From e7cc7906c516f6bda41913b6b43cc2b7d83e362e Mon Sep 17 00:00:00 2001
From: b1ackmai1er <39449559+b1ackmai1er@users.noreply.github.com>
Date: Fri, 3 Aug 2018 22:40:07 +0800
Subject: [PATCH] Fixes to port address and cleanups

---
 Source/HBIOS/sio.asm | 492 +++++--------------------------------------
 1 file changed, 53 insertions(+), 439 deletions(-)

diff --git a/Source/HBIOS/sio.asm b/Source/HBIOS/sio.asm
index ade6e588..c30ab09f 100644
--- a/Source/HBIOS/sio.asm
+++ b/Source/HBIOS/sio.asm
@@ -10,415 +10,39 @@
 ;    F   E   D   C   B   A   9   8     7   6   5   4   3   2   1   0
 ;       -- MSB (D REGISTER) --           -- LSB (E REGISTER) --
 ;
-;               
+; FOR THE ECB-ZILOG-PERIPHERALS BOARD, INFORMATION ON JUMPER SETTINGS 
+; AND BAUD RATES CAN BE FOUND HERE:
+; https://www.retrobrewcomputers.org/doku.php?id=boards:ecb:zilog-peripherals:clock-divider
+; 
+; SIO PORT A (COM1:) and SIO PORT B (COM2:) ARE MAPPED TO DEVICE UC1: AND UL1: IN CP/M.
+;             
 SIO_NONE	.EQU	0
 SIO_SIO		.EQU	1
 ;               
 #IF (SIOMODE == SIOMODE_RC)
-SIOA_CMD	.EQU	SIOBASE + $00	; PS	
-SIOA_DAT	.EQU	SIOBASE + $01	; PS 
-SIOB_CMD	.EQU	SIOBASE + $02	; PS 
-SIOB_DAT	.EQU	SIOBASE + $03	; PS
+SIOA_CMD	.EQU	SIOBASE + $00	
+SIOA_DAT	.EQU	SIOBASE + $01
+SIOB_CMD	.EQU	SIOBASE + $02
+SIOB_DAT	.EQU	SIOBASE + $03
 #ENDIF	
 ;	
 #IF (SIOMODE == SIOMODE_SMB)	
-SIOA_CMD	.EQU	SIOBASE + $02	; PS
-SIOA_DAT	.EQU	SIOBASE + $00	; PS
-SIOB_CMD	.EQU	SIOBASE + $03	; PS
-SIOB_WR4	.EQU	SIOBASE + $01	; PS
+SIOA_CMD	.EQU	SIOBASE + $02
+SIOA_DAT	.EQU	SIOBASE + $00
+SIOB_CMD	.EQU	SIOBASE + $03
+SIOB_DAT	.EQU	SIOBASE + $01
 #ENDIF
 ;
-#IF (SIOMODE == SIOMODE_ZP)		; PS	
-SIOA_CMD	.EQU	SIOBASE + $06	; PS
-SIOA_DAT	.EQU	SIOBASE + $04	; PS 
-SIOB_CMD	.EQU	SIOBASE + $07	; PS 
-SIOB_DAT	.EQU	SIOBASE + $05	; PS 
-#ENDIF					; PS 
-;
-#IF (DEFSIOCLK/DEFSIODIV/1 ==     75) 
-SIOBAUD1 .EQU  0 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==    150) 
-SIOBAUD1 .EQU  1 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==    300) 
-SIOBAUD1  .EQU  2 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==    600) 
-SIOBAUD1  .EQU  3 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==   1200) 
-SIOBAUD1  .EQU  4 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==   2400) 
-SIOBAUD1  .EQU  5 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==   4800) 
-SIOBAUD1  .EQU  6 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==   9600) 
-SIOBAUD1  .EQU  7 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==  19200) 
-SIOBAUD1  .EQU  8 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==  38400) 
-SIOBAUD1  .EQU  9 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==  76800) 
-SIOBAUD1  .EQU 10 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 == 153600) 
-SIOBAUD1  .EQU 11 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 == 307200) 
-SIOBAUD1  .EQU 12 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 == 614400) 
-SIOBAUD1  .EQU 13 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==1228800) 
-SIOBAUD1  .EQU 14 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==2457600) 
-SIOBAUD1  .EQU 15 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==    225) 
-SIOBAUD1  .EQU 16 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==    450) 
-SIOBAUD1  .EQU 17 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==    900) 
-SIOBAUD1  .EQU 18 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==   1800) 
-SIOBAUD1  .EQU 19 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==   3600) 
-SIOBAUD1  .EQU 20 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==   7200) 
-SIOBAUD1  .EQU 21 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==  14400) 
-SIOBAUD1  .EQU 22 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==  28800) 
-SIOBAUD1  .EQU 23 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==  57600) 
-SIOBAUD1  .EQU 24 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 == 115200) 
-SIOBAUD1  .EQU 25 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 == 230400) 
-SIOBAUD1  .EQU 26 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 == 921600) 
-SIOBAUD1  .EQU 28 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==1843200) 
-SIOBAUD1  .EQU 29 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==3686400) 
-SIOBAUD1  .EQU 30 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/1 ==7372800) 
-SIOBAUD1  .EQU 31 
+#IF (SIOMODE == SIOMODE_ZP)		
+SIOA_CMD	.EQU	SIOBASE + $06
+SIOA_DAT	.EQU	SIOBASE + $04 
+SIOB_CMD	.EQU	SIOBASE + $07
+SIOB_DAT	.EQU	SIOBASE + $05
 #ENDIF
 ;
-#IF (DEFSIOCLK/DEFSIODIV/16 ==     75) 
-SIOBAUD2 .EQU  0 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==    150) 
-SIOBAUD2  .EQU  1 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==    300) 
-SIOBAUD2  .EQU  2 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==    600) 
-SIOBAUD2  .EQU  3 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==   1200) 
-SIOBAUD2  .EQU  4 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==   2400) 
-SIOBAUD2  .EQU  5 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==   4800) 
-SIOBAUD2  .EQU  6 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==   9600) 
-SIOBAUD2  .EQU  7 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==  19200) 
-SIOBAUD2  .EQU  8 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==  38400) 
-SIOBAUD2  .EQU  9 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==  76800) 
-SIOBAUD2  .EQU 10 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 == 153600) 
-SIOBAUD2  .EQU 11 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 == 307200) 
-SIOBAUD2  .EQU 12 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 == 614400) 
-SIOBAUD2  .EQU 13 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==1228800) 
-SIOBAUD2  .EQU 14 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==2457600) 
-SIOBAUD2  .EQU 15 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==    225) 
-SIOBAUD2  .EQU 16 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==    450) 
-SIOBAUD2  .EQU 17 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==    900) 
-SIOBAUD2  .EQU 18 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==   1800) 
-SIOBAUD2  .EQU 19 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==   3600) 
-SIOBAUD2  .EQU 20 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==   7200) 
-SIOBAUD2  .EQU 21 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==  14400) 
-SIOBAUD2  .EQU 22 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==  28800) 
-SIOBAUD2  .EQU 23 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==  57600) 
-SIOBAUD2  .EQU 24 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 == 115200) 
-SIOBAUD2  .EQU 25 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 == 230400) 
-SIOBAUD2  .EQU 26 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 == 460800) 
-SIOBAUD2  .EQU 27 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 == 921600) 
-SIOBAUD2  .EQU 28 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==1843200) 
-SIOBAUD2  .EQU 29 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==3686400) 
-SIOBAUD2  .EQU 30 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/16 ==7372800) 
-SIOBAUD2  .EQU 31 
-#ENDIF
+; CONDITIONALS THAT DETERMINE THE ENCODED VALUE OF THE BAUD RATE
 ;
-#IF (DEFSIOCLK/DEFSIODIV/32 ==     75) 
-SIOBAUD3  .EQU  0 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==    150) 
-SIOBAUD3  .EQU  1 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==    300) 
-SIOBAUD3  .EQU  2 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==    600) 
-SIOBAUD3  .EQU  3 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==   1200) 
-SIOBAUD3  .EQU  4 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==   2400) 
-SIOBAUD3  .EQU  5 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==   4800) 
-SIOBAUD3  .EQU  6 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==   9600) 
-SIOBAUD3  .EQU  7 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==  19200) 
-SIOBAUD3  .EQU  8 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==  38400) 
-SIOBAUD3  .EQU  9 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==  76800) 
-SIOBAUD3  .EQU 10 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 == 153600) 
-SIOBAUD3  .EQU 11 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 == 307200) 
-SIOBAUD3  .EQU 12 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 == 614400) 
-SIOBAUD3  .EQU 13 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==1228800) 
-SIOBAUD3  .EQU 14 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==2457600) 
-SIOBAUD3  .EQU 15 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==    225) 
-SIOBAUD3  .EQU 16 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==    450) 
-SIOBAUD3  .EQU 17 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==    900) 
-SIOBAUD3  .EQU 18 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==   1800) 
-SIOBAUD3  .EQU 19 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==   3600) 
-SIOBAUD3  .EQU 20 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==   7200) 
-SIOBAUD3  .EQU 21 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==  14400) 
-SIOBAUD3  .EQU 22 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==  28800) 
-SIOBAUD3  .EQU 23 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==  57600) 
-SIOBAUD3  .EQU 24 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 == 115200) 
-SIOBAUD3  .EQU 25 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 == 230400) 
-SIOBAUD3  .EQU 26 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 == 460800) 
-SIOBAUD3  .EQU 27 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 == 921600) 
-SIOBAUD3  .EQU 28 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==1843200) 
-SIOBAUD3  .EQU 29 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==3686400) 
-SIOBAUD3  .EQU 30 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/32 ==7372800) 
-SIOBAUD3  .EQU 31 
-#ENDIF
-;
-#IF (DEFSIOCLK/DEFSIODIV/64 ==     75) 
-SIOBAUD4  .EQU  0 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==    150) 
-SIOBAUD4  .EQU  1 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==    300) 
-SIOBAUD4  .EQU  2 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==    600) 
-SIOBAUD4  .EQU  3 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==   1200) 
-SIOBAUD4  .EQU  4 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==   2400) 
-SIOBAUD4  .EQU  5 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==   4800) 
-SIOBAUD4  .EQU  6 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==  9600) 
-SIOBAUD4  .EQU  7 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==  19200) 
-SIOBAUD4  .EQU  8 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==  38400) 
-SIOBAUD4  .EQU  9 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==  76800) 
-SIOBAUD4  .EQU 10 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 == 153600) 
-SIOBAUD4  .EQU 11 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 == 307200) 
-SIOBAUD4  .EQU 12 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 == 614400) 
-SIOBAUD4  .EQU 13 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==1228800) 
-SIOBAUD4  .EQU 14 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==2457600) 
-SIOBAUD4  .EQU 15 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==    225) 
-SIOBAUD4  .EQU 16 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==    450) 
-SIOBAUD4  .EQU 17 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==    900) 
-SIOBAUD4  .EQU 18 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==   1800) 
-SIOBAUD4  .EQU 19 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==   3600) 
-SIOBAUD4  .EQU 20 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==   7200) 
-SIOBAUD4  .EQU 21 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==  14400) 
-SIOBAUD4  .EQU 22 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==  28800) 
-SIOBAUD4  .EQU 23 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==  57600) 
-SIOBAUD4  .EQU 24 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 == 115200) 
-SIOBAUD4  .EQU 25 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 == 230400) 
-SIOBAUD4  .EQU 26 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 == 460800) 
-SIOBAUD4  .EQU 27 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 == 921600) 
-SIOBAUD4  .EQU 28 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==1843200) 
-SIOBAUD4  .EQU 29 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==3686400) 
-SIOBAUD4  .EQU 30 
-#ENDIF
-#IF (DEFSIOCLK/DEFSIODIV/64 ==7372800) 
-SIOBAUD4  .EQU 31 
-#ENDIF
+#INCLUDE "siobaud.inc"	
 ;
 SIO_PREINIT:
 ;
@@ -786,21 +410,25 @@ SIO_OST:
 	INC	A			; ACCUM := 1 TO SIGNAL 1 BUFFER POSITION
 	RET				; DONE
 ;
+; AT INITIALIZATION THE SETUP PARAMETER WORD IS TRANSLATED TO THE FORMAT 
+; REQUIRED BY THE SIO AND STORED IN A PORT/REGISTER INITIALIZATION TABLE, 
+; WHICH IS THEN LOADED INTO THE SIO.
 ;
+; RTS, DTR AND XON SETTING IS NOT CURRENTLY SUPPORTED.
+; MARK & SPACE PARITY AND 1.5 STOP BITS IS NOT SUPPORTED BY THE SIO.
+; INITIALIZATION WILL NOT BE COMPLETED IF AN INVALID SETTING IS DETECTED.
 ;
 SIO_INITDEV:
 ;
-	; TEST FOR -1 WHICH MEANS USE CURRENT CONFIG (JUST REINIT)	; PS
-	LD	A,D			; TEST DE FOR			; PS
-	AND	E			; ... VALUE OF -1		; PS
-	INC	A			; ... SO Z SET IF -1		; PS
-	JR	NZ,SIO_INITDEV1	; IF DE == -1, REINIT CURRENT CONFIG	; PS
+	; TEST FOR -1 WHICH MEANS USE CURRENT CONFIG (JUST REINIT)
+	LD	A,D			; TEST DE FOR
+	AND	E			; ... VALUE OF -1
+	INC	A			; ... SO Z SET IF -1
+	JR	NZ,SIO_INITDEV1	; IF DE == -1, REINIT CURRENT CONFIG
 ;
-	; LOAD EXISTING CONFIG TO REINIT				; PS
-	LD	E,(IY+4)		; LOW BYTE			; PS
-	LD	D,(IY+5)		; HIGH BYTE			; PS
-;
-; CHANGE INIT TABLE BASED ON DESIRED SERIAL LINE CHARACTERISTICS
+	; LOAD EXISTING CONFIG TO REINIT
+	LD	E,(IY+4)		; LOW BYTE
+	LD	D,(IY+5)		; HIGH BYTE	
 ;
 SIO_INITDEV1:
 	PUSH	DE			; SAVE CONFIG
@@ -815,8 +443,13 @@ SIO_INITDEV1:
 	PRTC(']')
 	POP	AF
 #ENDIF
-
-	CP	SIOBAUD1		; We set the divider and the lower bit (d2) of the baud rate here
+;
+; ONLY FOUR BAUD RATES ARE POSSIBLE WITH A FIXED CLOCK.
+; THESE ARE PREDETERMINED BY HARDWARE SETTINGS AND MATCHING
+; CONFIGURATION SETTINGS. WE PRECALCULATED THE FOUR 
+; POSSIBLE ENCODED VALUES.
+;
+	CP	SIOBAUD1		; We set the divider and the lower bit (d2) of the stop bits
 	LD	D,$04			; /1 N,8,1
 	JR	Z,BROK	
 	CP	SIOBAUD2	
@@ -827,8 +460,8 @@ SIO_INITDEV1:
 	JR	Z,BROK	
 	CP	SIOBAUD4	
 	LD	D,$C4			; /64 N,8,1
-	JR	Z,BROK			; RET NZ
-
+	JR	Z,BROK			
+	
 #IF (SIODEBUG)
 	PUSH	AF
 	PRTS(" BR FAIL[$")	
@@ -857,43 +490,24 @@ BROK:
 	SRL	A			; we know top bits are zero from previous test
 	SRL	A			; add stop bits
 	OR	D 			; carry = 0
-	
+;	
+; SET DIVIDER, STOP AND PARITY WR4
+;	
 	LD	BC,SIO_INITVALS+3
 	LD	(BC),A
 	
 #IF (SIODEBUG)
 	PUSH	AF
-	PRTS(" MODE[$")
+	PRTS(" WR4[$")
 	CALL	PRTHEXBYTE
 	PRTC(']')
 	POP	AF
 #ENDIF
 
-; THE # DATA BITS NEED TO BE CONVERTED FROM THE 
-; ROMWBW REPRESENTATION TO THE SIO ZILOG CODING
-	
-;	XOR A
-;	RR E				; d0 of bits into carry
-;	RR A				; d0 into msb
-;	RR E				; d1 of bits into carry
-;	RR A				; d1 into msb
-;;	SCF				; 1 into msb
-;	RR A
-;	OR $8a
-
-	LD	A,E
-
-	#IF (SIODEBUG)
-	PUSH	AF
-	PRTS(" BITS[$")
-	CALL	PRTHEXBYTE
-	PRTC(']')
-	POP	AF
-#ENDIF	
-					; 112233445566d1d0 CC
+	LD	A,E			; 112233445566d1d0 CC
 	RRA				; CC112233445566d1 d0
 	RRA				; d0CC112233445566 d1
-	RRA 				; d1d0CC1122334455 66
+	RRA 			; d1d0CC1122334455 66
 	LD	D,A	
 	RRA				; 66d1d0CC11223344 55
 	AND	$60			; 0011110000000000 00
@@ -906,7 +520,7 @@ BROK:
 
 #IF (SIODEBUG)
 	PUSH	AF
-	PRTS(" TXDATA[$")
+	PRTS(" WR5[$")
 	CALL	PRTHEXBYTE
 	PRTC(']')
 	POP	AF
@@ -923,7 +537,7 @@ BROK:
 
 #IF (SIODEBUG)
 	PUSH	AF
-	PRTS(" RXDATA[$")
+	PRTS(" WR3[$")
 	CALL	PRTHEXBYTE
 	PRTC(']')
 	POP	AF
@@ -969,7 +583,7 @@ BROK:
 ;
 SIO_INITVALS:
 	.DB	$00, $18		; WR0: CHANNEL RESET
-	.DB	$04, $00		; WR4: CLK BAUD PARITY STOP BIT ; PST
+	.DB	$04, $00		; WR4: CLK BAUD PARITY STOP BIT
 #IF (INTMODE == 0)
 	.DB	$01, $00		; WR1: NO INTERRUPTS
 #ELSE