X-Git-Url: http://cloudbase.mooo.com/gitweb/ddt180.git/blobdiff_plain/c9705ee41ef7084154b4cf8bffe9fb3b6a054143..e128c8d94b2dcd029077ecaa2854ce7864f62a3c:/ddt180.z80

diff --git a/ddt180.z80 b/ddt180.z80
index 2f43399..d042c76 100644
--- a/ddt180.z80
+++ b/ddt180.z80
@@ -58,7 +58,7 @@ 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
@@ -135,9 +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
 
@@ -181,6 +183,8 @@ l0093h:
 
 	ds	CONBUF_SIZE + 3 - ($ - conbuf)
 
+;-------------------------------------------------------------------------------
+
 CMDTAB:
 	dw	cmd_@		;examine/substitute the displacement register @
 	dw	cmd_A		;Assemble
@@ -212,7 +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
@@ -249,7 +253,9 @@ exe_hl:
 	call CALL_HL
 	jr mainloop
 
-l0146h:
+;-------------------------------------------------------------------------------
+
+p_msg_error:
 	call	pstr_inl
 	dc	'?'
 	;fall thru
@@ -290,7 +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
@@ -337,12 +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:
@@ -352,11 +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,'"'
@@ -398,10 +402,6 @@ outbl:
 	ld a,' '
 	jr outchar
 
-p_char_lparen:
-	ld a,'('
-	jr outchar
-
 outquote:
 	ld a,''''
 outchar:
@@ -460,7 +460,7 @@ p_goto_col:
 	call	outbl
 	jr	p_goto_col
 
-
+;-------------------------------------------------------------------------------
 
 inchar:
 	push ix
@@ -498,6 +498,8 @@ get_line:
 	pop hl
 	ret
 
+;-------------------------------------------------------------------------------
+
 get_char_upper:
 	ld a,(de)
 toupper:
@@ -518,6 +520,8 @@ tolower:
 	or 020h
 	ret
 
+;-------------------------------------------------------------------------------
+
 skipbl0:
 	inc de
 skipbl:
@@ -542,18 +546,22 @@ 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
@@ -578,6 +586,8 @@ sub_hl_a:
 	pop	bc
 	ret
 
+;-------------------------------------------------------------------------------
+
 sym_getname:
 	push	de
 	push	hl
@@ -644,6 +654,8 @@ pl_e:
 	pop	hl
 	ret
 
+;-------------------------------------------------------------------------------
+
 lookupch:
 	ld b,0
 l02f5h:
@@ -662,7 +674,7 @@ l0300h:
 	ret
 
 sub_0303h:
-	ld hl,b_0cc3_start
+	ld hl,t_reg_names
 	ld b,07fh
 	jr l030ch
 
@@ -768,7 +780,7 @@ sub_0377h:
 	jr l0366h
 
 b_037c_start:
-	defb 0e6h
+	defb 0e6h		;and a,..  clear carry
 get_arg_range:
 	scf
 	ex af,af'
@@ -780,7 +792,7 @@ 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
@@ -826,6 +838,8 @@ l03b8h:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
+
 expr:
 	call skipbl
 expr1:
@@ -845,6 +859,8 @@ expr1:
 	pop de
 	ret
 
+;-------------------------------------------------------------------------------
+
 do_op_eq:
 	jr z,l03edh
 	jr l03ech
@@ -1074,6 +1090,8 @@ tblf_opa:
 	dw	doop_xor
 	dw	0
 
+;-------------------------------------------------------------------------------
+
 fact_factor:
 	call do_factor
 	ret nc
@@ -1127,6 +1145,8 @@ do_factor:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
+
 fact_reg.Y:
 	call get.decdigit
 	jr c,error1
@@ -1243,19 +1263,17 @@ fs_nxtsym:
 	inc	b
 	push	hl			;symtbl ptr
 	push	de			;inpsym ptr
-fs_2:
+fs_nxtchar:
 	ld	a,(de)
 	djnz	fs_3
-	cp	a,':'
-	jr	nz,fs_21
-	inc	de
-	pop	hl
-	jr	fs_cont_1
-
-fs_21:
 	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
@@ -1265,12 +1283,13 @@ fs_21:
 	or	a			;clear carry
 	pop	bc
 	ret
+
 fs_3:
 	inc	de
 	dec	hl
 	xor	(hl)
 	and	c
-	jr	z,fs_2
+	jr	z,fs_nxtchar
 fs_cont:				;start over
 	pop	de			;inpsym ptr
 fs_cont_1:
@@ -1280,6 +1299,8 @@ fs_cont_1:
 	call	sub_hl_a
 	jr	fs_nxtsym
 
+;-------------------------------------------------------------------------------
+
 get.number:
 	call get.hexdigit
 	ret c
@@ -1353,7 +1374,7 @@ error11:
 
 sub_060ch:
 	call get_char_upper
-	cp '['
+	cp 'Z'+1
 	jr l0614h
 
 get.hexdigit:
@@ -1386,6 +1407,8 @@ l0625h:
 	sub '0'
 	ret
 
+;-------------------------------------------------------------------------------
+
 p_cpustat0:
 	call assert_eol
 p_cpustat:
@@ -1431,24 +1454,25 @@ 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
@@ -1532,6 +1556,10 @@ 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
@@ -1549,6 +1577,7 @@ l0740h:
 	call bp_enter
 	jp user_go
 
+;-------------------------------------------------------------------------------
 
 bpl_init:
 	ld	b,BP_CNT
@@ -1580,6 +1609,19 @@ bp_clr_temporary:
 	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
@@ -1659,6 +1701,7 @@ bp_pr_cont:
 	call bpl_next
 	ret
 
+;-------------------------------------------------------------------------------
 ; Add break points to list
 ;   A = 1	 Permanent (B command)
 ;   A = 2	 Temporary (G command)
@@ -1754,6 +1797,8 @@ bp_get_condition:
 	ld hl,(expr_p2)
 	ret
 
+;-------------------------------------------------------------------------------
+
 bpddtz:
 	ld (reg.l),hl
 	pop hl
@@ -1940,6 +1985,8 @@ l0a1dh:
 	call	bpl_next
 	ret
 
+;-------------------------------------------------------------------------------
+
 user_go:
 	sub a
 	ld (b_21e2_start),a
@@ -1973,6 +2020,8 @@ l0a41h:
 	ld sp,(reg_sp)
 	jp reg.iff
 
+;-------------------------------------------------------------------------------
+
 bp_clr_condition:
 	ld a,(ix+000h)
 	and 003h
@@ -2025,6 +2074,12 @@ 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
@@ -2073,6 +2128,14 @@ 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
@@ -2086,7 +2149,7 @@ 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
@@ -2145,43 +2208,41 @@ 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:
@@ -2201,7 +2262,7 @@ sub_0caeh:
 	scf
 	ret
 
-b_0cc3_start:
+t_reg_names:
 	DC	'BC'''
 	DC	'DE'''
 	DC	'HL'''
@@ -2302,6 +2363,10 @@ b_0cfa_start:
 	db	000h
 	dw	reg.f
 
+;-------------------------------------------------------------------------------
+; > S [startaddr]
+;      Substitute memory
+
 cmd_S:
 	ld hl,(last_S)
 	call get_lastarg_def
@@ -2338,6 +2403,10 @@ l0d8ah:
 	call sub_0ef8h
 	jr l0d60h
 
+;-------------------------------------------------------------------------------
+; > @
+;      examine (substitute) displacement register @
+
 cmd_@:
 	call assert_eol
 	ld hl,msg_@
@@ -2348,6 +2417,10 @@ cmd_@:
 msg_@:
 	dc	'@'
 
+;-------------------------------------------------------------------------------
+; >>I [port]
+;      Input a byte from port
+
 cmd_I:
 	ld hl,cmd_I
 	ld (cmd_rpt),hl
@@ -2364,6 +2437,10 @@ 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
@@ -2382,6 +2459,10 @@ cmd_O:
 	out (c),a
 	ret
 
+;-------------------------------------------------------------------------------
+; > Vstartaddr endaddr targetaddr
+;      Verify (compare) two memory areas
+
 cmd_V:
 	call sub_034eh
 l0dedh:
@@ -2413,6 +2494,10 @@ l0e10h:
 	jr nz,l0dedh
 	ret
 
+;-------------------------------------------------------------------------------
+; > M[V] startaddr endaddr destaddr
+;      Move memory [and verify]
+
 cmd_M:
 	call get_char_upper
 	cp 'V'
@@ -2443,6 +2528,17 @@ 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'
@@ -2527,6 +2623,10 @@ psym_e:
 	jp	crlf
 
 
+;-------------------------------------------------------------------------------
+; > Q[J] startaddr endaddr bytes
+;      Query memory for a byte string [Justified]
+
 cmd_Q:
 	call get_char_upper
 	sub 'J'
@@ -2566,6 +2666,10 @@ l0eb0h:
 	pop bc
 	ret
 
+;-------------------------------------------------------------------------------
+; > Z startaddr endaddr bytes
+;      Zap (fill) memory with a byte string
+
 cmd_Z:
 	call get_arg_range
 	push bc
@@ -2593,7 +2697,7 @@ sub_0ed7h:
 	push	de
 	push bc
 l0edah:
-	call get_char_upper
+	ld a,(de)
 	cp (hl)
 	jr nz,l0ee2h
 	inc de
@@ -2679,6 +2783,10 @@ 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
@@ -2747,6 +2855,10 @@ l0fach:
 	ld a,'.'
 	ret
 
+;-------------------------------------------------------------------------------
+; > Fcommandline
+;      specifiy filenames and command line
+
 cmd_F:
 	push de
 	ld hl,DMA_BUF+1
@@ -2876,6 +2988,8 @@ sub_1043h:
 	cp ','
 	ret
 
+;-------------------------------------------------------------------------------
+
 setup_fcb:
 	push de
 	ld hl,12
@@ -2892,6 +3006,8 @@ l1052h:
 	pop de
 	ret
 
+;-------------------------------------------------------------------------------
+
 file_open:
 	ld (cur_fcb),de
 	call setup_fcb
@@ -3015,6 +3131,10 @@ 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
@@ -3217,18 +3337,21 @@ 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'
@@ -3245,6 +3368,8 @@ test_whitespace:
 	cp	TAB
 	ret
 
+;-------------------------------------------------------------------------------
+
 p_max_high0:
 	call assert_eol
 p_max_high:
@@ -3262,6 +3387,10 @@ p_max_high:
 	call out_hl
 	jp crlf
 
+;-------------------------------------------------------------------------------
+; > Wstartaddr endaddr
+;      Write a file to disk
+
 cmd_W:
 	call get_arg_range
 	call assert_eol
@@ -3323,6 +3452,10 @@ 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
@@ -3365,7 +3498,7 @@ cmda_lpend:
 	jr cmda_loop
 
 cmda_restart:
-	call l0146h
+	call p_msg_error
 	ld sp,(l1262h)
 	jr cmda_loop
 
@@ -3392,6 +3525,8 @@ asemble_line:
 CALL_HL:
 	jp (hl)
 
+;-------------------------------------------------------------------------------
+
 b_1289_start:
 	dw	as.ADC_SBC		;ADC
 	db	088h			;
@@ -3549,6 +3684,8 @@ b_1289_start:
 	dw	as.TSTIO		;TSTIO
 	db	074h       		;
 
+;-------------------------------------------------------------------------------
+
 as.TST:
 	call arg.r_HL_A		;
 	jr nc,as.tst_0
@@ -4482,6 +4619,10 @@ test_paren_close:
 	inc de
 	ret
 
+;-------------------------------------------------------------------------------
+; >>L [startaddr] [endaddr]
+;      List disassembled code
+
 cmd_L:
 	ld hl,cmd_L
 	ld (cmd_rpt),hl
@@ -4515,6 +4656,8 @@ l190fh:
 	jr	c,l190fh
 	ret
 
+;-------------------------------------------------------------------------------
+
 cmdl_p_line:
 	push	hl
 	call	p_disas_line
@@ -4545,6 +4688,8 @@ p_disas_line:
 	call	outbl
 	jp	p_symbol
 
+;-------------------------------------------------------------------------------
+
 p_offset:
 	ld de,(var.@)
 	ld a,d
@@ -4558,6 +4703,8 @@ p_offset:
 	add	hl,de
 	jp out_rparen
 
+;-------------------------------------------------------------------------------
+
 p_disas_instr:
 	sub a
 	ld (disas_argtype),a
@@ -4617,6 +4764,8 @@ l19b1h:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
+
 disas_pfx.DDFD:
 	inc iy
 	ld hl,b_19ef_start
@@ -4643,6 +4792,7 @@ l19edh:
 	and a
 	ret
 
+;-------------------------------------------------------------------------------
 ; DD/FD 3 byte (ix+d)/(iy+d)
 b_19ef_start:
 	db	034h
@@ -4690,6 +4840,8 @@ l1a0ah:
 	db	0f9h
 	db	0
 
+;-------------------------------------------------------------------------------
+
 disas_pfx.ED:
 	inc iy
 	ld hl,b_1bc9_start
@@ -4710,6 +4862,8 @@ disas_pfx.ED:
 	ld b,4
 	ret
 
+;-------------------------------------------------------------------------------
+
 disas_pfx.CB:
 	push iy
 	inc iy
@@ -4724,6 +4878,8 @@ l1a42h:
 	ld b,2
 	ret
 
+;-------------------------------------------------------------------------------
+
 disas_nopfx:
 	ld hl,b_1b54_start
 	call lookup_opc
@@ -4743,6 +4899,8 @@ disas_nopfx:
 	ld b,3
 	ret
 
+;-------------------------------------------------------------------------------
+
 sub_1a72h:
 	ld a,(hl)
 	cp 0ffh
@@ -4798,6 +4956,7 @@ get_mnemonic:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
 ; 1 byte opcodes (no parameters)
 ; Format: db opcode, t_MNEMONICS-index
 b_1ab6_start:
@@ -5051,6 +5210,8 @@ b_1c55_start:
 	dw p_arg_bitop
 	db 0
 
+;-------------------------------------------------------------------------------
+
 p_arg_r_r:
 	call p_arg_r
 	call p_char_comma
@@ -5113,8 +5274,7 @@ 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
@@ -5154,7 +5314,11 @@ 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
@@ -5191,27 +5355,30 @@ 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:
@@ -5264,6 +5431,16 @@ 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
@@ -5295,17 +5472,6 @@ 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
@@ -5330,20 +5496,18 @@ 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
@@ -5387,6 +5551,8 @@ p_arg:
 	call sel_dc_string
 	jp pstr
 
+;-------------------------------------------------------------------------------
+
 t_MNEMONICS:
 	DC	'ADC'
 	DC	'ADD'
@@ -5538,6 +5704,8 @@ t__C_:
 	DC	'(C)'
 	DB	0
 
+;-------------------------------------------------------------------------------
+
 sub_1ffeh:
 	ld hl,(reg.pc)
 	ld a,h
@@ -5569,6 +5737,8 @@ l2037h:
 	scf
 	ret
 
+;-------------------------------------------------------------------------------
+
 b_2039_start:
 	db 0ffh,0ddh,000h	;Prefix DD
 	dw l20a7h
@@ -5602,6 +5772,8 @@ b_2048_start:
 	dw l20c5h
 	db 0
 
+;-------------------------------------------------------------------------------
+
 l2080h:
 	ld a,(b_21e2_start)
 	and a
@@ -5707,10 +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
@@ -5824,6 +6010,8 @@ l21dah:
 	cp 045h
 	ret
 
+;-------------------------------------------------------------------------------
+
 b_21e2_start:
 	db	0
 trace_call_flag:
@@ -5942,6 +6130,8 @@ current_cseg	defl	$
 	ds	EXPR_BUF_SIZE - ($ - expr_buf)
 expr_bufe:
 
+;-------------------------------------------------------------------------------
+
 msg_Y:
 	dc	'Yn'
 reg_Y: