diff --git a/Source/CBIOS/cbios.asm b/Source/CBIOS/cbios.asm
index 969992e0..481d951c 100644
--- a/Source/CBIOS/cbios.asm
+++ b/Source/CBIOS/cbios.asm
@@ -432,6 +432,8 @@ WBOOT:
 #ENDIF
 ;
 #IFDEF PLTUNA
+	LD	SP,STACK		; STACK FOR INITIALIZATION
+
 	; RESTORE COMMAND PROCESSOR FROM UNA BIOS CACHE
 	LD	BC,$01FB		; UNA FUNC = SET BANK
 	LD	DE,(BNKBIOS)		; UBIOS_PAGE (SEE PAGES.INC)
@@ -1626,6 +1628,7 @@ LBA_IO:
 ;
 DSK_IO2:
 	PUSH	BC			; SAVE INCOMING FUNCTION, UNIT
+	RES	7,D			; CLEAR LBA BIT FOR UNA
 	LD	B,C			; UNIT TO B
 	LD	C,$41			; UNA SET LBA
 	RST	08			; CALL UNA
diff --git a/Source/Doc/Architecture.md b/Source/Doc/Architecture.md
index ed9a33e5..25988625 100644
--- a/Source/Doc/Architecture.md
+++ b/Source/Doc/Architecture.md
@@ -1399,7 +1399,7 @@ If the driver is able to generate the requested note, a success (0) is
 returned, otherwise a non-zero error state will be returned.
 
 The sound chip resolution and its oscillator limit the range and
-accuracy of the notes played. The typically range of the AY-3-8910
+accuracy of the notes played. The typical range of the AY-3-8910
 is six octaves, Bb2/A#2-A7, where each value is a unique tone. Values
 above and below can still be played but each quarter tone step may not
 result in a note change.
@@ -1409,18 +1409,18 @@ to the corresponding octave and note.
 
 | Note  | Oct 0 | Oct 1 | Oct 2 | Oct 3 | Oct 4 | Oct 5 | Oct 6 | Oct 7 |
 |:----- | -----:| -----:| -----:| -----:| -----:| -----:| -----:| -----:|
-| Bb/A# |   0   |   48  |  96   |  144  |  192  |  240  |  288  |  336  |
+| C     |   X   |   8   |   56  |  104  |  152  |  200  |  248  |  296  |
+| C#/Db |   X   |   12  |   60  |  108  |  156  |  204  |  252  |  300  |
+| D     |   X   |   16  |   64  |  112  |  160  |  208  |  256  |  304  |
+| D#/Eb |   X   |   20  |   68  |  116  |  164  |  212  |  260  |  308  |
+| E     |   X   |   24  |   72  |  120  |  168  |  216  |  264  |  312  |
+| F     |   X   |   28  |   76  |  124  |  172  |  220  |  268  |  316  |
+| F#/Gb |   X   |   32  |   80  |  128  |  176  |  224  |  272  |  320  |
+| G     |   X   |   36  |   84  |  132  |  180  |  228  |  276  |  324  |
+| G#/Ab |   X   |   40  |   88  |  136  |  184  |  232  |  280  |  328  |
+| A     |   X   |   44  |   92  |  140  |  188  |  236  |  284  |  332  |
+| A#/Bb |   0   |   48  |   96  |  144  |  192  |  240  |  288  |  336  |
 | B     |   4   |   52  |  100  |  148  |  196  |  244  |  292  |  340  |
-| C     |   8   |   56  |  104  |  152  |  200  |  248  |  296  |  344  |
-| C#/Db |   12  |   60  |  108  |  156  |  204  |  252  |  300  |  348  |
-| D     |   16  |   64  |  112  |  160  |  208  |  256  |  304  |  352  |
-| Eb/D# |   20  |   68  |  116  |  164  |  212  |  260  |  308  |  356  |
-| E     |   24  |   72  |  120  |  168  |  216  |  264  |  312  |  360  |
-| F     |   28  |   76  |  124  |  172  |  220  |  268  |  316  |  364  |
-| F#/Gb |   32  |   80  |  128  |  176  |  224  |  272  |  320  |  368  |
-| G     |   36  |   84  |  132  |  180  |  228  |  276  |  324  |  372  |
-| Ab/G# |   40  |   88  |  136  |  184  |  232  |  280  |  328  |  376  |
-| A     |   44  |   92  |  140  |  188  |  236  |  284  |  332  |  380  |
 
 ### Function 0x54 -- Sound Play (SNDPLAY)
 
diff --git a/Source/HBIOS/ay38910.asm b/Source/HBIOS/ay38910.asm
index 1d596dbd..c591e3b8 100644
--- a/Source/HBIOS/ay38910.asm
+++ b/Source/HBIOS/ay38910.asm
@@ -327,7 +327,8 @@ AY_NOTE:
 	LD	H, (HL)			; SO WE CAN UPDATE IT FOR THE REQUIRED OCTAVE
 	LD	L, A
 ;
-	LD	A,AY_SCALE-1		; THE NOTE TABLE PERIOD DATA HAS BEEN
+	;LD	A,AY_SCALE - 1		; THE NOTE TABLE PERIOD DATA HAS BEEN
+	LD	A,AY_SCALE		; THE NOTE TABLE PERIOD DATA HAS BEEN
 	ADD	A,C			; PRESCALED TO MAINTAIN RANGE SO ALLOW
 	LD	B,A			; FOR THIS WHEN CHANGING OCTAVE
 AY_NOTE1:
@@ -617,51 +618,51 @@ AYT_REGWR		.DB	"\r\nOUT AY-3-8910 $"
 ; ASSUMING A CLOCK OF 1843200 THIS MAPS TO A0#
 ;
 AY3NOTETBL:
-	.DW	AY_RATIO / 2913
-	.DW	AY_RATIO / 2956
-	.DW	AY_RATIO / 2999
-	.DW	AY_RATIO / 3042
-	.DW	AY_RATIO / 3086
-	.DW	AY_RATIO / 3131
-	.DW	AY_RATIO / 3177
-	.DW	AY_RATIO / 3223
-	.DW	AY_RATIO / 3270
-	.DW	AY_RATIO / 3318
-	.DW	AY_RATIO / 3366
-	.DW	AY_RATIO / 3415
-	.DW	AY_RATIO / 3464
-	.DW	AY_RATIO / 3515
-	.DW	AY_RATIO / 3566
-	.DW	AY_RATIO / 3618
-	.DW	AY_RATIO / 3670
-	.DW	AY_RATIO / 3724
-	.DW	AY_RATIO / 3778
-	.DW	AY_RATIO / 3833
-	.DW	AY_RATIO / 3889
-	.DW	AY_RATIO / 3945
-	.DW	AY_RATIO / 4003
-	.DW	AY_RATIO / 4061
-	.DW	AY_RATIO / 4120
-	.DW	AY_RATIO / 4180
-	.DW	AY_RATIO / 4241
-	.DW	AY_RATIO / 4302
-	.DW	AY_RATIO / 4365
-	.DW	AY_RATIO / 4428
-	.DW	AY_RATIO / 4493
-	.DW	AY_RATIO / 4558
-	.DW	AY_RATIO / 4624
-	.DW	AY_RATIO / 4692
-	.DW	AY_RATIO / 4760
-	.DW	AY_RATIO / 4829
-	.DW	AY_RATIO / 4899
-	.DW	AY_RATIO / 4971
-	.DW	AY_RATIO / 5043
-	.DW	AY_RATIO / 5116
-	.DW	AY_RATIO / 5191
-	.DW	AY_RATIO / 5266
-	.DW	AY_RATIO / 5343
-	.DW	AY_RATIO / 5421
-	.DW	AY_RATIO / 5499
-	.DW	AY_RATIO / 5579
-	.DW	AY_RATIO / 5661
-	.DW	AY_RATIO / 5743
+	.DW	AY_RATIO / 2913		; A0#/B0b	178977250 / 2913 = 61440; PROOF: 61440 >> 3 = 7680, 3579545 / 7680 / 16 = 29.13
+	.DW	AY_RATIO / 2956		;
+	.DW	AY_RATIO / 2999		;
+	.DW	AY_RATIO / 3042		;
+	.DW	AY_RATIO / 3086		; B0
+	.DW	AY_RATIO / 3131		; 
+	.DW	AY_RATIO / 3177		; 
+	.DW	AY_RATIO / 3223		; 
+	.DW	AY_RATIO / 3270		; C1
+	.DW	AY_RATIO / 3318		; 
+	.DW	AY_RATIO / 3366		; 
+	.DW	AY_RATIO / 3415		; 
+	.DW	AY_RATIO / 3464		; C1#/D1b
+	.DW	AY_RATIO / 3515		; 
+	.DW	AY_RATIO / 3566		; 
+	.DW	AY_RATIO / 3618		; 
+	.DW	AY_RATIO / 3670		; D1
+	.DW	AY_RATIO / 3724		; 
+	.DW	AY_RATIO / 3778		; 
+	.DW	AY_RATIO / 3833		; 
+	.DW	AY_RATIO / 3889		; D1#/E1b
+	.DW	AY_RATIO / 3945		; 
+	.DW	AY_RATIO / 4003		; 
+	.DW	AY_RATIO / 4061		; 
+	.DW	AY_RATIO / 4120		; E1
+	.DW	AY_RATIO / 4180		; 
+	.DW	AY_RATIO / 4241		; 
+	.DW	AY_RATIO / 4302		; 
+	.DW	AY_RATIO / 4365		; F1
+	.DW	AY_RATIO / 4428		; 
+	.DW	AY_RATIO / 4493		; 
+	.DW	AY_RATIO / 4558		; 
+	.DW	AY_RATIO / 4624		; F1#/G1b
+	.DW	AY_RATIO / 4692		; 
+	.DW	AY_RATIO / 4760		; 
+	.DW	AY_RATIO / 4829		; 
+	.DW	AY_RATIO / 4899		; G1
+	.DW	AY_RATIO / 4971		; 
+	.DW	AY_RATIO / 5043		; 
+	.DW	AY_RATIO / 5116		; 
+	.DW	AY_RATIO / 5191		; G1#/A1b
+	.DW	AY_RATIO / 5266		; 
+	.DW	AY_RATIO / 5343		; 
+	.DW	AY_RATIO / 5421		; 
+	.DW	AY_RATIO / 5499		; A1
+	.DW	AY_RATIO / 5579		; 
+	.DW	AY_RATIO / 5661		; 
+	.DW	AY_RATIO / 5743		; 
diff --git a/Source/HBIOS/cfg_dyno.asm b/Source/HBIOS/cfg_dyno.asm
index a9a43b45..a5400782 100644
--- a/Source/HBIOS/cfg_dyno.asm
+++ b/Source/HBIOS/cfg_dyno.asm
@@ -183,7 +183,7 @@ HDSKENABLE	.EQU	FALSE		; HDSK: ENABLE SIMH HDSK DISK DRIVER (HDSK.ASM)
 ;
 PIOENABLE	.EQU	FALSE		; PIO: ENABLE ZILOG PIO DRIVER (PIO.ASM)
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
diff --git a/Source/HBIOS/cfg_ezz80.asm b/Source/HBIOS/cfg_ezz80.asm
index 978c4274..74fd73a2 100644
--- a/Source/HBIOS/cfg_ezz80.asm
+++ b/Source/HBIOS/cfg_ezz80.asm
@@ -224,7 +224,7 @@ HDSKENABLE	.EQU	FALSE		; HDSK: ENABLE SIMH HDSK DISK DRIVER (HDSK.ASM)
 ;
 PIOENABLE	.EQU	FALSE		; PIO: ENABLE ZILOG PIO DRIVER (PIO.ASM)
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
diff --git a/Source/HBIOS/cfg_master.asm b/Source/HBIOS/cfg_master.asm
index 51b76c4e..fb57e607 100644
--- a/Source/HBIOS/cfg_master.asm
+++ b/Source/HBIOS/cfg_master.asm
@@ -300,10 +300,10 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
-CENCNT		.EQU	1		; CEN: NUMBER OF CHIPS TO DETECT (1-2)
-CEN0BASE	.EQU	$E8		; CEN 0: REGISTERS BASE ADR
-CEN1BASE	.EQU	$EC		; CEN 1: REGISTERS BASE ADR
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
+LPTCNT		.EQU	1		; LPT: NUMBER OF CHIPS TO DETECT (1-2)
+LPT0BASE	.EQU	$E8		; LPT 0: REGISTERS BASE ADR
+LPT1BASE	.EQU	$EC		; LPT 1: REGISTERS BASE ADR
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO4BASE	.EQU	$90		; PIO: PIO REGISTERS BASE ADR FOR ECB 4P BOARD
diff --git a/Source/HBIOS/cfg_mbc.asm b/Source/HBIOS/cfg_mbc.asm
index 6cc18977..8f0669d7 100644
--- a/Source/HBIOS/cfg_mbc.asm
+++ b/Source/HBIOS/cfg_mbc.asm
@@ -224,10 +224,10 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	TRUE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
-CENCNT		.EQU	1		; CEN: NUMBER OF CHIPS TO DETECT (1-2)
-CEN0BASE	.EQU	$E8		; CEN 0: REGISTERS BASE ADR
-CEN1BASE	.EQU	$EC		; CEN 1: REGISTERS BASE ADR
+LPTENABLE	.EQU	TRUE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
+LPTCNT		.EQU	1		; LPT: NUMBER OF CHIPS TO DETECT (1-2)
+LPT0BASE	.EQU	$E8		; LPT 0: REGISTERS BASE ADR
+LPT1BASE	.EQU	$EC		; LPT 1: REGISTERS BASE ADR
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO4BASE	.EQU	$90		; PIO: PIO REGISTERS BASE ADR FOR ECB 4P BOARD
diff --git a/Source/HBIOS/cfg_mk4.asm b/Source/HBIOS/cfg_mk4.asm
index 9c407215..46b10312 100644
--- a/Source/HBIOS/cfg_mk4.asm
+++ b/Source/HBIOS/cfg_mk4.asm
@@ -226,7 +226,7 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO4BASE	.EQU	$90		; PIO: PIO REGISTERS BASE ADR FOR ECB 4P BOARD
diff --git a/Source/HBIOS/cfg_n8.asm b/Source/HBIOS/cfg_n8.asm
index 78f37bcb..f303b55f 100644
--- a/Source/HBIOS/cfg_n8.asm
+++ b/Source/HBIOS/cfg_n8.asm
@@ -224,7 +224,7 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO4BASE	.EQU	$90		; PIO: PIO REGISTERS BASE ADR FOR ECB 4P BOARD
diff --git a/Source/HBIOS/cfg_rcz180.asm b/Source/HBIOS/cfg_rcz180.asm
index 4d485b0c..66536de4 100644
--- a/Source/HBIOS/cfg_rcz180.asm
+++ b/Source/HBIOS/cfg_rcz180.asm
@@ -240,7 +240,7 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
diff --git a/Source/HBIOS/cfg_rcz280.asm b/Source/HBIOS/cfg_rcz280.asm
index 9e593f4b..58fe389d 100644
--- a/Source/HBIOS/cfg_rcz280.asm
+++ b/Source/HBIOS/cfg_rcz280.asm
@@ -255,7 +255,7 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
diff --git a/Source/HBIOS/cfg_rcz80.asm b/Source/HBIOS/cfg_rcz80.asm
index 301da337..3fc50fb4 100644
--- a/Source/HBIOS/cfg_rcz80.asm
+++ b/Source/HBIOS/cfg_rcz80.asm
@@ -244,7 +244,7 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
diff --git a/Source/HBIOS/cfg_rph.asm b/Source/HBIOS/cfg_rph.asm
index 237f7fee..ebba0a25 100644
--- a/Source/HBIOS/cfg_rph.asm
+++ b/Source/HBIOS/cfg_rph.asm
@@ -224,7 +224,7 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO4BASE	.EQU	$90		; PIO: PIO REGISTERS BASE ADR FOR ECB 4P BOARD
diff --git a/Source/HBIOS/cfg_sbc.asm b/Source/HBIOS/cfg_sbc.asm
index 747b99df..cc64fff7 100644
--- a/Source/HBIOS/cfg_sbc.asm
+++ b/Source/HBIOS/cfg_sbc.asm
@@ -224,7 +224,7 @@ PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO4BASE	.EQU	$90		; PIO: PIO REGISTERS BASE ADR FOR ECB 4P BOARD
diff --git a/Source/HBIOS/cfg_scz180.asm b/Source/HBIOS/cfg_scz180.asm
index 06855ad9..a8947263 100644
--- a/Source/HBIOS/cfg_scz180.asm
+++ b/Source/HBIOS/cfg_scz180.asm
@@ -230,13 +230,13 @@ PPPENABLE	.EQU	FALSE		; PPP: ENABLE ZETA PARALLEL PORT PROPELLER BOARD DRIVER (P
 ;
 HDSKENABLE	.EQU	FALSE		; HDSK: ENABLE SIMH HDSK DISK DRIVER (HDSK.ASM)
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
-;
 PIOENABLE	.EQU	FALSE		; PIO: ENABLE ZILOG PIO DRIVER (PIO.ASM)
 PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
 PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
 PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
+;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
 PIO_SBC		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR 8255 CHIP
diff --git a/Source/HBIOS/cfg_zeta.asm b/Source/HBIOS/cfg_zeta.asm
index 746f9b31..3ac56328 100644
--- a/Source/HBIOS/cfg_zeta.asm
+++ b/Source/HBIOS/cfg_zeta.asm
@@ -164,11 +164,8 @@ PPPCONENABLE	.EQU	TRUE		; PPP: ENABLE PPP DRIVER VIDEO/KBD SUPPORT
 HDSKENABLE	.EQU	FALSE		; HDSK: ENABLE SIMH HDSK DISK DRIVER (HDSK.ASM)
 ;
 PIOENABLE	.EQU	FALSE		; PIO: ENABLE ZILOG PIO DRIVER (PIO.ASM)
-PIOCNT		.EQU	2		; PIO: NUMBER OF CHIPS TO DETECT (1-2), 2 CHANNELS PER CHIP
-PIO0BASE	.EQU	$B8		; PIO 0: REGISTERS BASE ADR
-PIO1BASE	.EQU	$BC		; PIO 1: REGISTERS BASE ADR
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
diff --git a/Source/HBIOS/cfg_zeta2.asm b/Source/HBIOS/cfg_zeta2.asm
index c4027774..8c40e759 100644
--- a/Source/HBIOS/cfg_zeta2.asm
+++ b/Source/HBIOS/cfg_zeta2.asm
@@ -176,7 +176,7 @@ HDSKENABLE	.EQU	FALSE		; HDSK: ENABLE SIMH HDSK DISK DRIVER (HDSK.ASM)
 ;
 PIOENABLE	.EQU	FALSE		; PIO: ENABLE ZILOG PIO DRIVER (PIO.ASM)
 ;
-CENENABLE	.EQU	FALSE		; CEN: ENABLE CENTRONICS DRIVER (CEN.ASM)
+LPTENABLE	.EQU	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 PIO_4P		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB 4P BOARD
 PIO_ZP		.EQU	FALSE		; PIO: ENABLE PARALLEL PORT DRIVER FOR ECB ZILOG PERIPHERALS BOARD (PIO.ASM)
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index c3dc3a0c..47cfe5bf 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -2826,6 +2826,45 @@ INITSYS4:
 	LDCTL	(C),HL
 #ENDIF
 ;
+#IFDEF TESTING
+;
+; ROUTINE TO BEEP THE DEAULT SOUND UNIT (NOT FINISHED)
+; NEED TO CHECK FOR EXISTENCE OF SOUND UNIT 0
+; NEED TO TEST AGAINST ALL SOUND DRIVERS
+; CAN SPEAKER DRIVER BE MODIFIED TO PLAY ARBITRARY DURATION?
+; WHICH CHANNEL SHOULD BE USED?  IS THERE A GOOD DEFAULT CHANNEL?
+;
+SNDUNIT	.EQU	0
+;
+HB_BEEP:
+	LD	B,$50			; SOUND RESET FUNCTION
+	LD	C,SNDUNIT		; SOUND UNIT NUMBER
+	CALL	SND_DISPATCH		; DO IT
+	LD	B,$51			; VOLUME
+	LD	C,SNDUNIT		; SOUND UNIT NUMBER
+	LD	L,$FF			; MAX
+	CALL	SND_DISPATCH		; DO IT
+	LD	B,$53			; SELECT NOTE
+	LD	C,SNDUNIT		; SOUND UNIT NUMBER
+	;LD	HL,0			; A0#
+	LD	HL,200			; C4
+	CALL	SND_DISPATCH		; DO IT
+	;LD	B,$56			; DURATION
+	;LD	C,SNDUNIT		; SOUND UNIT NUMBER
+	;LD	HL,500			; 1/2 SECOND
+	;CALL	SND_DISPATCH		; DO IT
+	LD	B,$54			; PLAY SOUND
+	LD	C,SNDUNIT		; SOUND UNIT NUMBER
+	LD	D,1			; CHANNEL 0
+	CALL	SND_DISPATCH		; DO IT
+	LD	DE,15625		; PLAY FOR 1/4 SECOND
+	CALL	VDELAY
+	LD	B,$50			; SOUND RESET FUNCTION
+	LD	C,SNDUNIT		; SOUND UNIT NUMBER
+	CALL	SND_DISPATCH		; DO IT
+;
+#ENDIF
+;
 #IFNDEF ROMBOOT
 ;
 	; COPY OS IMAGE: BID_USR:<IMG START> --> BID_USR:0
@@ -2931,8 +2970,8 @@ HB_PCINITTBL:
 #IF (PIOENABLE)
 	.DW	PIO_PREINIT
 #ENDIF
-#IF CENENABLE)
-	.DW	CEN_PREINIT
+#IF LPTENABLE)
+	.DW	LPT_PREINIT
 #ENDIF
 #IF (PIO_4P | PIO_ZP)
 	.DW	PIO_PREINIT
@@ -2986,6 +3025,18 @@ HB_INITTBL:
 #IF (ACIAENABLE)
 	.DW	ACIA_INIT
 #ENDIF
+#IF (PIOENABLE)
+	.DW	PIO_INIT
+#ENDIF
+#IF (LPTENABLE)
+	.DW	LPT_INIT
+#ENDIF
+#IF (PIO_4P | PIO_ZP)
+	.DW	PIO_INIT
+#ENDIF
+#IF (UFENABLE)
+	.DW	UF_INIT
+#ENDIF
 #IF (DSRTCENABLE)
 	.DW	DSRTC_INIT
 #ENDIF
@@ -3053,18 +3104,6 @@ HB_INITTBL:
 #IF (PPPENABLE)
 	.DW	PPP_INIT
 #ENDIF
-#IF (PIOENABLE)
-	.DW	PIO_INIT
-#ENDIF
-#IF (CENENABLE)
-	.DW	CEN_INIT
-#ENDIF
-#IF (PIO_4P | PIO_ZP)
-	.DW	PIO_INIT
-#ENDIF
-#IF (UFENABLE)
-	.DW	UF_INIT
-#ENDIF
 
 ;
 HB_INITTBLLEN	.EQU	(($ - HB_INITTBL) / 2)
@@ -4114,10 +4153,10 @@ SYS_GETCPUSPD:
 ;
 #IF (((PLATFORM == PLT_SBC) | (PLATFORM == PLT_MBC)) & (CPUSPDCAP==SPD_HILO))
 	LD	A,(HB_RTCVAL)
-	BIT	3,A
 #IF (PLATFORM == PLT_SBC)
 	XOR	%00001000		; SBC SPEED BIT IS INVERTED
 #ENDIF
+	BIT	3,A
 	LD	L,0			; ASSUME HALF SPEED
 	JR	Z,SYS_GETCPUSPD1
 	LD	L,1
@@ -5785,6 +5824,15 @@ SIZ_ASCI	.EQU	$ - ORG_ASCI
 		.ECHO	" bytes.\n"
 #ENDIF
 ;
+#IF (Z2UENABLE)
+ORG_Z2U	.EQU	$
+  #INCLUDE "z2u.asm"
+SIZ_Z2U	.EQU	$ - ORG_Z2U
+		.ECHO	"Z2U occupies "
+		.ECHO	SIZ_Z2U
+		.ECHO	" bytes.\n"
+#ENDIF
+;
 #IF (UARTENABLE)
 ORG_UART	.EQU	$
   #INCLUDE "uart.asm"
@@ -5821,12 +5869,39 @@ SIZ_ACIA	.EQU	$ - ORG_ACIA
 		.ECHO	" bytes.\n"
 #ENDIF
 ;
-#IF (Z2UENABLE)
-ORG_Z2U	.EQU	$
-  #INCLUDE "z2u.asm"
-SIZ_Z2U	.EQU	$ - ORG_Z2U
-		.ECHO	"Z2U occupies "
-		.ECHO	SIZ_Z2U
+#IF (PIOENABLE)
+ORG_PIO		.EQU	$
+  #INCLUDE "pio.asm"
+SIZ_PIO		.EQU	$ - ORG_PIO
+		.ECHO	"PIO occupies "
+		.ECHO	SIZ_PIO
+		.ECHO	" bytes.\n"
+#ENDIF
+;
+#IF (LPTENABLE)
+ORG_LPT		.EQU	$
+  #INCLUDE "lpt.asm"
+SIZ_LPT		.EQU	$ - ORG_LPT
+		.ECHO	"LPT occupies "
+		.ECHO	SIZ_LPT
+		.ECHO	" bytes.\n"
+#ENDIF
+;
+#IF (PIO_4P | PIO_ZP | PIO_SBC)
+ORG_PIO		.EQU	$
+  #INCLUDE "pio.asm"
+SIZ_PIO		.EQU	$ - ORG_PIO
+		.ECHO	"PIO occupies "
+		.ECHO	SIZ_PIO
+		.ECHO	" bytes.\n"
+#ENDIF
+;
+#IF (UFENABLE)
+ORG_UF	.EQU	$
+  #INCLUDE "uf.asm"
+SIZ_UF	.EQU	$ - ORG_UF
+		.ECHO	"UF occupies "
+		.ECHO	SIZ_UF
 		.ECHO	" bytes.\n"
 #ENDIF
 ;
@@ -6061,42 +6136,6 @@ SIZ_SPK	.EQU	$ - ORG_SPK
 		.ECHO	SIZ_SPK
 		.ECHO	" bytes.\n"
 #ENDIF
-;
-#IF (PIOENABLE)
-ORG_PIO		.EQU	$
-  #INCLUDE "pio.asm"
-SIZ_PIO		.EQU	$ - ORG_PIO
-		.ECHO	"PIO occupies "
-		.ECHO	SIZ_PIO
-		.ECHO	" bytes.\n"
-#ENDIF
-;
-#IF (CENENABLE)
-ORG_CEN		.EQU	$
-  #INCLUDE "cen.asm"
-SIZ_CEN		.EQU	$ - ORG_CEN
-		.ECHO	"CEN occupies "
-		.ECHO	SIZ_CEN
-		.ECHO	" bytes.\n"
-#ENDIF
-;
-#IF (PIO_4P | PIO_ZP | PIO_SBC)
-ORG_PIO		.EQU	$
-  #INCLUDE "pio.asm"
-SIZ_PIO		.EQU	$ - ORG_PIO
-		.ECHO	"PIO occupies "
-		.ECHO	SIZ_PIO
-		.ECHO	" bytes.\n"
-#ENDIF
-;
-#IF (UFENABLE)
-ORG_UF	.EQU	$
-  #INCLUDE "uf.asm"
-SIZ_UF	.EQU	$ - ORG_UF
-		.ECHO	"UF occupies "
-		.ECHO	SIZ_UF
-		.ECHO	" bytes.\n"
-#ENDIF
 #IF (KIOENABLE)
 ORG_KIO	.EQU	$
   #INCLUDE "kio.asm"
@@ -6921,7 +6960,7 @@ PS_FLP_DSTR:	.TEXT	"SD$"		; PS_FLPSD
 ;
 PS_SDSTRREF:
 	.DW	PS_SDUART, PS_SDASCI, PS_SDTERM, PS_SDPRPCON, PS_SDPPPCON
-	.DW	PS_SDSIO, PS_SDACIA, PS_SDPIO, PS_SDUF, PS_SDDUART, PS_SDZ2U, PS_SDCEN
+	.DW	PS_SDSIO, PS_SDACIA, PS_SDPIO, PS_SDUF, PS_SDDUART, PS_SDZ2U, PS_SDLPT
 ;
 PS_SDUART	.TEXT	"UART$"
 PS_SDASCI	.TEXT	"ASCI$"
@@ -6934,7 +6973,7 @@ PS_SDPIO	.TEXT	"PIO$"
 PS_SDUF		.TEXT	"UF$"
 PS_SDDUART	.TEXT	"DUART$"
 PS_SDZ2U	.TEXT	"Z2U$"
-PS_SDCEN	.TEXT	"CEN$"
+PS_SDLPT	.TEXT	"LPT$"
 ;
 ; CHARACTER SUB TYPE STRINGS
 ;
diff --git a/Source/HBIOS/hbios.inc b/Source/HBIOS/hbios.inc
index 93a9ef4a..d5e69636 100644
--- a/Source/HBIOS/hbios.inc
+++ b/Source/HBIOS/hbios.inc
@@ -183,7 +183,7 @@ CIODEV_PIO	.EQU	$70
 CIODEV_UF	.EQU	$80
 CIODEV_DUART	.EQU	$90
 CIODEV_Z2U	.EQU	$A0
-CIODEV_CEN	.EQU	$B0
+CIODEV_LPT	.EQU	$B0
 ;
 ; SUB TYPES OF CHAR DEVICES
 ;
diff --git a/Source/HBIOS/cen.asm b/Source/HBIOS/lpt.asm
similarity index 56%
rename from Source/HBIOS/cen.asm
rename to Source/HBIOS/lpt.asm
index 8c4a5c9a..2c007389 100644
--- a/Source/HBIOS/cen.asm
+++ b/Source/HBIOS/lpt.asm
@@ -1,10 +1,10 @@
 ;
 ;==================================================================================================
-; CENTRONICS INTERFACE DRIVER
+; CENTRONICS (LPT) INTERFACE DRIVER
 ;==================================================================================================
 ;
-; CENTRONICS-STYLE PARALLEL PRINTER DRIVER.  ASSUMES MBC PRINT BOARD
-; AS HARDWARE.
+; CENTRONICS-STYLE PARALLEL PRINTER DRIVER.  ASSUMES IBM STYLE
+; HARDWARE INTERFACE AS DESCRIBED BELOW.
 ;
 ; IMPLEMENTED AS A ROMWBW CHARACTER DEVICE.  CURRENTLY HANDLES OUPUT
 ; ONLY.
@@ -30,56 +30,56 @@
 ;     | STAT1 | STAT0 | ENBL  | PINT  | SEL   | RES   | LF    | STB   |
 ;     +-------+-------+-------+-------+-------+-------+-------+-------+
 ;
-CEN_NONE	.EQU	0
-CEN_MBC		.EQU	1
+LPT_NONE	.EQU	0		; NOT PRESENT
+LPT_IBM		.EQU	1		; IBM PC STYLE INTERFACE
 ;
 ; PRE-CONSOLE INITIALIZATION - DETECT AND INIT HARDWARE
 ;
-CEN_PREINIT:
+LPT_PREINIT:
 ;
 ; SETUP THE DISPATCH TABLE ENTRIES
 ; NOTE: INTS WILL BE DISABLED WHEN PREINIT IS CALLED AND THEY MUST REMIAIN
 ; DISABLED.
 ;
-	LD	B,CEN_CFGCNT		; LOOP CONTROL
+	LD	B,LPT_CFGCNT		; LOOP CONTROL
 	XOR	A			; ZERO TO ACCUM
-	LD	(CEN_DEV),A		; CURRENT DEVICE NUMBER
-	LD	IY,CEN_CFG		; POINT TO START OF CFG TABLE
-CEN_PREINIT0:
+	LD	(LPT_DEV),A		; CURRENT DEVICE NUMBER
+	LD	IY,LPT_CFG		; POINT TO START OF CFG TABLE
+LPT_PREINIT0:
 	PUSH	BC			; SAVE LOOP CONTROL
-	CALL	CEN_INITUNIT		; HAND OFF TO UNIT INIT CODE
+	CALL	LPT_INITUNIT		; HAND OFF TO UNIT INIT CODE
 	POP	BC			; RESTORE LOOP CONTROL
 ;
-	LD	A,(IY+1)		; GET THE CEN TYPE DETECTED
+	LD	A,(IY+1)		; GET THE LPT TYPE DETECTED
 	OR	A			; SET FLAGS
-	JR	Z,CEN_PREINIT2		; SKIP IT IF NOTHING FOUND
+	JR	Z,LPT_PREINIT2		; SKIP IT IF NOTHING FOUND
 ;
 	PUSH	BC			; SAVE LOOP CONTROL
 	PUSH	IY			; CFG ENTRY ADDRESS
 	POP	DE			; ... TO DE
-	LD	BC,CEN_FNTBL		; BC := FUNCTION TABLE ADDRESS
-	CALL	NZ,CIO_ADDENT		; ADD ENTRY IF CEN FOUND, BC:DE
+	LD	BC,LPT_FNTBL		; BC := FUNCTION TABLE ADDRESS
+	CALL	NZ,CIO_ADDENT		; ADD ENTRY IF LPT FOUND, BC:DE
 	POP	BC			; RESTORE LOOP CONTROL
 ;
-CEN_PREINIT2:
-	LD	DE,CEN_CFGSIZ		; SIZE OF CFG ENTRY
+LPT_PREINIT2:
+	LD	DE,LPT_CFGSIZ		; SIZE OF CFG ENTRY
 	ADD	IY,DE			; BUMP IY TO NEXT ENTRY
-	DJNZ	CEN_PREINIT0		; LOOP UNTIL DONE
+	DJNZ	LPT_PREINIT0		; LOOP UNTIL DONE
 ;
-CEN_PREINIT3:
+LPT_PREINIT3:
 	XOR	A			; SIGNAL SUCCESS
 	RET				; AND RETURN
 ;
-; CEN INITIALIZATION ROUTINE
+; LPT INITIALIZATION ROUTINE
 ;
-CEN_INITUNIT:
-	CALL	CEN_DETECT		; DETERMINE CEN TYPE
+LPT_INITUNIT:
+	CALL	LPT_DETECT		; DETERMINE LPT TYPE
 	LD	(IY+1),A		; SAVE IN CONFIG TABLE
 	OR	A			; SET FLAGS
 	RET	Z			; ABORT IF NOTHING THERE
 ;
-	; UPDATE WORKING CEN DEVICE NUM
-	LD	HL,CEN_DEV		; POINT TO CURRENT DEVICE NUM
+	; UPDATE WORKING LPT DEVICE NUM
+	LD	HL,LPT_DEV		; POINT TO CURRENT DEVICE NUM
 	LD	A,(HL)			; PUT IN ACCUM
 	INC	(HL)			; INCREMENT IT (FOR NEXT LOOP)
 	LD	(IY),A			; UPDATE UNIT NUM
@@ -88,44 +88,44 @@ CEN_INITUNIT:
 	LD	DE,-1			; LEAVE CONFIG ALONE
 	; CALL INITDEV TO IMPLEMENT CONFIG, BUT NOTE THAT WE CALL
 	; THE INITDEV ENTRY POINT THAT DOES NOT ENABLE/DISABLE INTS!
-	JP	CEN_INITDEVX		; IMPLEMENT IT AND RETURN
+	JP	LPT_INITDEVX		; IMPLEMENT IT AND RETURN
 ;
 ;
 ;
-CEN_INIT:
-	LD	B,CEN_CFGCNT		; COUNT OF POSSIBLE CEN UNITS
-	LD	IY,CEN_CFG		; POINT TO START OF CFG TABLE
-CEN_INIT1:
+LPT_INIT:
+	LD	B,LPT_CFGCNT		; COUNT OF POSSIBLE LPT UNITS
+	LD	IY,LPT_CFG		; POINT TO START OF CFG TABLE
+LPT_INIT1:
 	PUSH	BC			; SAVE LOOP CONTROL
-	LD	A,(IY+1)		; GET CEN TYPE
+	LD	A,(IY+1)		; GET LPT TYPE
 	OR	A			; SET FLAGS
-	CALL	NZ,CEN_PRTCFG		; PRINT IF NOT ZERO
+	CALL	NZ,LPT_PRTCFG		; PRINT IF NOT ZERO
 	POP	BC			; RESTORE LOOP CONTROL
-	LD	DE,CEN_CFGSIZ		; SIZE OF CFG ENTRY
+	LD	DE,LPT_CFGSIZ		; SIZE OF CFG ENTRY
 	ADD	IY,DE			; BUMP IY TO NEXT ENTRY
-	DJNZ	CEN_INIT1		; LOOP TILL DONE
+	DJNZ	LPT_INIT1		; LOOP TILL DONE
 ;
 	XOR	A			; SIGNAL SUCCESS
 	RET				; DONE
 ;
 ; DRIVER FUNCTION TABLE
 ;
-CEN_FNTBL:
-	.DW	CEN_IN
-	.DW	CEN_OUT
-	.DW	CEN_IST
-	.DW	CEN_OST
-	.DW	CEN_INITDEV
-	.DW	CEN_QUERY
-	.DW	CEN_DEVICE
-#IF (($ - CEN_FNTBL) != (CIO_FNCNT * 2))
-	.ECHO	"*** INVALID CEN FUNCTION TABLE ***\n"
+LPT_FNTBL:
+	.DW	LPT_IN
+	.DW	LPT_OUT
+	.DW	LPT_IST
+	.DW	LPT_OST
+	.DW	LPT_INITDEV
+	.DW	LPT_QUERY
+	.DW	LPT_DEVICE
+#IF (($ - LPT_FNTBL) != (CIO_FNCNT * 2))
+	.ECHO	"*** INVALID LPT FUNCTION TABLE ***\n"
 	!!!	; FORCE AN ASSEMBLY ERROR
 #ENDIF
 ;
 ; BYTE INTPUT
 ;
-CEN_IN:
+LPT_IN:
 	; INPUT NOT SUPPORTED - RETURN NULL BYTE
 	LD	E,0			; NULL BYTE
 	XOR	A			; SIGNAL SUCCESS
@@ -133,20 +133,19 @@ CEN_IN:
 ;
 ; BYTE OUTPUT
 ;
-CEN_OUT:
-	CALL	CEN_OST			; READY TO SEND?
-	JR	Z,CEN_OUT		; LOOP IF NOT
-	; *** ADD CODE TO OUTPUT BYTE ***
+LPT_OUT:
+	CALL	LPT_OST			; READY TO SEND?
+	JR	Z,LPT_OUT		; LOOP IF NOT
 	LD	A,(IY+3)
 	LD	C,A			; PORT 0 (DATA)
  	OUT	(C),E			; OUTPUT DATA TO PORT
- 	call 	DELAY   		; ignore anything back after a reset
-        ld      A,%00001101             ; select & strobe, LEDS OFF
+ 	CALL 	DELAY   		; IGNORE ANYTHING BACK AFTER A RESET
+        LD      A,%00001101             ; SELECT & STROBE, LEDS OFF
 	INC 	C 			; PUT CONTROL PORT IN C
 	INC 	C
         OUT	(C),A			; OUTPUT DATA TO PORT
-  	call 	DELAY   		; ignore anything back after a reset
-        ld      A,%00001100             ; select, LEDS OFF
+  	CALL 	DELAY   		; IGNORE ANYTHING BACK AFTER A RESET
+        LD      A,%00001100             ; SELECT, LEDS OFF
         OUT	(C),A			; OUTPUT DATA TO PORT
 
 	XOR	A			; SIGNAL SUCCESS
@@ -154,14 +153,14 @@ CEN_OUT:
 ;
 ; INPUT STATUS
 ;
-CEN_IST:
+LPT_IST:
 	; INPUT NOT SUPPORTED - RETURN NOT READY
 	XOR	A			; ZERO BYTES AVAILABLE
 	RET				; DONE
 ;
 ; OUTPUT STATUS
 ;
-CEN_OST:
+LPT_OST:
 	LD	A,(IY+3)
 	LD	C,A			; PORT 0 (DATA)
 	INC 	C			; SELECT STATUS PORT
@@ -171,16 +170,16 @@ CEN_OST:
 ;
 ; INITIALIZE DEVICE
 ;
-CEN_INITDEV:
+LPT_INITDEV:
 	HB_DI				; AVOID CONFLICTS
-	CALL	CEN_INITDEVX		; DO THE REAL WORK
+	CALL	LPT_INITDEVX		; DO THE REAL WORK
 	HB_EI				; INTS BACK ON
 	RET				; DONE
 ;
 ; THIS ENTRY POINT BYPASSES DISABLING/ENABLING INTS WHICH IS REQUIRED BY
 ; PREINIT ABOVE.  PREINIT IS NOT ALLOWED TO ENABLE INTS!
 ;
-CEN_INITDEVX:
+LPT_INITDEVX:
 	LD	A,(IY+3)
 	LD	C,A			; PORT 0 (DATA)
 	XOR	A			; CLEAR ACCUM
@@ -197,7 +196,7 @@ CEN_INITDEVX:
 ;
 ;
 ;
-CEN_QUERY:
+LPT_QUERY:
 	LD	E,(IY+4)		; FIRST CONFIG BYTE TO E
 	LD	D,(IY+5)		; SECOND CONFIG BYTE TO D
 	XOR	A			; SIGNAL SUCCESS
@@ -205,8 +204,8 @@ CEN_QUERY:
 ;
 ;
 ;
-CEN_DEVICE:
-	LD	D,CIODEV_CEN		; D := DEVICE TYPE
+LPT_DEVICE:
+	LD	D,CIODEV_LPT		; D := DEVICE TYPE
 	LD	E,(IY)			; E := PHYSICAL UNIT
 	LD	C,$40			; C := DEVICE TYPE, 0x40 IS PIO
 	LD	H,(IY+1)		; H := MODE
@@ -214,62 +213,71 @@ CEN_DEVICE:
 	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
-; CEN DETECTION ROUTINE
+; LPT DETECTION ROUTINE
 ;
-CEN_DETECT:
+LPT_DETECT:
 	LD	A,(IY+3)		; BASE PORT ADDRESS
-	ADD	A,2			; USE PORT 2 FOR DETECT
 	LD	C,A			; PUT IN C FOR I/O
-	CALL	CEN_DETECT2		; CHECK IT
-	JR	Z,CEN_DETECT1		; FOUND IT, RECORD IT
-	LD	A,CEN_NONE		; NOTHING FOUND
+	CALL	LPT_DETECT2		; CHECK IT
+	JR	Z,LPT_DETECT1		; FOUND IT, RECORD IT
+	LD	A,LPT_NONE		; NOTHING FOUND
 	RET				; DONE
 ;
-CEN_DETECT1:
-	; CEN FOUND, RECORD IT
-	LD	A,CEN_MBC		; RETURN CHIP TYPE
+LPT_DETECT1:
+	; LPT FOUND, RECORD IT
+	LD	A,LPT_IBM		; RETURN CHIP TYPE
 	RET				; DONE
 ;
-CEN_DETECT2:
-	; LOOK FOR CEN AT PORT ADDRESS IN C
-	XOR	A			; DEFAULT VALUE
+LPT_DETECT2:
+	; LOOK FOR LPT AT BASE PORT ADDRESS IN C
+	INC	C			; PORT C FOR I/O
+	INC	C			; ...
+	XOR	A			; DEFAULT VALUE (TRI-STATE OFF)
 	OUT	(C),A			; SEND IT
-	IN	A,(C)			; READ IT
-	AND	%11000000		; ISOLATE STATUS BITS
-	CP	%00000000		; CORRECT VALUE?
-	RET	NZ			; IF NOT, RETURN
-	LD	A,%11000000		; STATUS BITS ON (LEDS OFF)
+;
+	;IN	A,(C)			; READ IT
+	;AND	%11000000		; ISOLATE STATUS BITS
+	;CP	%00000000		; CORRECT VALUE?
+	;RET	NZ			; IF NOT, RETURN
+	;LD	A,%11000000		; STATUS BITS ON (LEDS OFF)
+	;OUT	(C),A			; SEND IT
+	;IN	A,(C)			; READ IT
+	;AND	%11000000		; ISOLATE STATUS BITS
+	;CP	%11000000		; CORRECT VALUE?
+;
+	DEC	C			; BACK TO BASE PORT
+	DEC	C			; ...
+	LD	A,$A5			; TEST VALUE
 	OUT	(C),A			; SEND IT
-	IN	A,(C)			; READ IT
-	AND	%11000000		; ISOLATE STATUS BITS
-	CP	%11000000		; CORRECT VALUE?
+	IN	A,(C)			; READ IT BACK
+	CP	$A5			; CORRECT?
 	RET				; RETURN (ZF SET CORRECTLY)
 ;
 ;
 ;
-CEN_PRTCFG:
+LPT_PRTCFG:
 	; ANNOUNCE PORT
 	CALL	NEWLINE			; FORMATTING
-	PRTS("CEN$")			; FORMATTING
+	PRTS("LPT$")			; FORMATTING
 	LD	A,(IY)			; DEVICE NUM
 	CALL	PRTDECB			; PRINT DEVICE NUM
 	PRTS(": IO=0x$")		; FORMATTING
 	LD	A,(IY+3)		; GET BASE PORT
 	CALL	PRTHEXBYTE		; PRINT BASE PORT
 
-	; PRINT THE CEN TYPE
+	; PRINT THE LPT TYPE
 	CALL	PC_SPACE		; FORMATTING
-	LD	A,(IY+1)		; GET CEN TYPE BYTE
+	LD	A,(IY+1)		; GET LPT TYPE BYTE
 	RLCA				; MAKE IT A WORD OFFSET
-	LD	HL,CEN_TYPE_MAP		; POINT HL TO TYPE MAP TABLE
+	LD	HL,LPT_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 CEN WAS DETECTED
-	LD	A,(IY+1)		; GET CEN TYPE BYTE
+	; ALL DONE IF NO LPT WAS DETECTED
+	LD	A,(IY+1)		; GET LPT TYPE BYTE
 	OR	A			; SET FLAGS
 	RET	Z			; IF ZERO, NOT PRESENT
 ;
@@ -280,41 +288,41 @@ CEN_PRTCFG:
 ;
 ;
 ;
-CEN_TYPE_MAP:
-		.DW	CEN_STR_NONE
-		.DW	CEN_STR_MBC
+LPT_TYPE_MAP:
+		.DW	LPT_STR_NONE
+		.DW	LPT_STR_IBM
 ;
-CEN_STR_NONE	.DB	"<NOT PRESENT>$"
-CEN_STR_MBC	.DB	"MBC$"
+LPT_STR_NONE	.DB	"<NOT PRESENT>$"
+LPT_STR_IBM	.DB	"IBM$"
 ;
 ; WORKING VARIABLES
 ;
-CEN_DEV		.DB	0		; DEVICE NUM USED DURING INIT
+LPT_DEV		.DB	0		; DEVICE NUM USED DURING INIT
 ;
-; CEN DEVICE CONFIGURATION TABLE
+; LPT DEVICE CONFIGURATION TABLE
 ;
-CEN_CFG:
+LPT_CFG:
 ;
-CEN0_CFG:
-	; CEN MODULE A CONFIG
+LPT0_CFG:
+	; LPT MODULE A CONFIG
 	.DB	0			; DEVICE NUMBER (SET DURING INIT)
-	.DB	0			; CEN TYPE (SET DURING INIT)
+	.DB	0			; LPT TYPE (SET DURING INIT)
 	.DB	0			; MODULE ID
-	.DB	CEN0BASE		; BASE PORT
+	.DB	LPT0BASE		; BASE PORT
 	.DW	0			; LINE CONFIGURATION
 ;
-CEN_CFGSIZ	.EQU	$ - CEN_CFG	; SIZE OF ONE CFG TABLE ENTRY
+LPT_CFGSIZ	.EQU	$ - LPT_CFG	; SIZE OF ONE CFG TABLE ENTRY
 ;
-#IF (CENCNT >= 2)
+#IF (LPTCNT >= 2)
 ;
-CEN1_CFG:
-	; CEN MODULE B CONFIG
+LPT1_CFG:
+	; LPT MODULE B CONFIG
 	.DB	0			; DEVICE NUMBER (SET DURING INIT)
-	.DB	0			; CEN TYPE (SET DURING INIT)
+	.DB	0			; LPT TYPE (SET DURING INIT)
 	.DB	1			; MODULE ID
-	.DB	CEN1BASE		; BASE PORT
+	.DB	LPT1BASE		; BASE PORT
 	.DW	0			; LINE CONFIGURATION
 ;
 #ENDIF
 ;
-CEN_CFGCNT	.EQU	($ - CEN_CFG) / CEN_CFGSIZ
+LPT_CFGCNT	.EQU	($ - LPT_CFG) / LPT_CFGSIZ
diff --git a/Source/ver.inc b/Source/ver.inc
index db0222ef..9124b396 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,4 +2,4 @@
 #DEFINE	RMN	1
 #DEFINE	RUP	1
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.1.1-pre.173"
+#DEFINE BIOSVER	"3.1.1-pre.176"
diff --git a/Source/ver.lib b/Source/ver.lib
index ef0cffc3..817ec6ea 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	1
 rup	equ	1
 rtp	equ	0
 biosver	macro
-	db	"3.1.1-pre.173"
+	db	"3.1.1-pre.176"
 	endm