X-Git-Url: http://cloudbase.mooo.com/gitweb/ddt180.git/blobdiff_plain/51e6b03ccac806251df3586d47ffd2155b30402a..e800d6bed1ffbe37835710a9224d5adb63a0e97a:/ddt180.z80

diff --git a/ddt180.z80 b/ddt180.z80
index c4caedf..937faa6 100644
--- a/ddt180.z80
+++ b/ddt180.z80
@@ -6,90 +6,8 @@
 ;   - Use Digital Research Link-80 to generate a .PRL file (op switch).
 ;   - Cut the .PRL header (first 256 byte) end rename the result to DDTZ.COM.
 
-;-------------------------------------------------------------------------------
-; Relocation loader
-;
-TPA	equ	0100h
-	cseg
-	.phase	TPA
-
-	LD	SP,ldr_end+(stack-ddtz_base)
-	LD	DE,signon
-	LD	C,BDOS_PSTR
-	CALL	BDOS
-
-	LD	HL,ldr_end+ddtz_size	;start of reloc bitmap
-	ld	bc,0108h		;init bit counter
-
-	EXX
-	LD	HL,(BDOS+1)
-	LD	(ldr_end+1),HL
-	LD	BC,ddtz_size-1
-	LD	D,B
-	LD	E,0FFH
-	INC	DE			;size rounded up to next page boundary
-	INC	BC			;ddtz_size
-	OR	A
-	SBC	HL,DE			;BDOS - size
-	LD	(BDOS+1),HL		;-> new BDOS entry
-
-	push	hl
-	PUSH	BC
-	ld	de,ldr_end
-	sbc	hl,de
-	EX	DE,HL			;-> DE
-	LD	HL,ldr_size
-	add	hl,bc
-	ld	b,h
-	ld	c,l
-	LD	HL,TPA
-reloc_lp:
-	EXX
-	djnz	reloc_nl
-	ld	b,c			;reload bit counter
-	LD	e,(HL)			;get next 8 relocation bits
-	INC	HL
-reloc_nl:
-	sla	e
-	EXX
-	JR	NC,reloc_next
-	DEC	HL
-	LD	A,(HL)
-	ADD	A,E
-	LD	(HL),A
-	INC	HL
-	LD	A,(HL)
-	ADC	A,D
-	LD	(HL),A
-reloc_next:
-	cpi
-	jp	pe,reloc_lp
-	dec	hl
-
-	POP	BC
-	pop	de
-	EX	DE,HL
-	ADD	HL,BC
-	EX	DE,HL
-	DEC	DE
-	LDDR
-	LD	HL,conbuf+2-ddtz_base
-	ADD	HL,DE
-	JP	(HL)
 
-signon:
-	db	'DDTZ/180'
-	db	' - Version '
-	maclib	version.inc
-	defvers
-	db	CR,LF,'$'
-ldr_end:
-ldr_size	equ	$ - TPA
-
-	.dephase
-;-------------------------------------------------------------------------------
-; DDT/Z core
-;
+	maclib	config.inc
 
 ; Some greneral definitions
 
@@ -105,10 +23,6 @@ CNTRX		equ	'X'-'@'
 BDOS		equ	5
 TPA		equ	0100h
 
-; BDOS function calls
-
-BDOS_PSTR	equ	9       ;Print String
-
 ; ddtz specific definitions
 
 STACK_SIZE	equ	80	;ddtz internal stack
@@ -116,118 +30,483 @@ CONBUF_SIZE	equ	80	;Size of console input buffer
 BP_CNT		equ	12	;Number of breakpoints
 BP_SIZE		equ	4	;Size of a breakpoint record
 
+bitmap_size	equ	(prog_size+7)/8
+
 ;-------------------------------------------------------------------------------
 
+	cseg
+start:
 ddtz_base:
-	jp 0
+	jr reloc
+	nop
 l0003h:
-	rst 30h
-di_or_ei:
+	rst 30h			;rst used by ddtz
+di_or_ei:			;ints enabled/disabled while ddtz is running
 	nop
 	ret
 
-	ds	STACK_SIZE
-
-stack:
-reg.l2:	db	000h
-reg.h2:	db	000h
-reg.e2:	db	000h
-reg.d2:	db	000h
-reg.c2:	db	000h
-reg.b2:	db	000h
-reg.f2:	db	000h
-reg.a2:	db	000h
-	db	000h
-reg.i:	db	000h
-reg.iy:	dw	0000h
-reg.ix:	dw	0000h
-reg.f:	db	000h
-reg.a:	db	000h
-reg.c:	db	000h
-reg.b:	db	000h
-reg.e:	db	000h
-reg.d:	db	000h
-reg.l:	db	000h
-reg.h:	db	000h
-reg_sp:	dw	TPA
-reg.iff:
-	db	0f3h
-	db	0c3h
-reg.pc:	dw	TPA
+;-------------------------------------------------------------------------------
 
-cmd_rpt:dw	mainloop
+signon:
+	db	'DDTZ/180'
+	db	' - Version '
+	maclib	version.inc
+	defvers
+	dc	'  ('
 
 ;-------------------------------------------------------------------------------
 
-conbuf:
-	db	CONBUF_SIZE
-
-	ld sp,stack
+reloc_getbit	macro
+	local	nextbit
 	exx
-	ld de,ddtz_base
-	call cp_hl_de
-	jr c,l0079h
-	ex de,hl
-l0079h:
-	ld de,TPA
-l007ch:
-	dec hl
-	ld (hl),000h
-	ld a,h
-	sub d
-	ld b,a
-	ld a,l
-	sub e
-	or b
-	jr nz,l007ch
-	ld a,i
-	ld (reg.i),a
-	ld a,0f3h
-	jp po,l0093h
-	ld a,0fbh
-l0093h:
-	ld (reg.iff),a
-	call di_or_ei
-	ld hl,ddtz_base
-	ld l,000h
-	ld (reg_sp),hl
-
-	ld hl,(1)		;wboot addr
-	ld de,?const
-	ld b,6
-vini_l:
+	djnz	nextbit
+	ld	b,8			;reload bit counter
+	ld	e,(hl)			;get next 8 relocation bits
 	inc	hl
+nextbit:
+	sla	e
+	exx
+	endm
+
+;-------------------------------------------------------------------------------
+; Clear old position
+
+cmde_clr:
+	ld	(hl),0
 	inc	hl
+	dec	bc
+	ld	a,b
+	or	c
+	jr	nz,cmde_clr
+
+; Determine current position
+
+reloc:
+	ld	bc,(028h-2)
+	ld	de,(028h)
+	ld	a,i			;get iff2
+	ex	af,af'
+	di
+	ld	sp,028h			;rst instr needs a minimal stack
+	ld	hl,0e9e1h		;opcpdes pop hl/jp (hl)
+	ld	(028h),hl
+	rst	028h
+wearehere:
+	ld	(028h-2),bc
+	ld	(028h),de
+	ld	de,-(wearehere-ddtz_base)
+	add	hl,de			; hl:
+
+	ld	de,ddtz_base		; de:
+	or	a
+	sbc	hl,de
+	ex	de,hl			; de: reloc offset
+	ld	hl,stack
+	add	hl,de
+	ld	sp,hl
+	ex	af,af'
+	push	af
+	pop	bc
+	bit	2,c
+	jr	z,$+3
+	ei
+	ld	hl,ddtz_end		;start of reloc bitmap
+	add	hl,de
+	push	hl
+	exx
+	pop	hl
+	ld	b,1			;init bit counter b
+	exx
+
+	LD	HL,ddtz_base
+	add	hl,de			;--> ddtz_base
+
+reloc_lp:
+	push	de
+	push	hl
+
+	ld	de,4
+	ld	a,2
+	ld	hl,0
+reloc_l:
+	reloc_getbit
+	jr	nc,reloc_got
+	cp	16
+	jr	z,reloc_done
+	add	hl,de
+	ld	b,a
+	ex	de,hl
+reloc_l1:
+	add	hl,hl
+	djnz	reloc_l1
+	ex	de,hl
+	add	a,a
+	jr	reloc_l
+reloc_got:
+	ex	de,hl
+	ld	hl,0
+	ld	b,a
+reloc_bitloop:
+	reloc_getbit
+	adc	hl,hl
+	djnz	reloc_bitloop
+	add	hl,de
+	pop	de
+	add	hl,de
+	pop	de
+
+	LD	A,(HL)
+	ADD	A,E
+	LD	(HL),A
+	INC	HL
+	LD	A,(HL)
+	ADC	A,D
+	LD	(HL),A
 	inc	hl
+	jr	reloc_lp
+reloc_done:
+	exx
+	ld	(bitmap_end),hl
+;-------------------------------------------------------------------------------
+
+
+init:
+	LD	SP,stack
+
+    if CPM
+
+	ld 	hl,(1)		;wboot addr
+	ld 	de,convec
 	ex	de,hl
+	ld 	b,3
+vini_l:
+	inc	de
+	inc	de
+	inc	de
 	inc	hl
 	ld	(hl),e
 	inc	hl
 	ld	(hl),d
 	inc	hl
-	ex	de,hl
 	djnz	vini_l
+    else
+	xor	a
+	dec	a
+	daa			; Z80: 099H, x180+: 0F9H
+	cp	99h		; Result on 180 type cpus is F9 here. Thanks Hitachi
+	jr	z,ini_z80
+
+	xor	a
+	call	cinit
+	ld	a,1
+	call	cinit
+	jr	ini_sign
+ini_z80:
+;      if ...
+;	.printx Error: Not yet implemented!
+;	db "Stop
+;      endif
+    endif	; CPM
+
+ini_sign:
+	ld	hl,signon
+	call	pstr
+	ld	hl,ddtz_base
+	call	out_hl
+	call	pstr_inl
+	dc	' - '
+	ld	hl,(bitmap_end)
+	dec	hl
+	call	out_hl
+	call	pstr_inl
+	dc	')',CR,LF
+
+	ld 	a,i
+	ld 	(reg.i),a
+	ld 	a,0f3h
+	jp 	po,l0093h
+	ld 	a,0fbh
+l0093h:
+	ld 	(reg.iff),a
+	call 	di_or_ei
+	ld 	hl,ddtz_base
+	ld 	l,000h
+	ld 	(reg_sp),hl
+
+	jp 	mainloop
+
+;-------------------------------------------------------------------------------
+
+    if CPM
+
+convec:
+const:	jp	0		; return console input status
+conin:	jp	0		; return console input character
+conout:	jp	0		; send console output character
+
+    else
+
+	include	z180reg.inc
+
+iobyte	equ	3
+
+max_device	equ 3
+
+;-------------------------------------------------------------------------------
+
+; init device
+cinit:				; a = device
+	call	vector_io_0
+	dw	as0init
+	dw	rret
+	dw	rret
+	dw	rret
+
+; character input status
+const:				; return a != 0 if character waiting
+	call	vector_io
+	dw	as0ista
+	dw	null$status
+	dw	csio_ista
+	dw	null$status
+
+; character input
+conin:				; return a = input char
+	call	vector_io
+	dw	as0inp
+	dw	null$input
+	dw	csio_inp
+	dw	null$input
+
+; character output
+conout:				; c = output char
+	call	vector_io
+	dw	as0out
+	dw	rret
+	dw	csio_out
+	dw	rret
+
+;-------------------------------------------------------------------------------
+
+vector_io:
+	ld	a,(iobyte)
+vector_io_0:
+	pop	hl
+	cp	max_device
+	jr	c,exist
+	ld	a,max_device	; use null device if a >= max$device
+exist:
+	call	add_hl_a2
+	ld	a,(hl)
+	inc	hl
+	ld	h,(hl)
+	ld	l,a
+	jp	(hl)
+
+;-------------------------------------------------------------------------------
+
+null$input:
+	ld	a,1Ah
+rret:
+	ret
+ret$true:
+	or	0FFh
+	ret
+
+null$status:
+	xor	a
+	ret
+
+;-------------------------------------------------------------------------------
+;
+; TC = (f PHI /(2*baudrate*Clock_mode)) - 2
+;
+; TC = (f PHI / (32 * baudrate)) - 2
+;
+; Init Serial I/O for console input and output (ASCI1)
+;
+
+
+
+as0init:
+	ld	hl,initab0
+	jp	ioiniml
+
+as1init:
+	ld	hl,initab1
+	jp	ioiniml
+
+
+	ld	a,M_MPBT
+	out0	(cntlb1),a
+	ld	a,M_RE + M_TE + M_MOD2	;Rx/Tx enable
+	out0	(cntla1),a
+	ld	a,M_RIE
+	out0	(stat1),a	;Enable rx interrupts
+
+	ret			;
+
 
-	jr mainloop
+initab0:
+	db	1,stat0,0		;Disable rx/tx interrupts
+					;Enable baud rate generator
+	db	1,asext0,M_BRGMOD+M_DCD0DIS+M_CTS0DIS
+	db	2,astc0l,low 28, high 28
+	db	1,cntlb0,M_MPBT		;No MP Mode, X16
+	db	1,cntla0,M_RE+M_TE+M_MOD2 ;Rx/Tx enable, 8N1
+	db	0
+
+initab1:
+	db	1,stat1,0		;Disable rx/tx ints, disable CTS1
+	db	1,asext1,M_BRGMOD	;Enable baud rate generator
+	db	2,astc1l,low 3, high 3
+	db	1,cntlb1,M_MPBT		;No MP Mode, X16
+	db	1,cntla1,M_RE+M_TE+M_MOD2 ;Rx/Tx enable, 8N1
+	db	0
 
-	ds	CONBUF_SIZE + 3 - ($ - conbuf)
+;-------------------------------------------------------------------------------
+
+ioiniml:
+	push	bc
+	xor	a
+ioml_lp:
+	ld	b,(hl)
+	inc	hl
+	cp	b
+	jr	z,ioml_e
+
+	ld	c,(hl)
+	inc	hl
+	otimr
+	jr	ioml_lp
+ioml_e:
+	pop	bc
+	ret
 
 ;-------------------------------------------------------------------------------
 
-?const:	jp	0		; return console input status
-?conin:	jp	0		; return console input character
-?cono:	jp	0		; send console output character
-?list:	jp	0		; send list output character
-?auxo:	jp      0		; send auxiliary output character
-?auxi:	jp      0		; return auxiliary input character
+as0ista:
+	in0	a,(stat0)
+	rlca
+	sbc	a,a
+	ret
+
+as1ista:
+	in0	a,(stat1)
+	rlca
+	sbc	a,a
+	ret
+
+as0inp:
+	in0	a,(stat0)
+	rlca
+	jr	nc,as0inp
+	in0	a,rdr0
+	ret
+
+as1inp:
+	in0	a,(stat1)
+	rlca
+	jr	nc,as1inp
+	in0	a,rdr1
+	ret
+
+as0out:
+	in0	a,(stat0)
+	and	M_TDRE
+	jr	z,as0out
+	out0	(tdr0),c
+	ld	a,c
+	ret
+
+as1out:
+	in0	a,(stat1)
+	and	M_TDRE
+	jr	z,as1out
+	out0	(tdr1),c
+	ld	a,c
+	ret
+
+;-------------------------------------------------------------------------------
+
+
+csio_rx_tmp:	db	0ffh
+
+csio_ista:
+	ld	hl,csio_rx_tmp
+	ld	a,(hl)
+	cp	0ffh
+	jr	nz,csist_1
+	ld	a,01
+	call	csio_wr
+	call	csio_rd
+	call	csio_rd
+	ld	(hl),a
+	sub	a,0ffh
+	ret	z
+csist_1:
+	or	0ffh
+	ret
+
+csio_inp:
+	ld	hl,csio_rx_tmp
+	ld	a,(hl)
+	ld	(hl),0ffh
+	cp	0ffh
+	ret	nz
+csin_1:
+	ld	a,01
+	call	csio_wr
+	call	csio_rd
+	call	csio_rd
+	cp	0ffh
+	jr	z,csin_1
+	ret
+
+csio_rd:
+	ld	a,M_CSIO_RE
+	call	csio_cmd_wait
+	in0	a,(trdr)
+	ret
+
+csio_out:
+	ld	a,02
+	call	csio_wr
+	call	csio_rd
+	call	csio_rd
+	or	a
+	jr	z,csio_out
+
+	ld	a,c
+	inc	a		;ff..02 --> 00..03
+	cp	04h
+	jr	nc,csout_1
+	ld	a,00h
+	call	csio_wr
+csout_1:
+	ld	a,c
+csio_wr:
+	out0	(trdr),a
+	ld	a,M_CSIO_TE
+csio_cmd_wait:
+	out0	(cntr),a
+cswr_wait:
+	in0	a,(cntr)
+	and	M_CSIO_TE+M_CSIO_RE
+	jr	nz,cswr_wait
+	ret
+
+    endif ; CPM
+
+;-------------------------------------------------------------------------------
 
 CMDTAB:
-	dw	ERROR ;cmd_@	;examine/substitute the displacement register @
-	dw	ERROR ;cmd_A	;Assemble
+;	dw	ERROR ;cmd_@	;examine/substitute the displacement register @
+;	dw	ERROR ;cmd_A	;Assemble
 	dw	cmd_B		;Breakpoints display/set/clear
 	dw	ERROR ;cmd_C	;trace over Calls
 	dw	cmd_D		;Display memory in hex and ascii
-	dw	ERROR		;
+	dw	cmd_E		;rElocate debugger
 	dw	ERROR ;cmd_F	;specify Filename and command line
 	dw	cmd_G		;Go
 	dw	cmd_H		;compute Hex and other expressions
@@ -273,9 +552,9 @@ mainloop:
 	push hl
 	ld (cmd_rpt),hl
 	inc de
-	sub '@'
+	sub 'B'
 	jr c,ERROR
-	cp 'Z'+1-'@'
+	cp 'Z'+1-'B'
 	jr nc,ERROR
 	ld hl,CMDTAB
 	call add_hl_a2
@@ -301,8 +580,7 @@ crlf:
 sub_01d9h:
 	call	pstr_inl
 	dc	'-'
-	dec hl
-	jp cpl.hl
+	jp neg.hl
 
 out_hl_dec_neg:
 	push hl
@@ -369,9 +647,8 @@ out.bin.b:
 l01c9h:
 	rlca
 	push	af
-	ld	a,'0'/2
-	adc	a,a
-	call	outchar
+	and	1
+	call	out_dgt
 	pop af
 	djnz l01c9h
 	ld a,'"'
@@ -422,7 +699,7 @@ outchar:
 	push af
 	and 07fh
 	ld	c,a
-	call	?cono
+	call	conout
 	ld hl,con_col
 	inc (hl)
 	pop af
@@ -455,10 +732,10 @@ inchar:
 	push hl
 	push de
 	push bc
-	call	?const
+	call	const
 	and a
 	jr	z,inch1
-	call	?conin
+	call	conin
 	scf
 inch1:
 	pop bc
@@ -476,7 +753,6 @@ DELC:
 	call	DELC1
 	dec	hl
 	dec	b
-	inc	c
 	ld	a,(hl)
 	cp	' '
 	ret	nc
@@ -497,13 +773,10 @@ DELL:
 get_line:
 	push hl			;
 	ld hl,conbuf		;
-	ld c,(hl)		;
-	inc hl			;
-	ld b,000h		;
-	inc hl			;
+	ld b,0			;
 inlnxtch:
-	ld a,c			;
-	or a			;
+	ld a,b			;
+	cp CONBUF_SIZE		;
 	jr z,inl_e		;
 	call incharw		;
 	cp CR			;
@@ -539,16 +812,12 @@ gl_5:
 	call outchar		;
 	inc hl			;
 	inc b			;
-	dec c			;
 	jr inlnxtch		;
 
 inl_e:
 	ld (hl),0
-	ld hl,conbuf+1		;
-	ld (hl),b		;
 	call CRLF		;
-	inc	hl
-	ex	de,hl
+	ld de,conbuf		;
 	pop hl			;
 	ret			;
 
@@ -703,12 +972,12 @@ l0348h:
 	ret m
 	jr l0348h
 
-sub_034eh:
+get_arg_range_target:
 	call get_arg_range
 	push hl
 	push bc
 	call next_arg
-	call sub_0363h
+	call get_arg_final
 	ex de,hl
 	pop bc
 	pop hl
@@ -719,7 +988,7 @@ sub_035dh:
 	jr c,error0
 	ret
 
-sub_0363h:
+get_arg_final:
 	call sub_035dh
 l0366h:
 	jp assert_eol
@@ -983,6 +1252,9 @@ do_factor:
 	ld hl,TPA
 	cp 'L'
 	ret z
+	ld hl,(reg.pc)
+	cp '$'
+	ret z
 	cp '-'
 	jr z,fact_factneg
 	cp '~'
@@ -1035,14 +1307,19 @@ fact_reg.CPU:
 	inc hl
 	ld h,(hl)
 	ld l,a
-	and a
+	xor a			;clr cy, a=0
 	bit 0,c
 	ret nz
-	ld h,000h
+	ld h,a
 	ret
 
+fact_factinv:
+	call fact_factor
+	jr cpl.hl
+
 fact_factneg:
 	call fact_factor
+neg.hl:
 	dec hl
 cpl.hl:
 	ld a,h
@@ -1053,10 +1330,6 @@ cpl.hl:
 	ld l,a
 	ret
 
-fact_factinv:
-	call fact_factor
-	jr cpl.hl
-
 fact_mem:
 	call expr1
 	jr c,error1
@@ -1334,6 +1607,56 @@ b_0709_start:
 	db	000h
 	db	000h
 
+;-------------------------------------------------------------------------------
+; > E addr
+;      relocate debugger to addr
+; > ER addr
+;      relocate just below addr
+;
+; Move debugger to given address and restart.
+; New location must not overlap with current location.
+
+
+cmd_E:
+	call	skipbl
+	sub	'R'
+	jr	nz,$+3
+	 inc	de
+	push	af
+	call	get_arg_final
+
+	ex	de,hl
+	ld	hl,(bitmap_end)
+	ld	bc,ddtz_base
+	or	a
+	sbc	hl,bc
+	ld	b,h
+	ld	c,l
+	ex	de,hl
+	pop	af
+	jr	nz,cmde_bottom
+	sbc	hl,bc
+cmde_bottom:
+	ld	ix,cmde_clr-ddtz_base
+	ex	de,hl			;de = dst
+	add	ix,de
+	ld	hl,ddtz_base		;hl = src
+
+	push	hl
+	or	a
+	sbc	hl,de
+	call	c,neg.hl		;abs(distance)
+	or	a
+	sbc	hl,bc
+	jp	c,error
+	pop	hl
+	push	hl
+	push	bc
+	ldir
+	pop	bc
+	pop	hl
+	jp	(ix)
+
 ;-------------------------------------------------------------------------------
 ; > G [startaddr] [;breakp..]
 ;      Go [to start] [with temporary breakpoints]
@@ -1599,18 +1922,18 @@ bp_tst_@pc:
 	call	bpl_init
 
 	ld a,(ix+000h)
-	and 003h
-	jr z,bp_tst_e
+	and 003h		;User bp (temporary or permanent)?
+	jr z,bp_tst_e		;No, check next
 	ld e,(ix+002h)
 	ld d,(ix+003h)
 	ld hl,(reg.pc)
-	call cp_hl_de
-	ret z
+	call cp_hl_de		;Current PC is on a User bp
+	ret z			;Return zero
 bp_tst_e:
 	call	bpl_next
 	sub a
-	inc a
-	ret
+	inc a			;Not on a user bp
+	ret			;Return not zero
 
 bp_trace_enter:
 	call bp_get_freeslot
@@ -1648,7 +1971,6 @@ bp_set_to_mem:
 	inc hl
 	ld (hl),d
 l0a1dh:
-
 	call	bpl_next
 	ret
 
@@ -1723,7 +2045,7 @@ cmd_X:
 	call get_line
 	call skipbl
 	jr z,l0c30h
-	call sub_0363h
+	call get_arg_final
 	ex de,hl
 	pop bc
 	pop hl
@@ -1995,11 +2317,11 @@ cmd_O:
 	ret
 
 ;-------------------------------------------------------------------------------
-; > Vstartaddr endaddr targetaddr
+; > V startaddr endaddr targetaddr
 ;      Verify (compare) two memory areas
 
 cmd_V:
-	call sub_034eh
+	call get_arg_range_target
 l0dedh:
 	push bc
 	ld a,(de)
@@ -2031,7 +2353,7 @@ l0e10h:
 ;      Move memory
 
 cmd_M:
-	call sub_034eh
+	call get_arg_range_target
 	call cp_hl_de
 	jr nc,cmdm_up
 	add hl,bc
@@ -2041,7 +2363,7 @@ cmd_M:
 	dec hl
 	dec de
 	lddr
-	db 01h		;swallow ldir instruction (ld bc,...)
+	ret
 cmdm_up:
 	ldir
 	ret
@@ -2140,9 +2462,9 @@ l0ed3h:
 	ret
 
 sub_0ee6h:
-	ld hl,conbuf+1
+	ld hl,conbuf
 	call sub_0ef7h
-	ld de,conbuf+1
+	ld de,conbuf
 	and a
 	sbc hl,de
 	ld b,l
@@ -2353,12 +2675,14 @@ i.getchar:
 i.storebyte:
 	push af
 	push de
-	ld de,TPA		;lowest allowed load address
+	ld de,ddtz_base		;don't load over ddtz
 	call cp_hl_de
-	jr c,error2
-	ld de,(BDOS+1)		;highest allowed load address
+	jr nc,ist_1
+
+	ld de,(bitmap_end)
 	call cp_hl_de
 	jr nc,error2
+ist_1:
 	ld de,(high_load)
 	call cp_hl_de
 	jr c,l1157h
@@ -3544,6 +3868,7 @@ l208bh:
 	scf
 	ret
 
+;jr, djnz
 l2093h:
 	ld c,(iy+001h)
 	ld a,c
@@ -3587,6 +3912,8 @@ l20b8h:
 	jr z,l20dch
 	and a
 	ret
+
+;ret cc
 l20c5h:
 	ld a,(iy+000h)
 	ld (l20d7h),a
@@ -3604,6 +3931,7 @@ l20d7h:
 	inc hl
 	jp (hl)
 
+;ret
 l20dch:
 l20edh:
 	ld hl,(reg_sp)		;break on return address
@@ -3612,10 +3940,12 @@ l20edh:
 	ld d,(hl)
 	ex de,hl
 	call bp_trace_enter
+;rst 8
 l2115h:
 	and a
 	ret
 
+;rst n
 l20f9h:
 	ld a,(l0003h)
 	cp (iy+000h)
@@ -3624,9 +3954,6 @@ l20f9h:
 	and 038h
 	ld l,a
 	ld h,000h
-	ld a,(b_21e2_start)
-	and a
-	ret z
 	scf
 	ret
 
@@ -3720,7 +4047,52 @@ last_L:
 pbl_loop_adr:
 	dw	0addeh
 
+bitmap_end:
+	dw	0
+
+;-------------------------------------------------------------------------------
+
+conbuf:
+	ds	CONBUF_SIZE+1
+
+;-------------------------------------------------------------------------------
+
+	rept	(STACK_SIZE+3)/4
+	db	0deh,0adh,0beh,0efh
+	endm
+stack:
+reg.l2:	db	000h
+reg.h2:	db	000h
+reg.e2:	db	000h
+reg.d2:	db	000h
+reg.c2:	db	000h
+reg.b2:	db	000h
+reg.f2:	db	000h
+reg.a2:	db	000h
+	db	000h
+reg.i:	db	000h
+reg.iy:	dw	0000h
+reg.ix:	dw	0000h
+reg.f:	db	000h
+reg.a:	db	000h
+reg.c:	db	000h
+reg.b:	db	000h
+reg.e:	db	000h
+reg.d:	db	000h
+reg.l:	db	000h
+reg.h:	db	000h
+reg_sp:	dw	TPA
+reg.iff:
+	db	0f3h
+	db	0c3h
+reg.pc:	dw	TPA
+
+cmd_rpt:dw	mainloop
+	db	0ffh,0ffh,0ffh
+;-------------------------------------------------------------------------------
+
 ddtz_size	equ	$-ddtz_base
+prog_size	equ	$-start
 ddtz_end:
 
 ;-------------------------------------------------------------------------------