From add0f3df07e563cfaada5582a41101ecd5b14878 Mon Sep 17 00:00:00 2001
From: b1ackmai1er <39449559+b1ackmai1er@users.noreply.github.com>
Date: Fri, 3 Aug 2018 19:46:24 +0800
Subject: [PATCH 1/5] Separate the baud encoding conditional for readability

---
 Source/HBIOS/siobaud.inc | 390 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 390 insertions(+)
 create mode 100644 Source/HBIOS/siobaud.inc

diff --git a/Source/HBIOS/siobaud.inc b/Source/HBIOS/siobaud.inc
new file mode 100644
index 00000000..bb819775
--- /dev/null
+++ b/Source/HBIOS/siobaud.inc
@@ -0,0 +1,390 @@
+;
+; SIOBAUD1, SIOBAUD2, SIOBAUD3, SIOBAUD4 ARE SET TO THE
+; ENCODED VALUE OF EACH POSSIBLE BAUD RATE WITH A FIXED CLOCK.
+;
+
+#IF (DEFSIOCLK/DEFSIODIV/1 ==     75) 
+SIOBAUD1 .EQU  0 E
+#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 
+#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
+
+#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

From f66b6f155e2be5cd61b068cfe0ee5986af66d13d Mon Sep 17 00:00:00 2001
From: b1ackmai1er <39449559+b1ackmai1er@users.noreply.github.com>
Date: Fri, 3 Aug 2018 22:37:17 +0800
Subject: [PATCH 2/5] Fixes port address and cleanups

---
 sio.asm | 725 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 725 insertions(+)
 create mode 100644 sio.asm

diff --git a/sio.asm b/sio.asm
new file mode 100644
index 00000000..c30ab09f
--- /dev/null
+++ b/sio.asm
@@ -0,0 +1,725 @@
+;
+;==================================================================================================
+; SIO DRIVER (SERIAL PORT)
+;==================================================================================================
+;
+;  SETUP PARAMETER WORD:
+;  +-------+---+-------------------+ +---+---+-----------+---+-------+
+;  |       |RTS| ENCODED BAUD RATE | |DTR|XON|  PARITY   |STP| 8/7/6 |
+;  +-------+---+---+---------------+ ----+---+-----------+---+-------+
+;    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	
+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
+SIOA_DAT	.EQU	SIOBASE + $00
+SIOB_CMD	.EQU	SIOBASE + $03
+SIOB_DAT	.EQU	SIOBASE + $01
+#ENDIF
+;
+#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
+;
+; CONDITIONALS THAT DETERMINE THE ENCODED VALUE OF THE BAUD RATE
+;
+#INCLUDE "siobaud.inc"	
+;
+SIO_PREINIT:
+;
+; SETUP THE DISPATCH TABLE ENTRIES
+;
+	LD	B,SIO_CNT		; LOOP CONTROL
+	LD	C,0			; PHYSICAL UNIT INDEX
+	XOR	A			; ZERO TO ACCUM
+	LD	(SIO_DEV),A		; CURRENT DEVICE NUMBER
+SIO_PREINIT0:	
+	PUSH	BC			; SAVE LOOP CONTROL
+	LD	A,C			; PHYSICAL UNIT TO A
+	RLCA				; MULTIPLY BY CFG TABLE ENTRY SIZE (8 BYTES)
+	RLCA				; ...
+	RLCA				; ... TO GET OFFSET INTO CFG TABLE
+	LD	HL,SIO_CFG		; POINT TO START OF CFG TABLE
+	CALL	ADDHLA			; HL := ENTRY ADDRESS
+	PUSH	HL			; SAVE IT
+	PUSH	HL			; COPY CFG DATA PTR
+	POP	IY			; ... TO IY
+	CALL	SIO_INITUNIT		; HAND OFF TO GENERIC INIT CODE
+	POP	DE			; GET ENTRY ADDRESS BACK, BUT PUT IN DE
+	POP	BC			; RESTORE LOOP CONTROL
+;
+	LD	A,(IY+1)		; GET THE SIO TYPE DETECTED
+	OR	A			; SET FLAGS
+	JR	Z,SIO_PREINIT2		; SKIP IT IF NOTHING FOUND
+;	
+	PUSH	BC			; SAVE LOOP CONTROL
+	LD	BC,SIO_FNTBL		; BC := FUNCTION TABLE ADDRESS
+	CALL	NZ,CIO_ADDENT		; ADD ENTRY IF SIO FOUND, BC:DE
+	POP	BC			; RESTORE LOOP CONTROL
+;
+SIO_PREINIT2:	
+	INC	C			; NEXT PHYSICAL UNIT
+	DJNZ	SIO_PREINIT0		; LOOP UNTIL DONE
+;
+#IF (INTMODE == 1)
+	; ADD IM1 INT CALL LIST ENTRY IF APPROPRIATE
+	LD	A,(SIO_DEV)		; GET NEXT DEVICE NUM
+	OR	A			; SET FLAGS
+	JR	Z,SIO_PREINIT3		; IF ZERO, NO SIO DEVICES
+	LD	HL,SIO_INT		; GET INT VECTOR
+	CALL	HB_ADDIM1		; ADD TO IM1 CALL LIST
+#ENDIF
+;
+#IF (INTMODE == 2)
+	; SETUP SIO INTERRUPT VECTOR IN IVT
+	LD	HL,INT_SIO
+	LD	(HBX_IVT + IVT_SER0),HL
+#ENDIF
+;
+SIO_PREINIT3:
+	XOR	A			; SIGNAL SUCCESS
+	RET				; AND RETURN
+;
+; SIO INITIALIZATION ROUTINE
+;
+SIO_INITUNIT:
+	CALL	SIO_DETECT		; DETERMINE SIO TYPE
+	LD	(IY+1),A		; SAVE IN CONFIG TABLE
+	OR	A			; SET FLAGS
+	RET	Z			; ABORT IF NOTHING THERE
+
+	; UPDATE WORKING SIO DEVICE NUM
+	LD	HL,SIO_DEV		; POINT TO CURRENT UART DEVICE NUM
+	LD	A,(HL)			; PUT IN ACCUM
+	INC	(HL)			; INCREMENT IT (FOR NEXT LOOP)
+	LD	(IY),A			; UPDATE UNIT NUM
+	
+	; SET DEFAULT CONFIG
+	LD	DE,-1			; LEAVE CONFIG ALONE
+	JP	SIO_INITDEV		; IMPLEMENT IT AND RETURN
+;
+;
+;
+SIO_INIT:
+	LD	B,SIO_CNT		; COUNT OF POSSIBLE SIO UNITS
+	LD	C,0			; INDEX INTO SIO CONFIG TABLE
+SIO_INIT1:
+	PUSH	BC			; SAVE LOOP CONTROL
+	
+	LD	A,C			; PHYSICAL UNIT TO A
+	RLCA				; MULTIPLY BY CFG TABLE ENTRY SIZE (8 BYTES)
+	RLCA				; ...
+	RLCA				; ... TO GET OFFSET INTO CFG TABLE
+	LD	HL,SIO_CFG		; POINT TO START OF CFG TABLE
+	CALL	ADDHLA			; HL := ENTRY ADDRESS
+	PUSH	HL			; COPY CFG DATA PTR
+	POP	IY			; ... TO IY
+	
+	LD	A,(IY+1)		; GET SIO TYPE
+	OR	A			; SET FLAGS
+	CALL	NZ,SIO_PRTCFG		; PRINT IF NOT ZERO
+	
+	POP	BC			; RESTORE LOOP CONTROL
+	INC	C			; NEXT UNIT
+	DJNZ	SIO_INIT1		; LOOP TILL DONE
+;
+	XOR	A			; SIGNAL SUCCESS
+	RET				; DONE
+;
+; RECEIVE INTERRUPT HANDLER
+;
+#IF (INTMODE > 0)
+;
+SIO_INT:
+SIOA_INT:
+	; CHECK FOR RECEIVE PENDING ON CHANNEL A
+	XOR	A			; A := 0
+	OUT	(SIOA_CMD),A		; ADDRESS RD0
+	IN	A,(SIOA_CMD)		; GET RD0
+	AND	$01			; ISOLATE RECEIVE READY BIT
+	JR	Z,SIOB_INT		; CHECK CHANNEL B
+;
+SIOA_INT00:
+	; HANDLE CHANNEL A
+	IN	A,(SIOA_DAT)		; READ PORT
+	LD	E,A			; SAVE BYTE READ
+	LD	A,(SIOA_CNT)		; GET CURRENT BUFFER USED COUNT
+	CP	SIOA_BUFSZ		; COMPARE TO BUFFER SIZE
+	RET	Z			; BAIL OUT IF BUFFER FULL, RCV BYTE DISCARDED
+	INC	A			; INCREMENT THE COUNT
+	LD	(SIOA_CNT),A		; AND SAVE IT
+	CP	SIOA_BUFSZ - 5		; BUFFER GETTING FULL?
+	JR	NZ,SIOA_INT0		; IF NOT, BYPASS CLEARING RTS
+	LD	A,5			; RTS IS IN WR5
+	OUT	(SIOA_CMD),A		; ADDRESS WR5
+	LD	A,$E8			; VALUE TO CLEAR RTS
+	OUT	(SIOA_CMD),A		; DO IT
+SIOA_INT0:
+	LD	HL,(SIOA_HD)		; GET HEAD POINTER
+	LD	A,L			; GET LOW BYTE
+	CP	SIOA_BUFEND & $FF	; PAST END?
+	JR	NZ,SIOA_INT1		; IF NOT, BYPASS POINTER RESET
+	LD	HL,SIOA_BUF		; ... OTHERWISE, RESET TO START OF BUFFER
+SIOA_INT1:
+	LD	A,E			; RECOVER BYTE READ
+	LD	(HL),A			; SAVE RECEIVED BYTE TO HEAD POSITION
+	INC	HL			; INCREMENT HEAD POINTER
+	LD	(SIOA_HD),HL		; SAVE IT
+;
+	; CHECK FOR MORE PENDING...
+	XOR	A			; A := 0
+	OUT	(SIOA_CMD),A		; ADDRESS RD0
+	IN	A,(SIOA_CMD)		; GET RD0
+	RRA				; READY BIT TO CF
+	JR	C,SIOA_INT00		; IF SET, DO SOME MORE
+	OR	$FF			; NZ SET TO INDICATE INT HANDLED
+	RET				; AND RETURN
+;
+SIOB_INT:
+	; CHECK FOR RECEIVE PENDING ON CHANNEL B
+	XOR	A			; A := 0
+	OUT	(SIOB_CMD),A		; ADDRESS RD0
+	IN	A,(SIOB_CMD)		; GET RD0
+	AND	$01			; ISOLATE RECEIVE READY BIT
+	RET	Z			; IF NOT, RETURN WITH Z SET
+;
+SIOB_INT00:
+	; HANDLE CHANNEL B
+	IN	A,(SIOB_DAT)		; READ PORT
+	LD	E,A			; SAVE BYTE READ
+	LD	A,(SIOB_CNT)		; GET CURRENT BUFFER USED COUNT
+	CP	SIOB_BUFSZ		; COMPARE TO BUFFER SIZE
+	RET	Z			; BAIL OUT IF BUFFER FULL, RCV BYTE DISCARDED
+	INC	A			; INCREMENT THE COUNT
+	LD	(SIOB_CNT),A		; AND SAVE IT
+	CP	SIOB_BUFSZ - 5		; BUFFER GETTING FULL?
+	JR	NZ,SIOB_INT0		; IF NOT, BYPASS CLEARING RTS
+	LD	A,5			; RTS IS IN WR5
+	OUT	(SIOB_CMD),A		; ADDRESS WR5
+	LD	A,$E8			; VALUE TO CLEAR RTS
+	OUT	(SIOB_CMD),A		; DO IT
+SIOB_INT0:
+	LD	HL,(SIOB_HD)		; GET HEAD POINTER
+	LD	A,L			; GET LOW BYTE
+	CP	SIOB_BUFEND & $FF	; PAST END?
+	JR	NZ,SIOB_INT1		; IF NOT, BYPASS POINTER RESET
+	LD	HL,SIOB_BUF		; ... OTHERWISE, RESET TO START OF BUFFER
+SIOB_INT1:
+	LD	A,E			; RECOVER BYTE READ
+	LD	(HL),A			; SAVE RECEIVED BYTE TO HEAD POSITION
+	INC	HL			; INCREMENT HEAD POINTER
+	LD	(SIOB_HD),HL		; SAVE IT
+;
+	; CHECK FOR MORE PENDING...
+	XOR	A			; A := 0
+	OUT	(SIOB_CMD),A		; ADDRESS RD0
+	IN	A,(SIOB_CMD)		; GET RD0
+	RRA				; READY BIT TO CF
+	JR	C,SIOB_INT00		; IF SET, DO SOME MORE
+	OR	$FF			; NZ SET TO INDICATE INT HANDLED
+	RET				; AND RETURN
+;
+#ENDIF
+;
+; DRIVER FUNCTION TABLE
+;
+SIO_FNTBL:
+	.DW	SIO_IN
+	.DW	SIO_OUT
+	.DW	SIO_IST
+	.DW	SIO_OST
+	.DW	SIO_INITDEV
+	.DW	SIO_QUERY
+	.DW	SIO_DEVICE
+#IF (($ - SIO_FNTBL) != (CIO_FNCNT * 2))
+	.ECHO	"*** INVALID SIO FUNCTION TABLE ***\n"
+#ENDIF
+;
+;
+;
+#IF (INTMODE == 0)
+;
+SIO_IN:
+	CALL	SIO_IST			; CHAR WAITING?
+	JR	Z,SIO_IN		; LOOP IF NOT
+	LD	C,(IY+3)		; C := SIO CMD PORT
+#IF (SIOMODE == SIOMODE_RC)
+	INC	C			; BUMP TO DATA PORT
+#ENDIF
+#IF ((SIOMODE == SIOMODE_SMB) | (SIOMODE == SIOMODE_ZP))
+	DEC	C			; DECREMENT CMD PORT TWICE TO GET DATA PORT
+	DEC	C
+#ENDIF
+	IN	E,(C)			; GET CHAR
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+#ELSE
+;
+SIO_IN:
+	LD	A,(IY+2)		; GET CHANNEL
+	OR	A			; SET FLAGS
+	JR	Z,SIOA_IN		; HANDLE CHANNEL A
+	DEC	A			; TEST FOR NEXT DEVICE
+	JR	Z,SIOB_IN		; HANDLE CHANNEL B
+	CALL 	PANIC			; ELSE FATAL ERROR
+	RET				; ... AND RETURN
+;
+SIOA_IN:
+	CALL	SIOA_IST		; RECEIVED CHAR READY?
+	JR	Z,SIOA_IN		; LOOP TILL WE HAVE SOMETHING IN BUFFER
+	HB_DI				; AVOID COLLISION WITH INT HANDLER
+	LD	A,(SIOA_CNT)		; GET COUNT
+	DEC	A			; DECREMENT COUNT
+	LD	(SIOA_CNT),A		; SAVE SAVE IT
+	CP	5			; BUFFER LOW THRESHOLD
+	JR	NZ,SIOA_IN0		; IF NOT, BYPASS SETTING RTS
+	LD	A,5			; RTS IS IN WR5
+	OUT	(SIOA_CMD),A		; ADDRESS WR5
+	LD	A,$EA			; VALUE TO SET RTS
+	OUT	(SIOA_CMD),A		; DO IT
+SIOA_IN0:
+	LD	HL,(SIOA_TL)		; GET BUFFER TAIL POINTER
+	LD	E,(HL)			; GET BYTE
+	INC	HL			; BUMP TAIL POINTER
+	LD	A,L			; GET LOW BYTE
+	CP	SIOA_BUFEND & $FF	; PAST END?
+	JR	NZ,SIOA_IN1		; IF NOT, BYPASS POINTER RESET
+	LD	HL,SIOA_BUF		; ... OTHERWISE, RESET TO START OF BUFFER
+SIOA_IN1:
+	LD	(SIOA_TL),HL		; SAVE UPDATED TAIL POINTER
+	HB_EI				; INTERRUPTS OK AGAIN
+	XOR	A			; SIGNAL SUCCESS
+	RET				; AND DONE
+;
+SIOB_IN:
+	CALL	SIOB_IST		; RECEIVED CHAR READY?
+	JR	Z,SIOB_IN		; LOOP TILL WE HAVE SOMETHING IN BUFFER
+	HB_DI				; AVOID COLLISION WITH INT HANDLER
+	LD	A,(SIOB_CNT)		; GET COUNT
+	DEC	A			; DECREMENT COUNT
+	LD	(SIOB_CNT),A		; SAVE SAVE IT
+	CP	5			; BUFFER LOW THRESHOLD
+	JR	NZ,SIOB_IN0		; IF NOT, BYPASS SETTING RTS
+	LD	A,5			; RTS IS IN WR5
+	OUT	(SIOB_CMD),A		; ADDRESS WR5
+	LD	A,$EA			; VALUE TO SET RTS
+	OUT	(SIOB_CMD),A		; DO IT
+SIOB_IN0:
+	LD	HL,(SIOB_TL)		; GET BUFFER TAIL POINTER
+	LD	E,(HL)			; GET BYTE
+	INC	HL			; BUMP TAIL POINTER
+	LD	A,L			; GET LOW BYTE
+	CP	SIOB_BUFEND & $FF	; PAST END?
+	JR	NZ,SIOB_IN1		; IF NOT, BYPASS POINTER RESET
+	LD	HL,SIOB_BUF		; ... OTHERWISE, RESET TO START OF BUFFER
+SIOB_IN1:
+	LD	(SIOB_TL),HL		; SAVE UPDATED TAIL POINTER
+	HB_EI				; INTERRUPTS OK AGAIN
+	XOR	A			; SIGNAL SUCCESS
+	RET				; AND DONE
+;
+#ENDIF
+;
+;
+;
+SIO_OUT:
+	CALL	SIO_OST			; READY FOR CHAR?
+	JR	Z,SIO_OUT		; LOOP IF NOT
+	LD	C,(IY+3)		; C := SIO CMD PORT
+#IF (SIOMODE == SIOMODE_RC)
+	INC	C			; BUMP TO DATA PORT
+#ENDIF
+#IF ((SIOMODE == SIOMODE_SMB) | (SIOMODE == SIOMODE_ZP))
+	DEC C				; DECREMENT CMD PORT TWICE TO GET DATA PORT
+	DEC C
+#ENDIF
+	OUT	(C),E			; SEND CHAR FROM E
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+;
+;
+#IF (INTMODE == 0)
+;
+SIO_IST:
+	LD	C,(IY+3)		; CMD PORT
+	XOR	A			; WR0
+	OUT	(C),A			; DO IT
+	IN	A,(C)			; GET STATUS
+	AND	$01			; ISOLATE BIT 0 (RX READY)
+	JP	Z,CIO_IDLE		; NOT READY, RETURN VIA IDLE PROCESSING
+	XOR	A			; ZERO ACCUM
+	INC	A			; ASCCUM := 1 TO SIGNAL 1 CHAR WAITING
+	RET				; DONE
+;
+#ELSE
+;
+SIO_IST:
+	LD	A,(IY+2)		; GET CHANNEL
+	OR	A			; SET FLAGS
+	JR	Z,SIOA_IST		; HANDLE CHANNEL A
+	DEC	A			; TEST FOR NEXT DEVICE
+	JR	Z,SIOB_IST		; HANDLE CHANNEL B
+	CALL 	PANIC			; ELSE FATAL ERROR
+	RET				; ... AND RETURN
+;
+SIOA_IST:
+	LD	A,(SIOA_CNT)		; GET BUFFER UTILIZATION COUNT
+	OR	A			; SET FLAGS
+	JP	Z,CIO_IDLE		; NOT READY, RETURN VIA IDLE PROCESSING
+	RET				; AND DONE
+;
+SIOB_IST:
+	LD	A,(SIOB_CNT)		; GET BUFFER UTILIZATION COUNT
+	OR	A			; SET FLAGS
+	JP	Z,CIO_IDLE		; NOT READY, RETURN VIA IDLE PROCESSING
+	RET				; DONE
+;
+#ENDIF
+;
+;
+;
+SIO_OST:
+	LD	C,(IY+3)		; CMD PORT
+	XOR	A			; WR0
+	OUT	(C),A			; DO IT
+	IN	A,(C)			; GET STATUS
+	AND	$04			; ISOLATE BIT 2 (TX EMPTY)
+	JP	Z,CIO_IDLE		; NOT READY, RETURN VIA IDLE PROCESSING
+	XOR	A			; ZERO ACCUM
+	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)
+	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
+	LD	E,(IY+4)		; LOW BYTE
+	LD	D,(IY+5)		; HIGH BYTE	
+;
+SIO_INITDEV1:
+	PUSH	DE			; SAVE CONFIG
+
+	LD	A,D			; GET CONFIG MSB
+	AND	$1F			; ISOLATE ENCODED BAUD RATE
+
+#IF (SIODEBUG)
+	PUSH	AF
+	PRTS(" ENCODE[$")
+	CALL	PRTHEXBYTE
+	PRTC(']')
+	POP	AF
+#ENDIF
+;
+; 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	
+	LD	D,$44			; /16 N,8,1
+	JR	Z,BROK	
+	CP	SIOBAUD3	
+	LD	D,$84			; /32 N,8,1
+	JR	Z,BROK	
+	CP	SIOBAUD4	
+	LD	D,$C4			; /64 N,8,1
+	JR	Z,BROK			
+	
+#IF (SIODEBUG)
+	PUSH	AF
+	PRTS(" BR FAIL[$")	
+	CALL PRTHEXBYTE
+	PRTC(']')
+	POP	AF
+#ENDIF
+;
+EXITINIT:
+	POP	DE
+	RET				; NZ status here indicating fail / invalid baud rate.
+	
+BROK:
+	LD	A,E
+	AND	$E0
+	JR	NZ,EXITINIT		; NZ status here indicates dtr, xon, parity mark or space so return
+
+	LD	A,E			;  set stop bit (d3) and add divider
+	AND	$04
+	RLA
+	OR	D			; carry gets reset here
+	LD	D,A
+	
+	LD	A,E			; get the parity bits
+	SRL	A			; move them to bottom two bits
+	SRL	A			; we know top bits are zero from previous test
+	SRL	A			; add stop bits
+	OR	D 			; carry = 0
+;	
+; SET DIVIDER, STOP AND PARITY WR4
+;	
+	LD	BC,SIO_INITVALS+3
+	LD	(BC),A
+	
+#IF (SIODEBUG)
+	PUSH	AF
+	PRTS(" WR4[$")
+	CALL	PRTHEXBYTE
+	PRTC(']')
+	POP	AF
+#ENDIF
+
+	LD	A,E			; 112233445566d1d0 CC
+	RRA				; CC112233445566d1 d0
+	RRA				; d0CC112233445566 d1
+	RRA 			; d1d0CC1122334455 66
+	LD	D,A	
+	RRA				; 66d1d0CC11223344 55
+	AND	$60			; 0011110000000000 00
+	OR	$8a
+;	
+; SET TRANSMIT DATA BITS WR5	
+;
+	LD	BC,SIO_INITVALS+11
+	LD	(BC),A	
+
+#IF (SIODEBUG)
+	PUSH	AF
+	PRTS(" WR5[$")
+	CALL	PRTHEXBYTE
+	PRTC(']')
+	POP	AF
+#ENDIF	
+;
+; SET RECEIVE DATA BITS WR3 
+;	
+	LD	A,D
+	AND	$C0
+	OR	$01
+	
+	LD	BC,SIO_INITVALS+9
+	LD	(BC),A	
+
+#IF (SIODEBUG)
+	PUSH	AF
+	PRTS(" WR3[$")
+	CALL	PRTHEXBYTE
+	PRTC(']')
+	POP	AF
+#ENDIF	
+	
+	POP	DE			; RESTORE CONFIG
+
+	LD	(IY+4),E		; SAVE LOW WORD
+	LD	(IY+5),D		; SAVE HI WORD
+	
+	HB_DI				; AVOID CONFLICTS
+;
+	; PROGRAM THE SIO CHIP CHANNEL
+	LD	C,(IY+3)		; COMMAND PORT
+	LD	HL,SIO_INITVALS		; POINT TO INIT VALUES
+	LD	B,SIO_INITLEN		; COUNT OF BYTES TO WRITE
+	OTIR				; WRITE ALL VALUES
+;
+	; RESET THE RECEIVE BUFFER
+	LD	E,(IY+6)
+	LD	D,(IY+7)		; DE := _CNT
+	XOR	A			; A := 0
+	LD	(DE),A			; _CNT = 0
+	INC	DE			; DE := ADR OF _HD
+	PUSH	DE			; SAVE IT
+	INC	DE
+	INC	DE
+	INC	DE
+	INC	DE			; DE := ADR OF _BUF
+	POP	HL			; HL := ADR OF _HD
+	LD	(HL),E
+	INC	HL
+	LD	(HL),D			; _HD := _BUF
+	INC	HL
+	LD	(HL),E
+	INC	HL
+	LD	(HL),D			; _TL := _BUF
+;
+	HB_EI				; READY FOR INTS AGAIN
+	XOR	A			; SIGNAL SUCCESS
+	RET				; RETURN
+;
+;
+SIO_INITVALS:
+	.DB	$00, $18		; WR0: CHANNEL RESET
+	.DB	$04, $00		; WR4: CLK BAUD PARITY STOP BIT
+#IF (INTMODE == 0)
+	.DB	$01, $00		; WR1: NO INTERRUPTS
+#ELSE
+	.DB	$01, $18		; WR1: INTERRUPT ON ALL RECEIVE CHARACTERS
+#ENDIF
+	.DB	$02, IVT_SER0		; WR2: INTERRUPT VECTOR OFFSET
+	.DB	$03, $C1		; WR3: 8 BIT RCV, RX ENABLE
+	.DB	$05, $EA		; WR5: DTR, 8 BITS SEND,  TX ENABLE, RTS 1 11 0 1 0 1 0 (1=DTR,11=8bits,0=sendbreak,1=TxEnable,0=sdlc,1=RTS,0=txcrc)
+SIO_INITLEN	.EQU	$ - SIO_INITVALS
+;
+;
+;
+SIO_QUERY:
+	LD	E,(IY+4)		; FIRST CONFIG BYTE TO E
+	LD	D,(IY+5)		; SECOND CONFIG BYTE TO D
+	XOR	A			; SIGNAL SUCCESS
+	RET				; DONE
+;
+;
+;
+SIO_DEVICE:
+	LD	D,CIODEV_SIO		; D := DEVICE TYPE
+	LD	E,(IY)			; E := PHYSICAL UNIT
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+; SIO DETECTION ROUTINE
+;
+SIO_DETECT:
+	LD	C,(IY+3)		; COMMAND PORT
+	XOR	A	
+	OUT	(C),A			; ACCESS RD0
+	IN	A,(C)			; GET RD0 VALUE
+	LD	B,A			; SAVE IT
+	LD	A,1	
+	OUT	(C),A			; ACCESS RD1
+	IN	A,(C)			; GET RD1 VALUE
+	CP	B			; COMPARE
+	LD	A,SIO_NONE		; ASSUME NOTHING THERE
+	RET	Z			; RD0=RD1 MEANS NOTHING THERE
+	LD	A,SIO_SIO		; GUESS WE HAVE A VALID SIO HERE
+	RET				; DONE
+;
+;
+;
+SIO_PRTCFG:
+	; ANNOUNCE PORT
+	CALL	NEWLINE			; FORMATTING
+	PRTS("SIO$")			; FORMATTING
+	LD	A,(IY)			; DEVICE NUM
+	CALL	PRTDECB			; PRINT DEVICE NUM
+	PRTS(": IO=0x$")		; FORMATTING
+	LD	A,(IY+3)		; GET BASE PORT
+	CALL	PRTHEXBYTE		; PRINT BASE PORT
+
+	; PRINT THE SIO TYPE
+	CALL	PC_SPACE		; FORMATTING
+	LD	A,(IY+1)		; GET SIO TYPE BYTE
+	RLCA				; MAKE IT A WORD OFFSET
+	LD	HL,SIO_TYPE_MAP		; POINT HL TO TYPE MAP TABLE
+	CALL	ADDHLA			; HL := ENTRY
+	LD	E,(HL)			; DEREFERENCE
+	INC	HL			; ...
+	LD	D,(HL)			; ... TO GET STRING POINTER
+	CALL	WRITESTR		; PRINT IT
+;
+	; ALL DONE IF NO SIO WAS DETECTED
+	LD	A,(IY+1)		; GET SIO TYPE BYTE
+	OR	A			; SET FLAGS
+	RET	Z			; IF ZERO, NOT PRESENT
+;
+	PRTS(" MODE=$")			; FORMATTING
+	LD	E,(IY+4)		; LOAD CONFIG
+	LD	D,(IY+5)		; ... WORD TO DE
+	CALL	PS_PRTSC0		; PRINT CONFIG
+;
+	XOR	A
+	RET
+;
+;
+;
+SIO_TYPE_MAP:
+		.DW	SIO_STR_NONE
+		.DW	SIO_STR_SIO
+
+SIO_STR_NONE	.DB	"<NOT PRESENT>$"
+SIO_STR_SIO	.DB	"SIO$"
+;
+; WORKING VARIABLES
+;
+SIO_DEV		.DB	0		; DEVICE NUM USED DURING INIT
+;
+#IF (INTMODE == 0)
+;
+SIOA_RCVBUF	.EQU	0
+SIOB_RCVBUF	.EQU	0
+;
+#ELSE
+;
+; CHANNEL A RECEIVE BUFFER
+SIOA_RCVBUF:
+SIOA_CNT	.DB	0		; CHARACTERS IN RING BUFFER
+SIOA_HD		.DW	SIOA_BUF	; BUFFER HEAD POINTER
+SIOA_TL		.DW	SIOA_BUF	; BUFFER TAIL POINTER
+SIOA_BUF	.FILL	32,0		; RECEIVE RING BUFFER
+SIOA_BUFEND	.EQU	$		; END OF BUFFER
+SIOA_BUFSZ	.EQU	$ - SIOA_BUF	; SIZE OF RING BUFFER
+;
+; CHANNEL B RECEIVE BUFFER
+SIOB_RCVBUF:
+SIOB_CNT	.DB	0		; CHARACTERS IN RING BUFFER
+SIOB_HD		.DW	SIOB_BUF	; BUFFER HEAD POINTER
+SIOB_TL		.DW	SIOB_BUF	; BUFFER TAIL POINTER
+SIOB_BUF	.FILL	32,0		; RECEIVE RING BUFFER
+SIOB_BUFEND	.EQU	$		; END OF BUFFER
+SIOB_BUFSZ	.EQU	$ - SIOB_BUF	; SIZE OF RING BUFFER
+;
+#ENDIF
+;
+; SIO PORT TABLE
+;
+SIO_CFG:
+	; SIO CHANNEL A
+	.DB	0			; DEVICE NUMBER (SET DURING INIT)
+	.DB	0			; SIO TYPE (SET DURING INIT)
+	.DB	0			; SIO CHANNEL (A)
+	.DB	SIOA_CMD		; BASE PORT (CMD PORT)
+	.DW	DEFSIOACFG		; LINE CONFIGURATION
+	.DW	SIOA_RCVBUF		; POINTER TO RCV BUFFER STRUCT
+;
+	; SIO CHANNEL B
+	.DB	0			; DEVICE NUMBER (SET DURING INIT)
+	.DB	0			; SIO TYPE (SET DURING INIT)
+	.DB	1			; SIO CHANNEL (B)
+	.DB	SIOB_CMD		; BASE PORT (CMD PORT)
+	.DW	DEFSIOBCFG		; LINE CONFIGURATION
+	.DW	SIOB_RCVBUF		; POINTER TO RCV BUFFER STRUCT
+;
+SIO_CNT	.EQU	($ - SIO_CFG) / 8

From 41c5eba03434017cb5a80cee6f1223c7b274e0b8 Mon Sep 17 00:00:00 2001
From: b1ackmai1er <39449559+b1ackmai1er@users.noreply.github.com>
Date: Fri, 3 Aug 2018 22:38:58 +0800
Subject: [PATCH 3/5] Delete sio.asm

---
 sio.asm | 725 --------------------------------------------------------
 1 file changed, 725 deletions(-)
 delete mode 100644 sio.asm

diff --git a/sio.asm b/sio.asm
deleted file mode 100644
index c30ab09f..00000000
--- a/sio.asm
+++ /dev/null
@@ -1,725 +0,0 @@
-;
-;==================================================================================================
-; SIO DRIVER (SERIAL PORT)
-;==================================================================================================
-;
-;  SETUP PARAMETER WORD:
-;  +-------+---+-------------------+ +---+---+-----------+---+-------+
-;  |       |RTS| ENCODED BAUD RATE | |DTR|XON|  PARITY   |STP| 8/7/6 |
-;  +-------+---+---+---------------+ ----+---+-----------+---+-------+
-;    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	
-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
-SIOA_DAT	.EQU	SIOBASE + $00
-SIOB_CMD	.EQU	SIOBASE + $03
-SIOB_DAT	.EQU	SIOBASE + $01
-#ENDIF
-;
-#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
-;
-; CONDITIONALS THAT DETERMINE THE ENCODED VALUE OF THE BAUD RATE
-;
-#INCLUDE "siobaud.inc"	
-;
-SIO_PREINIT:
-;
-; SETUP THE DISPATCH TABLE ENTRIES
-;
-	LD	B,SIO_CNT		; LOOP CONTROL
-	LD	C,0			; PHYSICAL UNIT INDEX
-	XOR	A			; ZERO TO ACCUM
-	LD	(SIO_DEV),A		; CURRENT DEVICE NUMBER
-SIO_PREINIT0:	
-	PUSH	BC			; SAVE LOOP CONTROL
-	LD	A,C			; PHYSICAL UNIT TO A
-	RLCA				; MULTIPLY BY CFG TABLE ENTRY SIZE (8 BYTES)
-	RLCA				; ...
-	RLCA				; ... TO GET OFFSET INTO CFG TABLE
-	LD	HL,SIO_CFG		; POINT TO START OF CFG TABLE
-	CALL	ADDHLA			; HL := ENTRY ADDRESS
-	PUSH	HL			; SAVE IT
-	PUSH	HL			; COPY CFG DATA PTR
-	POP	IY			; ... TO IY
-	CALL	SIO_INITUNIT		; HAND OFF TO GENERIC INIT CODE
-	POP	DE			; GET ENTRY ADDRESS BACK, BUT PUT IN DE
-	POP	BC			; RESTORE LOOP CONTROL
-;
-	LD	A,(IY+1)		; GET THE SIO TYPE DETECTED
-	OR	A			; SET FLAGS
-	JR	Z,SIO_PREINIT2		; SKIP IT IF NOTHING FOUND
-;	
-	PUSH	BC			; SAVE LOOP CONTROL
-	LD	BC,SIO_FNTBL		; BC := FUNCTION TABLE ADDRESS
-	CALL	NZ,CIO_ADDENT		; ADD ENTRY IF SIO FOUND, BC:DE
-	POP	BC			; RESTORE LOOP CONTROL
-;
-SIO_PREINIT2:	
-	INC	C			; NEXT PHYSICAL UNIT
-	DJNZ	SIO_PREINIT0		; LOOP UNTIL DONE
-;
-#IF (INTMODE == 1)
-	; ADD IM1 INT CALL LIST ENTRY IF APPROPRIATE
-	LD	A,(SIO_DEV)		; GET NEXT DEVICE NUM
-	OR	A			; SET FLAGS
-	JR	Z,SIO_PREINIT3		; IF ZERO, NO SIO DEVICES
-	LD	HL,SIO_INT		; GET INT VECTOR
-	CALL	HB_ADDIM1		; ADD TO IM1 CALL LIST
-#ENDIF
-;
-#IF (INTMODE == 2)
-	; SETUP SIO INTERRUPT VECTOR IN IVT
-	LD	HL,INT_SIO
-	LD	(HBX_IVT + IVT_SER0),HL
-#ENDIF
-;
-SIO_PREINIT3:
-	XOR	A			; SIGNAL SUCCESS
-	RET				; AND RETURN
-;
-; SIO INITIALIZATION ROUTINE
-;
-SIO_INITUNIT:
-	CALL	SIO_DETECT		; DETERMINE SIO TYPE
-	LD	(IY+1),A		; SAVE IN CONFIG TABLE
-	OR	A			; SET FLAGS
-	RET	Z			; ABORT IF NOTHING THERE
-
-	; UPDATE WORKING SIO DEVICE NUM
-	LD	HL,SIO_DEV		; POINT TO CURRENT UART DEVICE NUM
-	LD	A,(HL)			; PUT IN ACCUM
-	INC	(HL)			; INCREMENT IT (FOR NEXT LOOP)
-	LD	(IY),A			; UPDATE UNIT NUM
-	
-	; SET DEFAULT CONFIG
-	LD	DE,-1			; LEAVE CONFIG ALONE
-	JP	SIO_INITDEV		; IMPLEMENT IT AND RETURN
-;
-;
-;
-SIO_INIT:
-	LD	B,SIO_CNT		; COUNT OF POSSIBLE SIO UNITS
-	LD	C,0			; INDEX INTO SIO CONFIG TABLE
-SIO_INIT1:
-	PUSH	BC			; SAVE LOOP CONTROL
-	
-	LD	A,C			; PHYSICAL UNIT TO A
-	RLCA				; MULTIPLY BY CFG TABLE ENTRY SIZE (8 BYTES)
-	RLCA				; ...
-	RLCA				; ... TO GET OFFSET INTO CFG TABLE
-	LD	HL,SIO_CFG		; POINT TO START OF CFG TABLE
-	CALL	ADDHLA			; HL := ENTRY ADDRESS
-	PUSH	HL			; COPY CFG DATA PTR
-	POP	IY			; ... TO IY
-	
-	LD	A,(IY+1)		; GET SIO TYPE
-	OR	A			; SET FLAGS
-	CALL	NZ,SIO_PRTCFG		; PRINT IF NOT ZERO
-	
-	POP	BC			; RESTORE LOOP CONTROL
-	INC	C			; NEXT UNIT
-	DJNZ	SIO_INIT1		; LOOP TILL DONE
-;
-	XOR	A			; SIGNAL SUCCESS
-	RET				; DONE
-;
-; RECEIVE INTERRUPT HANDLER
-;
-#IF (INTMODE > 0)
-;
-SIO_INT:
-SIOA_INT:
-	; CHECK FOR RECEIVE PENDING ON CHANNEL A
-	XOR	A			; A := 0
-	OUT	(SIOA_CMD),A		; ADDRESS RD0
-	IN	A,(SIOA_CMD)		; GET RD0
-	AND	$01			; ISOLATE RECEIVE READY BIT
-	JR	Z,SIOB_INT		; CHECK CHANNEL B
-;
-SIOA_INT00:
-	; HANDLE CHANNEL A
-	IN	A,(SIOA_DAT)		; READ PORT
-	LD	E,A			; SAVE BYTE READ
-	LD	A,(SIOA_CNT)		; GET CURRENT BUFFER USED COUNT
-	CP	SIOA_BUFSZ		; COMPARE TO BUFFER SIZE
-	RET	Z			; BAIL OUT IF BUFFER FULL, RCV BYTE DISCARDED
-	INC	A			; INCREMENT THE COUNT
-	LD	(SIOA_CNT),A		; AND SAVE IT
-	CP	SIOA_BUFSZ - 5		; BUFFER GETTING FULL?
-	JR	NZ,SIOA_INT0		; IF NOT, BYPASS CLEARING RTS
-	LD	A,5			; RTS IS IN WR5
-	OUT	(SIOA_CMD),A		; ADDRESS WR5
-	LD	A,$E8			; VALUE TO CLEAR RTS
-	OUT	(SIOA_CMD),A		; DO IT
-SIOA_INT0:
-	LD	HL,(SIOA_HD)		; GET HEAD POINTER
-	LD	A,L			; GET LOW BYTE
-	CP	SIOA_BUFEND & $FF	; PAST END?
-	JR	NZ,SIOA_INT1		; IF NOT, BYPASS POINTER RESET
-	LD	HL,SIOA_BUF		; ... OTHERWISE, RESET TO START OF BUFFER
-SIOA_INT1:
-	LD	A,E			; RECOVER BYTE READ
-	LD	(HL),A			; SAVE RECEIVED BYTE TO HEAD POSITION
-	INC	HL			; INCREMENT HEAD POINTER
-	LD	(SIOA_HD),HL		; SAVE IT
-;
-	; CHECK FOR MORE PENDING...
-	XOR	A			; A := 0
-	OUT	(SIOA_CMD),A		; ADDRESS RD0
-	IN	A,(SIOA_CMD)		; GET RD0
-	RRA				; READY BIT TO CF
-	JR	C,SIOA_INT00		; IF SET, DO SOME MORE
-	OR	$FF			; NZ SET TO INDICATE INT HANDLED
-	RET				; AND RETURN
-;
-SIOB_INT:
-	; CHECK FOR RECEIVE PENDING ON CHANNEL B
-	XOR	A			; A := 0
-	OUT	(SIOB_CMD),A		; ADDRESS RD0
-	IN	A,(SIOB_CMD)		; GET RD0
-	AND	$01			; ISOLATE RECEIVE READY BIT
-	RET	Z			; IF NOT, RETURN WITH Z SET
-;
-SIOB_INT00:
-	; HANDLE CHANNEL B
-	IN	A,(SIOB_DAT)		; READ PORT
-	LD	E,A			; SAVE BYTE READ
-	LD	A,(SIOB_CNT)		; GET CURRENT BUFFER USED COUNT
-	CP	SIOB_BUFSZ		; COMPARE TO BUFFER SIZE
-	RET	Z			; BAIL OUT IF BUFFER FULL, RCV BYTE DISCARDED
-	INC	A			; INCREMENT THE COUNT
-	LD	(SIOB_CNT),A		; AND SAVE IT
-	CP	SIOB_BUFSZ - 5		; BUFFER GETTING FULL?
-	JR	NZ,SIOB_INT0		; IF NOT, BYPASS CLEARING RTS
-	LD	A,5			; RTS IS IN WR5
-	OUT	(SIOB_CMD),A		; ADDRESS WR5
-	LD	A,$E8			; VALUE TO CLEAR RTS
-	OUT	(SIOB_CMD),A		; DO IT
-SIOB_INT0:
-	LD	HL,(SIOB_HD)		; GET HEAD POINTER
-	LD	A,L			; GET LOW BYTE
-	CP	SIOB_BUFEND & $FF	; PAST END?
-	JR	NZ,SIOB_INT1		; IF NOT, BYPASS POINTER RESET
-	LD	HL,SIOB_BUF		; ... OTHERWISE, RESET TO START OF BUFFER
-SIOB_INT1:
-	LD	A,E			; RECOVER BYTE READ
-	LD	(HL),A			; SAVE RECEIVED BYTE TO HEAD POSITION
-	INC	HL			; INCREMENT HEAD POINTER
-	LD	(SIOB_HD),HL		; SAVE IT
-;
-	; CHECK FOR MORE PENDING...
-	XOR	A			; A := 0
-	OUT	(SIOB_CMD),A		; ADDRESS RD0
-	IN	A,(SIOB_CMD)		; GET RD0
-	RRA				; READY BIT TO CF
-	JR	C,SIOB_INT00		; IF SET, DO SOME MORE
-	OR	$FF			; NZ SET TO INDICATE INT HANDLED
-	RET				; AND RETURN
-;
-#ENDIF
-;
-; DRIVER FUNCTION TABLE
-;
-SIO_FNTBL:
-	.DW	SIO_IN
-	.DW	SIO_OUT
-	.DW	SIO_IST
-	.DW	SIO_OST
-	.DW	SIO_INITDEV
-	.DW	SIO_QUERY
-	.DW	SIO_DEVICE
-#IF (($ - SIO_FNTBL) != (CIO_FNCNT * 2))
-	.ECHO	"*** INVALID SIO FUNCTION TABLE ***\n"
-#ENDIF
-;
-;
-;
-#IF (INTMODE == 0)
-;
-SIO_IN:
-	CALL	SIO_IST			; CHAR WAITING?
-	JR	Z,SIO_IN		; LOOP IF NOT
-	LD	C,(IY+3)		; C := SIO CMD PORT
-#IF (SIOMODE == SIOMODE_RC)
-	INC	C			; BUMP TO DATA PORT
-#ENDIF
-#IF ((SIOMODE == SIOMODE_SMB) | (SIOMODE == SIOMODE_ZP))
-	DEC	C			; DECREMENT CMD PORT TWICE TO GET DATA PORT
-	DEC	C
-#ENDIF
-	IN	E,(C)			; GET CHAR
-	XOR	A			; SIGNAL SUCCESS
-	RET
-;
-#ELSE
-;
-SIO_IN:
-	LD	A,(IY+2)		; GET CHANNEL
-	OR	A			; SET FLAGS
-	JR	Z,SIOA_IN		; HANDLE CHANNEL A
-	DEC	A			; TEST FOR NEXT DEVICE
-	JR	Z,SIOB_IN		; HANDLE CHANNEL B
-	CALL 	PANIC			; ELSE FATAL ERROR
-	RET				; ... AND RETURN
-;
-SIOA_IN:
-	CALL	SIOA_IST		; RECEIVED CHAR READY?
-	JR	Z,SIOA_IN		; LOOP TILL WE HAVE SOMETHING IN BUFFER
-	HB_DI				; AVOID COLLISION WITH INT HANDLER
-	LD	A,(SIOA_CNT)		; GET COUNT
-	DEC	A			; DECREMENT COUNT
-	LD	(SIOA_CNT),A		; SAVE SAVE IT
-	CP	5			; BUFFER LOW THRESHOLD
-	JR	NZ,SIOA_IN0		; IF NOT, BYPASS SETTING RTS
-	LD	A,5			; RTS IS IN WR5
-	OUT	(SIOA_CMD),A		; ADDRESS WR5
-	LD	A,$EA			; VALUE TO SET RTS
-	OUT	(SIOA_CMD),A		; DO IT
-SIOA_IN0:
-	LD	HL,(SIOA_TL)		; GET BUFFER TAIL POINTER
-	LD	E,(HL)			; GET BYTE
-	INC	HL			; BUMP TAIL POINTER
-	LD	A,L			; GET LOW BYTE
-	CP	SIOA_BUFEND & $FF	; PAST END?
-	JR	NZ,SIOA_IN1		; IF NOT, BYPASS POINTER RESET
-	LD	HL,SIOA_BUF		; ... OTHERWISE, RESET TO START OF BUFFER
-SIOA_IN1:
-	LD	(SIOA_TL),HL		; SAVE UPDATED TAIL POINTER
-	HB_EI				; INTERRUPTS OK AGAIN
-	XOR	A			; SIGNAL SUCCESS
-	RET				; AND DONE
-;
-SIOB_IN:
-	CALL	SIOB_IST		; RECEIVED CHAR READY?
-	JR	Z,SIOB_IN		; LOOP TILL WE HAVE SOMETHING IN BUFFER
-	HB_DI				; AVOID COLLISION WITH INT HANDLER
-	LD	A,(SIOB_CNT)		; GET COUNT
-	DEC	A			; DECREMENT COUNT
-	LD	(SIOB_CNT),A		; SAVE SAVE IT
-	CP	5			; BUFFER LOW THRESHOLD
-	JR	NZ,SIOB_IN0		; IF NOT, BYPASS SETTING RTS
-	LD	A,5			; RTS IS IN WR5
-	OUT	(SIOB_CMD),A		; ADDRESS WR5
-	LD	A,$EA			; VALUE TO SET RTS
-	OUT	(SIOB_CMD),A		; DO IT
-SIOB_IN0:
-	LD	HL,(SIOB_TL)		; GET BUFFER TAIL POINTER
-	LD	E,(HL)			; GET BYTE
-	INC	HL			; BUMP TAIL POINTER
-	LD	A,L			; GET LOW BYTE
-	CP	SIOB_BUFEND & $FF	; PAST END?
-	JR	NZ,SIOB_IN1		; IF NOT, BYPASS POINTER RESET
-	LD	HL,SIOB_BUF		; ... OTHERWISE, RESET TO START OF BUFFER
-SIOB_IN1:
-	LD	(SIOB_TL),HL		; SAVE UPDATED TAIL POINTER
-	HB_EI				; INTERRUPTS OK AGAIN
-	XOR	A			; SIGNAL SUCCESS
-	RET				; AND DONE
-;
-#ENDIF
-;
-;
-;
-SIO_OUT:
-	CALL	SIO_OST			; READY FOR CHAR?
-	JR	Z,SIO_OUT		; LOOP IF NOT
-	LD	C,(IY+3)		; C := SIO CMD PORT
-#IF (SIOMODE == SIOMODE_RC)
-	INC	C			; BUMP TO DATA PORT
-#ENDIF
-#IF ((SIOMODE == SIOMODE_SMB) | (SIOMODE == SIOMODE_ZP))
-	DEC C				; DECREMENT CMD PORT TWICE TO GET DATA PORT
-	DEC C
-#ENDIF
-	OUT	(C),E			; SEND CHAR FROM E
-	XOR	A			; SIGNAL SUCCESS
-	RET
-;
-;
-;
-#IF (INTMODE == 0)
-;
-SIO_IST:
-	LD	C,(IY+3)		; CMD PORT
-	XOR	A			; WR0
-	OUT	(C),A			; DO IT
-	IN	A,(C)			; GET STATUS
-	AND	$01			; ISOLATE BIT 0 (RX READY)
-	JP	Z,CIO_IDLE		; NOT READY, RETURN VIA IDLE PROCESSING
-	XOR	A			; ZERO ACCUM
-	INC	A			; ASCCUM := 1 TO SIGNAL 1 CHAR WAITING
-	RET				; DONE
-;
-#ELSE
-;
-SIO_IST:
-	LD	A,(IY+2)		; GET CHANNEL
-	OR	A			; SET FLAGS
-	JR	Z,SIOA_IST		; HANDLE CHANNEL A
-	DEC	A			; TEST FOR NEXT DEVICE
-	JR	Z,SIOB_IST		; HANDLE CHANNEL B
-	CALL 	PANIC			; ELSE FATAL ERROR
-	RET				; ... AND RETURN
-;
-SIOA_IST:
-	LD	A,(SIOA_CNT)		; GET BUFFER UTILIZATION COUNT
-	OR	A			; SET FLAGS
-	JP	Z,CIO_IDLE		; NOT READY, RETURN VIA IDLE PROCESSING
-	RET				; AND DONE
-;
-SIOB_IST:
-	LD	A,(SIOB_CNT)		; GET BUFFER UTILIZATION COUNT
-	OR	A			; SET FLAGS
-	JP	Z,CIO_IDLE		; NOT READY, RETURN VIA IDLE PROCESSING
-	RET				; DONE
-;
-#ENDIF
-;
-;
-;
-SIO_OST:
-	LD	C,(IY+3)		; CMD PORT
-	XOR	A			; WR0
-	OUT	(C),A			; DO IT
-	IN	A,(C)			; GET STATUS
-	AND	$04			; ISOLATE BIT 2 (TX EMPTY)
-	JP	Z,CIO_IDLE		; NOT READY, RETURN VIA IDLE PROCESSING
-	XOR	A			; ZERO ACCUM
-	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)
-	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
-	LD	E,(IY+4)		; LOW BYTE
-	LD	D,(IY+5)		; HIGH BYTE	
-;
-SIO_INITDEV1:
-	PUSH	DE			; SAVE CONFIG
-
-	LD	A,D			; GET CONFIG MSB
-	AND	$1F			; ISOLATE ENCODED BAUD RATE
-
-#IF (SIODEBUG)
-	PUSH	AF
-	PRTS(" ENCODE[$")
-	CALL	PRTHEXBYTE
-	PRTC(']')
-	POP	AF
-#ENDIF
-;
-; 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	
-	LD	D,$44			; /16 N,8,1
-	JR	Z,BROK	
-	CP	SIOBAUD3	
-	LD	D,$84			; /32 N,8,1
-	JR	Z,BROK	
-	CP	SIOBAUD4	
-	LD	D,$C4			; /64 N,8,1
-	JR	Z,BROK			
-	
-#IF (SIODEBUG)
-	PUSH	AF
-	PRTS(" BR FAIL[$")	
-	CALL PRTHEXBYTE
-	PRTC(']')
-	POP	AF
-#ENDIF
-;
-EXITINIT:
-	POP	DE
-	RET				; NZ status here indicating fail / invalid baud rate.
-	
-BROK:
-	LD	A,E
-	AND	$E0
-	JR	NZ,EXITINIT		; NZ status here indicates dtr, xon, parity mark or space so return
-
-	LD	A,E			;  set stop bit (d3) and add divider
-	AND	$04
-	RLA
-	OR	D			; carry gets reset here
-	LD	D,A
-	
-	LD	A,E			; get the parity bits
-	SRL	A			; move them to bottom two bits
-	SRL	A			; we know top bits are zero from previous test
-	SRL	A			; add stop bits
-	OR	D 			; carry = 0
-;	
-; SET DIVIDER, STOP AND PARITY WR4
-;	
-	LD	BC,SIO_INITVALS+3
-	LD	(BC),A
-	
-#IF (SIODEBUG)
-	PUSH	AF
-	PRTS(" WR4[$")
-	CALL	PRTHEXBYTE
-	PRTC(']')
-	POP	AF
-#ENDIF
-
-	LD	A,E			; 112233445566d1d0 CC
-	RRA				; CC112233445566d1 d0
-	RRA				; d0CC112233445566 d1
-	RRA 			; d1d0CC1122334455 66
-	LD	D,A	
-	RRA				; 66d1d0CC11223344 55
-	AND	$60			; 0011110000000000 00
-	OR	$8a
-;	
-; SET TRANSMIT DATA BITS WR5	
-;
-	LD	BC,SIO_INITVALS+11
-	LD	(BC),A	
-
-#IF (SIODEBUG)
-	PUSH	AF
-	PRTS(" WR5[$")
-	CALL	PRTHEXBYTE
-	PRTC(']')
-	POP	AF
-#ENDIF	
-;
-; SET RECEIVE DATA BITS WR3 
-;	
-	LD	A,D
-	AND	$C0
-	OR	$01
-	
-	LD	BC,SIO_INITVALS+9
-	LD	(BC),A	
-
-#IF (SIODEBUG)
-	PUSH	AF
-	PRTS(" WR3[$")
-	CALL	PRTHEXBYTE
-	PRTC(']')
-	POP	AF
-#ENDIF	
-	
-	POP	DE			; RESTORE CONFIG
-
-	LD	(IY+4),E		; SAVE LOW WORD
-	LD	(IY+5),D		; SAVE HI WORD
-	
-	HB_DI				; AVOID CONFLICTS
-;
-	; PROGRAM THE SIO CHIP CHANNEL
-	LD	C,(IY+3)		; COMMAND PORT
-	LD	HL,SIO_INITVALS		; POINT TO INIT VALUES
-	LD	B,SIO_INITLEN		; COUNT OF BYTES TO WRITE
-	OTIR				; WRITE ALL VALUES
-;
-	; RESET THE RECEIVE BUFFER
-	LD	E,(IY+6)
-	LD	D,(IY+7)		; DE := _CNT
-	XOR	A			; A := 0
-	LD	(DE),A			; _CNT = 0
-	INC	DE			; DE := ADR OF _HD
-	PUSH	DE			; SAVE IT
-	INC	DE
-	INC	DE
-	INC	DE
-	INC	DE			; DE := ADR OF _BUF
-	POP	HL			; HL := ADR OF _HD
-	LD	(HL),E
-	INC	HL
-	LD	(HL),D			; _HD := _BUF
-	INC	HL
-	LD	(HL),E
-	INC	HL
-	LD	(HL),D			; _TL := _BUF
-;
-	HB_EI				; READY FOR INTS AGAIN
-	XOR	A			; SIGNAL SUCCESS
-	RET				; RETURN
-;
-;
-SIO_INITVALS:
-	.DB	$00, $18		; WR0: CHANNEL RESET
-	.DB	$04, $00		; WR4: CLK BAUD PARITY STOP BIT
-#IF (INTMODE == 0)
-	.DB	$01, $00		; WR1: NO INTERRUPTS
-#ELSE
-	.DB	$01, $18		; WR1: INTERRUPT ON ALL RECEIVE CHARACTERS
-#ENDIF
-	.DB	$02, IVT_SER0		; WR2: INTERRUPT VECTOR OFFSET
-	.DB	$03, $C1		; WR3: 8 BIT RCV, RX ENABLE
-	.DB	$05, $EA		; WR5: DTR, 8 BITS SEND,  TX ENABLE, RTS 1 11 0 1 0 1 0 (1=DTR,11=8bits,0=sendbreak,1=TxEnable,0=sdlc,1=RTS,0=txcrc)
-SIO_INITLEN	.EQU	$ - SIO_INITVALS
-;
-;
-;
-SIO_QUERY:
-	LD	E,(IY+4)		; FIRST CONFIG BYTE TO E
-	LD	D,(IY+5)		; SECOND CONFIG BYTE TO D
-	XOR	A			; SIGNAL SUCCESS
-	RET				; DONE
-;
-;
-;
-SIO_DEVICE:
-	LD	D,CIODEV_SIO		; D := DEVICE TYPE
-	LD	E,(IY)			; E := PHYSICAL UNIT
-	XOR	A			; SIGNAL SUCCESS
-	RET
-;
-; SIO DETECTION ROUTINE
-;
-SIO_DETECT:
-	LD	C,(IY+3)		; COMMAND PORT
-	XOR	A	
-	OUT	(C),A			; ACCESS RD0
-	IN	A,(C)			; GET RD0 VALUE
-	LD	B,A			; SAVE IT
-	LD	A,1	
-	OUT	(C),A			; ACCESS RD1
-	IN	A,(C)			; GET RD1 VALUE
-	CP	B			; COMPARE
-	LD	A,SIO_NONE		; ASSUME NOTHING THERE
-	RET	Z			; RD0=RD1 MEANS NOTHING THERE
-	LD	A,SIO_SIO		; GUESS WE HAVE A VALID SIO HERE
-	RET				; DONE
-;
-;
-;
-SIO_PRTCFG:
-	; ANNOUNCE PORT
-	CALL	NEWLINE			; FORMATTING
-	PRTS("SIO$")			; FORMATTING
-	LD	A,(IY)			; DEVICE NUM
-	CALL	PRTDECB			; PRINT DEVICE NUM
-	PRTS(": IO=0x$")		; FORMATTING
-	LD	A,(IY+3)		; GET BASE PORT
-	CALL	PRTHEXBYTE		; PRINT BASE PORT
-
-	; PRINT THE SIO TYPE
-	CALL	PC_SPACE		; FORMATTING
-	LD	A,(IY+1)		; GET SIO TYPE BYTE
-	RLCA				; MAKE IT A WORD OFFSET
-	LD	HL,SIO_TYPE_MAP		; POINT HL TO TYPE MAP TABLE
-	CALL	ADDHLA			; HL := ENTRY
-	LD	E,(HL)			; DEREFERENCE
-	INC	HL			; ...
-	LD	D,(HL)			; ... TO GET STRING POINTER
-	CALL	WRITESTR		; PRINT IT
-;
-	; ALL DONE IF NO SIO WAS DETECTED
-	LD	A,(IY+1)		; GET SIO TYPE BYTE
-	OR	A			; SET FLAGS
-	RET	Z			; IF ZERO, NOT PRESENT
-;
-	PRTS(" MODE=$")			; FORMATTING
-	LD	E,(IY+4)		; LOAD CONFIG
-	LD	D,(IY+5)		; ... WORD TO DE
-	CALL	PS_PRTSC0		; PRINT CONFIG
-;
-	XOR	A
-	RET
-;
-;
-;
-SIO_TYPE_MAP:
-		.DW	SIO_STR_NONE
-		.DW	SIO_STR_SIO
-
-SIO_STR_NONE	.DB	"<NOT PRESENT>$"
-SIO_STR_SIO	.DB	"SIO$"
-;
-; WORKING VARIABLES
-;
-SIO_DEV		.DB	0		; DEVICE NUM USED DURING INIT
-;
-#IF (INTMODE == 0)
-;
-SIOA_RCVBUF	.EQU	0
-SIOB_RCVBUF	.EQU	0
-;
-#ELSE
-;
-; CHANNEL A RECEIVE BUFFER
-SIOA_RCVBUF:
-SIOA_CNT	.DB	0		; CHARACTERS IN RING BUFFER
-SIOA_HD		.DW	SIOA_BUF	; BUFFER HEAD POINTER
-SIOA_TL		.DW	SIOA_BUF	; BUFFER TAIL POINTER
-SIOA_BUF	.FILL	32,0		; RECEIVE RING BUFFER
-SIOA_BUFEND	.EQU	$		; END OF BUFFER
-SIOA_BUFSZ	.EQU	$ - SIOA_BUF	; SIZE OF RING BUFFER
-;
-; CHANNEL B RECEIVE BUFFER
-SIOB_RCVBUF:
-SIOB_CNT	.DB	0		; CHARACTERS IN RING BUFFER
-SIOB_HD		.DW	SIOB_BUF	; BUFFER HEAD POINTER
-SIOB_TL		.DW	SIOB_BUF	; BUFFER TAIL POINTER
-SIOB_BUF	.FILL	32,0		; RECEIVE RING BUFFER
-SIOB_BUFEND	.EQU	$		; END OF BUFFER
-SIOB_BUFSZ	.EQU	$ - SIOB_BUF	; SIZE OF RING BUFFER
-;
-#ENDIF
-;
-; SIO PORT TABLE
-;
-SIO_CFG:
-	; SIO CHANNEL A
-	.DB	0			; DEVICE NUMBER (SET DURING INIT)
-	.DB	0			; SIO TYPE (SET DURING INIT)
-	.DB	0			; SIO CHANNEL (A)
-	.DB	SIOA_CMD		; BASE PORT (CMD PORT)
-	.DW	DEFSIOACFG		; LINE CONFIGURATION
-	.DW	SIOA_RCVBUF		; POINTER TO RCV BUFFER STRUCT
-;
-	; SIO CHANNEL B
-	.DB	0			; DEVICE NUMBER (SET DURING INIT)
-	.DB	0			; SIO TYPE (SET DURING INIT)
-	.DB	1			; SIO CHANNEL (B)
-	.DB	SIOB_CMD		; BASE PORT (CMD PORT)
-	.DW	DEFSIOBCFG		; LINE CONFIGURATION
-	.DW	SIOB_RCVBUF		; POINTER TO RCV BUFFER STRUCT
-;
-SIO_CNT	.EQU	($ - SIO_CFG) / 8

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 4/5] 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

From 1fc2017db50cd9c1c02e5958760e8270cd9dc51b Mon Sep 17 00:00:00 2001
From: b1ackmai1er <39449559+b1ackmai1er@users.noreply.github.com>
Date: Fri, 3 Aug 2018 22:45:13 +0800
Subject: [PATCH 5/5] Fix typo.

---
 Source/HBIOS/siobaud.inc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Source/HBIOS/siobaud.inc b/Source/HBIOS/siobaud.inc
index bb819775..c315c9bf 100644
--- a/Source/HBIOS/siobaud.inc
+++ b/Source/HBIOS/siobaud.inc
@@ -4,7 +4,7 @@
 ;
 
 #IF (DEFSIOCLK/DEFSIODIV/1 ==     75) 
-SIOBAUD1 .EQU  0 E
+SIOBAUD1 .EQU  0
 #ENDIF
 #IF (DEFSIOCLK/DEFSIODIV/1 ==    150) 
 SIOBAUD1 .EQU  1