From bb2a68e066bc818701eeb25ba0b239137844ff26 Mon Sep 17 00:00:00 2001
From: b1ackmai1er <difficultylevelhigh@gmail.com>
Date: Sat, 31 Dec 2022 11:22:34 +0800
Subject: [PATCH] Update romldr.asm

---
 Source/HBIOS/romldr.asm | 103 ++++++++++++++++++----------------------
 1 file changed, 46 insertions(+), 57 deletions(-)

diff --git a/Source/HBIOS/romldr.asm b/Source/HBIOS/romldr.asm
index d27c823b..51441a62 100644
--- a/Source/HBIOS/romldr.asm
+++ b/Source/HBIOS/romldr.asm
@@ -505,11 +505,11 @@ setcon:
 	push	de			; for a matching entry
 	ld	de,tbl_baud
 nextbaud:
-	ex	de,hl			; hl = tbl_baud, de = msb
-	ld	a,d
-	cp	(hl)
-	inc	hl
-	jr	nz,mm1
+	ex	de,hl			; hl = tbl_baud, de = msw
+	ld	a,d			; check all four bytes
+	cp	(hl)			; against HL:BC
+	inc	hl			; exit to next table
+	jr	nz,mm1			; entry on mismatch
 	ld	a,e
 	cp	(hl)
 	inc	hl
@@ -532,10 +532,10 @@ nextbaud:
 mm1:	inc	hl
 mm2:	inc	hl
 mm3:	inc	hl
-mm4:	ex	(sp),hl			; hl= count value, stack= tbl_baud, de=msb
+mm4:	ex	(sp),hl			; hl = count value, stack = tbl_baud, de = msw
 	dec	l
-	ex	(sp),hl			; hl=tbl_baud, stack= count
-	ex	de,hl			; hl = msb, de = tbl_baud
+	ex	(sp),hl			; hl = tbl_baud, stack= count
+	ex	de,hl			; hl = msw, de = tbl_baud
 	jr	nz,nextbaud
 ;
 	; Failed to match
@@ -601,8 +601,8 @@ docon:	ld	hl,str_newcon		; new console msg
 ; Get numeric chars at DE and convert to BCD number returned in HL:BC
 ;=======================================================================
 ;
-getbnum:ld	bc,0		; lsb
-	ld	hl,0		; msb
+getbnum:ld	bc,0		; lsw
+	ld	hl,0		; msw
 getbnum1:
 	ld	a,(de)		; get the active char
 	cp	'0'		; compare to ascii '0'
@@ -615,8 +615,8 @@ getbnum1:
 	push	de		; save char posn
 	push	hl		; save hl bcd
 ;
-	ld	hl,tmpbcd
-	ld	(hl),c
+	ld	hl,tmpbcd	; rotate 1 nyble in A
+	ld	(hl),c		; through HL:BC
 	rld
 	ld	c,(hl)
 	ld	(hl),b
@@ -640,58 +640,47 @@ getbnum2:
 	or	a		; with flags set, CF is cleared
 	ret
 ;
-tmpbcd:	.db	0
+tmpbcd:	.db	0		
 ;
-#DEFINE LW(a,b,c,d,e,f,g) \
+#DEFINE PACK(a,b,c,d,e,f,g) \
 #DEFCONT \ 	.db	(16*('0'-'0'))+(a-'0'))
 #DEFCONT \ 	.db	(16*(b-'0'))+(c-'0'))
 #DEFCONT \ 	.db	(16*(d-'0'))+(e-'0'))
 #DEFCONT \ 	.db	(16*(f-'0'))+(g-'0'))	
 ;
 tbl_baud:
-	LW('0','0','0','0','0','7','5')
-	LW('0','0','0','0','1','5','0')
-	LW('0','0','0','0','2','2','5')
-	LW('0','0','0','0','3','0','0')
-	LW('0','0','0','0','4','5','0')
-	LW('0','0','0','0','6','0','0')
-	LW('0','0','0','0','9','0','0')
-	LW('0','0','0','1','2','0','0')
-	LW('0','0','0','1','8','0','0')
-	LW('0','0','0','2','4','0','0')
-	LW('0','0','0','3','6','0','0')
-	LW('0','0','0','4','8','0','0')
-	LW('0','0','0','7','2','0','0')
-	LW('0','0','0','9','6','0','0')
-	LW('0','0','1','4','4','0','0')
-	LW('0','0','1','9','2','0','0')
-	LW('0','0','2','8','8','0','0')
-	LW('0','0','3','8','4','0','0')
-	LW('0','0','5','7','6','0','0')
-	LW('0','0','7','6','8','0','0')
-	LW('0','1','1','5','2','0','0')
-	LW('0','1','5','3','6','0','0')
-	LW('0','2','3','0','4','0','0')
-	LW('0','3','0','7','2','0','0')
-	LW('0','4','6','0','8','0','0')
-	LW('0','6','1','4','4','0','0')
-	LW('0','9','2','1','6','0','0')
-	LW('1','2','2','8','8','0','0')
-	LW('1','8','4','3','2','0','0')
-	LW('2','4','5','7','6','0','0')
-	LW('3','6','8','6','4','0','0')
-	LW('7','3','7','2','8','0','0')
-;
-;------|----------|------|----------|------|----------|------|----------|
-;   0  |      75  |   8  |    1800  |  16  |   28800  |  24  |  460800  |
-;   1  |     150  |   9  |    2400  |  17  |   38400  |  25  |  614400  |
-;   2  |     225  |  10  |    3600  |  18  |   57600  |  26  |  921600  |
-;   3  |     300  |  11  |    4800  |  19  |   76800  |  27  | 1228800  |
-;   4  |     450  |  12  |    7200  |  20  |  115200  |  28  | 1843200  |
-;   5  |     600  |  13  |    9600  |  21  |  153600  |  29  | 2457600  |
-;   6  |     900  |  14  |   14400  |  22  |  230400  |  30  | 3686400  |
-;   7  |    1200  |  15  |   19200  |  23  |  307200  |  31  | 7372800  |
-;------------------------------------------------------------------------
+	PACK('0','0','0','0','0','7','5') ;      75  0 >  0
+	PACK('0','0','0','0','1','5','0') ;     150  1 >  1
+	PACK('0','0','0','0','2','2','5') ;     225  2 > 16
+	PACK('0','0','0','0','3','0','0') ;     300  3 >  2
+	PACK('0','0','0','0','4','5','0') ;     450  4 > 17
+	PACK('0','0','0','0','6','0','0') ;     600  5 >  3
+	PACK('0','0','0','0','9','0','0') ;     900  6 > 18
+	PACK('0','0','0','1','2','0','0') ;    1200  7 >  4
+	PACK('0','0','0','1','8','0','0') ;    1800  8 > 19
+	PACK('0','0','0','2','4','0','0') ;    2400  9 >  5
+	PACK('0','0','0','3','6','0','0') ;    3600 10 > 20
+	PACK('0','0','0','4','8','0','0') ;    4800 11 >  6
+	PACK('0','0','0','7','2','0','0') ;    7200 12 > 21
+	PACK('0','0','0','9','6','0','0') ;    9600 13 >  7
+	PACK('0','0','1','4','4','0','0') ;   14400 14 > 22
+	PACK('0','0','1','9','2','0','0') ;   19200 15 >  8
+	PACK('0','0','2','8','8','0','0') ;   28800 16 > 23
+	PACK('0','0','3','8','4','0','0') ;   38400 17 >  9
+	PACK('0','0','5','7','6','0','0') ;   57600 18 > 24
+	PACK('0','0','7','6','8','0','0') ;   76800 19 > 10
+	PACK('0','1','1','5','2','0','0') ;  115200 20 > 25
+	PACK('0','1','5','3','6','0','0') ;  153600 21 > 11
+	PACK('0','2','3','0','4','0','0') ;  230400 22 > 26
+	PACK('0','3','0','7','2','0','0') ;  307200 23 > 12
+	PACK('0','4','6','0','8','0','0') ;  460800 24 > 27
+	PACK('0','6','1','4','4','0','0') ;  614400 25 > 13
+	PACK('0','9','2','1','6','0','0') ;  921600 26 > 28
+	PACK('1','2','2','8','8','0','0') ; 1228800 27 > 14
+	PACK('1','8','4','3','2','0','0') ; 1843200 28 > 29
+	PACK('2','4','5','7','6','0','0') ; 2457600 29 > 15
+	PACK('3','6','8','6','4','0','0') ; 3686400 30 > 30
+	PACK('7','3','7','2','8','0','0') ; 7372800 31 > 31
 ;
 #endif
 ;