0

;? found, count it in b

	inc	B

scnq0:	

	dec	C
	jr	nz,scnq

;number of ?'s in c, move to a and return with flags set
<EFBFBD>	ld	A,B
	or	A
	ret

intvec:
;intrinsic function names (all are four characters)

	defb	'DIR '
	defb	'ERA '
	defb	'TYPE'
	defb	'SAVE'
	defb	'REN '
	defb	'USER'

intlen	equ	($-intvec)/4	;intrinsic function length


intrinsic:
;look for intrinsic functions (comfcb has been filled)

	ld	hl,intvec
	ld	C,0		;c counts intrinsics as scanned

intrin0:	

	l<>	A,C
	cp	intlen		;done with scan?
	ret	nc

;no, more to scan

	ld	de,comfcb+1	;beginning of name
	ld	B,4		;length of match is in b

intrin1:	

	ld	a,(de)
	cp	(hl)		;match?
	jr	nz,intrin2	;skip if no match
	inc	de
	inc	hl
	dec	B
	jr	nz,intrin1	;loop while matching

;complete match on name, check for blank in fcb

	ld	a,(de)
	cp	' '
	jr	nz,intrin3	;otherwise matched
	ld	A,C
	ret			;with intrinsic number in a

intrin2:	
;mismatch, move to end of intrinsic
	
	inc	hl
	dec	B
	jr	nz,intrin2

intrin3:	
;try next intrinsic
	
	inc	C		;to next intrinsic number
	jr	intrin0		;for another round

ccpclear:
;clear the command buffer

	xor	A
	ld	(comlen),a

;drop through to start ccp

ccpstart:
;enter here from boot loader

	ld	sp,stack
	push	bc		;save initial disk number

;(high order 4bits=user code, low 4bits=disk#)

	ld	A,C
	rra
	rra
	rra
	rra
	and	0fh		;user code
	ld	E,A
	call	setuser		;user code selected
	ld	hl,(SUBADDR)
	dec	hl
	ld	A,(hl)
	ld	(hl),0
	or	A
	call	nz,INITIALIZE
	pop	bc		;recall user code and disk number
	ld	A,C
	and	0fh		;disk number in accumulator
	ld	(cdisk),a	;clears user code nibble
	call	select		;proper disk is selected, now check sub files

;check for initial command

	ld	a,(comlen)
	or	A
	jr	nz,ccp0		;assume typed already
<EFBFBD>ccp:
;enter here on each command or error condition

	ld	sp,stack
	call	crlf		;print d> prompt, where d is disk name
	ld	a,(USERNO)
	or	A
	jr	z,CCP002
	cp	10
	jr	c,CCP001
	push	af
	ld	A,'1'
	call	PRINTCHAR
	pop	af
	sub	10

CCP001:

	add	a,30H
	call	PRINTCHAR

CCP002:

	call	cselect		;get current disk number
	add	a,'A'
	call	printchar
	ld	A,'>'
	call	printchar
	call	readcom		;command buffer filled
ccp0:	
;(enter here from initialization with command full)

	call	SETDMABUFF	;default dma address at buff
	call	cselect
	ld	(cdisk),a	;current disk number saved
	call	fillfcb0	;command fcb filled
	call	nz,comerr	;the name cannot be an ambiguous reference
	ld	a,(sdisk)
	or	A
	jp	nz,userfunc

;check for an intrinsic function

	call	intrinsic
	ld	hl,jmptab	;index is in the accumulator
	ld	E,A
	ld	D,0
	add	hl,de
	add	hl,de		;index in d,e
	ld	A,(hl)
	inc	hl
	ld	H,(hl)
	ld	L,A
	jp	(hl)

;pc changes to the proper intrinsic or user function

jmptab:

	defw	direct		;directory search
	defw	erase		;file erase
	defw	type		;type file
	defw	save		;save memory image
	defw	rename		;file rename
	defw	user		;user number
	defw	userfunc	;user-defined function

;
;utility subroutines for intrinsic handlers
;

readerr:
;print the read error message

	ld	bc,rdmsg
	jp	print

rdmsg:	defb	'READ ERROR',0 


nofile:
;print no file message

	ld	bc,nofmsg
	jp	print

nofmsg:	defb	'NO FILE',0


getnumber:	
;read a number from the command line

	call	fillfcb0	;should be number
	ld	a,(sdisk)
	or	A
	jp	nz,comerr	;cannot be prefixed

;convert the byte value in comfcb to binary

	ld	hl,comfcb+1
	ld	bc,11		;(b=0, c=11)

;value accumulated in b, c counts name length to zero

conv0:	

	ld	A,(hl)
	cp	' '
	jr	z,conv1
<EFBFBD>;more to scan, convert char to binary and add

	inc	hl
	sub	'0'
	cp	10
	jp	nc,comerr	;valid?
	ld	D,A		;save value
	ld	A,B		;mult by 10
	and	11100000b
	jp	nz,comerr
	ld	A,B		;recover value
	rlca
	rlca
	rlca			;*8
	add	a,B
	jp	c,comerr
	add	a,B
	jp	c,comerr	;*8+*2 = *10
	add	a,D
	jp	c,comerr	;+digit
	ld	B,A
	dec	C
	jr	nz,conv0	;for another digit
	ret

conv1:	
;end of digits, check for all blanks

	ld	A,(hl)
	cp	' '
	jp	nz,comerr	;blanks?
	inc	hl
	dec	C
	jr	nz,conv1
	ld	A,B		;recover value
	ret

movename:
;move 3 characters from h,l to d,e addresses

	ld	B,3

move0:	

	ld	A,(hl)
	ld	(de),a
	inc	hl
	inc	de
	dec	B
	jr	nz,move0
	ret

addhcf:	
;buff + a + c to h,l followed by fetch

	ld	hl,buff
	add	a,C
	call	addh
	ld	A,(hl)
	ret

setdisk:
;change disks for this command, if requested

	xor	A
	ld	(comfcb),a	;clear disk name from fcb
	ld	a,(sdisk)
	or	A
	ret	z		;no action if not specified
	dec	A
	ld	hl,cdisk
	cp	(hl)
	ret	z		;already selected
	jp	select

resetdisk:
;return to original disk after command

	ld	a,(sdisk)
	or	A
	ret	z		;no action if not selected
	dec	A
	ld	hl,cdisk
	cp	(hl)
	ret	z		;same disk
	ld	a,(cdisk)
	jp	select

;
;individual intrinsics follow
;

direct:
;directory search

	call	fillfcb0	;comfcb gets file name
	call	setdisk		;change disk drives if requested
	ld	hl,comfcb+1
	ld	A,(hl)		;may be empty request
	cp	' '
	jr	nz,dir1		;skip fill of ??? if not blank

;set comfcb to all ??? for current disk

	ld	B,11		;length of fill ????????.???

dir0:	

	ld	(hl),'?'
	inc	hl
	dec	B
	jr	nz,dir0

;not a blank request, must be in comfcb

dir1:	

	l<>	E,0
	push	de		;e counts directory entries
	call	searchcom	;first one has been found
	call	z,nofile	;not found message

dir2:	

	jr	z,endir

;found, but may be system file
<EFBFBD>	ld	a,(dcnt)	;get the location of the element
	rrca
	rrca
	rrca
	and	1100000b
	ld	C,A

;c contains base index into buff for dir entry

	ld	A,sysfile
	call	addhcf		;value to a
	rla
	jr	c,dir6		;skip if system file

;c holds index into buffer
;another fcb found, new line?

	pop	de
	ld	A,E
	inc	E
	push	de

;e=0,1,2,3,...new line if mod 4 = 0

	and	11b
	push	af		;and save the test
	jr	nz,dirhdr0	;header on current line
	call	crlf
	push	bc
	call	cselect
	pop	bc

;current disk in a

	add	a,'A'
	call	printbc
	ld	A,':'
	call	printbc
	jr	dirhdr1		;skip current line hdr

dirhdr0:	

	call	blank		;after last one
	ld	A,':'
	call	printbc

dirhdr1:

	call	blank

;compute position of name in buffer

	ld	B,1		;start with first character of name

dir3:	

	ld	A,B
	call	addhcf		;buff+a+c fetched
	and	7fh		;mask flags

;may delete trailing blanks

	cp	' '
	jr	nz,dir4		;check for blank type
	pop	af
	push	af		;may be 3rd item
	cp	3
	jr	nz,dirb		;place blank at end if not
	ld	A,9
	call	addhcf		;first char of type
	and	7fh
	cp	' '
	jr	z,dir5

;not a blank in the file type field

dirb:	

	ld	A,' '		;restore trailing filename chr

dir4:

	call	printbc		;char printed
	inc	B
	ld	A,B
	cp	12
	jr	nc,dir5

;check for break between names

	cp	9
	jr	nz,dir3		;for another char

;print a blank between names

	call	blank
	jr	dir3

dir5:	
;end of current entry

	pop	af		;discard the directory counter (mod 4)

dir6:	

	call	break$key	;check for interrupt at keyboard
	jr	nz,endir	;abort directory search
	call	searchn
	jr	dir2		;for another entry

endir:	
;end of directory scan

	pop	de		;discard directory counter
	jp	retcom

erase:

	call	fillfcb0	;cannot be all ???'s
	cp	11
	jr	nz,erasefile
<EFBFBD>;erasing all of the disk

	ld	bc,ermsg
	call	print

	call	readcom
	ld	hl,comlen
	dec	(hl)
	jp	nz,ccp		;bad input
	inc	hl
	ld	A,(hl)
	cp	'Y'
	jp	nz,ccp

;ok, erase the entire diskette

	inc	hl
	ld	(comaddr),hl	;otherwise error at retcom

erasefile:

	call	setdisk
	ld	de,comfcb
	call	delete
	inc	A		;255 returned if not found
	call	z,nofile	;no file message if so
	jp	retcom


ermsg:	defb	'ALL (Y/N)?',0


type:

	call	fillfcb0
	jp	nz,comerr	;don't allow ?'s in file name
	call	setdisk
	call	openc		;open the file
	jr	z,typerr	;zero flag indicates not found

;file opened, read 'til eof

	call	crlf
	ld	hl,bptr
	ld	(hl),255	;read first buffer

type0:	
;loop on bptr

	ld	hl,bptr
	ld	A,(hl)
	cp	128		;end buffer
	jr	c,type1
	push	hl		;carry if 0,1,...,127

;read another buffer full

	call	diskreadc
	pop	hl		;recover address of bptr
	jr	nz,typeof	;hard end of file
	xor	A
	ld	(hl),A		;bptr = 0

type1:	
;read character at bptr and print

	inc	(hl)		;bptr = bptr + 1
	ld	hl,buff
	call	addh		;h,l addresses char
	ld	A,(hl)
	cp	eofile
	jp	z,retcom
	call	printchar
	call	break$key
	jp	nz,retcom	;abort if break
	jr	type0		;for another character

typeof:	
;end of file, check for errors

	dec	A
	jp	z,retcom
	call	readerr

typerr:	

	call	resetdisk
	jp	comerr

save:

	call	getnumber	; value to register a
	push	af		;save it for later

;should be followed by a file to save the memory image

	call	fillfcb0
	jp	nz,comerr	;cannot be ambiguous
	call	setdisk		;may be a disk change
	ld	de,comfcb
	push	de
	call	delete		;existing file removed
	pop	de
	call	make		;create a new file on disk
	jr	z,saverr	;no directory space
	xor	A
	ld	(comrec),a	; clear next record field
	pop	af		;#pages to write is in a, change to #sectors
<EFBFBD>	ld	L,A
	ld	H,0
	add	hl,hl

	ld	de,tran		;h,l is sector count, d,e is load address

save0:	
;check for sector count zero

	ld	A,H
	or	L
	jr	z,save1		;may be completed
	dec	hl		;sector count = sector count - 1
	push	hl		;save it for next time around
	ld	hl,128
	add	hl,de
	push	hl		;next dma address saved
	call	setdma		;current dma address set
	ld	de,comfcb
	call	diskwrite
	pop	de
	pop	hl		;dma address, sector count
	jr	nz,saverr	;may be disk full case
	jr	save0		;for another sector

save1:	
;end of dump, close the file

	ld	de,comfcb
	call	close
	inc	A		; 255 becomes 00 if error
	jr	nz,retsave	;for another command

saverr:	
;must be full or read only disk

	ld	bc,fullmsg
	call	print

retsave:
;reset dma buffer

	call	setdmabuff
	jp	retcom


fullmsg:	defb	'NO SPACE',0


rename:
;rename a file on a specific disk

	call	fillfcb0
	jp	nz,comerr	;must be unambiguous
	ld	a,(sdisk)
	push	af		;save for later compare
	call	setdisk		;disk selected
	call	searchcom	;is new name already there?
	jr	nz,renerr3

;file doesn't exist, move to second half of fcb

	ld	hl,comfcb
	ld	de,comfcb+16
	ld	B,16
	call	move0

;check for = or left arrow

	ld	hl,(comaddr)
	ex	de,hl
	call	deblank
	cp	'='
	jr	z,ren1		;ok if =
	cp	la
	jr	nz,renerr2

ren1:	

	ex	de,hl
	inc	hl
	ld	(comaddr),hl	;past delimiter

;proper delimiter found

	call	fillfcb0
	jr	nz,renerr2

;check for drive conflict

	pop	af
	ld	B,A		;previous drive number
	ld	hl,sdisk
	ld	A,(hl)
	or	A
	jr	z,ren2

;drive name was specified.  same one?

	cp	B
	ld	(hl),B
	jr	nz,renerr2

ren2:	

	ld	(hl),B		;store the name in case drives switched
	xor	A
	ld	(comfcb),a
	call	searchcom	;is old file there?
	jr	z,renerr1

;everything is ok, rename the file

	ld	de,comfcb
	call	renam
	jp	retcom

renerr1:	
; no file on disk
	
	call	nofile
	jp	retcom

renerr2:	
; ambigous reference/name conflict

	call	resetdisk
	jp	comerr

renerr3:	
; file already exists

	ld	bc,renmsg
	call	print
	jp	retcom


renmsg:	defb	'FILE EXISTS',0

user:
;set user number

	call	getnumber	; leaves the value in the accumulator
	cp	16
	jp	nc,comerr	; must be between 0 and 15
	ld	E,A		;save for setuser call
	ld	a,(comfcb+1)
	cp	' '
	jp	z,comerr
	ld	A,E
	call	setuser		;new user number set
 	jp	endcom

userfunc:
;load user function and set up for execution

	ld	a,(comfcb+1)
	cp	' '
	jr	nz,user0

;no file name, but may be disk switch

	ld	a,(sdisk)
	or	A
	jp	z,endcom	;no disk name if 0
	dec	A
	ld	(cdisk),a	;set user/disk
	call	select
	jp	endcom

user0:	
;file name is present

	ld	de,comfcb+9
	ld	a,(de)
	cp	' '
	jp	nz,comerr	;type ' '
	push	de
	call	setdisk
	pop	de
	ld	hl,comtype	;.com
	call	movename	;file type is set to .com
	call	openc
	jp	z,userer

;file opened properly, read it into memory

	ld	hl,tran		;transient program base

load0:	

	push	hl		;save dma address

	ex	de,hl
	call	setdma
	ld	de,comfcb
	call	diskread
	jr	nz,load1

;sector loaded, set new dma address and compare

	pop	hl
	ld	de,128
	add	hl,de
	ld	de,tranm	;has the load overflowed?
	ld	A,L
	sub	E
	ld	A,H
	sbc	a,D
	jr	nc,loaderr
	jr	load0		;for another sector

load1:	

	pop	hl
	dec	A
	jr	nz,loaderr	;end file is 1
	call	resetdisk	;back to original disk
	call	fillfcb0
	ld	hl,sdisk
	push	hl
	ld	A,(hl)
	ld	(comfcb),a	;drive number set
	ld	A,16
	call	fillfcb		;move entire fcb to memory
	pop	hl
	ld	A,(hl)
	ld	(comfcb+16),a
	xor	A
	ld	(comrec),a	;record number set to zero
	ld	de,fcb
	ld	hl,comfcb
	ld	B,33
	call	move0

;move command line to buff

	ld	hl,combuf

bmove0:	

	ld	A,(hl)
	or	A
	jr	z,bmove1
	cp	' '
	jr	z,bmove1
	inc	hl
	jr	bmove0		;for another scan

;first blank position found

bmove1:	

	ld	B,0
	ld	de,buff+1

;ready for the move

bmove2:	

	ld	A,(hl)
	ld	(de),a
	or	A
	jr	z,bmove3
<EFBFBD>;more to move

	inc	B
	inc	hl
	inc	de
	jr	bmove2

bmove3:	
;b has character count

	ld	A,B
	ld	(buff),a
	call	crlf

;now go to the loaded program

	call	setdmabuff	;default dma
	call	saveuser	;user code saved
	ld	hl,(ZEROADD)
	ld	C,4

ZMOVE:	

	ld	(hl),0
	inc	hl
	dec	C
	jr	nz,ZMOVE

;low memory diska contains user code

	call	tran		;gone to the loaded program
	ld	sp,stack	;may come back here
	ld	a,(USERNO)
	ld	E,A
	call	SETUSER
	ld	a,(CDISK)
	call	select
	jp	ccp

userer:	
;arrive here on command error

	call	resetdisk
	jp	comerr

loaderr:	
;cannot load the program
	
	ld	bc,loadmsg
	call	print
	jr	retcom


loadmsg:	defb	'BAD LOAD',0
comtype:	defb	'COM'	;for com files



retcom:	
;reset disk before end of command check

	call	resetdisk

endcom:	
;end of intrinsic command

	call	fillfcb0	;to check for garbage at end of line
	ld	a,(comfcb+1)
	sub	' '
	ld	hl,sdisk
	or	(hl)

;0 in accumulator if no disk selected, and blank fcb

	jp	nz,comerr
	jp	ccp

;
;	data areas
;
	defs	16	;8 level stack

stack:

;
;	'submit' file control block
;

subfcb:	defb	1,'$$$     '	;file name is $$$
	defb	'SUB',0

sub$s1:	defb	0	;file type is sub
submod:	defb	0	;module number
subrc:	defs	1	;record count filed
	defs	16	;disk map
subcr:	defs	1	;current record to read

;
;	command file control block
;
<EFBFBD>comfcb:	defs	32	;fields filled in later
comrec:	defs	1	;current record to read/write
dcnt:	defs	1	;disk directory count (used for error codes)
cdisk:	defs	1	;current disk
sdisk:	defs	1	;selected disk for current operation
			;none=0, a=1, b=2 ...

USERNO:	defs	1	;CURRENT USER NUMBER
bptr:	defs	1	;buffer pointer

	; this is code tto make the BDOS (which follows) be on a 
	; 256 byte page boundry. (make the linker happy)
last:	defb	0
	org	(((last-base)+255) and 0FF00h) -1
	defb	0

	end	ccploc