X-Git-Url: http://cloudbase.mooo.com/gitweb/ddt180.git/blobdiff_plain/0c461f1d8b5869c9d263dae1929c3c74c7caa6fd..d1d6fee5bb2d081bc54378ed610ab021fd768128:/ddt180.z80?ds=sidebyside

diff --git a/ddt180.z80 b/ddt180.z80
index f9a4014..3d4e6e7 100644
--- a/ddt180.z80
+++ b/ddt180.z80
@@ -14,6 +14,7 @@ TPA	equ	0100h
 	.phase	TPA
 
 	jp	start
+	ds	3
 
 ldr_end:
 ldr_size	equ	$ - TPA
@@ -57,13 +58,17 @@ BDOS_SETDMA	equ	26      ;Set DMA Address
 
 ; ddtz specific definitions
 
-STACK_SIZE	equ	64	;ddtz internal stack
+STACK_SIZE	equ	80	;ddtz internal stack
 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
+
 ;-------------------------------------------------------------------------------
 
 ddtz_base:
@@ -75,6 +80,14 @@ sub_0004h:
 	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
@@ -122,9 +135,11 @@ reg.pc:	dw	TPA
 var.$:	dw	0000h
 var.@:	dw	0
 
-error_func:dw	l0146h
+error_func:dw	p_msg_error
 cmd_rpt:dw	mainloop
 
+;-------------------------------------------------------------------------------
+
 conbuf:
 	db	CONBUF_SIZE
 
@@ -168,6 +183,8 @@ l0093h:
 
 	ds	CONBUF_SIZE + 3 - ($ - conbuf)
 
+;-------------------------------------------------------------------------------
+
 CMDTAB:
 	dw	cmd_@		;examine/substitute the displacement register @
 	dw	cmd_A		;Assemble
@@ -199,7 +216,7 @@ CMDTAB:
 
 mainloop:
 	ld sp,stack
-	ld hl,l0146h
+	ld hl,p_msg_error
 	ld (error_func),hl
 	ld hl,(reg.pc)
 	ld (var.$),hl
@@ -236,7 +253,9 @@ exe_hl:
 	call CALL_HL
 	jr mainloop
 
-l0146h:
+;-------------------------------------------------------------------------------
+
+p_msg_error:
 	call	pstr_inl
 	dc	'?'
 	;fall thru
@@ -277,7 +296,7 @@ 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
@@ -324,12 +343,10 @@ 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:
@@ -339,11 +356,11 @@ 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,'"'
@@ -434,7 +451,7 @@ p_align_@_sym:
 	ld	a,d
 	or	e
 	pop	de
-	ld	a,(symlen_max)
+	ld	a,(symlen_cur)
 	jr	z,$+4
 	add	a,6
 	add	a,c
@@ -447,9 +464,10 @@ p_goto_col:
 	call	outbl
 	jr	p_goto_col
 
-
+;-------------------------------------------------------------------------------
 
 inchar:
+	push ix
 	push hl
 	push de
 	push bc
@@ -464,6 +482,7 @@ l0284h:
 	pop bc
 	pop de
 	pop hl
+	pop ix
 	ret
 
 get_line:
@@ -483,16 +502,30 @@ get_line:
 	pop hl
 	ret
 
+;-------------------------------------------------------------------------------
+
 get_char_upper:
 	ld a,(de)
 toupper:
 	cp 'a'
 	ret c
 	cp 'z'+1
-	ret nc
+	ccf
+	ret c
 	and 05fh
 	ret
 
+tolower:
+	cp 'A'
+	ret c
+	cp 'Z'+1
+	ccf
+	ret c
+	or 020h
+	ret
+
+;-------------------------------------------------------------------------------
+
 skipbl0:
 	inc de
 skipbl:
@@ -517,18 +550,22 @@ assert_eol:
 to_error:
 	jp ERROR
 
+;-------------------------------------------------------------------------------
+
 chk_stack:
 	push hl
 	push de
 	ld hl,0
 	add hl,sp
-	ld de,stack-40
+	ld de,stack-(STACK_SIZE-28)
 	call cp_hl_de
 	pop de
 	pop hl
 	jr c,to_error
 	ret
 
+;-------------------------------------------------------------------------------
+
 add_hl_a:
 	add a,l
 	ld l,a
@@ -553,6 +590,8 @@ sub_hl_a:
 	pop	bc
 	ret
 
+;-------------------------------------------------------------------------------
+
 sym_getname:
 	push	de
 	push	hl
@@ -619,6 +658,8 @@ pl_e:
 	pop	hl
 	ret
 
+;-------------------------------------------------------------------------------
+
 lookupch:
 	ld b,0
 l02f5h:
@@ -637,7 +678,7 @@ l0300h:
 	ret
 
 sub_0303h:
-	ld hl,b_0cc3_start
+	ld hl,t_reg_names
 	ld b,07fh
 	jr l030ch
 
@@ -743,7 +784,7 @@ sub_0377h:
 	jr l0366h
 
 b_037c_start:
-	defb 0e6h
+	defb 0e6h		;and a,..  clear carry
 get_arg_range:
 	scf
 	ex af,af'
@@ -755,7 +796,7 @@ 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
@@ -801,6 +842,8 @@ l03b8h:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
+
 expr:
 	call skipbl
 expr1:
@@ -820,6 +863,8 @@ expr1:
 	pop de
 	ret
 
+;-------------------------------------------------------------------------------
+
 do_op_eq:
 	jr z,l03edh
 	jr l03ech
@@ -1049,6 +1094,8 @@ tblf_opa:
 	dw	doop_xor
 	dw	0
 
+;-------------------------------------------------------------------------------
+
 fact_factor:
 	call do_factor
 	ret nc
@@ -1077,6 +1124,9 @@ do_factor:
 	ld hl,(var.$)
 	cp '$'
 	ret z
+	ld hl,ddtz_base
+	cp 'Z'
+	ret z
 	cp '-'
 	jr z,fact_factneg
 	cp '~'
@@ -1099,6 +1149,8 @@ do_factor:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
+
 fact_reg.Y:
 	call get.decdigit
 	jr c,error1
@@ -1201,6 +1253,11 @@ error1:
 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
@@ -1210,12 +1267,17 @@ fs_nxtsym:
 	inc	b
 	push	hl			;symtbl ptr
 	push	de			;inpsym ptr
-fs_2:
+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
@@ -1225,19 +1287,24 @@ fs_2:
 	or	a			;clear carry
 	pop	bc
 	ret
+
 fs_3:
 	inc	de
 	dec	hl
-	cp	(hl)
-	jr	z,fs_2
+	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:
 	call get.hexdigit
 	ret c
@@ -1281,7 +1348,7 @@ l05dbh:
 	jr next_bindigit
 l05e4h:
 	cp '"'
-	jp nz,ERROR
+	jr nz,error11
 	call get.bindigit
 	jr nc,l05dbh
 	or a
@@ -1306,11 +1373,12 @@ next_decdigit:
 decnum_done:
 	cp '.'
 	ret z
+error11:
 	jp ERROR
 
 sub_060ch:
 	call get_char_upper
-	cp '['
+	cp 'Z'+1
 	jr l0614h
 
 get.hexdigit:
@@ -1343,6 +1411,8 @@ l0625h:
 	sub '0'
 	ret
 
+;-------------------------------------------------------------------------------
+
 p_cpustat0:
 	call assert_eol
 p_cpustat:
@@ -1489,6 +1559,10 @@ b_0709_start:
 	db	000h
 	db	000h
 
+;-------------------------------------------------------------------------------
+; > G [startaddr] [;breakp..]
+;      Go [to start] [with temporary breakpoints]
+
 cmd_G:
 	sub a
 	ld (trace_call_flag),a
@@ -1506,19 +1580,51 @@ l0740h:
 	call bp_enter
 	jp user_go
 
+;-------------------------------------------------------------------------------
+
+bpl_init:
+	ld	b,BP_CNT
+	ld	ix,bp_tab
+	ex	(sp),hl
+	ld	(pbl_loop_adr),hl
+	ex	(sp),hl
+	ret
+
+bpl_next:
+	ld	de,BP_SIZE
+	add	ix,de
+	dec	b
+	ret	z
+
+	ex	(sp),hl
+	ld	hl,(pbl_loop_adr)
+	ex	(sp),hl
+	ret
+
 bp_clr_temporary:
-	ld b,BP_CNT
-	ld ix,bp_tab
-l075ah:
+	call	bpl_init
+
 	ld a,(ix+000h)
 	and 0f1h
 	ld (ix+000h),a
 	call bp_clr_condition
-	ld de,BP_SIZE
-	add ix,de
-	djnz l075ah
+
+	call bpl_next
 	ret
 
+;-------------------------------------------------------------------------------
+; > B
+;      display all breakpoints
+; > B breakp [breakp..]
+;      set breakpoints
+; > BX
+;      clear all breakpoints
+; > BX address [address..]
+;      clear breakpoints
+;
+; where breakp is:
+;      [R] expression [I condition]
+
 cmd_B:
 	call skipbl
 	jr z,bp_print
@@ -1543,9 +1649,8 @@ bp_clr_next:
 bp_clr_all:
 	scf
 bp_clr:
-	ld b,BP_CNT
-	ld ix,bp_tab
-l0799h:
+	call	bpl_init
+
 	push af
 	jr c,l07a7h
 	ld e,(ix+002h)
@@ -1556,16 +1661,13 @@ l07a7h:
 	ld (ix+000h),000h
 	call bp_clr_condition
 l07aeh:
-	ld de,BP_SIZE
-	add ix,de
 	pop af
-	djnz l0799h
+	call bpl_next
 	ret
 
 bp_print:
-	ld b,BP_CNT
-	ld ix,bp_tab
-bp_pr_l:
+	call	bpl_init
+
 	bit 0,(ix+000h)
 	jr z,bp_pr_cont
 	ld a,'R'
@@ -1599,11 +1701,10 @@ l07cdh:
 l0805h:
 	call crlf
 bp_pr_cont:
-	ld de,BP_SIZE
-	add ix,de
-	djnz bp_pr_l
+	call bpl_next
 	ret
 
+;-------------------------------------------------------------------------------
 ; Add break points to list
 ;   A = 1	 Permanent (B command)
 ;   A = 2	 Temporary (G command)
@@ -1619,7 +1720,7 @@ bp_enter:
 bp_e_1:
 	push bc
 	call expr
-	jp c,ERROR
+	jr c,error12
 	pop bc
 	bit 0,b
 	push bc
@@ -1644,17 +1745,14 @@ bp_e_1:
 	jr bp_enter
 
 bp_get_freeslot:
-	ld b,BP_CNT
-	ld ix,bp_tab
-bp_gf_l:
+	call	bpl_init
+
 	ld a,(ix+000h)
 	and 00fh
 	ret z
-	push bc
-	ld bc,BP_SIZE
-	add ix,bc
-	pop bc
-	djnz bp_gf_l
+
+	call	bpl_next
+error12
 	jp ERROR
 
 bp_get_count:
@@ -1664,7 +1762,7 @@ bp_get_count:
 	ret nz
 	inc de
 	call expr
-	jp c,ERROR
+	jr c,error12
 	ret
 
 bp_get_condition:
@@ -1676,7 +1774,7 @@ bp_get_condition:
 	call skipbl
 	push de
 	call expr
-	jp c,ERROR
+	jr c,error12
 	ex de,hl
 	pop de
 	push de
@@ -1688,7 +1786,7 @@ bp_get_condition:
 	add hl,bc
 	ld de,expr_bufe
 	call cp_hl_de
-	jp nc,ERROR
+	jr nc,error12
 	pop hl
 	ld (expr_p2),hl
 	pop de
@@ -1702,6 +1800,8 @@ bp_get_condition:
 	ld hl,(expr_p2)
 	ret
 
+;-------------------------------------------------------------------------------
+
 bpddtz:
 	ld (reg.l),hl
 	pop hl
@@ -1756,9 +1856,8 @@ sub_0913h:
 	ex af,af'
 	sub a
 	ld (l0941h),a
-	ld b,BP_CNT
-	ld ix,bp_tab
-l0920h:
+	call	bpl_init
+
 	ld a,(ix+000h)
 	and 007h
 	jr z,l0938h
@@ -1770,9 +1869,8 @@ l0920h:
 	call z,sub_0942h
 	pop bc
 l0938h:
-	ld de,BP_SIZE
-	add ix,de
-	djnz l0920h
+
+	call	bpl_next
 	ex af,af'
 	ret
 
@@ -1810,9 +1908,8 @@ l0974h:
 	ret
 
 sub_097ah:
-	ld b,BP_CNT
-	ld ix,bp_tab
-l0980h:
+	call	bpl_init
+
 	bit 5,(ix+000h)
 	res 5,(ix+000h)
 	jr z,l099ah
@@ -1825,15 +1922,13 @@ l0980h:
 	ld (hl),a
 l099ah:
 	res 3,(ix+000h)
-	ld de,BP_SIZE
-	add ix,de
-	djnz l0980h
+
+	call	bpl_next
 	ret
 
 sub_09a6h:
-	ld b,BP_CNT
-	ld ix,bp_tab
-l09ach:
+	call	bpl_init
+
 	ld a,(ix+000h)
 	and 003h
 	jr z,l09c0h
@@ -1843,9 +1938,8 @@ l09ach:
 	call cp_hl_de
 	ret z
 l09c0h:
-	ld de,BP_SIZE
-	add ix,de
-	djnz l09ach
+
+	call	bpl_next
 	sub a
 	inc a
 	ret
@@ -1862,15 +1956,14 @@ sub_09cah:
 	and a
 	ld a,008h
 	jr nz,l09edh
-	ld a,004h
+	rra
 l09edh:
 	ld (ix+000h),a
 	ret
 
-sub_09f1h:
-	ld b,BP_CNT
-	ld ix,bp_tab
-l09f7h:
+bp_set_to_mem:
+	call	bpl_init
+
 	ld a,(ix+000h)
 	and c
 	jr z,l0a1dh
@@ -1891,11 +1984,12 @@ l09f7h:
 	inc hl
 	ld (hl),d
 l0a1dh:
-	ld de,BP_SIZE
-	add ix,de
-	djnz l09f7h
+
+	call	bpl_next
 	ret
 
+;-------------------------------------------------------------------------------
+
 user_go:
 	sub a
 	ld (b_21e2_start),a
@@ -1910,7 +2004,7 @@ user_go:
 	call sub_1ffeh
 	ld c,008h
 l0a41h:
-	call sub_09f1h
+	call bp_set_to_mem
 	ld sp,reg.l2
 	pop hl
 	pop de
@@ -1929,6 +2023,8 @@ l0a41h:
 	ld sp,(reg_sp)
 	jp reg.iff
 
+;-------------------------------------------------------------------------------
+
 bp_clr_condition:
 	ld a,(ix+000h)
 	and 003h
@@ -1981,6 +2077,12 @@ l0ab0h:
 	ld (iy+007h),d
 	ret
 
+;-------------------------------------------------------------------------------
+; > Y
+;      examine all Y variables
+; > Y[0..9]
+;      examine (and substitute) an Y variable
+
 cmd_Y:
 	call get.decdigit
 	jr c,l0bc3h
@@ -2029,6 +2131,14 @@ sub_0bdch:
 	ld c,003h
 	jp l0c33h
 
+;-------------------------------------------------------------------------------
+; > X
+;      eXamine (display) all cpu registers and
+;      the instruction at the current program counter
+; > X register
+;      eXamine (and substitute) a register
+
+
 cmd_X:
 	call skipbl
 	call sub_0caeh
@@ -2042,7 +2152,7 @@ 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
@@ -2101,43 +2211,41 @@ l0c5fh:
 
 sub_0c6ah:
 	push af
-	ld b,000h
 	call outbl
 	call assert_eol
 	call get_line
 	pop af
 	ex af,af'
+	ld b,0
 l0c76h:
 	call skipbl
 	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:
@@ -2157,7 +2265,7 @@ sub_0caeh:
 	scf
 	ret
 
-b_0cc3_start:
+t_reg_names:
 	DC	'BC'''
 	DC	'DE'''
 	DC	'HL'''
@@ -2258,6 +2366,10 @@ b_0cfa_start:
 	db	000h
 	dw	reg.f
 
+;-------------------------------------------------------------------------------
+; > S [startaddr]
+;      Substitute memory
+
 cmd_S:
 	ld hl,(last_S)
 	call get_lastarg_def
@@ -2294,6 +2406,10 @@ l0d8ah:
 	call sub_0ef8h
 	jr l0d60h
 
+;-------------------------------------------------------------------------------
+; > @
+;      examine (substitute) displacement register @
+
 cmd_@:
 	call assert_eol
 	ld hl,msg_@
@@ -2304,6 +2420,10 @@ cmd_@:
 msg_@:
 	dc	'@'
 
+;-------------------------------------------------------------------------------
+; >>I [port]
+;      Input a byte from port
+
 cmd_I:
 	ld hl,cmd_I
 	ld (cmd_rpt),hl
@@ -2320,6 +2440,10 @@ cmd_I:
 	call out.bin.b
 	jp crlf
 
+;-------------------------------------------------------------------------------
+; >>O [byte] [port]
+;      Output a byte to a port
+
 cmd_O:
 	ld hl,cmd_O
 	ld (cmd_rpt),hl
@@ -2338,6 +2462,10 @@ cmd_O:
 	out (c),a
 	ret
 
+;-------------------------------------------------------------------------------
+; > Vstartaddr endaddr targetaddr
+;      Verify (compare) two memory areas
+
 cmd_V:
 	call sub_034eh
 l0dedh:
@@ -2369,6 +2497,10 @@ l0e10h:
 	jr nz,l0dedh
 	ret
 
+;-------------------------------------------------------------------------------
+; > M[V] startaddr endaddr destaddr
+;      Move memory [and verify]
+
 cmd_M:
 	call get_char_upper
 	cp 'V'
@@ -2399,6 +2531,17 @@ cmdm_up:
 	jr z,l0dedh
 	ret
 
+;-------------------------------------------------------------------------------
+; > 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'
@@ -2443,7 +2586,7 @@ l0e5eh:
 p_sym_list:
 	inc	de
 	call	assert_eol
-	ld	a,(symlen_max)
+	ld	a,(symlen_cur)
 	add	a,7
 	ld	b,a
 	ld	c,0
@@ -2467,7 +2610,7 @@ psym_nxtsym:
 	ld	a,c
 	add	b
 	ld	c,a
-	ld	a,80			;screen width
+	ld	a,(screen_width)
 	sub	b
 	cp	c
 	jr	nc,psym_nxtsym
@@ -2483,6 +2626,10 @@ psym_e:
 	jp	crlf
 
 
+;-------------------------------------------------------------------------------
+; > Q[J] startaddr endaddr bytes
+;      Query memory for a byte string [Justified]
+
 cmd_Q:
 	call get_char_upper
 	sub 'J'
@@ -2522,6 +2669,10 @@ l0eb0h:
 	pop bc
 	ret
 
+;-------------------------------------------------------------------------------
+; > Z startaddr endaddr bytes
+;      Zap (fill) memory with a byte string
+
 cmd_Z:
 	call get_arg_range
 	push bc
@@ -2549,7 +2700,7 @@ sub_0ed7h:
 	push	de
 	push bc
 l0edah:
-	call get_char_upper
+	ld a,(de)
 	cp (hl)
 	jr nz,l0ee2h
 	inc de
@@ -2635,6 +2786,10 @@ l0f42h:
 	ld (last_S),hl
 	ret
 
+;-------------------------------------------------------------------------------
+; >>D [startaddr] [endaddr]
+;      Display memory in hex and ASCII
+
 cmd_D:
 	ld hl,cmd_D
 	ld (cmd_rpt),hl
@@ -2703,6 +2858,10 @@ l0fach:
 	ld a,'.'
 	ret
 
+;-------------------------------------------------------------------------------
+; > Fcommandline
+;      specifiy filenames and command line
+
 cmd_F:
 	push de
 	ld hl,DMA_BUF+1
@@ -2800,6 +2959,7 @@ sub_1012h:
 	cp '.'
 	ret z
 	ld c,'?'
+	call toupper
 	cp '*'
 	ret
 
@@ -2831,6 +2991,8 @@ sub_1043h:
 	cp ','
 	ret
 
+;-------------------------------------------------------------------------------
+
 setup_fcb:
 	push de
 	ld hl,12
@@ -2847,6 +3009,8 @@ l1052h:
 	pop de
 	ret
 
+;-------------------------------------------------------------------------------
+
 file_open:
 	ld (cur_fcb),de
 	call setup_fcb
@@ -2970,6 +3134,10 @@ read_hexbyte0:
 	pop	bc
 	ret
 
+;-------------------------------------------------------------------------------
+; > R [displacement]
+;      Read a binary or hex file and or symbol file [add displacement]
+
 cmd_R:
 	ld hl,0
 	call get_lastarg_def
@@ -3056,8 +3224,10 @@ read_symfile:
 	call pstr_inl
 	db	'SYMBOLS',CR,LF+80h
 
-	dec de
-	call file_open
+	dec	de
+	call	file_open
+	ld	a,(symattrib)
+	ld	c,a
 rs_1:
 	call	read_byte
 rs_2:
@@ -3089,11 +3259,17 @@ rs_5:
 	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,b		;
-	cp	10h+1		;
-	jr	c,rs_5		;
+	ld	a,(symlen_max)	;
+	cp	b		;
+	jr	nc,rs_5		;
 error3:
 	jp	ERROR		;
 
@@ -3126,14 +3302,15 @@ rs_61:
 	ld	de,(BDOS+1)	;
 	ld	(BDOS+1),hl	;
 	ex	de,hl		;
-	pop	af		; symlen
-	ld	(hl),a		;
+	pop	bc		; symlen
+	ld	(hl),b		;
 	inc	hl		;
 	pop	de		; symval
 	ld	(hl),e		;
 	inc	hl		;
 	ld	(hl),d		;
-	ld	hl,symlen_max	;
+	ld	a,b		;
+	ld	hl,symlen_cur	;
 	cp	(hl)		; new max?
 	jr	c,$+3		;
 	ld	(hl),a		;
@@ -3163,18 +3340,21 @@ test_sym_char:
 ; return nc if valid alfanumeric char
 
 test_alphanum:
-	cp	'z'+1
+	cp	'z'
+	ret	z
 	ccf
 	ret	c
 	cp	'a'
 	ret	nc
-	cp	'Z'+1
+	cp	'Z'
+	ret	z
 	ccf
 	ret	c
 	cp	'?'
 	ret	nc
 test_numeral:
-	cp	'9'+1
+	cp	'9'
+	ret	z
 	ccf
 	ret	c
 	cp	'0'
@@ -3191,6 +3371,8 @@ test_whitespace:
 	cp	TAB
 	ret
 
+;-------------------------------------------------------------------------------
+
 p_max_high0:
 	call assert_eol
 p_max_high:
@@ -3208,6 +3390,10 @@ p_max_high:
 	call out_hl
 	jp crlf
 
+;-------------------------------------------------------------------------------
+; > Wstartaddr endaddr
+;      Write a file to disk
+
 cmd_W:
 	call get_arg_range
 	call assert_eol
@@ -3269,6 +3455,10 @@ close_file:
 	ld c,BDOS_CLOSE
 	jp ddtz_bdos
 
+;-------------------------------------------------------------------------------
+; > A [startaddr]
+;      Assemble Zilog Z180 mnemonics
+
 cmd_A:
 	ld hl,(last_A)
 	call get_lastarg_def
@@ -3311,7 +3501,7 @@ cmda_lpend:
 	jr cmda_loop
 
 cmda_restart:
-	call l0146h
+	call p_msg_error
 	ld sp,(l1262h)
 	jr cmda_loop
 
@@ -3338,6 +3528,8 @@ asemble_line:
 CALL_HL:
 	jp (hl)
 
+;-------------------------------------------------------------------------------
+
 b_1289_start:
 	dw	as.ADC_SBC		;ADC
 	db	088h			;
@@ -3495,6 +3687,8 @@ b_1289_start:
 	dw	as.TSTIO		;TSTIO
 	db	074h       		;
 
+;-------------------------------------------------------------------------------
+
 as.TST:
 	call arg.r_HL_A		;
 	jr nc,as.tst_0
@@ -4428,6 +4622,10 @@ test_paren_close:
 	inc de
 	ret
 
+;-------------------------------------------------------------------------------
+; >>L [startaddr] [endaddr]
+;      List disassembled code
+
 cmd_L:
 	ld hl,cmd_L
 	ld (cmd_rpt),hl
@@ -4461,6 +4659,8 @@ l190fh:
 	jr	c,l190fh
 	ret
 
+;-------------------------------------------------------------------------------
+
 cmdl_p_line:
 	push	hl
 	call	p_disas_line
@@ -4491,6 +4691,8 @@ p_disas_line:
 	call	outbl
 	jp	p_symbol
 
+;-------------------------------------------------------------------------------
+
 p_offset:
 	ld de,(var.@)
 	ld a,d
@@ -4504,6 +4706,8 @@ p_offset:
 	add	hl,de
 	jp out_rparen
 
+;-------------------------------------------------------------------------------
+
 p_disas_instr:
 	sub a
 	ld (disas_argtype),a
@@ -4563,6 +4767,8 @@ l19b1h:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
+
 disas_pfx.DDFD:
 	inc iy
 	ld hl,b_19ef_start
@@ -4589,6 +4795,7 @@ l19edh:
 	and a
 	ret
 
+;-------------------------------------------------------------------------------
 ; DD/FD 3 byte (ix+d)/(iy+d)
 b_19ef_start:
 	db	034h
@@ -4636,6 +4843,8 @@ l1a0ah:
 	db	0f9h
 	db	0
 
+;-------------------------------------------------------------------------------
+
 disas_pfx.ED:
 	inc iy
 	ld hl,b_1bc9_start
@@ -4656,6 +4865,8 @@ disas_pfx.ED:
 	ld b,4
 	ret
 
+;-------------------------------------------------------------------------------
+
 disas_pfx.CB:
 	push iy
 	inc iy
@@ -4670,6 +4881,8 @@ l1a42h:
 	ld b,2
 	ret
 
+;-------------------------------------------------------------------------------
+
 disas_nopfx:
 	ld hl,b_1b54_start
 	call lookup_opc
@@ -4689,6 +4902,8 @@ disas_nopfx:
 	ld b,3
 	ret
 
+;-------------------------------------------------------------------------------
+
 sub_1a72h:
 	ld a,(hl)
 	cp 0ffh
@@ -4744,6 +4959,7 @@ get_mnemonic:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
 ; 1 byte opcodes (no parameters)
 ; Format: db opcode, t_MNEMONICS-index
 b_1ab6_start:
@@ -4997,6 +5213,8 @@ b_1c55_start:
 	dw p_arg_bitop
 	db 0
 
+;-------------------------------------------------------------------------------
+
 p_arg_r_r:
 	call p_arg_r
 	call p_char_comma
@@ -5333,6 +5551,8 @@ p_arg:
 	call sel_dc_string
 	jp pstr
 
+;-------------------------------------------------------------------------------
+
 t_MNEMONICS:
 	DC	'ADC'
 	DC	'ADD'
@@ -5484,6 +5704,8 @@ t__C_:
 	DC	'(C)'
 	DB	0
 
+;-------------------------------------------------------------------------------
+
 sub_1ffeh:
 	ld hl,(reg.pc)
 	ld a,h
@@ -5515,6 +5737,8 @@ l2037h:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
+
 b_2039_start:
 	db 0ffh,0ddh,000h	;Prefix DD
 	dw l20a7h
@@ -5548,6 +5772,8 @@ b_2048_start:
 	dw l20c5h
 	db 0
 
+;-------------------------------------------------------------------------------
+
 l2080h:
 	ld a,(b_21e2_start)
 	and a
@@ -5653,10 +5879,24 @@ l2113h:
 l2115h:
 	and a
 	ret
+
+;-------------------------------------------------------------------------------
+; >>C[N][J] [steps]
+; >>C[N][J] W expression
+; >>C[N][J] U expression
+;     trace over Calls [No list] [Jumps only] /.While./.Until.
+
 cmd_C:
 	ld hl,cmd_C
 	ld a,1
 	jr l2122h
+
+;-------------------------------------------------------------------------------
+; >>T[N][J] [steps]
+; >>T[N][J] W expression
+; >>T[N][J] U expression
+;      Trace [no List] [Jumps only] / .While. / .Until.
+
 cmd_T:
 	xor a
 	ld hl,cmd_T
@@ -5770,6 +6010,8 @@ l21dah:
 	cp 045h
 	ret
 
+;-------------------------------------------------------------------------------
+
 b_21e2_start:
 	db	0
 trace_call_flag:
@@ -5888,6 +6130,8 @@ current_cseg	defl	$
 	ds	EXPR_BUF_SIZE - ($ - expr_buf)
 expr_bufe:
 
+;-------------------------------------------------------------------------------
+
 msg_Y:
 	dc	'Yn'
 reg_Y:
@@ -5939,7 +6183,10 @@ disas_arg_16:
 disas_argtype:
 	db	0
 
-symlen_max:		;max length of symbols read so far
+pbl_loop_adr:
+	dw	0
+
+symlen_cur:		;max length of symbols read so far
 	db	0
 cur_fcb:
 	dw	0