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; Library:	RCPIOM for Z34RCP
; Author:	Carson Wilson
; Version:	1.1
; Date:		August 12, 1989
; Changes:	POKE and PORT now respond dynamically to QUIET flag, 
;		  eliminating "noise."

; Author:	Carson Wilson
; Version:	1.0
; Date:		June 15, 1988
;
; Commands:	PEEK, POKE, and PORT

; ------------------------------------------------------------------
;
; Command:	PEEK
; Function:	Display memory contents
;
; Form:
;		PEEK startadr		128 bytes displayed
;		PEEK startadr endadr	Range of bytes displayed

	 if	peekon
peek:
	call	retsave
	ld	hl,tbuff+1	; Find first number
nxtpeek	equ	$+1		; Pointer for in-the-code modification
	ld	de,100h		; Default peek address if none
	call	sksp		; Skip to first token (if any)
	call	nz,hexnum	; Get start address if any
	push	de		; Save starting address
	ld	bc,peeklen	; Compute default ending address
	ex	de,hl
	add	hl,bc

	 if	peekchk		; Check for overflow
	jr	nc,peek0	; If no overflow past FFFF, go on
	ld	hl,0ffffh	; Else use FFFF as ending address
peek0:
	 endif	;peekchk

	ex	de,hl		; End address in DE
	call	sksp		; Skip to next token (if any)
	call	nz,hexnum	; Get 2nd number in DE (else default)
peek1:	pop	hl		; HL is start address, DE is end address

	 if	peekhdr
	push	hl		; Save starting address again
	ld	b,8		; Output leading spaces
peek0a:	call	spac
	djnz	peek0a
	ld	b,16		; Display 16 column headers
peek0b:	ld	a,l		; Get low byte of address
	and	0fh		; Display low hex digit
	call	pashc
	inc	hl
	djnz	peek0b
;
; Display header for ASCII area
;
	call	print	
	db	' ',' '+80H	; Space over to ASCII area
	pop	hl		; Get address
	push	hl
	ld	b,16		; Display 16 chars. ASCII header
peek0b1:ld	a,l		; Get byte
	and	0fh		; Mask
	call	pah		; Print ASCII char.
	inc	hl		; Next byte
	djnz	peek0b1

	 if	peekbdr
	call	crlf
	ld	b,8
peek0c:	call	spac		; Print leading spaces
	djnz	peek0c
	ld	b,16
peek0d:	call	print
	db	' -','-'+80h
	djnz	peek0d

; Print border at ASCII area

	call	print
	db	' ',' '+80h	; Space to ASCII border
	ld	b,16		; 16 dashes
peek0e:	call	print
	db	'-'+80h
	djnz	peek0e
	 endif	;peekbdr

	pop	hl		; Restore starting address
	 endif	;peekhdr

	ld	c,0ffh		; Use C as continue flag
	call	peek2		; Do peek
	ld	(nxtpeek),hl	; Set continued peek address
	jp	exit
peek2:
	ld	a,c		; Check continuation flag
	or	a
	ret	z

; Print line header

peek2a:	call	crlf		; New line
	ld	a,h		; Print address
	call	pashc
	ld	a,l
	call	pahc
	call	dash		; Print leader
	ld	b,16		; 16 bytes to display
	push	hl		; Save start address

; Print hex values for 16 bytes

peek3:	ld	a,(hl)		; Get next byte
	call	pashc		; Print with leading space

; Check for last address.  If C is already 0, leave it that way.
;  Otherwise check for end address and if so set C to zero.

	ld	a,c		; See if continue flag already cleared
	or	a
	jr	z,peek3a	; If so, skip test
	ld	a,h
	sub	a,d		; See if h = d
	ld	c,a
	ld	a,l
	sub	a,e		; See if l = e
	or	c		; Combine two tests
	ld	c,a
peek3a:	inc	hl		; Pt to next
	djnz	peek3

; Print ASCII equivalents for 16 bytes

	pop	hl		; Pt to first address again
	ld	b,16		; 16 bytes
	call	print		; Space and fence
	db	' '
	db	fence+80h
	push	bc		; Save flag in c
peek4:	ld	a,(hl)		; Get next byte
	ld	c,'.'		; Assume dot
	and	7fh		; Mask it
	cp	' '		; Dot if less than space
	jr	c,peek5
	cp	7fh		; Don't print del
	jr	z,peek5
	ld	c,a		; Char in c
peek5:	ld	a,c		; Get char
	call	conout		; Send it
	inc	hl		; Pt to next
	djnz	peek4
	call	print		; Closing fence
	db	fence+80h
	pop	bc		; Get flag in c back
	call	break		; Allow abort
	jr	peek2
	 endif			; Peekon

; PAHC - Print A as 2 hex chars
; PASHC - With leading space

	 if	peekon or pokeon or porton
pashc:
	push	af		; Save A
	call	spac
	pop	af
pahc:	push	bc		; Save bc
	ld	c,a		; Byte in c
	rrca			; Exchange nybbles
	rrca
	rrca
	rrca
	call	pah		; Print hex char
	ld	a,c		; Get low
	pop	bc		; Restore bc and fall thru to pah
pah:	and	0fh		; Mask
	add	'0'		; Convert to ascii
	cp	'9'+1		; Letter?
	jr	c,pah1
	add	7		; Adjust to letter
pah1:	jp	conout
	 endif			; Peekon or pokeon or porton

; --------------------------------------------------------------------
;
; Command: POKE
; Function:  Place Values into Memory
;
; Form:
;	POKE startadr val1 val2 ...
;
	 if	pokeon
poke:
	call	retsave
	ld	hl,tbuff+1	; Pt to first char
	call	sksp		; Skip to non-blank
	jp	z,numerr	; Numerical error
	call	hexnum		; Convert to number
	call	qplug		; Shut off output if quiet
	call	print
	db	' Pok','e'+80h
	call	adrat		; Print at message (quiet sensitive)
	call	unplug		; Turn on output

; Loop for storing hex values sequentially via POKE

poke1:	push	de		; Save address
	call	sksp		; Skip to non-blank
	jp	z,exit		; Done
	cp	'"'		; Quoted text?
	jr	z,poke2
	call	hexnum		; Get number
	ld	a,e		; Get low
	pop	de		; Get address
	ld	(de),a		; Store number
	inc	de		; Pt to next
	jr	poke1

; Store ASCII chars.

poke2:	pop	de		; Get next address
	inc	hl		; Pt to next char
poke3:	ld	a,(hl)		; Get next char
	or	a		; Done?
	jp	z,exit
	ld	(de),a		; Put char
	inc	hl		; Pt to next
	inc	de
	jr	poke3

	 endif			; Pokeon

; -------------------------------------------------------------------
;
; Command: PORT
; Function:  Display or Set I/O Port Data
;
; Forms:
;	PORT addr		- Read port and display value
;	PORT addr value 	- Output value to port
;
	 if	porton
port:
	call	retsave
	ld	hl,tbuff+1	; Find first number
	call	sksp		; Skip to first command-line token
	jp	z,numerr	; Numerical error
	call	hexnum		; Get start address into de
	push	hl		; Save pointer to command tail
	ld	hl,portadl	; Modify code
	ld	(hl),e		; Move specified port addr into place
	dec	hl		; Point to opcode position
	ld	(hl),0dbh	; Poke 'in' opcode
	dec	hl
	ld	(hl),d		; Save MSB for port address
	inc	hl
	ex	(sp),hl		; Get tail pointer back while saving this one
	call	qplug		; Shut off output if quiet
	call	print		; Print header
	db	' Por','t'+80h
	ld	a,e
	call	pashc		; Print port address
	call	sksp		; Skip to possible second value
	jr	z,portin	; Proceed with port input
	call	hexnum		; Get 2nd number in de
	ex	(sp),hl		; Get pointer to opcode back
	ld	(hl),0d3h	; Poke 'out' opcode
	call	print
	db	': OU','T'+80h
	ld	a,e		; Get value to output
	jr	paddr
portin:
	call	print
	db	': I','N'+80h
	xor	a		; Make sure high port address = 0 (for hd64180)
portadh	equ	$+1
paddr:	ld	b,0		; ..for both in and out instructions
opcode:
	db	0		; Opcode for in or out inserted by code above
portadl:
	db	0		; Port address inserted by code above
	call	pashc
	call	unplug		; Turn on output
	pop	hl		; Clean up stack
	jp	exit

	 endif			; Porton

; End RCPIOM.Z80