X-Git-Url: http://cloudbase.mooo.com/gitweb/ddt180.git/blobdiff_plain/b0451b39fb513da895b5b327efe484228dbc28a9..d0ff7c76b85c1d1f7e76672462c0ba85861ab9b3:/ddt180.z80

diff --git a/ddt180.z80 b/ddt180.z80
index 37695d4..da5cfe6 100644
--- a/ddt180.z80
+++ b/ddt180.z80
@@ -63,11 +63,6 @@ CONBUF_SIZE	equ	80	;Size of console input buffer
 EXPR_BUF_SIZE	equ	128	;expressen buffer for conditional breakpoints
 BP_CNT		equ	12	;Number of breakpoints
 BP_SIZE		equ	8	;Size of a breakpoint record
-YREG_CNT	equ	10	;Number of Y registers (0..9)
-
-SYMCASE_SENS	equ	0	;Symbols are case sensitive
-SYMCASE_CONV	equ	1	;Convert case when symbols are loaded
-SYMCASE_LOWER	equ	2	;Convert to lower case if set, else to upper case
 
 ;-------------------------------------------------------------------------------
 
@@ -75,24 +70,16 @@ ddtz_base:
 	jp ddtz_bdos
 l0003h:
 	rst 30h
-sub_0004h:
+di_or_ei:
 	nop
 	ret
 ddtz_bdos:
 	jp	0
-screen_width:
-	db	80
-symlen_max:
-	db	16
-
-symattrib:
-	db	0
-
 
 current_cseg	defl	$ - current_cseg
 	.phase	current_phase + current_cseg
 signon:
-	db	'Symbolic DDTZ/180'
+	db	'DDTZ/180'
 	db	' - Version '
 	maclib	version.inc
 	defvers
@@ -133,9 +120,7 @@ reg.iff:
 	db	0c3h
 reg.pc:	dw	TPA
 var.$:	dw	0000h
-var.@:	dw	0
 
-error_func:dw	p_msg_error
 cmd_rpt:dw	mainloop
 
 ;-------------------------------------------------------------------------------
@@ -146,9 +131,7 @@ conbuf:
 	ld sp,stack
 	exx
 	ld de,ddtz_base
-	or a
-	sbc hl,de
-	add hl,de
+	call cp_hl_de
 	jr c,l0079h
 	ex de,hl
 l0079h:
@@ -170,11 +153,10 @@ l007ch:
 	ld a,0fbh
 l0093h:
 	ld (reg.iff),a
-	call sub_0004h
+	call di_or_ei
 	ld hl,ddtz_base
 	ld l,000h
 	ld (reg_sp),hl
-	call cpy_fcb2
 	ld a,(dfcb1+1)
 	cp ' '
 	ld hl,0
@@ -186,8 +168,8 @@ l0093h:
 ;-------------------------------------------------------------------------------
 
 CMDTAB:
-	dw	cmd_@		;examine/substitute the displacement register @
-	dw	cmd_A		;Assemble
+	dw	ERROR ;cmd_@	;examine/substitute the displacement register @
+	dw	ERROR ;cmd_A	;Assemble
 	dw	cmd_B		;Breakpoints display/set/clear
 	dw	cmd_C		;trace over Calls
 	dw	cmd_D		;Display memory in hex and ascii
@@ -204,25 +186,29 @@ CMDTAB:
 	dw	cmd_O		;Output a byte to port
 	dw	ERROR		;
 	dw	cmd_Q		;Qery memory for byte string
-	dw	cmd_R		;Read binary or hex file and/or symbol file
+	dw	cmd_R		;Read binary or hex file
 	dw	cmd_S		;Substitute memory
 	dw	cmd_T		;Trace
 	dw	ERROR		;
 	dw	cmd_V		;Verify (compare) two memory areas
 	dw	cmd_W		;Write a file to disk
 	dw	cmd_X		;eXamine [and substitute] registers
-	dw	cmd_Y		;examine [and substitute] Y variables
+	dw	ERROR ;cmd_Y	;examine [and substitute] Y variables
 	dw	cmd_Z		;Zap (fill) memory with a byte string
 
+ERROR:
+p_msg_error:
+	call	pstr_inl
+	dc	'?',CR,LF
+	;fall thru
 mainloop:
 	ld sp,stack
-	ld hl,p_msg_error
-	ld (error_func),hl
 	ld hl,(reg.pc)
 	ld (var.$),hl
 	call bp_clr_temporary
 	ld hl,(cmd_rpt)
 	ld de,mainloop
+	push de
 	call cp_hl_de
 	ld a,'>'
 	call outchar
@@ -231,7 +217,8 @@ mainloop:
 	call get_line
 	call skipbl
 	jr z,exe_hl
-	ld hl,mainloop
+	pop hl
+	push hl
 	ld (cmd_rpt),hl
 	inc de
 	sub '@'
@@ -245,48 +232,21 @@ mainloop:
 	inc hl
 	ld h,(hl)
 	ld l,a
-	jr exe_hl
 
-ERROR:
-	ld hl,(error_func)
 exe_hl:
-	call CALL_HL
-	jr mainloop
+	jp (hl)
 
 ;-------------------------------------------------------------------------------
 
-p_msg_error:
-	call	pstr_inl
-	dc	'?'
-	;fall thru
 crlf:
 	call	pstr_inl
-	db	CR,LF+80h
+	dc	CR,LF
 	call inchar
 	ld a,0
 	ld (con_col),a
 	jr c,mainloop
 	ret
 
-out.hl.@:
-	call out_hl
-	push de
-	push hl
-	ld de,(var.@)
-	ld a,d
-	or e
-	jr z,l01bfh
-	call outbl
-	call	pstr_inl
-	dc	'@'
-	and a
-	sbc hl,de
-	call out_hl
-l01bfh:
-	pop hl
-	pop de
-	ret
-
 sub_01d9h:
 	call	pstr_inl
 	dc	'-'
@@ -296,7 +256,7 @@ sub_01d9h:
 out_hl_dec_neg:
 	push hl
 	call sub_01d9h
-	defb 03eh
+	defb 03eh		;ld a,..  swallow push hl
 out.hl.dec:
 	push hl
 	ld b,006h
@@ -343,12 +303,10 @@ out_hex:
 	pop af
 
 out_dgt:
-	and 0fh
-	cp 10
-	jr c,l0229h
-	add a,007h
-l0229h:
-	add a,'0'
+	or	0f0h
+	daa
+	add	a,0a0h
+	adc	a,040h
 	jr outchar
 
 out.bin.w:
@@ -358,11 +316,11 @@ out.bin.w:
 out.bin.b:
 	ld b,8
 l01c9h:
-	add a,a
-	push af
-	ld a,00
-	adc a,a
-	call out_dgt
+	rlca
+	push	af
+	ld	a,'0'/2
+	adc	a,a
+	call	outchar
 	pop af
 	djnz l01c9h
 	ld a,'"'
@@ -404,10 +362,6 @@ outbl:
 	ld a,' '
 	jr outchar
 
-p_char_lparen:
-	ld a,'('
-	jr outchar
-
 outquote:
 	ld a,''''
 outchar:
@@ -447,17 +401,6 @@ pstr_inl:
 	ex	(sp),hl
 	ret
 
-p_align_@_sym:
-	push	de
-	ld	de,(var.@)
-	ld	a,d
-	or	e
-	pop	de
-	ld	a,(symlen_cur)
-	jr	z,$+4
-	add	a,6
-	add	a,c
-	ld	c,a
 p_goto_col:
 	ld	a,(con_col)
 	cp	c
@@ -517,15 +460,6 @@ toupper:
 	and 05fh
 	ret
 
-tolower:
-	cp 'A'
-	ret c
-	cp 'Z'+1
-	ccf
-	ret c
-	or 020h
-	ret
-
 ;-------------------------------------------------------------------------------
 
 skipbl0:
@@ -580,86 +514,6 @@ cp_hl_de:
 	sbc hl,de
 	add hl,de
 	ret
-
-sub_hl_a1:
-	dec	hl
-sub_hl_a:
-	push	bc
-	ld	c,a
-	ld	b,0
-	or	a
-	sbc	hl,bc
-	pop	bc
-	ret
-
-;-------------------------------------------------------------------------------
-
-sym_getname:
-	push	de
-	push	hl
-	ld	hl,ddtz_base+2
-sgn_l:
-	ld	d,(hl)
-	dec	hl
-	ld	e,(hl)
-	dec	hl
-	ld	a,(hl)
-	cp	0c3h
-	jr	z,sgn_e
-
-	ex	(sp),hl
-	call	cp_hl_de
-	jr	z,sgn_e
-	ex	(sp),hl
-	call	sub_hl_a1
-	jr	sgn_l
-sgn_e:
-	sub	0c3h
-	pop	hl
-	pop	de
-	ret
-
-p_symstr:
-	push	bc
-	ld	b,(hl)
-pss_l:
-	dec	hl
-	ld	a,(hl)
-	call	outchar
-	djnz	pss_l
-	dec	hl
-	pop	bc
-	ret
-
-p_symbol:
-  if 0
-	ld	a,(dash_flag)
-	or	a
-	ret	nz
-  endif
-	push	hl
-	call	sym_getname
-	call	nz,p_symstr
-	pop	hl
-	ret
-
-p_label:
-  if 0
-	ld	a,(dash_flag)
-	or	a
-	ret	nz
-  endif
-	push	hl
-	call	sym_getname
-	jr	z,pl_e
-	call	p_symstr
-	call	pstr_inl
-	dc	':'
-	call	crlf
-pl_e:
-	pop	hl
-	ret
-
 ;-------------------------------------------------------------------------------
 
 lookupch:
@@ -680,12 +534,8 @@ l0300h:
 	ret
 
 sub_0303h:
-	ld hl,b_0cc3_start
+	ld hl,t_reg_names
 	ld b,07fh
-	jr l030ch
-
-sub_030ah:
-	ld b,0ffh
 l030ch:
 	inc b
 	ld a,(hl)
@@ -696,10 +546,6 @@ l030ch:
 	res 7,b
 	ret
 
-sub_0318h:
-	push bc
-	res 7,b
-	defb 03eh		;ld a,nn
 sub_031ch:
 	push bc
 	push de
@@ -786,7 +632,7 @@ sub_0377h:
 	jr l0366h
 
 b_037c_start:
-	defb 0e6h
+	defb 0e6h		;and a,..  clear carry
 get_arg_range:
 	scf
 	ex af,af'
@@ -798,7 +644,7 @@ get_arg_range:
 	jr c,error0
 	ex af,af'
 	pop hl
-	defb 03eh
+	defb 03eh		;ld a,..  swallow pop af
 l038ch:
 	pop af
 	call get_range
@@ -1005,40 +851,33 @@ doop_mod:
 ;     de: r  (x%y)
 
 div_hl_de:
-	push bc
-	ex de,hl
-	ld b,h
-	ld c,l
-	ld hl,0
-	ld a,16
+	push	bc
+	ex	de,hl		;de: x
+	ld	b,h		;bc: y
+	ld	c,l
+	ld	hl,0		;hl: r
+	ld	a,16
 
 ;  de: x   (x shifted out, q shifted in)
 ;  bc: y
 ;  hl: r   (initially 0)
 
-l047eh:
-	push af
-	add hl,hl
-	ex de,hl
-	xor a
-	add hl,hl
-	ex de,hl
-	adc a,l
-	sub c
-	ld l,a
-	ld a,h
-	sbc a,b
-	ld h,a
-	inc de
-	jr nc,l048fh
-	add hl,bc
-	dec de
-l048fh:
-	pop af
-	dec a
-	jr nz,l047eh
-	ex de,hl
-	pop bc
+div_lp:
+	ex	de,hl
+	add	hl,hl		;x <<= 1
+	ex	de,hl
+	adc	hl,hl		;r <<= 1
+	inc	de
+	or	a
+	sbc	hl,bc
+	jr 	nc,div_norestore
+	dec	de
+	add	hl,bc
+div_norestore:
+	dec	a
+	jr	nz,div_lp
+	ex	de,hl
+	pop	bc
 	ret
 
 doop_and:
@@ -1120,9 +959,6 @@ do_factor:
 	ld hl,TPA
 	cp 'L'
 	ret z
-	ld hl,(var.@)
-	cp '@'
-	ret z
 	ld hl,(var.$)
 	cp '$'
 	ret z
@@ -1137,37 +973,18 @@ do_factor:
 	jr z,fact_factor
 	cp '^'
 	jr z,fact_reg.CPU
-	cp 'Y'
-	jr z,fact_reg.Y
 	cp '('
 	jr z,fact_mem
 	cp '['
 	jr z,expr_brckt
 	cp ''''
 	jr z,fact_factstring
-	cp '.'
-	jr z,fact_symbol
 	dec de
 	scf
 	ret
 
 ;-------------------------------------------------------------------------------
 
-fact_reg.Y:
-	call get.decdigit
-	jr c,error1
-	inc de
-get_y_val:
-	add a,a
-	ld hl,reg_Y
-	call add_hl_a
-	ld a,(hl)
-	inc hl
-	ld h,(hl)
-	ld l,a
-	and a
-	ret
-
 fact_factstring:
 	ld hl,0
 l054bh:
@@ -1252,59 +1069,6 @@ expr_brckt:
 error1:
 	jp ERROR
 
-fact_symbol:
-	push	bc
-	ld	hl,ddtz_base		;symtbl start
-	ld	a,(symattrib)
-	ld	c,07fh
-	rra
-	jr	c,fs_nxtsym
-	res	5,c
-
-fs_nxtsym:
-	ld	a,(hl)			;symlen
-	cp	0c3h
-	jr	z,error1
-	ld	b,a			;symlen
-	inc	b
-	push	hl			;symtbl ptr
-	push	de			;inpsym ptr
-fs_nxtchar:
-	ld	a,(de)
-	djnz	fs_3
-	call	test_sym_char
-	jr	z,fs_cont
-	pop	hl			;inpsym ptr (discard)
-	inc	de
-	cp	a,':'
-	jr	z,fs_cont_1
-	dec	de
-
-	pop	hl			;symtbl ptr
-	inc	hl
-	ld	a,(hl)			;symval h
-	inc	hl
-	ld	h,(hl)			;symval l
-	ld	l,a
-	or	a			;clear carry
-	pop	bc
-	ret
-
-fs_3:
-	inc	de
-	dec	hl
-	xor	(hl)
-	and	c
-	jr	z,fs_nxtchar
-fs_cont:				;start over
-	pop	de			;inpsym ptr
-fs_cont_1:
-	pop	hl			;symtbl ptr
-	ld	a,(hl)
-	add	a,3
-	call	sub_hl_a
-	jr	fs_nxtsym
-
 ;-------------------------------------------------------------------------------
 
 get.number:
@@ -1380,7 +1144,7 @@ error11:
 
 sub_060ch:
 	call get_char_upper
-	cp '['
+	cp 'Z'+1
 	jr l0614h
 
 get.hexdigit:
@@ -1426,6 +1190,7 @@ p_cpustat:
 l063eh:
 	call p_regs
 	djnz l063eh
+	call outbl6
 	push hl
 	push de
 	ld iy,(reg.pc)
@@ -1442,8 +1207,6 @@ l065bh:
 	djnz l065bh
 	pop af
 	pop hl
-	call nz,outbl6
-	call nz,p_offset
 	jp crlf
 
 p_f:
@@ -1460,24 +1223,25 @@ p_f2:
 	jp outbl
 
 p_flags:
-	ld b,a
-	ld a,'S'
-	call sub_06aah
-	ld a,'Z'
-	call sub_06aah
-	rl b
-	ld a,'H'
-	call sub_06aah
-	rl b
-	ld a,'V'
-	call sub_06aah
-	ld a,'N'
-	call sub_06aah
-	ld a,'C'
-sub_06aah:
-	rl b
-	jp c,outchar
-	jp outbl
+	push	hl
+	ld	hl,t_flag_names+7
+	ld	c,a
+	ld	b,8
+fl_loop:
+	ld	a,' '
+	cp	(hl)
+	ld	a,c
+	rlca
+	ld	c,a
+	jr	z,fl_skip
+	ld	a,(hl)
+	call	c,outchar
+	call	nc,outbl
+fl_skip:
+	dec	hl
+	djnz	fl_loop
+	pop	hl
+	ret
 
 p_regs:
 	push de
@@ -1499,12 +1263,6 @@ p_regs:
 	inc hl
 	ld d,(hl)
 	ex de,hl
-	dec a
-	jr z,l06d9h
-	call out.hl.@
-	call z,outbl6
-	jr l06e2h
-l06d9h:
 	call out_hl
 	jr l06e2h
 l06deh:
@@ -1568,18 +1326,19 @@ b_0709_start:
 cmd_G:
 	sub a
 	ld (trace_call_flag),a
-	ld (l0941h),a
+	ld (bp_p_cpu_flag),a
 	call expr
 	jr c,l0740h
 	ld (reg.pc),hl
 l0740h:
 	call skipbl
-	jp z,user_go
+	jr z,user_go0
 	cp ';'
 	jp nz,ERROR
 	inc de
 	ld a,002h
 	call bp_enter
+user_go0:
 	jp user_go
 
 ;-------------------------------------------------------------------------------
@@ -1594,7 +1353,9 @@ bpl_init:
 
 bpl_next:
 	ld	de,BP_SIZE
+	push	af
 	add	ix,de
+	pop	af
 	dec	b
 	ret	z
 
@@ -1636,6 +1397,7 @@ cmd_B:
 	dec de
 	ld a,001h
 	jp bp_enter
+
 bp_clr0:
 	call skipbl
 	jr z,bp_clr_all
@@ -1681,13 +1443,9 @@ l07cdh:
 	call outbl
 	ld l,(ix+002h)
 	ld h,(ix+003h)
-	call out.hl.@
-	call	outbl
-	call	p_symbol
-	ld	c,9
-	call	p_align_@_sym
+	call out_hl
 	call 	pstr_inl
-	dc	':'
+	dc	'  :'
 	ld l,(ix+004h)
 	ld h,(ix+005h)
 	call out_hl
@@ -1789,20 +1547,19 @@ bp_get_condition:
 	ld de,expr_bufe
 	call cp_hl_de
 	jr nc,error12
-	pop hl
-	ld (expr_p2),hl
-	pop de
-	ex de,hl
+	pop	de
+	pop	hl
+	push	de
 	ldir
-	xor a
-	ld (de),a
-	inc de
 	ex de,hl
+	ld (hl),c		; trailing 0
+	inc hl
 	ld (expr_p1),hl
-	ld hl,(expr_p2)
+	pop	hl
 	ret
 
 ;-------------------------------------------------------------------------------
+; Breakpoint handling routine.
 
 bpddtz:
 	ld (reg.l),hl
@@ -1817,13 +1574,13 @@ bpddtz:
 	push ix
 	push iy
 	ld a,i
-	call sub_0004h
+	call di_or_ei
 	ld h,a
 	ld l,000h
 	push hl
-	ld a,0f3h
+	ld a,0f3h		; EI
 	jp po,l08dfh
-	ld a,0fbh
+	ld a,0fbh		; DI
 l08dfh:
 	ld (reg.iff),a
 	ex af,af'
@@ -1832,18 +1589,18 @@ l08dfh:
 	push bc
 	push de
 	push hl
-	call sub_097ah
+	call bp_restore_mem
 	ld a,(b_21e2_start)
 	dec a
 	jr z,l090bh
-	call inchar
-	jr c,l0902h
+	call inchar		;Keyboard hit?
+	jr c,do_break		;yes
 	call sub_0913h
 	and a
 	jp z,user_go
 	and 083h
 	jp z,l2151h
-l0902h:
+do_break:
 	call bp_clr_temporary
 	call p_cpustat
 	jp mainloop
@@ -1857,7 +1614,7 @@ sub_0913h:
 	ld a,080h
 	ex af,af'
 	sub a
-	ld (l0941h),a
+	ld (bp_p_cpu_flag),a
 	call	bpl_init
 
 	ld a,(ix+000h)
@@ -1901,7 +1658,7 @@ l0969h:
 	bit 4,(ix+000h)
 	ret z
 	ld a,001h
-	ld (l0941h),a
+	ld (bp_p_cpu_flag),a
 	ret
 l0974h:
 	ex af,af'
@@ -1909,7 +1666,7 @@ l0974h:
 	ex af,af'
 	ret
 
-sub_097ah:
+bp_restore_mem:
 	call	bpl_init
 
 	bit 5,(ix+000h)
@@ -1928,25 +1685,24 @@ l099ah:
 	call	bpl_next
 	ret
 
-sub_09a6h:
+bp_tst_@pc:
 	call	bpl_init
 
 	ld a,(ix+000h)
 	and 003h
-	jr z,l09c0h
+	jr z,bp_tst_e
 	ld e,(ix+002h)
 	ld d,(ix+003h)
 	ld hl,(reg.pc)
 	call cp_hl_de
 	ret z
-l09c0h:
-
+bp_tst_e:
 	call	bpl_next
 	sub a
 	inc a
 	ret
 
-sub_09cah:
+bp_trace_enter:
 	call bp_get_freeslot
 	ld (ix+004h),001h
 	ld (ix+005h),000h
@@ -1957,9 +1713,9 @@ sub_09cah:
 	ld a,(b_21e2_start)
 	and a
 	ld a,008h
-	jr nz,l09edh
+	jr nz,bp_t_e
 	rra
-l09edh:
+bp_t_e:
 	ld (ix+000h),a
 	ret
 
@@ -1995,15 +1751,15 @@ l0a1dh:
 user_go:
 	sub a
 	ld (b_21e2_start),a
-	ld a,(l0941h)
+	ld a,(bp_p_cpu_flag)
 	and a
 	call nz,p_cpustat
-	call sub_09a6h
+	call bp_tst_@pc
 	ld c,007h
 	jr nz,l0a41h
 	ld a,001h
 	ld (b_21e2_start),a
-	call sub_1ffeh
+	call tc_set_bp
 	ld c,008h
 l0a41h:
 	call bp_set_to_mem
@@ -2085,53 +1841,6 @@ l0ab0h:
 ; > Y[0..9]
 ;      examine (and substitute) an Y variable
 
-cmd_Y:
-	call get.decdigit
-	jr c,l0bc3h
-	inc de
-	push af
-	call assert_eol
-	pop af
-	call sub_0bdch
-	jp l0c15h
-l0bc3h:
-	call assert_eol
-	xor a
-l0bc7h:
-	push af
-	call sub_0bdch
-	call	outbl
-	pop af
-	push af
-	call get_y_val
-	call p_symbol
-	pop af
-	inc a
-	push af
-	rra
-	push	af
-	ld	c,11
-	call	c,p_align_@_sym
-	pop	af
-	call 	nc,crlf
-	pop af
-	cp YREG_CNT
-	jr c,l0bc7h
-	ret
-
-sub_0bdch:
-	ld c,a
-	ld b,0
-	add a,'0'+080h
-	ld de,msg_Y+1
-	ld (de),a
-	dec de
-	ld hl,reg_Y
-	add hl,bc
-	add hl,bc
-	ex de,hl
-	ld c,003h
-	jp l0c33h
 
 ;-------------------------------------------------------------------------------
 ; > X
@@ -2154,11 +1863,11 @@ cmd_X:
 	cp 01dh
 	jp z,ERROR
 	ex de,hl
-	ld hl,b_0cc3_start
+	ld hl,t_reg_names
 	call sel_dc_string
 l0c12h:
 	call l0c33h
-l0c15h:
+
 	call outbl
 	push de
 	push bc
@@ -2192,9 +1901,7 @@ l0c33h:
 	ld a,(de)
 	dec de
 	ld h,a
-	bit 1,c
-	jp z,out_hl
-	jp out.hl.@
+	jp out_hl
 
 l0c4fh:
 	call p_f
@@ -2224,32 +1931,30 @@ l0c76h:
 	ld a,b
 	ret z
 	push bc
-	ld hl,b_0ca4_start
+	ld hl,t_flag_names
 	call lookupch
 	jp nc,ERROR
-	ld a,b
-	cp 008h
-	jr z,l0c97h
-	pop bc
-	rlca
-	rlca
-	rlca
-	add a,0c0h
-	ld (l0c94h),a
-	defb 0cbh
-l0c94h:
-	defb 0c0h
+	inc	b
+	xor	a
+	scf
+nxt_f:
+	rla
+	djnz	nxt_f
+	pop	bc
+	jr	c,l0c97h
+	or	b
+	ld	b,a
 	jr l0c76h
+
 l0c97h:
 	ex af,af'
 	jp nc,ERROR
 	ex af,af'
 	ld a,0fbh
 	ld (reg.iff),a
-	pop bc
 	jr l0c76h
 
-b_0ca4_start:
+t_flag_names:
 	db	'CNV H ZSE',0
 
 sub_0caeh:
@@ -2269,7 +1974,7 @@ sub_0caeh:
 	scf
 	ret
 
-b_0cc3_start:
+t_reg_names:
 	DC	'BC'''
 	DC	'DE'''
 	DC	'HL'''
@@ -2379,7 +2084,7 @@ cmd_S:
 	call get_lastarg_def
 l0d60h:
 	ld (last_S),hl
-	call out.hl.@
+	call out_hl
 	call outbl
 	ld a,(hl)
 	call out_hex
@@ -2414,22 +2119,13 @@ l0d8ah:
 ; > @
 ;      examine (substitute) displacement register @
 
-cmd_@:
-	call assert_eol
-	ld hl,msg_@
-	ld de,var.@
-	ld c,001h
-	jp l0c12h
-
-msg_@:
-	dc	'@'
+;cmd_@:
 
 ;-------------------------------------------------------------------------------
 ; >>I [port]
 ;      Input a byte from port
 
 cmd_I:
-	ld hl,cmd_I
 	ld (cmd_rpt),hl
 	ld hl,(last_I)
 	call get_lastarg_def
@@ -2449,7 +2145,6 @@ cmd_I:
 ;      Output a byte to a port
 
 cmd_O:
-	ld hl,cmd_O
 	ld (cmd_rpt),hl
 	ld hl,(last_O_val)
 	call get_arg_def
@@ -2479,7 +2174,7 @@ l0dedh:
 	cp b
 	jr z,l0e10h
 	ld c,a
-	call out.hl.@
+	call out_hl
 	call outbl
 	ld a,b
 	call out_hex
@@ -2488,7 +2183,7 @@ l0dedh:
 	call out_hex
 	call outbl
 	ex de,hl
-	call out.hl.@
+	call out_hl
 	ex de,hl
 	call crlf
 l0e10h:
@@ -2539,38 +2234,13 @@ cmdm_up:
 ; > H
 ;      display Highest load address of last filed loaded, Maximum "High"
 ;      off all loaded files, and Top address of available memory
-; > HS
-;      display symbol list
 ; > H expression
 ;      evaluate expression and display result in hex, decimal and other formats
-; > H expression expression
-;      display sum und difference of expressions
 
 cmd_H:
-	call get_char_upper
-	cp 'S'
-	jr z,p_sym_list
-
 	call expr
 	jp c,p_max_high0
-	call next_arg
-	push hl
-	call expr
-	push af
 	call assert_eol
-	pop af
-	ex de,hl
-	pop hl
-	jr c,l0e5eh
-	push hl
-	push de
-	add hl,de
-	call l0e5eh
-	pop de
-	pop hl
-	and a
-	sbc hl,de
-l0e5eh:
 	call out_hl
 	call outbl2
 	call out_hl_neg
@@ -2580,56 +2250,11 @@ l0e5eh:
 	call out_hl_dec_neg
 	call outbl4
 	call out.bin.w
-	call outbl
+	call outbl2
 	ld a,l
 	call out.ascii
-	call	outbl2
-	call p_symbol
 	jp crlf
 
-p_sym_list:
-	inc	de
-	call	assert_eol
-	ld	a,(symlen_cur)
-	add	a,7
-	ld	b,a
-	ld	c,0
-	ld	hl,ddtz_base+2
-psym_nxtsym:
-	ld	d,(hl)
-	dec	hl
-	ld	e,(hl)
-	dec	hl
-	ld	a,(hl)
-	cp	0c3h
-	jr	z,psym_e
-
-	call	p_goto_col
-	ex	de,hl
-	call	out_hl
-	call	outbl
-	ex	de,hl
-	call	p_symstr
-
-	ld	a,c
-	add	b
-	ld	c,a
-	ld	a,(screen_width)
-	sub	b
-	cp	c
-	jr	nc,psym_nxtsym
-
-	call	crlf
-	ld	c,0
-	jr	psym_nxtsym
-
-psym_e:
-	ld	a,c
-	or	a
-	ret	z
-	jp	crlf
-
-
 ;-------------------------------------------------------------------------------
 ; > Q[J] startaddr endaddr bytes
 ;      Query memory for a byte string [Justified]
@@ -2795,7 +2420,6 @@ l0f42h:
 ;      Display memory in hex and ASCII
 
 cmd_D:
-	ld hl,cmd_D
 	ld (cmd_rpt),hl
 	ld hl,(last_D)
 	ld bc,128
@@ -2807,7 +2431,7 @@ sub_0f58h:
 	push hl
 	push af
 l0f5ch:
-	call out.hl.@
+	call out_hl
 	call z,outbl2
 	call outbl
 	ld de,0
@@ -2885,16 +2509,8 @@ l0fb6h:
 	ld de,dfcb1
 	call parse_filename
 	ld de,dfcb2
-	call parse_filename
 	;fall thru
 
-cpy_fcb2:
-	ld hl,dfcb2
-	ld de,fcbsym
-	ld bc,16
-	ldir
-	ret
-
 parse_filename:
 	call sub_102ch
 	push de
@@ -3122,35 +2738,15 @@ hex_digit_v:
 error2:
 	jp ERROR
 
-read_hexbyte:
-	call	read_byte
-read_hexbyte0:
-	push	bc
-	call	hex_digit_v
-	rlca
-	rlca
-	rlca
-	rlca
-	ld	c,a
-	call	read_byte
-	call	hex_digit_v
-	or	c
-	pop	bc
-	ret
-
 ;-------------------------------------------------------------------------------
 ; > R [displacement]
-;      Read a binary or hex file and or symbol file [add displacement]
+;      Read a binary or hex file  [add displacement]
 
 cmd_R:
 	ld hl,0
 	call get_lastarg_def
 read_file:
-	ld de,dfcb1+1
-	ld a,(de)
-	cp '?'
-	jr z,read_symfile
-	dec de
+	ld de,dfcb1
 	push hl
 	ld hl,0
 	ld (high_load),hl
@@ -3168,7 +2764,7 @@ l108eh:
 	call read_sector
 	jr nz,read_file_nxt
 	pop hl
-	jr read_symfile
+	jp p_max_high
 
 read_file_nxt:
 	ld de,DMA_BUF
@@ -3212,163 +2808,12 @@ l10cch:
 	call read_hexchar	; CHKSUM
 	ld a,c
 	and a
-	jr nz,error3
+	jp nz,ERROR
 	jr l10aeh
 rdhex_done:
 	pop hl
-	jr read_symfile
-
-read_symfile:
-	ld de,fcbsym+1
-	ld a,(de)
-	cp ' '
-	jp z,p_max_high
-
-	push	hl		; offset
-	call pstr_inl
-	db	'SYMBOLS',CR,LF+80h
+	jp p_max_high
 
-	dec	de
-	call	file_open
-	ld	a,(symattrib)
-	ld	c,a
-rs_1:
-	call	read_byte
-rs_2:
-	pop	de		; offset
-	cp	1ah
-	jp	z,p_max_high
-	push	de		; offset
-	cp	'!'
-	jr	c,rs_1
-	call	read_hexbyte0	; symval H
-	ld	h,a
-	call	read_hexbyte	; symval L
-	ld	l,a
-	add	hl,de
-	call	read_byte
-	cp	' '
-	jr	z,rs_4
-rs_3:	call	read_byte
-	cp	' '
-	jr	nc,rs_3
-	jr	rs_2
-
-rs_4:
-	push	hl		; symval
-	ld	hl,(BDOS+1)	;
-	ld	b,0		; setup symlen
-rs_5:
-	dec	hl		;
-	call	read_byte	; next char of symbol name
-	call	test_sym_char	; valid char?
-	jr	nz,rs_6
-	bit	SYMCASE_CONV,c
-	jr	z,rs_51
-	call	toupper
-	bit	SYMCASE_LOWER,c
-	call	nz,tolower
-rs_51:
-	ld	(hl),a		;
-	inc	b		; symlen++
-	ld	a,(symlen_max)	;
-	cp	b		;
-	jr	nc,rs_5		;
-error3:
-	jp	ERROR		;
-
-rs_6:
-	call	test_symterm_ch
-	jr	nz,error3
-
-	push	bc		; symlen
-	ex	de,hl		;
-	ld	hl,(BDOS+1)	;
-	inc	hl		;
-	ld	c,(hl)		;
-	inc	hl		;
-	ld	b,(hl)		;
-	ex	de,hl
-	ld	(hl),b		;
-	dec	hl		;
-	ld	(hl),c		;
-	dec	hl		;
-	ld	(hl),0c3h	;
-
-	ld	de,(max_load)	;
-	call	cp_hl_de	;
-	jr	c,error3	;
-	ld	de,(reg_sp)	;
-	call	cp_hl_de	;
-	jr	nc,rs_61	;
-	ld	(reg_sp),hl	;
-rs_61:
-	ld	de,(BDOS+1)	;
-	ld	(BDOS+1),hl	;
-	ex	de,hl		;
-	pop	bc		; symlen
-	ld	(hl),b		;
-	inc	hl		;
-	pop	de		; symval
-	ld	(hl),e		;
-	inc	hl		;
-	ld	(hl),d		;
-	ld	a,b		;
-	ld	hl,symlen_cur	;
-	cp	(hl)		; new max?
-	jr	c,$+3		;
-	ld	(hl),a		;
-	jp	rs_1		;
-
-
-; test for valid character for symbols
-; return z if valid
-
-test_sym_char:
-	cp	'$'
-	ret	z
-	cp	'%'
-	ret	z
-	cp	'.'
-	ret	z
-	cp	'_'
-	ret	z
-	call	test_alphanum
-	ret	c		; cy == 1 --> z == 0
-	cp	a		; return z
-	ret
-
-
-; check if char is in [0..9,?,@,A..Z,a..z]
-; return cy if invalid
-; return nc if valid alfanumeric char
-
-test_alphanum:
-	cp	'z'
-	ret	z
-	ccf
-	ret	c
-	cp	'a'
-	ret	nc
-	cp	'Z'
-	ret	z
-	ccf
-	ret	c
-	cp	'?'
-	ret	nc
-test_numeral:
-	cp	'9'
-	ret	z
-	ccf
-	ret	c
-	cp	'0'
-	ret
-
-test_symterm_ch:
-	cp	CR
-	ret	z
-	cp	LF
-	ret	z
 test_whitespace:
 	cp	' '
 	ret	z
@@ -3435,1203 +2880,59 @@ l11cch:
 	ld c,e
 	ldir
 	call write_sector
-	ex (sp),hl
-	ld bc,0ff80h
-	add hl,bc
-	ex (sp),hl
-	pop bc
-	jr l11cch
-
-write_sector:
-	push hl
-	ld de,dfcb1
-	ld c,BDOS_WRITE
-	call ddtz_bdos
-	pop hl
-	and a
-	ret z
-	call close_file
-error4:
-	jp ERROR
-
-close_file:
-	ld de,dfcb1
-	ld c,BDOS_CLOSE
-	jp ddtz_bdos
-
-;-------------------------------------------------------------------------------
-; > A [startaddr]
-;      Assemble Zilog Z180 mnemonics
-
-cmd_A:
-	ld hl,(last_A)
-	call get_lastarg_def
-	ld (last_A),hl
-	ld (cmd_A_prev),hl
-	ld hl,cmda_restart
-	ld (error_func),hl
-	ld (l1262h),sp
-cmda_loop:
-	ld hl,(last_A)
-	ld (var.$),hl
-	push hl
-	call p_disas_line
-	ld c,19
-	call p_align_@_sym
-	ld c,b
-	push bc
-	call get_line
-	pop bc
-	pop hl
-	call skipbl
-	cp '.'
-	ret z
-	cp '-'
-	jr nz,l124bh
-	ld hl,(cmd_A_prev)
-	jr cmda_lpend
-l124bh:
-	push hl
-	pop iy
-	push hl
-	and a
-	call nz,asemble_line
-	ld b,0
-	pop hl
-	ld (cmd_A_prev),hl
-	add hl,bc
-cmda_lpend:
-	ld (last_A),hl
-	jr cmda_loop
-
-cmda_restart:
-	call p_msg_error
-	ld sp,(l1262h)
-	jr cmda_loop
-
-asemble_line:
-	call skipbl
-	ld hl,t_MNEMONICS
-	call sub_030ah
-	jr nc,error4
-	call skipbl
-	push de
-	ld a,b
-	add a,b
-	add a,b
-	ld hl,b_1289_start
-	call add_hl_a
-	ld e,(hl)
-	inc hl
-	ld d,(hl)
-	inc hl
-	ld b,(hl)
-	ex de,hl
-	pop de
-
-CALL_HL:
-	jp (hl)
-
-;-------------------------------------------------------------------------------
-
-b_1289_start:
-	dw	as.ADC_SBC		;ADC
-	db	088h			;
-	dw	as.ADD			;ADD
-	db	080h			;
-	dw	as.AND_CP_OR_SUB_XOR	;AND
-	db	0a0h			;
-	dw	as.BITOP		;BIT
-	db	040h			;
-	dw	as.CALL			;CALL
-	db	0c4h			;
-	dw	as.opc.noarg		;CCF
-	db	03fh			;
-	dw	as.AND_CP_OR_SUB_XOR	;CP
-	db	0b8h			;
-	dw	gen.opc.ED2		;CPD
-	db	0a9h			;
-	dw	gen.opc.ED2		;CPDR
-	db	0b9h			;
-	dw	gen.opc.ED2		;CPI
-	db	0a1h			;
-	dw	gen.opc.ED2		;CPIR
-	db	0b1h			;
-	dw	as.opc.noarg		;CPL
-	db	02fh			;
-	dw	as.opc.noarg		;DAA
-	db	027h			;
-	dw	as.DEC_INC		;DEC
-	db	005h			;
-	dw	as.opc.noarg		;DI
-	db	0f3h			;
-	dw	as.DJNZ			;DJNZ
-	db	010h			;
-	dw	as.opc.noarg		;EI
-	db	0fbh			;
-	dw	as.EX			;EX
-	db	0e3h			;
-	dw	as.opc.noarg		;EXX
-	db	0d9h			;
-	dw	as.opc.noarg		;HALT
-	db	076h			;
-	dw	as.IM			;IM
-	db	046h			;
-	dw	as.IN			;IN
-	db	040h			;
-	dw	as.DEC_INC		;INC
-	db	004h			;
-	dw	gen.opc.ED2		;IND
-	db	0aah			;
-	dw	gen.opc.ED2		;INDR
-	db	0bah			;
-	dw	gen.opc.ED2		;INI
-	db	0a2h			;
-	dw	gen.opc.ED2		;INIR
-	db	0b2h			;
-	dw	as.JP			;JP
-	db	0c2h			;
-	dw	as.JR			;JR
-	db	020h			;
-	dw	as.LD			;LD
-	db	040h			;
-	dw	gen.opc.ED2		;LDD
-	db	0a8h			;
-	dw	gen.opc.ED2		;LDDR
-	db	0b8h			;
-	dw	gen.opc.ED2		;LDI
-	db	0a0h			;
-	dw	gen.opc.ED2		;LDIR
-	db	0b0h			;
-	dw	gen.opc.ED2		;NEG
-	db	044h			;
-	dw	as.opc.noarg		;NOP
-	db	000h			;
-	dw	as.AND_CP_OR_SUB_XOR 	;OR
-	db	0b0h			;
-	dw	gen.opc.ED2		;OTDR
-	db	0bbh			;
-	dw	gen.opc.ED2		;OTIR
-	db	0b3h			;
-	dw	as.OUT			;OUT
-	db	041h			;
-	dw	gen.opc.ED2		;OUTD
-	db	0abh			;
-	dw	gen.opc.ED2		;OUTI
-	db	0a3h			;
-	dw	as.POP_PUSH		;POP
-	db	0c1h			;
-	dw	as.POP_PUSH		;PUSH
-	db	0c5h			;
-	dw	as.BITOP		;RES
-	db	080h			;
-	dw	as.RET			;RET
-	db	0c0h			;
-	dw	gen.opc.ED2		;RETI
-	db	04dh			;
-	dw	gen.opc.ED2		;RETN
-	db	045h			;
-	dw	as.SHIFTOP		;RL
-	db	010h			;
-	dw	as.opc.noarg		;RLA
-	db	017h			;
-	dw	as.SHIFTOP		;RLC
-	db	000h			;
-	dw	as.opc.noarg		;RLCA
-	db	007h			;
-	dw	gen.opc.ED2		;RLD
-	db	06fh			;
-	dw	as.SHIFTOP		;RR
-	db	018h			;
-	dw	as.opc.noarg		;RRA
-	db	01fh			;
-	dw	as.SHIFTOP		;RRC
-	db	008h			;
-	dw	as.opc.noarg		;RRCA
-	db	00fh			;
-	dw	gen.opc.ED2		;RRD
-	db	067h			;
-	dw	as.RST			;RST
-	db	0c7h			;
-	dw	as.ADC_SBC		;SBC
-	db	098h			;
-	dw	as.opc.noarg		;SCF
-	db	037h			;
-	dw	as.BITOP		;SET
-	db	0c0h			;
-	dw	as.SHIFTOP		;SLA
-	db	020h			;
-	dw	as.SHIFTOP		;SRA
-	db	028h			;
-	dw	as.SHIFTOP		;SRL
-	db	038h			;
-	dw	as.AND_CP_OR_SUB_XOR 	;SUB
-	db	090h			;
-	dw	as.AND_CP_OR_SUB_XOR 	;XOR
-	db	0a8h			;
-
-	dw	as.IN0			;IN0
-	db	000h       		;
-	dw	as.MLT			;MLT
-	db	04ch       		;
-	dw	gen.opc.ED2		;OTDM
-	db	08bh       		;
-	dw	gen.opc.ED2		;OTDMR
-	db	09bh       		;
-	dw	gen.opc.ED2		;OTIM
-	db	083h       		;
-	dw	gen.opc.ED2		;OTIMR
-	db	093h       		;
-	dw	as.OUTO    		;OUT0
-	db	001h       		;
-	dw	gen.opc.ED2		;SLP
-	db	076h       		;
-	dw	as.TST			;TST
-	db	004h       		;
-	dw	as.TSTIO		;TSTIO
-	db	074h       		;
-
-;-------------------------------------------------------------------------------
-
-as.TST:
-	call arg.r_HL_A		;
-	jr nc,as.tst_0
-	rlca
-	rlca
-	rlca
-	add a,b
-	ld b,a
-	jp gen.opc.ED2
-as.tst_0:
-	ld b,064h
-as.TSTIO:
-	call arg.imm_8bit	;
-	jr as.store_io0
-
-as.IN0:
-	call arg.r_HL_A		;
-	jr nc,error5
-	cp 006h
-	jr z,error5
-	rlca
-	rlca
-	rlca
-	add a,b
-	ld b,a
-	call assert_comma	;
-	call arg.addr_8bit	;
-	jr as.store_io0
-
-as.OUTO:
-	call arg.addr_8bit	;
-	call assert_comma	;
-	call arg.r_HL_A		;
-	jr nc,error5
-	cp 006h
-	jr z,error5
-	rlca
-	rlca
-	rlca
-	add a,b
-	ld b,a
-
-as.store_io0:
-	call assert_eol
-	ld (iy+000h),0edh
-	ld (iy+001h),b
-	ld (iy+002h),l
-	ld c,003h
-	ret
-
-as.MLT:
-	call arg.ww		;
-	jr nc,error5
-	add a,b
-	ld b,a
-	jp gen.opc.ED2
-
-error5:
-	jp ERROR
-
-as.LD:
-	call arg.r_HL_A
-	jr c,l13d4h
-	call arg.IDX_displcmnt
-	jp c,l1471h
-	call arg.ww
-	jp c,l149ch
-	call arg.IX_IY
-	jp c,l14f5h
-	call get_char_upper
-	cp 'I'
-	jp z,l1511h
-	cp 'R'
-	jp z,l1519h
-	cp '('
-	jr nz,error5
-	inc de
-	call arg.ww
-	jp c,l1528h
-	call test_expr
-	call test_paren_close
-	call assert_comma
-	call arg.ww
-	jr c,l13c2h
-	call arg.IX_IY
-	jr nc,l13aah
-	ld b,022h
-l1395h:
-	call assert_eol
-	ld a,(prefix_ixiy)
-l139bh:
-	ld (iy+000h),a
-	ld (iy+001h),b
-	ld (iy+002h),l
-	ld (iy+003h),h
-	ld c,004h
-	ret
-
-l13aah:
-	call get_char_upper
-	cp 'A'
-	jr nz,error5
-	inc de
-	ld b,032h
-
-as.store_3:
-	call assert_eol
-	ld (iy+000h),b
-	ld (iy+001h),l
-	ld (iy+002h),h
-	ld c,003h
-	ret
-
-l13c2h:
-	cp 020h
-	jr z,l13d0h
-	add a,043h
-	ld b,a
-l13c9h:
-	call assert_eol
-	ld a,0edh
-	jr l139bh
-l13d0h:
-	ld b,022h
-	jr as.store_3
-
-l13d4h:
-	ld b,a
-	call assert_comma
-	call arg.r_HL_A
-	jr nc,l13f0h
-	push af
-	ld a,b
-	rlca
-	rlca
-	rlca
-	ld b,a
-	pop af
-	add a,b
-	add a,040h
-	cp 076h
-	jr z,error60
-l13ech:
-	ld b,a
-	jp as.opc.noarg
-
-l13f0h:
-	call arg.IDX_displcmnt
-	jr nc,l1413h
-	ld a,b
-	rlca
-	rlca
-	rlca
-	add a,046h
-	cp 076h
-	jr z,error60
-
-l1400h:
-	ld b,a
-	call assert_eol
-	ld (iy+001h),b
-	ld (iy+002h),c
-	ld a,(prefix_ixiy)
-	ld (iy+000h),a
-	ld c,003h
-	ret
-
-l1413h:
-	call get_char_upper
-	cp 'I'
-	jr z,l1426h
-	cp 'R'
-	jr nz,l1432h
-	ld a,b
-	cp 007h
-	jr nz,error60
-	ld b,05fh
-	jr l142eh
-
-l1426h:
-	ld a,b
-	cp 007h
-	jr nz,error60
-	ld b,057h
-l142eh:
-	inc de
-	jp gen.opc.ED2
-l1432h:
-	cp '('
-	jr z,l144ch
-	call arg.imm_8bit
-	ld a,b
-	rlca
-	rlca
-	rlca
-	add a,006h
-l143fh:
-	ld b,a
-as.store_2:
-	call assert_eol
-	ld (iy+000h),b
-	ld (iy+001h),l
-	ld c,002h
-	ret
-l144ch:
-	inc de
-	ld a,b
-	cp 007h
-	jr nz,error60
-	call arg.ww
-	jr nc,l1466h
-	cp 030h
-	jr nc,error60
-	add a,00ah
-	ld b,a
-	call test_paren_close
-	jp as.opc.noarg
-
-error60:
-	jp error
-
-l1466h:
-	call test_expr
-	call test_paren_close
-	ld b,03ah
-	jp as.store_3
-
-l1471h:
-	call assert_comma
-	call arg.r_HL_A
-	jr nc,l1483h
-	cp 006h
-	jr z,error60
-	add a,070h
-	jp l1400h
-
-l1483h:
-	call arg.imm_8bit
-	call assert_eol
-	ld a,(prefix_ixiy)
-	ld (iy+000h),a
-	ld (iy+001h),036h
-	ld (iy+002h),c
-	ld (iy+003h),l
-	ld c,004h
-	ret
-l149ch:
-	ld b,a
-	call assert_comma
-	ld hl,t_HL.AF
-	call sub_0318h
-	jr c,l14c3h
-	call arg.IX_IY
-	jr nc,l14cch
-	ld a,b
-	cp 030h
-	jr nz,error6
-	ld b,0f9h
-l14b4h:
-	call assert_eol
-	ld a,(prefix_ixiy)
-	ld (iy+000h),a
-	ld (iy+001h),b
-	ld c,002h
-	ret
-
-l14c3h:
-	ld a,b
-	cp 030h
-	jr nz,error6
-	ld b,0f9h
-	jr as.opc.noarg	;14ca
-
-l14cch:
-	call get_char_upper
-	cp '('
-	jr nz,l14e8h
-	inc de
-	call test_expr
-	call test_paren_close
-	ld a,b
-	cp 020h
-	jr z,l14e3h
-	add a,04bh
-	ld b,a
-	jp l13c9h
-
-l14e3h:
-	ld b,02ah
-	jp as.store_3
-
-l14e8h:
-	call test_expr
-	call assert_eol
-	ld a,001h
-	add a,b
-	ld b,a
-	jp as.store_3
-l14f5h:
-	call assert_comma
-	call get_char_upper
-	cp '('
-	jr nz,l1509h
-	inc de
-	call test_expr
-	call test_paren_close
-	ld b,02ah
-	jp l1395h
-
-l1509h:
-	call test_expr
-	ld b,021h
-	jp l1395h
-
-l1511h:
-	inc de
-	call assert_comma
-	ld b,047h
-	jr l151fh
-
-l1519h:
-	inc de
-	call assert_comma
-	ld b,04fh
-l151fh:
-	call get_char_upper
-	inc de
-	cp 'A'
-	jr z,gen.opc.ED2
-error6:
-	jp ERROR
-
-l1528h:
-	cp 020h
-	jr nc,error6
-	add a,002h
-	ld b,a
-	call test_paren_close
-	call assert_comma
-	call get_char_upper
-	cp 'A'
-	jr nz,error6
-	inc de
-as.opc.noarg:
-	call assert_eol
-	ld (iy+000h),b
-	ld c,001h
-	ret
-
-gen.opc.ED2:
-	call assert_eol
-	ld (iy+000h),0edh
-	ld (iy+001h),b
-	ld c,002h
-	ret
-
-as.ADC_SBC:
-	ld hl,t_HL.AF
-	call sub_0318h
-	jr nc,as.AND_CP_OR_SUB_XOR
-	call assert_comma
-	call arg.ww
-	jr nc,error6
-	push af
-	ld a,b
-	cp 088h
-	ld b,04ah
-	jr z,l156ch
-	ld b,042h
-l156ch:
-	pop af
-	add a,b
-l156eh:
-	ld b,a
-	jr gen.opc.ED2
-
-as.ADD:
-	ld hl,t_HL.AF
-	call sub_0318h
-	jr c,l159ah
-	call arg.IX_IY
-	jr nc,as.AND_CP_OR_SUB_XOR
-	call assert_comma
-	ld hl,t_BC.DE.IX.SP
-	ld a,(prefix_ixiy)
-	cp 0fdh
-	jr nz,l158eh
-	ld hl,t_BC.DE.IY.SP
-l158eh:
-	call arg.reg_16bit
-	jr nc,error6
-	add a,009h
-l1596h:
-	ld b,a
-	jp l14b4h
-l159ah:
-	call assert_comma
-	call arg.ww
-error61nc:
-	jr nc,error6
-	add a,009h
-	jp l13ech
-as.AND_CP_OR_SUB_XOR:
-	call get_char_upper
-	cp 'A'
-	jr nz,l15b8h
-	push de
-	inc de
-	call next_arg
-	jr z,l15b7h
-	pop de
-	jr l15b8h
-l15b7h:
-	pop af
-l15b8h:
-	call arg.r_HL_A
-	jr c,l15cbh
-	call arg.IDX_displcmnt
-	jr c,l15cfh
-	call arg.imm_8bit
-	ld a,b
-	add a,046h
-	jp l143fh
-l15cbh:
-	add a,b
-	jp l13ech
-l15cfh:
-	ld a,b
-	add a,006h
-	jp l1400h
-
-as.SHIFTOP:
-	call arg.r_HL_A
-	jr c,l15fah
-	call arg.IDX_displcmnt
-	jr nc,error61nc
-	ld a,b
-	add a,006h
-	ld b,a
-l15e4h:
-	call assert_eol
-	ld a,(prefix_ixiy)
-	ld (iy+000h),a
-	ld (iy+001h),0cbh
-	ld (iy+002h),c
-	ld (iy+003h),b
-	ld c,004h
-	ret
-
-l15fah:
-	add a,b
-l15fbh:
-	ld b,a
-	call assert_eol
-	ld (iy+001h),b
-	ld (iy+000h),0cbh
-	ld c,002h
-	ret
-
-as.BITOP:
-	call arg.bit
-	call assert_comma
-	call arg.r_HL_A
-	jr c,l1624h
-	call arg.IDX_displcmnt
-	jr nc,error61nc
-	ld a,l
-	rlca
-	rlca
-	rlca
-	add a,006h
-	add a,b
-	ld b,a
-	jr l15e4h
-l1624h:
-	add a,b
-	ld b,a
-	ld a,l
-	rlca
-	rlca
-	rlca
-	add a,b
-	jr l15fbh
-
-as.CALL:
-	push de
-	call arg.cc_ZCPS
-	jr nc,l163ch
-	add a,b
-	ld b,a
-	call next_arg
-	jr z,l163eh
-	pop de
-	push de
-l163ch:
-	ld b,0cdh
-l163eh:
-	pop af
-	call test_expr
-	jp as.store_3
-
-as.RET:
-	call arg.cc_ZCPS
-	jr nc,l164eh
-	add a,b
-	ld b,a
-	jr l1650h
-l164eh:
-	ld b,0c9h
-l1650h:
-	jp as.opc.noarg
-
-as.JP:
-	push de
-	call arg.cc_ZCPS
-	jr c,l1666h
-l1659h:
-	pop de
-	ld hl,l168ch
-	call sub_030ah
-	jr c,l1674h
-	ld b,0c3h
-	jr l166eh
-
-l1666h:
-	add a,b
-	ld b,a
-	call next_arg
-	jr nz,l1659h
-	pop af
-l166eh:
-	call test_expr
-	jp as.store_3
-l1674h:
-	call assert_eol
-	ld a,b
-	and a
-	jr nz,l1680h
-	ld b,0e9h
-	jp as.opc.noarg
-l1680h:
-	ld b,0ddh
-	dec a
-	jr z,l1687h
-	ld b,0fdh
-l1687h:
-	ld l,0e9h
-	jp as.store_2
-
-l168ch:
-	DC	'(HL)'
-	DC	'(IX)'
-	DC	'(IY)'
-	DB	0
-
-as.DJNZ:
-	call next_arg
-	ld b,010h
-	jr l16aeh
-as.JR:
-	call arg.cc_ZC
-	jr c,l16a9h
-	ld b,018h
-	jr l16aeh
-l16a9h:
-	add a,b
-	ld b,a
-	call assert_comma
-l16aeh:
-	call arg.j_displ
-	jp as.store_2
-
-as.IM:
-	call arg.imm_8bit
-	ld a,l
-	cp 003h
-	jr nc,error7
-	and a
-	jr z,l16c7h
-	ld b,056h
-	cp 001h
-	jr z,l16c7h
-	ld b,05eh
-l16c7h:
-	jp gen.opc.ED2
-
-as.RST:
-	call arg.imm_8bit
-	ld a,l
-	push af
-	add a,b
-	ld b,a
-	pop af
-	and 0c7h
-	jr nz,error7
-	jp as.opc.noarg
-
-as.POP_PUSH:
-	call arg.IX_IY
-	jr c,l16e7h
-	call arg.zz
-	jr nc,error7
-	add a,b
-	jp l13ech
-l16e7h:
-	ld a,b
-	add a,020h
-	jp l1596h
-
-as.IN:
-	call arg.r_HL_A
-	jr nc,error7
-	cp 006h
-	jr z,error7
-	rlca
-	rlca
-	rlca
-	add a,b
-	ld b,a
-	cp 078h
-	jr nz,l170fh
-	call assert_comma
-	call sub_171bh
-	jr c,l1715h
-	call arg.addr_8bit
-	ld b,0dbh
-	jp as.store_2
-l170fh:
-	call assert_comma
-	call sub_171bh
-l1715h:
-	jp c,gen.opc.ED2
-error7:
-	jp ERROR
-
-sub_171bh:
-	ld hl,t__C_
-	jp sub_0318h
-
-as.OUT:
-	call sub_171bh
-	jr nc,l1739h
-	call assert_comma
-	call arg.r_HL_A
-	jr nc,error7
-	cp 006h
-	jr z,error7
-	rlca
-	rlca
-	rlca
-	add a,b
-	jp l156eh
-
-l1739h:
-	call arg.addr_8bit
-	call assert_comma
-	cp 'A'
-	jr nz,error7
-	inc de
-	ld b,0d3h
-	jp as.store_2
-
-as.EX:
-	ld hl,b_176d_start
-	call sub_030ah
-	jr nc,error7
-	ld c,b
-	call assert_eol
-	ld b,000h
-	ld hl,l178eh
-	add hl,bc
-	add hl,bc
-	ld a,(hl)
-	ld (iy+000h),a
-	ld c,001h
-	inc hl
-	ld a,(hl)
-	and a
-	ret z
-	ld (iy+001h),a
-	ld c,002h
-	ret
-
-b_176d_start:
-	DC	'AF,AF'''
-l1773h:
-	DC	'DE,HL'
-	DC	'(SP),HL'
-	DC	'(SP),IX'
-	DC	'(SP),IY'
-	db	0
-l178eh:
-	db	008h,000h
-	db	0ebh,000h
-	db	0e3h,000h
-	db	0ddh,0e3h
-	db	0fdh,0e3h
-
-as.DEC_INC:
-	call arg.IX_IY
-	jr c,l17b3h
-	call arg.ww
-	jr c,l17bfh
-	call arg.r_HL_A
-	jr c,l17cch
-	call arg.IDX_displcmnt
-	jr nc,error8
-	ld a,b
-	add a,030h
-	jp l1400h
-l17b3h:
-	ld a,b
-	ld b,023h
-	cp 004h
-	jr z,l17bch
-	ld b,02bh
-l17bch:
-	jp l14b4h
-l17bfh:
-	push af
-	ld a,b
-	ld b,003h
-	cp 004h
-	jr z,l17c9h
-	ld b,00bh
-l17c9h:
-	pop af
-	jr l17cfh
-l17cch:
-	rlca
-	rlca
-	rlca
-l17cfh:
-	add a,b
-	jp l13ech
-
-arg.bit:
-	call arg.imm_8bit
-	ld a,l
-	cp 008h
-	jr nc,error8
-	ret
-
-arg.j_displ:
-	call test_expr
-	push bc
-	push iy
-	pop bc
-	and a
-	sbc hl,bc
-	dec hl
-	dec hl
+	ex (sp),hl
+	ld bc,0ff80h
+	add hl,bc
+	ex (sp),hl
 	pop bc
-	call sub_1802h
-	ld a,h
-	xor l
-	bit 7,a
-	jr nz,error8
-	ret
-
-arg.addr_8bit:
-	call get_char_upper
-	cp '('
-	jr nz,arg.imm_8bit
-	inc de
-	call arg.imm_8bit
-	jp test_paren_close
+	jr l11cch
 
-arg.imm_8bit:
-	call test_expr
-sub_1802h:
-	ld a,h
+write_sector:
+	push hl
+	ld de,dfcb1
+	ld c,BDOS_WRITE
+	call ddtz_bdos
+	pop hl
 	and a
 	ret z
-	inc a
-	ret z
-	jr error8
-
-test_expr:
-	push bc
-	call expr
-	pop bc
-	ret nc
-error8:
+	call close_file
+error4:
 	jp ERROR
 
-arg.zz:
-	push hl
-	ld hl,t_BC.DE.HL.AF
-	jr l181fh
+close_file:
+	ld de,dfcb1
+	ld c,BDOS_CLOSE
+	jp ddtz_bdos
 
-arg.reg_16bit:
-	push hl
-	jr l181fh
+;-------------------------------------------------------------------------------
+; > A [startaddr]
+;      Assemble Zilog Z180 mnemonics
 
-arg.ww:
-	push hl
-	ld hl,t_BC.DE.HL.SP
-l181fh:
-	push bc
-	call sub_030ah
-	jr nc,l182bh
-	ld a,b
-	rlca
-	rlca
-	rlca
-	rlca
-	scf
-l182bh:
-	pop bc
-	pop hl
-	ret
+;cmd_A:
 
-arg.r_HL_A:
-	call skipbl
-	push bc
-	push hl
-	ld hl,t_BCDEHL_HL_A
-	call sub_030ah
-	ld a,b
-	pop hl
-	pop bc
-	ret
 
-arg.IX_IY:
-	push hl
-	push bc
-	ld hl,t_IX.IY
-	call sub_030ah
-	jr nc,l1852h
-	ld a,0ddh
-	dec b
-	jr nz,l184eh
-	ld a,0fdh
-l184eh:
-	ld (prefix_ixiy),a
-	scf
-l1852h:
-	pop bc
-	pop hl
-	ret
+CALL_HL:
+	jp (hl)
 
-arg.IDX_displcmnt:
-	push hl
-	push bc
-	call get_char_upper
-	cp '('
-	jr nz,l18a1h
-	push de
-	inc de
-	ld hl,t_IX.IY
-	call sub_030ah
-	jr nc,l18a0h
-	pop af
-	ld a,0ddh
-	dec b
-	jr nz,l186eh
-	ld a,0fdh
-l186eh:
-	ld (prefix_ixiy),a
-	call get_char_upper
-	cp '+'
-	jr z,l1882h
-	cp ')'
-	ld hl,0
-	jr z,l189ah
-	cp '-'
-	jr nz,error9
-l1882h:
-	push af
-	inc de
-	call arg.imm_8bit
-	pop af
-	cp '+'
-	jr z,l1894h
-	ld b,h
-	ld c,l
-	ld hl,0
-	and a
-	sbc hl,bc
-l1894h:
-	call get_char_upper
-	cp ')'
-	jr nz,error9
-l189ah:
-	inc de
-	pop bc
-	ld c,l
-	pop hl
-	scf
-	ret
-l18a0h:
-	pop de
-l18a1h:
-	pop bc
-	pop hl
-	and a
-	ret
+;-------------------------------------------------------------------------------
 
-arg.cc_ZCPS:
-	ld hl,t_tstfl_ZCPS
-	ld c,007h
-	jr l18b1h
 
-arg.cc_ZC:
-	ld hl,t_tstfl_ZC
-	ld c,003h
-l18b1h:
-	push bc
-	call sub_030ah
-	ld a,b
-	pop bc
-	ret nc
-	and c
-	rlca
-	rlca
-	rlca
-	scf
-	ret
 
-assert_comma:
-	call next_arg
-	ret z
-error9:
-	jp ERROR
 
-test_paren_close:
-	call get_char_upper
-	cp ')'
-	jr nz,error9
-	inc de
-	ret
+b_176d_start:
+	DC	'AF,AF'''
+l1773h:
+	DC	'DE,HL'
+	DC	'(SP),HL'
+	DC	'(SP),IX'
+	DC	'(SP),IY'
+	db	0
 
 ;-------------------------------------------------------------------------------
 ; >>L [startaddr] [endaddr]
 ;      List disassembled code
 
 cmd_L:
-	ld hl,cmd_L
 	ld (cmd_rpt),hl
 	call expr
 	jr nc,l18dbh
@@ -4677,9 +2978,8 @@ cmdl_p_line:
 	ret
 
 p_disas_line:
-	call p_label
 	call outbl2
-	call out.hl.@
+	call out_hl
 	call z,outbl
 	call outbl
 	sub a
@@ -4691,24 +2991,9 @@ p_disas_line:
 
 	ld	c,15
 	call	p_goto_col
-	call	p_offset
-	call	outbl
-	jp	p_symbol
-
+	; fall thru
 ;-------------------------------------------------------------------------------
-
-p_offset:
-	ld de,(var.@)
-	ld a,d
-	or e
-	ret z
-	call	pstr_inl
-	dc	'(@'
-	and a
-	sbc hl,de
-	call out_hl
-	add	hl,de
-	jp out_rparen
+	ret
 
 ;-------------------------------------------------------------------------------
 
@@ -5281,8 +3566,7 @@ l1ce5h:
 sub_1ce8h:
 	call p_char_lparen
 	call p_arg_ww
-out_rparen:
-	jp p_char_rparen
+	jr out_rparen
 
 l1cf5h:
 	call p_A_comma
@@ -5322,7 +3606,11 @@ l1d29h:
 sub_1d2ch:
 	call p_char_lparen
 	ld a,(iy+001h)
-	jp l1e6bh
+p_arg_nn_rp:
+	call out_hex
+out_rparen:
+	jr p_char_rparen
+
 l1d37h:
 	call sub_1d2ch
 	jr p_char_comma_A
@@ -5359,27 +3647,30 @@ p_arg_addr_a:
 	call p_arg_addr
 p_char_comma_A:
 	call p_char_comma
+	jr p_char_A
+
+p_A_comma:
+	call p_char_A
+p_char_comma:
+	ld a,','
+	db 021h
 p_char_A:
 	ld a,'A'
-	jr outchar1
-p_arg_a_addr:
-	call p_A_comma
-	jp p_arg_addr
+	db 021h
 l1d85h:
 	ld a,'0'
-	jr outchar1
+	db 021h
 l1d89h:
 	ld a,'1'
-	jr outchar1
+	db 021h
 l1d8dh:
 	ld a,'2'
-	jr outchar1
-
-p_A_comma:
-	call p_char_A
-p_char_comma:
-	ld a,','
-outchar1:
+	db 021h
+p_char_rparen:
+	ld a,')'
+	db 021h
+p_char_lparen:
+	ld a,'('
 	jp outchar
 
 l1d92h:
@@ -5432,6 +3723,16 @@ p_arg_ww_addr:
 	call p_char_comma
 	jr p_arg_addr
 
+p_arg_a_addr:
+	call p_A_comma
+p_arg_addr:
+	call p_char_lparen
+	ld l,(iy+001h)
+	ld h,(iy+002h)
+	ld a,001h
+	call sub_1d50h
+	jr p_char_rparen
+
 p_arg_bitop:
 	ld a,(isprefix_ixiy)
 	and a
@@ -5463,17 +3764,6 @@ l1e0eh:
 l1e11h:
 	jr p_arg_r0
 
-p_arg_addr:
-	call p_char_lparen
-	ld l,(iy+001h)
-	ld h,(iy+002h)
-	ld a,001h
-	call sub_1d50h
-
-p_char_rparen:
-	ld a,')'
-	jp outchar
-
 p_arg_r:
 	ld a,(iy+000h)
 	rra
@@ -5498,20 +3788,18 @@ p_arg_r0:
 l1e4dh:
 	call pstr
 	ld a,(iy+001h)
-	and a
-	jp m,l1e61h
-	call	pstr_inl
-	dc	'+'
-	ld a,(iy+001h)
-	jr l1e6bh
-l1e61h:
-	call	pstr_inl
-	dc	'-'
-	ld a,(iy+001h)
+	push af
+	rlca
+	ld a,'+'
+	jr nc,l1e61h
+	pop af
 	neg
-l1e6bh:
-	call out_hex
-	jr p_char_rparen
+	push af
+	ld a,'-'
+l1e61h:
+	call outchar
+	pop af
+	jp p_arg_nn_rp
 
 p_arg_r1:
 	ld hl,t_BCDEHL_HL_A
@@ -5656,38 +3944,16 @@ t_BC.DE.HL.SP:
 t_BC.DE.HL.AF:
 	DC	'BC'
 	DC	'DE'
-t_HL.AF:
+
 	DC	'HL'
 	DC	'AF'
 	DB	0
-t_BC.DE.IY.SP:
-	DC	'BC'
-	DC	'DE'
-	DC	'IY'
-	DC	'SP'
-	DB	0
-t_BC.DE.IX.SP:
-	DC	'BC'
-	DC	'DE'
-	DC	'IX'
-	DC	'SP'
-	DB	0
 t_HL.IX.IY:
 	DC	'HL'
-t_IX.IY:
+
 	DC	'IX'
 	DC	'IY'
 	DB	0
-t_tstfl_ZC:
-	DC	'NZ'
-	DC	'Z'
-	DC	'NC'
-	DC	'C'
-	DC	'NE'
-	DC	'EQ'
-	DC	'GE'
-	DC	'LT'
-	DB	0
 t_tstfl_ZCPS:
 	DC	'NZ'
 	DC	'Z'
@@ -5710,7 +3976,7 @@ t__C_:
 
 ;-------------------------------------------------------------------------------
 
-sub_1ffeh:
+tc_set_bp:
 	ld hl,(reg.pc)
 	ld a,h
 	or l
@@ -5727,7 +3993,7 @@ sub_1ffeh:
 	ld b,0
 	ld hl,(reg.pc)
 	add hl,bc
-	call sub_09cah
+	call bp_trace_enter
 	ld iy,(reg.pc)
 	ld hl,b_2039_start
 	call lookup_opc
@@ -5736,7 +4002,7 @@ sub_1ffeh:
 	ex de,hl
 l2031h:
 	call CALL_HL
-	call c,sub_09cah
+	call c,bp_trace_enter
 l2037h:
 	scf
 	ret
@@ -5762,22 +4028,22 @@ b_2048_start:
 	dw l20dch
 	db 0ffh,0cfh,000h	;rst 8
 	dw l2115h
-	db 0c7h,0c7h,000h	;
+	db 0c7h,0c7h,000h	;rst n
 	dw l20f9h
-	db 0c7h,0c4h,000h	;
+	db 0c7h,0c4h,000h	;call cc,mn
 	dw l2080h
-	db 0f7h,010h,000h	;
+	db 0f7h,010h,000h	;djnz d; jr d
 	dw l2093h
-	db 0e7h,020h,000h	;
+	db 0e7h,020h,000h	;jr cc,d
 	dw l2093h
-	db 0c7h,0c2h,000h	;
+	db 0c7h,0c2h,000h	;jp cc,mn
 	dw l208bh
-	db 0c7h,0c0h,000h	;
+	db 0c7h,0c0h,000h	;ret cc
 	dw l20c5h
 	db 0
 
 ;-------------------------------------------------------------------------------
-
+; call mn	call cc,mn
 l2080h:
 	ld a,(b_21e2_start)
 	and a
@@ -5785,11 +4051,14 @@ l2080h:
 	ld a,(trace_call_flag)
 	and a
 	ret nz
+
+; jp mn		jp cc,mn
 l208bh:
 	ld l,(iy+001h)
 	ld h,(iy+002h)
 	scf
 	ret
+
 l2093h:
 	ld c,(iy+001h)
 	ld a,c
@@ -5802,27 +4071,34 @@ l2093h:
 	inc hl
 	scf
 	ret
+
+; jp (hl)
 l20a2h:
 	ld hl,(reg.l)
 	scf
 	ret
+
+; Prefix DD
 l20a7h:
 	ld hl,(reg.ix)
 	jr l20afh
+; Prefix FD
 l20ach:
 	ld hl,(reg.iy)
 l20afh:
 	ld a,(iy+001h)
-	cp 0e9h
+	cp 0e9h			; jp (ix); jp (iy)
 	scf
 	ret z
 	and a
 	ret
+
+; Prefix ED
 l20b8h:
 	ld a,(iy+001h)
-	cp 04dh
+	cp 04dh			; reti
 	jr z,l20dch
-	cp 045h
+	cp 045h			; retn
 	jr z,l20dch
 	and a
 	ret
@@ -5859,7 +4135,8 @@ l20edh:
 	inc hl
 	ld d,(hl)
 	ex de,hl
-	call sub_09cah
+	call bp_trace_enter
+l2115h:
 	and a
 	ret
 
@@ -5880,9 +4157,6 @@ l20f9h:
 l2113h:
 	scf
 	ret
-l2115h:
-	and a
-	ret
 
 ;-------------------------------------------------------------------------------
 ; >>C[N][J] [steps]
@@ -5891,9 +4165,8 @@ l2115h:
 ;     trace over Calls [No list] [Jumps only] /.While./.Until.
 
 cmd_C:
-	ld hl,cmd_C
 	ld a,1
-	jr l2122h
+	jr cmd_tc
 
 ;-------------------------------------------------------------------------------
 ; >>T[N][J] [steps]
@@ -5903,33 +4176,32 @@ cmd_C:
 
 cmd_T:
 	xor a
-	ld hl,cmd_T
-l2122h:
+cmd_tc:
 	ld (cmd_rpt),hl
 	ld (trace_call_flag),a
 	call get_char_upper
 	sub 'N'
-	jr nz,l212eh
+	jr nz,tc_non
 	inc de
-l212eh:
+tc_non:
 	ld (trace_N_flag),a
 	call get_char_upper
 	sub 'J'
-	jr nz,l2137h
+	jr nz,tc_noj
 	inc de
-l2137h:
+tc_noj:
 	ld (trace_J_flag),a
-	call sub_21a6h
-	jr z,l2145h
-	ld hl,1
+	call tc_chk_u_or_w
+	jr z,tc_save_uw_expr_ptr
+	ld hl,1				;default: 1 step
 	call get_lastarg_def
-l2145h:
-	ld (trace_count),hl
+tc_save_uw_expr_ptr:
+	ld (trace_cnt_or_ptr),hl
 	sub a
-	ld (l0941h),a
+	ld (bp_p_cpu_flag),a
 l214ch:
-	call sub_1ffeh
-	jr l21a3h
+	call tc_set_bp
+	jr user_go1
 
 l2151h:
 	call bp_clr_temporary
@@ -5943,40 +4215,41 @@ l2151h:
 	call lookup_opc
 	jr nc,l214ch
 l216bh:
-	ld a,(trace_UW_flag)
+	ld a,(trace_UW_flag)		;0 or 'U' or 'W'
 	and a
-	jr z,l2188h
-	ld de,(trace_count)
+	jr z,tc_cnt			;flag is 0, check for step count.
+	ld de,(trace_cnt_or_ptr)
 	call expr
 	ld a,h
 	or l
 	add a,0ffh
 	sbc a,a
-	ld hl,trace_UW_flag
+	ld hl,trace_UW_flag		;'U' or 'W'
 	xor (hl)
-	bit 1,a
+	bit 1,a				;'U' = 55H, 'W' = 57H
 	jr z,l2193h
-l2185h:
-	jp l0902h
-l2188h:
-	ld hl,(trace_count)
+do_break0:				;print registers and go to main loop
+	jp do_break
+
+tc_cnt:
+	ld hl,(trace_cnt_or_ptr)
 	dec hl
-	ld (trace_count),hl
+	ld (trace_cnt_or_ptr),hl
 	ld a,h
 	or l
-	jr z,l2185h
+	jr z,do_break0
 l2193h:
-	call sub_1ffeh
-	jr nc,l2185h
+	call tc_set_bp
+	jr nc,do_break0
 	ld a,(trace_N_flag)
 	ld b,a
-	ld a,(l0941h)
+	ld a,(bp_p_cpu_flag)
 	or b
-	ld (l0941h),a
-l21a3h:
+	ld (bp_p_cpu_flag),a
+user_go1:
 	jp user_go
 
-sub_21a6h:
+tc_chk_u_or_w:
 	call skipbl
 	xor a
 	ld (trace_UW_flag),a
@@ -6016,25 +4289,25 @@ l21dah:
 
 ;-------------------------------------------------------------------------------
 
+con_col:
+	db	0
+
+;-------------------------------------------------------------------------------
+
 b_21e2_start:
 	db	0
 trace_call_flag:
 	db	0		;1=call, 0=trace
 trace_UW_flag:
 	db	0		;0 or 'U' or 'W'
-trace_count:
+trace_cnt_or_ptr:
 	dw	0
 trace_N_flag:
 	db	0		;0 if 'N'
 trace_J_flag:
 	db	0		;0 if 'J'
 
-;-------------------------------------------------------------------------------
-
-con_col:
-	db	0
-
-l0941h:
+bp_p_cpu_flag:
 	db	0
 
 bp_tab:
@@ -6046,8 +4319,6 @@ bp_tab:
 
 expr_p1:
 	dw	expr_buf
-expr_p2:
-	dw	expr_buf
 
 expr_buf:
 current_cseg	defl	$ - current_cseg
@@ -6136,13 +4407,6 @@ expr_bufe:
 
 ;-------------------------------------------------------------------------------
 
-msg_Y:
-	dc	'Yn'
-reg_Y:
-	rept	YREG_CNT
-	 dw	0
-	endm
-
 last_S:
 	dw	TPA
 
@@ -6168,16 +4432,6 @@ high_load:
 max_load:
 	dw	TPA
 
-l1262h:
-	dw	0
-last_A:
-	dw	TPA
-cmd_A_prev:
-	dw	TPA
-
-prefix_ixiy:
-	db	0
-
 isprefix_ixiy:
 	db	0
 last_L:
@@ -6190,12 +4444,8 @@ disas_argtype:
 pbl_loop_adr:
 	dw	0
 
-symlen_cur:		;max length of symbols read so far
-	db	0
 cur_fcb:
 	dw	0
-fcbsym:
-	ds	33
 
 ddtz_size	equ	$-ddtz_base
 ddtz_end: