X-Git-Url: http://cloudbase.mooo.com/gitweb/ddt180.git/blobdiff_plain/3f9577cdb9cd98760758b6318cfea767da850974..cab0d80a35d1c7871f2f8af22c52f6ff1b77fa3d:/ddt180.z80?ds=sidebyside

diff --git a/ddt180.z80 b/ddt180.z80
index 85e3705..5b531f6 100644
--- a/ddt180.z80
+++ b/ddt180.z80
@@ -9,7 +9,6 @@
 ;-------------------------------------------------------------------------------
 ; Relocation loader
 ;
-
 TPA	equ	0100h
 	cseg
 	.phase	TPA
@@ -80,8 +79,11 @@ ddtz_bdos:
 current_cseg	defl	$ - current_cseg
 	.phase	current_phase + current_cseg
 signon:
-	db	'DDT/180',TAB
-	db	'[8101] 003',CR,LF,'$'
+	db	'Symbolic DDTZ/180'
+	db	' - Version '
+	maclib	version.inc
+	defvers
+	db	CR,LF,'$'
 msgz80:
 	db	'Z80 or better required!',cr,lf,'$'
 
@@ -235,83 +237,18 @@ exe_hl:
 	jr mainloop
 
 l0146h:
-	ld a,'?'
-	call outchar
+	call	pstr_inl
+	dc	'?'
 	;fall thru
 crlf:
+	call	pstr_inl
+	db	CR,LF+80h
 	call inchar
-	ld a,CR
-	call outchar
-	ld a,LF
-	call outchar
 	ld a,0
 	ld (con_col),a
 	jr c,mainloop
 	ret
 
-get_line:
-	push hl
-	ld de,conbuf
-	ld c,BDOS_CBUF
-	call ddtz_bdos
-	call crlf
-	ld de,conbuf+1
-	ld a,(de)
-	ld b,a
-	ld c,0
-	inc b
-l0162h:
-	inc de
-	dec b
-	jr z,l0194h
-	ld a,(de)
-	bit 0,c
-	call z,toupper
-	ld (de),a
-	cp ''''
-	jr nz,l0162h
-	push de
-	dec de
-	ld a,(de)
-	cp ''''
-	jr z,l0190h
-	dec de
-	ld a,(de)
-	cp '^'
-	jr z,l0184h
-	dec de
-	ld a,(de)
-	cp '^'
-	jr nz,l0190h
-l0184h:
-	inc de
-	push bc
-	call sub_0303h
-	pop bc
-	dec de
-	ld a,(de)
-	cp ''''
-	jr z,l0191h
-l0190h:
-	inc c
-l0191h:
-	pop de
-	jr l0162h
-l0194h:
-	xor a
-	ld (de),a
-	ld de,conbuf+2
-	pop hl
-	ret
-
-toupper:
-	cp 'a'
-	ret c
-	cp 'z'+1
-	ret nc
-	and 05fh
-	ret
-
 out.hl.@:
 	call out_hl
 	push de
@@ -321,8 +258,8 @@ out.hl.@:
 	or e
 	jr z,l01bfh
 	call outbl
-	ld a,'@'
-	call outchar
+	call	pstr_inl
+	dc	'@'
 	and a
 	sbc hl,de
 	call out_hl
@@ -331,26 +268,9 @@ l01bfh:
 	pop de
 	ret
 
-out.bin.w:
-	ld a,h
-	call out.bin.b
-	ld a,l
-out.bin.b:
-	ld b,8
-l01c9h:
-	add a,a
-	push af
-	ld a,00
-	adc a,a
-	call out_dgt
-	pop af
-	djnz l01c9h
-	ld a,'"'
-	jp outchar
-
 sub_01d9h:
-	ld a,'-'
-	call outchar
+	call	pstr_inl
+	dc	'-'
 	dec hl
 	jp cpl.hl
 
@@ -363,12 +283,13 @@ out.hl.dec:
 	ld b,006h
 	call sub_01f9h
 	pop hl
-	ld a,'.'
-	call outchar
+	call	pstr_inl
+	dc	'.'
 l01f3h:
 	call outbl
 	djnz l01f3h
 	ret
+
 sub_01f9h:
 	dec b
 	push de
@@ -410,34 +331,59 @@ out_dgt:
 l0229h:
 	add a,'0'
 	jr outchar
-l022dh:
-	ld a,'-'
-	call outchar
-	ld a,040h
-out.ascii:
-	ex af,af'
-	call outquote
-	ex af,af'
+
+out.bin.w:
+	ld a,h
+	call out.bin.b
+	ld a,l
+out.bin.b:
+	ld b,8
+l01c9h:
+	add a,a
 	push af
+	ld a,00
+	adc a,a
+	call out_dgt
+	pop af
+	djnz l01c9h
+	ld a,'"'
+	jr outchar
+
+out.ascii:
+	push bc
+	ld c,a
 	res 7,a
 	cp ' '
+	push af
+	call nc,outbl
+	call outquote
+	pop af
 	jr nc,l0242h
 	sub 0c0h
+	ld b,a
+	call	pstr_inl
+	dc	'^'
+	ld a,b
 l0242h:
 	call outchar
-	push af
 	cp ''''
 	call z,outchar
-	pop af
-	ex af,af'
 	call outquote
-	pop af
-	or a
+	sla c
+	pop bc
+	ret nc
 	ld a,'.'
-	call m,outchar
-	ex af,af'
-	jr c,l022dh
-	ret
+	jr outchar
+
+outbl6:
+	call outbl2
+outbl4:
+	call outbl2
+outbl2:
+	call outbl
+outbl:
+	ld a,' '
+	jr outchar
 
 p_char_lparen:
 	ld a,'('
@@ -462,6 +408,29 @@ outchar:
 	pop hl
 	ret
 
+pstr:
+	ld a,(hl)
+	inc hl
+	and a
+	ret z
+	call outchar
+	and a
+	ret m
+	jr pstr
+
+pstr_inl:
+	ex	(sp),hl
+	call	pstr
+	ex	(sp),hl
+	ret
+
+p_fill_space:
+	call	outbl
+	ld	a,(con_col)
+	cp	c
+	jr	c,p_fill_space
+	ret
+
 inchar:
 	push hl
 	push de
@@ -479,49 +448,74 @@ l0284h:
 	pop hl
 	ret
 
-pstr:
+get_line:
+	push hl
+	ld de,conbuf
+	ld c,BDOS_CBUF
+	call ddtz_bdos
+	call crlf
+	ld de,conbuf+1
+	ld a,(de)
+	ld b,a
 	ld c,0
-l028ah:
-	ld a,(hl)
-	inc hl
-	and a
-	ret z
-	call outchar
+	inc b
+l0162h:
+	inc de
+	dec b
+	jr z,l0194h
+	ld a,(de)
+	bit 0,c
+	call z,toupper
+	ld (de),a
+	cp ''''
+	jr nz,l0162h
+	push de
+	dec de
+	ld a,(de)
+	cp ''''
+	jr z,l0190h
+	dec de
+	ld a,(de)
+	cp '^'
+	jr z,l0184h
+	dec de
+	ld a,(de)
+	cp '^'
+	jr nz,l0190h
+l0184h:
+	inc de
+	push bc
+	call sub_0303h
+	pop bc
+	dec de
+	ld a,(de)
+	cp ''''
+	jr z,l0191h
+l0190h:
 	inc c
-	and a
-	ret m
-	jr l028ah
-
-pstr_inl:
-	ex	(sp),hl
-	call	pstr
-	ex	(sp),hl
+l0191h:
+	pop de
+	jr l0162h
+l0194h:
+	xor a
+	ld (de),a
+	ld de,conbuf+2
+	pop hl
 	ret
 
-outbl6:
-	call outbl2
-outbl4:
-	call outbl2
-outbl2:
-	call outbl
-outbl:
-	ld a,' '
-	jr outchar
-
-add_hl_a:
-	add a,l
-	ld l,a
+toupper:
+	cp 'a'
+	ret c
+	cp 'z'+1
 	ret nc
-	inc h
+	and 05fh
 	ret
 
 skipbl0:
 	inc de
 skipbl:
 	ld a,(de)
-	cp ' '
-	jr z,skipbl0
-	cp TAB
+	call test_whitespace
 	jr z,skipbl0
 	or a
 	ret
@@ -553,12 +547,126 @@ chk_sp:
 	jr c,to_error
 	ret
 
+add_hl_a:
+	add a,l
+	ld l,a
+	ret nc
+	inc h
+	ret
+
 cp_hl_de:
 	and a
 	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_sym_space:
+  if 0
+	ld	a,(dash_flag)
+	or	a
+	ret	nz
+  endif
+
+	push	hl
+	push	bc
+	ld	c,a
+	ld	a,(con_col)
+	ld	b,a
+	call	sym_getname
+	jr	z,psb_align
+	bit	7,c
+	jr	z,psb_nd
+	call	pstr_inl
+	dc	' .'
+psb_nd:
+	call	p_symstr
+
+psb_align:
+	ld	a,(con_col)
+	sub	b
+	ld	b,a
+	ld	a,(symlen_max)
+	bit	7,c
+	jr	z,$+4
+	add	a,2
+	res	7,c
+	add	c
+	sub	b
+	ld	b,a
+	jr	z,psb_e
+psb_a_l:
+	call	outbl
+	djnz	psb_a_l
+psb_e:
+	pop	bc
+	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:
 	ld b,0
 l02f5h:
@@ -1030,17 +1138,20 @@ do_factor:
 	cp '('
 	jr z,fact_mem
 	cp '['
-	jp z,expr_brckt
+	jr z,expr_brckt
 	cp ''''
 	jr z,fact_factstring
+	cp '.'
+	jr z,fact_symbol
 	dec de
 	scf
 	ret
 
 fact_reg.Y:
 	call get.decdigit
-	jp c,ERROR
+	jr c,error1
 	inc de
+get_y_val:
 	add a,a
 	ld hl,reg_Y
 	call add_hl_a
@@ -1078,7 +1189,7 @@ l0557h:
 
 fact_reg.CPU:
 	call sub_0caeh
-	jr nc,error4
+	jr nc,error1
 	ld a,(hl)
 	inc hl
 	ld h,(hl)
@@ -1107,10 +1218,10 @@ fact_factinv:
 
 fact_mem:
 	call expr1
-	jr c,error4
+	jr c,error1
 	ld a,(de)
 	cp ')'
-	jr nz,error4
+	jr nz,error1
 	inc de
 	ld a,(hl)
 	inc hl
@@ -1127,14 +1238,54 @@ fact_mem:
 
 expr_brckt:
 	call expr1
-	jr c,error4
+	jr c,error1
 	ld a,(de)
 	cp ']'
 	inc de
 	ret z
-error4:
+error1:
 	jp ERROR
 
+fact_symbol:
+	push	bc
+	ld	hl,ddtz_base		;symtbl start
+
+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_2:
+	ld	a,(de)
+	djnz	fs_3
+	call	test_sym_char
+	jr	z,fs_cont
+	pop	hl			;inpsym ptr (discard)
+	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
+	cp	(hl)
+	jr	z,fs_2
+fs_cont:				;start over
+	pop	de			;inpsym ptr
+	pop	hl			;symtbl ptr
+	ld	a,(hl)
+	add	a,3
+	call	sub_hl_a
+	jr	fs_nxtsym
+
 get.number:
 	call get.hexdigit
 	ret c
@@ -1254,24 +1405,21 @@ l063eh:
 	push de
 	ld iy,(reg.pc)
 	call p_disas_instr
-	exx
-	ex af,af'
+	pop de
+	ex (sp),hl
+	push af
 	call crlf
 	call p_f2
 	call outbl2
-	pop de
-	pop hl
 	ld b,7
 l065bh:
 	call p_regs
 	djnz l065bh
-	exx
-	ex af,af'
+	pop af
+	pop hl
 	and a
-	jr z,l066bh
-	call outbl6
-	call p_offset
-l066bh:
+	call nz,outbl6
+	call nz,p_offset
 	jp crlf
 
 p_f:
@@ -1286,6 +1434,7 @@ p_f2:
 	ld a,(reg.f2)
 	call p_flags
 	jp outbl
+
 p_flags:
 	ld b,a
 	ld a,'S'
@@ -1307,11 +1456,10 @@ sub_06aah:
 	jp outbl
 
 p_regs:
-	push bc
 	push de
 	call pstr
-	ld a,'='
-	call outchar
+	call	pstr_inl
+	dc	'='
 	ex (sp),hl
 	ld e,(hl)
 	inc hl
@@ -1322,13 +1470,11 @@ p_regs:
 	push hl
 	and a
 	jr z,l06deh
-	push af
-	ld a,(de)
-	ld l,a
-	inc de
-	ld a,(de)
-	ld h,a
-	pop af
+	ex de,hl
+	ld e,(hl)
+	inc hl
+	ld d,(hl)
+	ex de,hl
 	dec a
 	jr z,l06d9h
 	call out.hl.@
@@ -1344,7 +1490,6 @@ l06e2h:
 	call outbl
 	pop de
 	pop hl
-	pop bc
 	ret
 
 b_06e9_start:
@@ -1424,24 +1569,24 @@ l075ah:
 
 cmd_B:
 	call skipbl
-	jr z,l07b7h
+	jr z,bp_print
 	inc de
 	cp 'X'
-	jr z,l077dh
+	jr z,bp_clr0
 	dec de
 	ld a,001h
 	jp bp_enter
-l077dh:
+bp_clr0:
 	call skipbl
 	jr z,bp_clr_all
-l0782h:
+bp_clr_next:
 	call expr
 	jp c,assert_eol
 	push de
 	call bp_clr
 	pop de
 	call next_arg
-	jr l0782h
+	jr bp_clr_next
 
 bp_clr_all:
 	scf
@@ -1465,12 +1610,12 @@ l07aeh:
 	djnz l0799h
 	ret
 
-l07b7h:
+bp_print:
 	ld b,BP_CNT
 	ld ix,bp_tab
-l07bdh:
+bp_pr_l:
 	bit 0,(ix+000h)
-	jr z,l0808h
+	jr z,bp_pr_cont
 	ld a,'R'
 	bit 4,(ix+000h)
 	jr nz,l07cdh
@@ -1481,9 +1626,10 @@ l07cdh:
 	ld l,(ix+002h)
 	ld h,(ix+003h)
 	call out.hl.@
-	call outbl2
-	ld a,':'
-	call outchar
+	ld a,82h
+	call p_sym_space
+	call 	pstr_inl
+	dc	':'
 	ld l,(ix+004h)
 	ld h,(ix+005h)
 	call out_hl
@@ -1493,16 +1639,15 @@ l07cdh:
 	or l
 	jr z,l0805h
 	call outbl4
-	ld a,'I'
-	call outchar
-	call outbl2
+	call	pstr_inl
+	dc	'I  '
 	call pstr
 l0805h:
 	call crlf
-l0808h:
+bp_pr_cont:
 	ld de,BP_SIZE
 	add ix,de
-	djnz l07bdh
+	djnz bp_pr_l
 	ret
 
 ; Add break points to list
@@ -1514,10 +1659,10 @@ bp_enter:
 	call skipbl
 	ret z
 	cp 'R'
-	jr nz,l081ch
+	jr nz,bp_e_1
 	inc de
 	set 4,b
-l081ch:
+bp_e_1:
 	push bc
 	call expr
 	jp c,ERROR
@@ -1547,7 +1692,7 @@ l081ch:
 bp_get_freeslot:
 	ld b,BP_CNT
 	ld ix,bp_tab
-l085ah:
+bp_gf_l:
 	ld a,(ix+000h)
 	and 00fh
 	ret z
@@ -1555,7 +1700,7 @@ l085ah:
 	ld bc,BP_SIZE
 	add ix,bc
 	pop bc
-	djnz l085ah
+	djnz bp_gf_l
 	jp ERROR
 
 bp_get_count:
@@ -1897,7 +2042,11 @@ l0bc3h:
 l0bc7h:
 	push af
 	call sub_0bdch
-	call outbl4
+	pop af
+	push af
+	call get_y_val
+	ld a,82h
+	call p_sym_space
 	pop af
 	inc a
 	bit 0,a
@@ -1947,15 +2096,14 @@ l0c15h:
 	call skipbl
 	jr z,l0c30h
 	call sub_0363h
-	ld b,h
-	ld c,l
-	pop af
+	ex de,hl
+	pop bc
 	pop hl
-	ld (hl),c
-	bit 0,a
+	ld (hl),e
+	bit 0,c
 	ret z
 	inc hl
-	ld (hl),b
+	ld (hl),d
 	ret
 l0c30h:
 	pop af
@@ -1963,19 +2111,18 @@ l0c30h:
 	ret
 
 l0c33h:
-	ld b,c
 	call pstr
-	ld a,'='
-	call outchar
+	call	pstr_inl
+	dc	'='
 	ld a,(de)
-	bit 0,b
+	bit 0,c
 	jp z,out_hex
 	ld l,a
 	inc de
 	ld a,(de)
 	dec de
 	ld h,a
-	bit 1,b
+	bit 1,c
 	jp z,out_hl
 	jp out.hl.@
 
@@ -1993,12 +2140,15 @@ l0c5fh:
 	call sub_0c6ah
 	ld (reg.f2),a
 	ret
+
 sub_0c6ah:
-	ex af,af'
+	push af
 	ld b,000h
 	call outbl
 	call assert_eol
 	call get_line
+	pop af
+	ex af,af'
 l0c76h:
 	call skipbl
 	ld a,b
@@ -2319,100 +2469,57 @@ l0e5eh:
 	call out_hl_dec_neg
 	call outbl4
 	call out.bin.w
-	call outbl2
+	call outbl
 	ld a,l
 	call out.ascii
+	ld a,80h
+	call p_sym_space
 	jp crlf
 
 p_symbols:
 	inc	de
 	call	assert_eol
+	ld	a,(symlen_max)
+	add	a,7
+	ld	b,a
+	ld	c,0
 	ld	hl,ddtz_base+2
-psym_l:
+psym_nxtsym:
 	ld	d,(hl)
 	dec	hl
 	ld	e,(hl)
 	dec	hl
-	ld	b,(hl)
-	dec	hl
-	ld	a,b
-	cp	10h
-	ret	nc
+	ld	a,(hl)
+	cp	0c3h
+	jr	z,psym_e
 
 	ex	de,hl
 	call	out_hl
-	ex	de,hl
 	call	outbl
-psymch_l:
-	ld	a,(hl)
-	dec	hl
-	call	outchar
-	djnz	psymch_l
-	call	crlf
-	jr	psym_l
-
-p_symstr:
-	ld	b,(hl)
-pss_l:
-	dec	hl
-	ld	a,(hl)
-	call	outchar
-	djnz	pss_l
-	ret
-
-
-p_label:
-  if 0
-	ld	a,(dash_flag)
-	or	a
-	ret	nz
-  endif
-	push	hl
-	call	sym_getname
-	jr	z,pl_e
+	ex	de,hl
 	call	p_symstr
-	ld	a,':'
-	call	outchar
-	call	crlf
-pl_e:
-	pop	hl
-	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
 
-sub_hl_a1:
-	dec	hl
-sub_hl_a:
-	push	bc
+	ld	a,c
+	add	b
 	ld	c,a
-	ld	b,0
+	ld	a,80			;screen width
+	sub	b
+	cp	c
+	jr	c,psym_nxtline
+	call	p_fill_space
+	jr	psym_nxtsym
+
+psym_nxtline:
+	ld	c,0
+	call	crlf
+	jr	psym_nxtsym
+
+psym_e:
+	ld	a,c
 	or	a
-	sbc	hl,bc
-	pop	bc
-	ret
+	ret	z
+	jp	crlf
+
 
 cmd_Q:
 	ld a,(de)
@@ -2577,7 +2684,7 @@ sub_0f58h:
 	push bc
 	push de
 	push hl
-	ex af,af'
+	push af
 l0f5ch:
 	call out.hl.@
 	call z,outbl2
@@ -2609,15 +2716,16 @@ l0f86h:
 	inc hl
 	dec e
 	jr nz,l0f86h
-	ex af,af'
+	pop af
+	push af
 	jr nc,l0f97h
 	ld (last_D),hl
 l0f97h:
-	ex af,af'
 	call crlf
 	ld a,b
 	or c
 	jr nz,l0f5ch
+	pop af
 	pop hl
 	pop de
 	pop bc
@@ -2793,6 +2901,7 @@ read_byte:
 	cp 080h
 	jr nz,l1111h
 	call read_sector
+	ld a,01ah
 	ret z
 	sub a
 l1111h:
@@ -2814,9 +2923,9 @@ read_sector:
 	ld de,(cur_fcb)
 	ld c,BDOS_READ
 	call ddtz_bdos
-	dec a
+	sub a,1
 	jr z,l1132h
-	jp p,ERROR
+	jr nc,error2
 l1132h:
 	pop bc
 	pop de
@@ -2828,10 +2937,10 @@ cmdR_storebyte:
 	push de
 	ld de,TPA
 	call cp_hl_de
-	jp c,ERROR
+	jr c,error2
 	ld de,(BDOS+1)
 	call cp_hl_de
-	jp nc,ERROR
+	jr nc,error2
 	ld de,(high_load)
 	call cp_hl_de
 	jr c,l1157h
@@ -2876,11 +2985,11 @@ read_hexchar:
 
 read_hexdigit:
 	call read_byte
-	jr z,error8
+	jr z,error2
 hex_digit_v:
 	call hex_digit
 	ret nc
-error8:
+error2:
 	jp ERROR
 
 read_hexbyte:
@@ -2919,12 +3028,15 @@ read_file:
 	pop hl
 	jr z,read_hexfile
 	ld de,TPA
-	add hl,de
 	push hl
+	add hl,de
 l108eh:
 	call read_sector
+	jr nz,read_file_nxt
 	pop hl
-	jr z,read_symfile
+	jr read_symfile
+
+read_file_nxt:
 	ld de,DMA_BUF
 	ld b,080h
 l109ah:
@@ -2933,29 +3045,28 @@ l109ah:
 	inc de
 	inc hl
 	djnz l109ah
-	push hl
 	jr l108eh
 
 read_hexfile:
 	push hl
 l10aeh:
-	call read_byte
+	call read_byte		; RECORD MARK
 	jr z,rdhex_done
 	cp ':'
 	jr nz,l10aeh
 	ld c,0
-	call read_hexchar
+	call read_hexchar	; RECLEN
 	ld b,a
-	call read_hexchar
+	call read_hexchar	; LOAD ADDR H
 	ld h,a
-	call read_hexchar
+	call read_hexchar	; LOAD ADDR L
 	ld l,a
 	ld a,b
 	and a
 	jr z,rdhex_done
-	call read_hexchar
+	call read_hexchar	; RECTYP
 l10cch:
-	call read_hexchar
+	call read_hexchar	; DATA
 	pop de
 	push de
 	push hl
@@ -2964,10 +3075,10 @@ l10cch:
 	pop hl
 	inc hl
 	djnz l10cch
-	call read_hexchar
+	call read_hexchar	; CHKSUM
 	ld a,c
 	and a
-	jr nz,error9
+	jr nz,error3
 	jr l10aeh
 rdhex_done:
 	pop hl
@@ -2979,88 +3090,144 @@ read_symfile:
 	cp ' '
 	jp z,p_max_high
 
+	push	hl		; offset
 	call pstr_inl
 	db	'SYMBOLS',CR,LF+80h
 
 	dec de
 	call file_open
-;------------------------------------------------------------------------
 rs_1:
 	call	read_byte
 rs_2:
+	pop	de		; offset
 	cp	1ah
-	jr	z,p_max_high
+	jp	z,p_max_high
+	push	de		; offset
 	cp	'!'
 	jr	c,rs_1
-	call	read_hexbyte0
-	ld	d,a
-	call	read_hexbyte	; symval
-	ld	e,a
-	push	de		; symval
+	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
-	pop	hl		; discard symval
 rs_3:	call	read_byte
 	cp	' '
-	jr	c,rs_2
-	jr	rs_3
-;
-rs_4:	ld	hl,(BDOS+1)	;
-	ld	e,0		; setup symlen
-rs_5:	dec	hl		;
-	call	read_byte	;
-	cp	TAB		;
-	jr	z,rs_6		;
-	cp	CR		;
-	jr	z,rs_6		;
-	cp	'!'		;
-	jr	c,error9		;
+	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
 	ld	(hl),a		;
-	inc	e		; symlen++
-	ld	a,e		;
+	inc	b		; symlen++
+	ld	a,b		;
 	cp	10h+1		;
 	jr	c,rs_5		;
-error9:
+error3:
 	jp	ERROR		;
-;
-rs_6:	push	de		; symlen
-	push	hl		;
+
+rs_6:
+	call	test_symterm_ch
+	jr	nz,error3
+
+	push	bc		; symlen
 	ex	de,hl		;
 	ld	hl,(BDOS+1)	;
 	inc	hl		;
-	ld	e,(hl)		;
+	ld	c,(hl)		;
 	inc	hl		;
-	ld	d,(hl)		;
-	pop	hl		;
-	ld	(hl),d		;
+	ld	b,(hl)		;
+	ex	de,hl
+	ld	(hl),b		;
 	dec	hl		;
-	ld	(hl),e		;
+	ld	(hl),c		;
 	dec	hl		;
 	ld	(hl),0c3h	;
 
 	ld	de,(max_load)	;
 	call	cp_hl_de	;
-	jr	c,error9	;
-
+	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	de		;
-	ld	(hl),e		; symlen
+	pop	af		; symlen
+	ld	(hl),a		;
 	inc	hl		;
 	pop	de		; symval
 	ld	(hl),e		;
 	inc	hl		;
 	ld	(hl),d		;
+	ld	hl,symlen_max	;
+	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'+1
+	ccf
+	ret	c
+	cp	'a'
+	ret	nc
+	cp	'Z'+1
+	ccf
+	ret	c
+	cp	'?'
+	ret	nc
+test_numeral:
+	cp	'9'+1
+	ccf
+	ret	c
+	cp	'0'
+	ret
+
+test_symterm_ch:
+	cp	CR
+	ret	z
+	cp	LF
+	ret	z
+test_whitespace:
+	cp	' '
+	ret	z
+	cp	TAB
+	ret
 
 p_max_high0:
 	call assert_eol
@@ -3073,6 +3240,10 @@ p_max_high:
 	DC	'  Max = '
 	ld hl,(max_load)
 	call out_hl
+	call pstr_inl
+	DC	'  Top = '
+	ld hl,(BDOS+1)
+	call out_hl
 	jp crlf
 
 cmd_W:
@@ -3089,7 +3260,7 @@ l11adh:
 	push bc
 	ld a,(dfcb1+1)
 	cp ' '
-	jr z,error5
+	jr z,error4
 	ld de,dfcb1
 	call setup_fcb
 	push de
@@ -3099,7 +3270,7 @@ l11adh:
 	ld c,BDOS_CREATE
 	call ddtz_bdos
 	inc a
-	jr z,error5
+	jr z,error4
 	pop bc
 	pop hl
 l11cch:
@@ -3128,7 +3299,7 @@ write_sector:
 	and a
 	ret z
 	call close_file
-error5:
+error4:
 	jp ERROR
 
 close_file:
@@ -3152,18 +3323,15 @@ l1211h:
 	push hl
 	call p_disas_line
 	pop iy
-	ld c,b
 	ld de,(var.@)
 	ld a,d
 	or e
-	ld b,011h
+	ld c,17
 	jr z,l122dh
-	ld b,019h
+	ld c,25
 l122dh:
-	call outbl
-	ld a,(con_col)
-	cp b
-	jr c,l122dh
+	call p_fill_space
+	ld c,b
 	push bc
 	call get_line
 	pop bc
@@ -3384,9 +3552,9 @@ as.TSTIO:
 
 as.IN0:
 	call arg.r_HL_A		;
-	jr nc,error7
+	jr nc,error5
 	cp 006h
-	jr z,error7
+	jr z,error5
 	rlca
 	rlca
 	rlca
@@ -3400,9 +3568,9 @@ as.OUTO:
 	call arg.addr_8bit	;
 	call assert_comma	;
 	call arg.r_HL_A		;
-	jr nc,error7
+	jr nc,error5
 	cp 006h
-	jr z,error7
+	jr z,error5
 	rlca
 	rlca
 	rlca
@@ -3419,12 +3587,12 @@ as.store_io0:
 
 as.MLT:
 	call arg.ww		;
-	jr nc,error7
+	jr nc,error5
 	add a,b
 	ld b,a
 	jp gen.opc.ED2
 
-error7:
+error5:
 	jp ERROR
 
 as.LD:
@@ -3923,7 +4091,7 @@ as.IM:
 	call arg.imm_8bit
 	ld a,l
 	cp 003h
-	jr nc,error2
+	jr nc,error7
 	and a
 	jr z,l16c7h
 	ld b,056h
@@ -3941,14 +4109,14 @@ as.RST:
 	ld b,a
 	pop af
 	and 0c7h
-	jr nz,error2
+	jr nz,error7
 	jp as.opc.noarg
 
 as.POP_PUSH:
 	call arg.IX_IY
 	jr c,l16e7h
 	call arg.zz
-	jr nc,error2
+	jr nc,error7
 	add a,b
 	jp l13ech
 l16e7h:
@@ -3958,9 +4126,9 @@ l16e7h:
 
 as.IN:
 	call arg.r_HL_A
-	jr nc,error2
+	jr nc,error7
 	cp 006h
-	jr z,error2
+	jr z,error7
 	rlca
 	rlca
 	rlca
@@ -3979,7 +4147,7 @@ l170fh:
 	call sub_171bh
 l1715h:
 	jp c,gen.opc.ED2
-error2:
+error7:
 	jp ERROR
 
 sub_171bh:
@@ -3991,9 +4159,9 @@ as.OUT:
 	jr nc,l1739h
 	call assert_comma
 	call arg.r_HL_A
-	jr nc,error2
+	jr nc,error7
 	cp 006h
-	jr z,error2
+	jr z,error7
 	rlca
 	rlca
 	rlca
@@ -4004,7 +4172,7 @@ l1739h:
 	call arg.addr_8bit
 	call assert_comma
 	cp 'A'
-	jr nz,error2
+	jr nz,error7
 	inc de
 	ld b,0d3h
 	jp as.store_2
@@ -4087,7 +4255,7 @@ arg.bit:
 	call arg.imm_8bit
 	ld a,l
 	cp 008h
-	jr nc,error3
+	jr nc,error8
 	ret
 
 arg.j_displ:
@@ -4104,7 +4272,7 @@ arg.j_displ:
 	ld a,h
 	xor l
 	bit 7,a
-	jr nz,error3
+	jr nz,error8
 	ret
 
 arg.addr_8bit:
@@ -4123,14 +4291,14 @@ sub_1802h:
 	ret z
 	inc a
 	ret z
-	jr error3
+	jr error8
 
 test_expr:
 	push bc
 	call expr
 	pop bc
 	ret nc
-error3:
+error8:
 	jp ERROR
 
 arg.zz:
@@ -4348,23 +4516,23 @@ p_disas_line:
 	and a
 	ret z
 
-l193fh:
-	call outbl
-	ld a,(con_col)
-	cp 16
-	jr c,l193fh
+	ld c,16
+	call p_fill_space
+	call	p_offset
+	ld	a,80h
+	jp	p_sym_space
 
 p_offset:
 	ld de,(var.@)
 	ld a,d
 	or e
 	ret z
-	call p_char_lparen
-	ld a,'@'
-	call outchar
+	call	pstr_inl
+	dc	'(@'
 	and a
 	sbc hl,de
 	call out_hl
+	add	hl,de
 	jp out_rparen
 
 p_disas_instr:
@@ -4557,14 +4725,11 @@ sub_1a72h:
 	inc hl
 	jr sub_1a72h
 l1a7fh:
+	ld de,l1c97h
 	inc hl
 	ld c,(hl)
-	ld hl,t_MNEMONICS
-	ld b,0
-	add hl,bc
-	ld de,l1c97h
-	scf
-	ret
+	jr get_mnemonic
+
 
 test_DDFD:
 	ld a,(hl)
@@ -4590,6 +4755,7 @@ lookup_opc:
 	and a
 	jr nz,lookup_opc
 	ret
+
 l1aa8h:
 	inc hl
 	ld c,(hl)
@@ -4597,8 +4763,9 @@ l1aa8h:
 	ld e,(hl)
 	inc hl
 	ld d,(hl)
+get_mnemonic:
 	ld hl,t_MNEMONICS
-	ld b,000h
+	ld b,0
 	add hl,bc
 	scf
 	ret
@@ -4622,7 +4789,7 @@ b_1ab6_start:
 	db 0ffh
 
 
-;	1 byte opcodes
+; 1 byte opcodes
 ; Format: db mask, match, t_MNEMONICS-index
 ;	  dw argument formating fuction
 b_1ad1_start:
@@ -4680,7 +4847,7 @@ b_1ad1_start:
 	dw l1ce5h
 	db 0
 
-;	2 byte opdodes
+; 2 byte opdodes
 b_1b54_start:
 	db 0c7h,006h,056h	;ld r,nn
 	dw l1cfah
@@ -4712,7 +4879,7 @@ b_1b54_start:
 	dw l1d29h
 	db 0
 
-;	3 byte opcodes
+; 3 byte opcodes
 b_1b9b_start:
 	db 0c7h,0c2h,052h	;jp cc,mn
 	dw p_arg_cc_mn
@@ -5135,13 +5302,13 @@ l1e4dh:
 	ld a,(iy+001h)
 	and a
 	jp m,l1e61h
-	ld a,'+'
-	call outchar
+	call	pstr_inl
+	dc	'+'
 	ld a,(iy+001h)
 	jr l1e6bh
 l1e61h:
-	ld a,'-'
-	call outchar
+	call	pstr_inl
+	dc	'-'
 	ld a,(iy+001h)
 	neg
 l1e6bh:
@@ -5191,14 +5358,11 @@ p_arg:
 	jp pstr
 
 p_mnemonic:
-	call pstr
-l1ebch:
-	call outbl
-	inc c
-	ld a,c
-	cp 5
-	jr c,l1ebch
-	ret
+	ld	a,(con_col)
+	add	a,5
+	ld	c,a
+	call	pstr
+	jp	p_fill_space
 
 t_MNEMONICS:
 	DC	'ADC'
@@ -5522,7 +5686,7 @@ l2115h:
 	ret
 cmd_C:
 	ld hl,cmd_C
-	ld a,001h
+	ld a,1
 	jr l2122h
 cmd_T:
 	xor a
@@ -5806,6 +5970,8 @@ l1ffbh:
 l1ffdh:
 	db	0
 
+symlen_max:		;max length of symbols read so far
+	db	0
 cur_fcb:
 	dw	0
 fcbsym: