diff --git a/Doc/Hard Disk Anatomy.pdf b/Doc/Hard Disk Anatomy.pdf
index fda44f88..d525eb68 100644
Binary files a/Doc/Hard Disk Anatomy.pdf and b/Doc/Hard Disk Anatomy.pdf differ
diff --git a/Doc/Testing Notes.txt b/Doc/Testing Notes.txt
deleted file mode 100644
index 9175409f..00000000
--- a/Doc/Testing Notes.txt	
+++ /dev/null
@@ -1,144 +0,0 @@
-SIMH (X)
-----
-- Test UART driver
-- Test HDSK driver
-
-Zeta 1 (X)
-------
-- Test UART driver
-- Test PPP detection (startup w/ and w/o PPP)
-- Test boot to CRT
-- Test PPPSD driver
-- Test PPPCON driver (video & kbd)
-- Test FD driver
-- Test FDU app
-
-Zeta 2 (X)
-------
-- Test UART driver
-- Test PPP detection (startup w/ and w/o PPP)
-- Test boot to CRT
-- Test PPPSD driver
-- Test PPPCON driver (video & kbd)
-- Test FD driver
-- Test FDU app
-
-RCBus (X)
-------
-- Test SIO driver (Serial Module)
-- Test ACIA driver (Dual Serial Module)
-- Test IDE driver (Compact Flash Module)
-- Test PPIDE driver (IDE Module)
-- Test FD driver (SMC and WDC)
-- Test FDU app (SMC and WDC)
-
-N8-2312 (X)
--------
-- Test ASCI driver
-- Test SD driver (CSIO mode)
-- Test FD driver
-- Test FDU app
-- Test TMS driver (video & kbd)
-
-N8-2511 (X)
--------
-- Test ASCI driver
-- Test SD driver (Juha mode)
-- Test FD driver
-- Test FDU app
-- Test TMS driver (video & kbd)
-
-SBC (X)
----
-- Test UART driver
-- Test PPIDE driver
-- Test PPISD driver
-- Test PRP detection
-- Test boot to CRT console
-
-MK4 (X)
----
-- Test ASCI driver
-- Test IDE driver
-- Test SD driver
-- Test PRP detection
-
-RAMF (X)
-----
-- Test RAMF driver
-
-PRP (X)
----
-- Test PRPSD driver
-- Test PRPCON driver (video & kbd)
-
-SCG (X)
----
-- Test TMS driver (video)
-
-VDU (X)
----
-- Test CVDU driver (video & kbd)
-
-CVDU (X)
-----
-- Test CVDU driver (video & kbd)
-
-VGA (X)
----
-- Test VGA driver (video & kbd)
-
-DIO (X)
----
-- Test FD driver
-- Test FDU app
-- Test IDE driver
-
-DIO3 (X)
-----
-- Test FD driver
-- Test FDU app
-- Test PPIDE driver
-
-DIDE (X)
-----
-- Test FD driver
-- Test FDU app
-- Test IDE driver
-
-DSD (X)
----
-- Test SD driver
-
-4UART (X)
------
-- Test UART driver
-
-
-UNA (X)
----
-- General Startup
-- Boot from disk functionality
-- Image loading
-- Monitor
-- XM app
-- ASSIGN app
-- MODE app
-- SYSCOPY app
-- OSLDR app
-- FDU app
-- FDISK80 app
-
-GENERAL (X)
--------
-- Boot to ROM
-- Boot to Disk
-- Boot to Monitor
-- XM app
-- XM port auto-detect
-- ASSIGN app
-- MODE app
-- SYSCOPY app
-- FDU app
-- FDISK80 app
-- TUNE app
diff --git a/Source/Doc/Graphics/Hard Disk Anatomy.vsd b/Source/Doc/Graphics/Hard Disk Anatomy.vsd
index 862442e7..a9c89c08 100644
Binary files a/Source/Doc/Graphics/Hard Disk Anatomy.vsd and b/Source/Doc/Graphics/Hard Disk Anatomy.vsd differ
diff --git a/Source/Doc/RomWBW Disk Layouts.xlsx b/Source/Doc/RomWBW Disk Layouts.xlsx
index da72b8c6..ccfebb5f 100644
Binary files a/Source/Doc/RomWBW Disk Layouts.xlsx and b/Source/Doc/RomWBW Disk Layouts.xlsx differ
diff --git a/Source/HBIOS/sd.asm b/Source/HBIOS/sd.asm
index aa04b885..a0785524 100644
--- a/Source/HBIOS/sd.asm
+++ b/Source/HBIOS/sd.asm
@@ -446,6 +446,7 @@ SD_CMD_READ_SNGL_BLK	.EQU	$40 + 17	; $51, CMD17 -> R1
 SD_CMD_WRITE_BLOCK	.EQU	$40 + 24	; $58, CMD24 -> R1
 SD_CMD_APP_CMD		.EQU	$40 + 55	; $77, CMD55 -> R1
 SD_CMD_READ_OCR		.EQU	$40 + 58	; $7A, CMD58 -> R3
+SD_CMD_CRC_ON_OFF	.EQU	$40 + 59	; $7B, CMD59 -> R1
 ;
 ; SD CARD APPLICATION COMMANDS (PRECEDED BY APP_CMD COMMAND)
 ;
@@ -941,19 +942,12 @@ SD_IO:
 	OR	A			; SET FLAGS
 	RET	Z			; ZERO SECTOR I/O, RETURN W/ E=0 & A=0
 ;
-#IF ((SDMODE == SDMODE_CSIO) | (SDMODE == SDMODE_MK4) | (SDMODE == SDMODE_SC) | (SDMODE == SDMODE_EPITX))
-	; CONSIDER CAPTURING CURRENT CNTR VALUE HERE AND USE IT
-	; IN SD_CSIO_DEF
-
 	; SET CSIO FOR HIGH SPEED OPERATION
-	CALL	SD_WAITTX		; MAKE SURE WE ARE DONE SENDING
-	CALL	DLY32			; WAIT A BIT MORE FOR FINAL BIT
-	XOR	A			; ZERO MEANS MAX SPEED
-	OUT0	(SD_CNTR),A		; NOW SET CSIO PORT
+	CALL	SD_SPD_FAST
+;
 	; HOOK RETURN TO RESTORE CSIO TO DEFAULT SPEED
-	LD	HL,SD_CSIO_DEF		; ROUTE RETURN
+	LD	HL,SD_SPD_STD		; ROUTE RETURN
 	PUSH	HL			; ... THRU CSIO RESTORE
-#ENDIF
 ;
 #IF (SDTRACE == 1)
 	LD	HL,SD_PRTERR		; SET UP SD_PRTERR
@@ -1045,6 +1039,9 @@ SD_MEDIA:
 	JR	NZ,SD_MEDIA1		; ERROR ACTIVE, GO RIGHT TO RESET
 ;
 	; USE SEND_CSD TO CHECK CARD
+	;;;LD	A,'C'			;;;
+	;;;CALL	COUT			;;;
+	CALL	SD_SPD_FAST		; GO FAST FOR COMPATIBILITY
 	CALL	SD_SELUNIT		; SET CUR UNIT
 	LD	A,SD_CMD_SEND_CSD	; SEND_CSD
 	CALL	SD_INITCMD		; SETUP COMMAND BUFFER
@@ -1057,9 +1054,14 @@ SD_MEDIA:
 	JR	Z,SD_MEDIA2		; IF SUCCESS, BYPASS RESET
 ;
 SD_MEDIA1:
+	;;;LD	A,'R'			;;;
+	;;;CALL	COUT			;;;
 	CALL	SD_RESET		; RESET CARD
 ;
 SD_MEDIA2:
+	;;;LD	A,'D'			;;;
+	;;;CALL	COUT			;;;
+	CALL	SD_SPD_STD		; BACK TO STD SPEED
 	LD	A,(IY+SD_STAT)		; GET STATUS
 	OR	A			; SET FLAGS
 	LD	D,0			; NO MEDIA CHANGE DETECTED
@@ -1072,7 +1074,6 @@ SD_MEDIA2:
 ;
 ;
 ;
-;
 SD_SEEK:
 	BIT	7,D			; CHECK FOR LBA FLAG
 	CALL	Z,HB_CHS2LBA		; CLEAR MEANS CHS, CONVERT TO LBA
@@ -1120,14 +1121,7 @@ SD_INITCARD:
 	CALL	SD_CHKCD		; CHECK CARD DETECT
 	JP	Z,SD_NOMEDIA		; Z=NO MEDIA, HANDLE IF SO
 ;
-#IF ((SDMODE == SDMODE_CSIO) | (SDMODE == SDMODE_MK4) | (SDMODE == SDMODE_SC) | (SDMODE == SDMODE_EPITX))
-	CALL	SD_CSIO_DEF		; ENSURE CSIO AT DEFAULT SPEED
-#ENDIF
-;
-#IF (SDMODE == SDMODE_FZ80)
-	;;; FORCE SLOW SPEED HERE?
-	;;; CALL SD_SELECT?
-#ENDIF
+	CALL	SD_SPD_SLOW		; SET SLOW SPEED FOR INIT
 ;
 	; WAKE UP THE CARD, KEEP DIN HI (ASSERTED) AND /CS HI (DEASSERTED)
 	LD	B,$10	; MIN 74 CLOCKS REQUIRED, WE USE 128 ($10 * 8)
@@ -1138,8 +1132,8 @@ SD_INITCARD1:
 	POP	BC			; RESTORE LOOP CONTROL
 	DJNZ	SD_INITCARD1		; LOOP AS NEEDED
 ;
-	; MAKE SURE WE FINISH SENDING
 #IF ((SDMODE == SDMODE_CSIO) | (SDMODE == SDMODE_MK4) | (SDMODE == SDMODE_SC) | (SDMODE == SDMODE_EPITX))
+	; MAKE SURE CSIO IS DONE SENDING DATA
 	CALL	SD_WAITTX		; WAIT FOR TE TO CLEAR
 	CALL	DLY32			; WAIT A BIT MORE FOR FINAL BIT
 #ENDIF
@@ -1234,9 +1228,25 @@ SD_INITCARD4:
 	CALL	SD_INITCMD		; SETUP COMMAND BUFFER
 	CALL	SD_EXECCMD		; EXECUTE COMMAND
 	RET	NZ			; ABORT ON ERROR
-	; CMD58 WORKED, GET OCR DATA AND SET CARD TYPE
-	CALL	SD_GET			; BITS 31-24
-	CALL	SD_DONE			; FINISH THE TRANSACTION
+	; CMD58 WORKED, GET OCR DATA
+	LD	B,4			; 4 BYTES OF OCR
+	LD	HL,SD_BUF		; PUT IN OUR PRIVATE BUFFER
+SD_INITCARD4B:
+	CALL	SD_GET			; GET NEXT BYTE
+	LD	(HL),A			; SAVE IT
+	INC	HL			; BUMP BUF PTR
+	DJNZ	SD_INITCARD4B		; LOOP AS NEEDED
+;
+#IF (SDTRACE >= 3)
+	; IF TRACING, DUMP THE OCR CONTENTS
+	CALL	SD_PRTPREFIX
+	LD	DE,SD_STR_OCR
+	CALL	WRITESTR
+	LD	DE,SD_BUF
+	LD	A,4
+	CALL	PRTHEXBUF
+#ENDIF
+	LD	A,(SD_BUF)		; FIRST BYTE OF BUF (BITS 31-24 OF OCR)
 	AND	$40			; ISOLATE BIT 30 (CCS)
 	LD	C,SD_TYPESDSC		; ASSUME V1 CARD
 	JR	Z,SD_INITCARD5		; IF BIT NOT SET, THIS IS SDSC CARD
@@ -1746,8 +1756,11 @@ SD_GETDATA3:
 	LD	A,D
 	OR	E
 	JR	NZ,SD_GETDATA3		; LOOP FOR ALL BYTES
+	;;;CALL	PC_SPACE
 	CALL	SD_GET			; DISCARD CRC BYTE 1
+	;;;CALL	PRTHEXBYTE
 	CALL	SD_GET			; DISCARD CRC BYTE 2
+	;;;CALL	PRTHEXBYTE
 #ENDIF
 	XOR	A			; RESULT IS ZERO
 SD_GETDATA4:
@@ -1858,6 +1871,11 @@ SD_DONE:
 	PUSH	AF
 	LD	A,$FF
 	CALL	SD_PUT
+#IF ((SDMODE == SDMODE_CSIO) | (SDMODE == SDMODE_MK4) | (SDMODE == SDMODE_SC) | (SDMODE == SDMODE_EPITX))
+	; MAKE SURE CSIO IS DONE SENDING DATA
+	CALL	SD_WAITTX		; WAIT FOR TE TO CLEAR
+	CALL	DLY32			; WAIT A BIT MORE FOR FINAL BIT
+#ENDIF
 	CALL	SD_DESELECT
 	POP	AF
 	RET
@@ -2306,11 +2324,26 @@ SD_GET1:
 #ENDIF
 	RET
 ;
-; SET CSIO TO DEFAULT SPEED
+; SET STANDARD SPEED (RESTORE SPI INTERFACE TO DEFAULTS)
+;
+SD_SPD_STD:
 ;
 #IF ((SDMODE == SDMODE_CSIO) | (SDMODE == SDMODE_MK4) | (SDMODE == SDMODE_SC) | (SDMODE == SDMODE_EPITX))
+	; SET CSIO FOR DEFAULT OPERATION
+	PUSH	AF			; PRESERVE AF
+	CALL	SD_WAITTX		; MAKE SURE WE ARE DONE SENDING
+	CALL	DLY32			; WAIT A BIT MORE FOR FINAL BIT
+	LD	A,Z180_CNTR_DEF		; DIV 1280, 14KHZ @ 18MHZ CLK
+	OUT0	(SD_CNTR),A		; DO IT
+	POP	AF			; RESTORE AF
+#ENDIF
+	RET
+;
+; SET SLOW SPEED
+;
+SD_SPD_SLOW:
 ;
-SD_CSIO_DEF:
+#IF ((SDMODE == SDMODE_CSIO) | (SDMODE == SDMODE_MK4) | (SDMODE == SDMODE_SC) | (SDMODE == SDMODE_EPITX))
 	; SET CSIO FOR DEFAULT OPERATION
 	PUSH	AF			; PRESERVE AF
 	CALL	SD_WAITTX		; MAKE SURE WE ARE DONE SENDING
@@ -2318,9 +2351,23 @@ SD_CSIO_DEF:
 	LD	A,Z180_CNTR_DEF		; DIV 1280, 14KHZ @ 18MHZ CLK
 	OUT0	(SD_CNTR),A		; DO IT
 	POP	AF			; RESTORE AF
+#ENDIF
 	RET
 ;
+; SET FAST SPEED
+;
+SD_SPD_FAST:
+;
+#IF ((SDMODE == SDMODE_CSIO) | (SDMODE == SDMODE_MK4) | (SDMODE == SDMODE_SC) | (SDMODE == SDMODE_EPITX))
+	; SET CSIO FOR HIGH SPEED OPERATION
+	PUSH	AF			; PRESERVE AF
+	CALL	SD_WAITTX		; MAKE SURE WE ARE DONE SENDING
+	CALL	DLY32			; WAIT A BIT MORE FOR FINAL BIT
+	XOR	A			; 0 IS HIGHEST CLOCK SPEED
+	OUT0	(SD_CNTR),A		; DO IT
+	POP	AF			; RESTORE AF
 #ENDIF
+	RET
 ;
 ;
 ;=============================================================================
@@ -2510,6 +2557,7 @@ SD_STR_TOK		.TEXT	" TOK=$"
 SD_STR_CSD		.TEXT	" CSD =$"
 SD_STR_CID		.TEXT	" CID =$"
 SD_STR_SCR		.TEXT	" SCR =$"
+SD_STR_OCR		.TEXT	" OCR =$"
 SD_STR_SDTYPE		.TEXT	" SD CARD TYPE ID=$"
 ;
 SD_STR_STOK		.TEXT	"OK$"
diff --git a/Source/ver.inc b/Source/ver.inc
index 8a60457c..86b639b2 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,7 +2,7 @@
 #DEFINE	RMN	5
 #DEFINE	RUP	0
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.5.0-dev.65"
+#DEFINE BIOSVER	"3.5.0-dev.66"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP
diff --git a/Source/ver.lib b/Source/ver.lib
index 959577f0..716dc825 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	5
 rup	equ	0
 rtp	equ	0
 biosver	macro
-	db	"3.5.0-dev.65"
+	db	"3.5.0-dev.66"
 	endm