diff --git a/Source/CBIOS/cbios.asm b/Source/CBIOS/cbios.asm
index 7c694d25..dacf7537 100644
--- a/Source/CBIOS/cbios.asm
+++ b/Source/CBIOS/cbios.asm
@@ -1602,13 +1602,12 @@ DPB_RAM:
 ;
 ; 4MB RAM FLOPPY DRIVE, 32 TRKS, 1024 SECS/TRK, 128 BYTES/SEC
 ; BLOCKSIZE (BLS) = 2K, DIRECTORY ENTRIES = 256
-; SEC/TRK ENGINEERED SO THAT AFTER DEBLOCKING, SECTOR NUMBER OCCUPIES 1 BYTE (0-255)
 ;
 	.DW	CKS_HD
 	.DW	ALS_HD
 	.DB	(2048 / 128)	; RECORDS PER BLOCK (BLS / 128)
 DPB_RF:
-	.DW  	1024		; SPT: SECTORS PER TRACK
+	.DW  	64		; SPT: SECTORS PER TRACK
 	.DB  	4		; BSH: BLOCK SHIFT FACTOR
 	.DB  	15		; BLM: BLOCK MASK
 	.DB  	0		; EXM: EXTENT MASK
diff --git a/Source/HBIOS/fd.asm b/Source/HBIOS/fd.asm
index 803663ff..a17b324d 100644
--- a/Source/HBIOS/fd.asm
+++ b/Source/HBIOS/fd.asm
@@ -125,22 +125,22 @@ FSST_COUNT	.EQU	(($ - FSST) / FSST_ENTSIZ)	; # ENTRIES IN TABLE
 ;
 ; FDC COMMANDS
 ;
-CMD_READ	.EQU	00000110B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
-CMD_READDEL	.EQU	00001100B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
-CMD_WRITE	.EQU	00000101B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
-CMD_WRITEDEL	.EQU	00001001B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
-CMD_READTRK	.EQU	00000010B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
-CMD_READID	.EQU	00001010B	; CMD,HDS/DS --> ST0,ST1,ST2,C,H,R,N
-CMD_FMTTRK	.EQU	00001101B	; CMD,HDS/DS,N,SC,GPL,D --> ST0,ST1,ST2,C,H,R,N
-CMD_SCANEQ	.EQU	00010001B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,STP --> ST0,ST1,ST2,C,H,R,N
-CMD_SCANLOEQ	.EQU	00011001B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,STP --> ST0,ST1,ST2,C,H,R,N
-CMD_SCANHIEQ	.EQU	00011101B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,STP --> ST0,ST1,ST2,C,H,R,N
-CMD_RECAL	.EQU	00000111B	; CMD,DS --> <EMPTY>
-CMD_SENSEINT	.EQU	00001000B	; CMD --> ST0,PCN
-CMD_SPECIFY	.EQU	00000011B	; CMD,SRT/HUT,HLT/ND --> <EMPTY>
-CMD_DRVSTAT	.EQU	00000100B	; CMD,HDS/DS --> ST3
-CMD_SEEK	.EQU	00001111B	; CMD,HDS/DS --> <EMPTY>
-CMD_VERSION	.EQU	00010000B	; CMD --> ST0
+CFD_READ	.EQU	00000110B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
+CFD_READDEL	.EQU	00001100B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
+CFD_WRITE	.EQU	00000101B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
+CFD_WRITEDEL	.EQU	00001001B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
+CFD_READTRK	.EQU	00000010B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,DTL --> ST0,ST1,ST2,C,H,R,N
+CFD_READID	.EQU	00001010B	; CMD,HDS/DS --> ST0,ST1,ST2,C,H,R,N
+CFD_FMTTRK	.EQU	00001101B	; CMD,HDS/DS,N,SC,GPL,D --> ST0,ST1,ST2,C,H,R,N
+CFD_SCANEQ	.EQU	00010001B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,STP --> ST0,ST1,ST2,C,H,R,N
+CFD_SCANLOEQ	.EQU	00011001B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,STP --> ST0,ST1,ST2,C,H,R,N
+CFD_SCANHIEQ	.EQU	00011101B	; CMD,HDS/DS,C,H,R,N,EOT,GPL,STP --> ST0,ST1,ST2,C,H,R,N
+CFD_RECAL	.EQU	00000111B	; CMD,DS --> <EMPTY>
+CFD_SENSEINT	.EQU	00001000B	; CMD --> ST0,PCN
+CFD_SPECIFY	.EQU	00000011B	; CMD,SRT/HUT,HLT/ND --> <EMPTY>
+CFD_DRVSTAT	.EQU	00000100B	; CMD,HDS/DS --> ST3
+CFD_SEEK	.EQU	00001111B	; CMD,HDS/DS --> <EMPTY>
+CFD_VERSION	.EQU	00010000B	; CMD --> ST0
 ;
 ;
 ; Specify Command:
@@ -347,48 +347,73 @@ FCS_VERSION	.DB	"VER$"
 ;
 ; FDC COMMAND TABLE
 ;
-FCT		.DB 	CMD_READ \	.DW	FCS_READ
+FCT		.DB 	CFD_READ \	.DW	FCS_READ
 FCT_ENTSIZ	.EQU	$ - FCT
-		.DB 	CMD_READDEL \	.DW	FCS_READDEL
-		.DB 	CMD_WRITE \	.DW	FCS_WRITE
-		.DB 	CMD_WRITEDEL \	.DW	FCS_WRITEDEL
-		.DB 	CMD_READTRK \	.DW	FCS_READTRK
-		.DB 	CMD_READID \	.DW	FCS_READID
-		.DB 	CMD_FMTTRK \	.DW	FCS_FMTTRK
-		.DB 	CMD_SCANEQ \	.DW	FCS_SCANEQ
-		.DB 	CMD_SCANLOEQ \	.DW	FCS_SCANLOEQ
-		.DB 	CMD_SCANHIEQ \	.DW	FCS_SCANHIEQ
-		.DB 	CMD_RECAL \	.DW	FCS_RECAL
-		.DB 	CMD_SENSEINT \	.DW	FCS_SENSEINT
-		.DB 	CMD_SPECIFY \	.DW	FCS_SPECIFY
-		.DB 	CMD_DRVSTAT \	.DW	FCS_DRVSTAT
-		.DB 	CMD_SEEK \	.DW	FCS_SEEK
-		.DB 	CMD_VERSION \	.DW	FCS_VERSION
+		.DB 	CFD_READDEL \	.DW	FCS_READDEL
+		.DB 	CFD_WRITE \	.DW	FCS_WRITE
+		.DB 	CFD_WRITEDEL \	.DW	FCS_WRITEDEL
+		.DB 	CFD_READTRK \	.DW	FCS_READTRK
+		.DB 	CFD_READID \	.DW	FCS_READID
+		.DB 	CFD_FMTTRK \	.DW	FCS_FMTTRK
+		.DB 	CFD_SCANEQ \	.DW	FCS_SCANEQ
+		.DB 	CFD_SCANLOEQ \	.DW	FCS_SCANLOEQ
+		.DB 	CFD_SCANHIEQ \	.DW	FCS_SCANHIEQ
+		.DB 	CFD_RECAL \	.DW	FCS_RECAL
+		.DB 	CFD_SENSEINT \	.DW	FCS_SENSEINT
+		.DB 	CFD_SPECIFY \	.DW	FCS_SPECIFY
+		.DB 	CFD_DRVSTAT \	.DW	FCS_DRVSTAT
+		.DB 	CFD_SEEK \	.DW	FCS_SEEK
+		.DB 	CFD_VERSION \	.DW	FCS_VERSION
 FCT_COUNT	.EQU	(($ - FCT) / FCT_ENTSIZ)	; # ENTRIES IN TABLE
 #ENDIF
 ;
 ;
 ;
 FD_DISPATCH:
+	CALL	FD_SELECTUNIT
+	RET	NZ
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
 	LD	A,B		; GET REQUESTED FUNCTION
-	AND	$0F
-	JP	Z,FD_READ
+	AND	$0F		; ISOLATE SUB-FUNCTION
+	JP	Z,FD_SEEK	; SUB-FUNC 0: SEEK
 	DEC	A
-	JP	Z,FD_WRITE
+	JP	Z,FD_READ	; SUB-FUNC 1: READ
 	DEC	A
-	JP	Z,FD_STATUS
+	JP	Z,FD_WRITE	; SUB-FUNC 2: WRITE
 	DEC	A
-	JP	Z,FD_MEDIA
+	JP	Z,FD_STATUS	; SUB-FUNC 3: STATUS
 	DEC	A
-	JP	Z,FD_CAP
+	JP	Z,FD_RESET	; SUB-FUNC 4: RESET
 	DEC	A
-	JP	Z,FD_GEOM
-	CALL	PANIC
-;
-; FD_MEDIA
-;
-FD_MEDIA:
-	CALL	FD_SELECTUNIT
+	JP	Z,FD_CAP	; SUB-FUNC 5: GET CAPACITY
+	DEC	A
+	JP	Z,FD_GEOM	; SUB-FUNC 6: GET GEOMETRY
+	DEC	A
+	JP	Z,FD_GETPAR	; SUB-FUNC 7: GET PARAMETERS
+	DEC	A
+	JP	Z,FD_SETPAR	; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC		; INVALID SUB-FUNCTION
+;;
+;	LD	A,B		; GET REQUESTED FUNCTION
+;	AND	$0F
+;	JP	Z,FD_READ
+;	DEC	A
+;	JP	Z,FD_WRITE
+;	DEC	A
+;	JP	Z,FD_STATUS
+;	DEC	A
+;	JP	Z,FD_MEDIA
+;	DEC	A
+;	JP	Z,FD_CAP
+;	DEC	A
+;	JP	Z,FD_GEOM
+;	CALL	PANIC
+;
+; FD_GETPAR
+;
+FD_GETPAR:
+	;CALL	FD_SELECTUNIT
 
 #IF (FDMAUTO)
 	; SETUP TO READ TRK 0, HD 0, SEC 0
@@ -425,7 +450,8 @@ FD_MEDIARETRY:
 	DJNZ	FD_MEDIARETRY
 	
 	; NO JOY, RETURN WITH A=0 (NO MEDIA)
-	XOR	A
+	LD	E,0
+	OR	$FF				; SIGNAL ERROR
 	RET
 
 FD_TESTMEDIA:
@@ -461,6 +487,15 @@ FD_MEDIA3:
 	CALL	PC_SPACE
 	CALL	PRTHEXBYTE
 #ENDIF
+	LD	E,A			; MOVE MEDIA VALUE TO E
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+;
+;
+FD_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
 	RET
 ;
 ;
@@ -482,8 +517,10 @@ FD_CAP:
 ;
 ;
 FD_GEOM:
-	LD	A,C		; GET DEVICE/UNIT
-	OR	$0F		; ISOLATE UNIT
+	;LD	A,C		; GET DEVICE/UNIT
+	;OR	$0F		; ISOLATE UNIT
+	LD	A,(FD_UNIT)	; GET DEVICE/UNIT
+	OR	A		; SET FLAGS
 	JR	Z,FD_GEOM0	; UNIT 0
 	DEC	A		; NOPE, TRY UNIT 1
 	JR	Z,FD_GEOM1	; UNIT 1
@@ -567,7 +604,7 @@ FD_IDLE:
 ; FD_STATUS
 ;
 FD_STATUS:
-	CALL	FD_SELECTUNIT
+	;CALL	FD_SELECTUNIT
 	LD	HL,(FDDS_TRKADR)
 	LD	A,(HL)			; A = CURRENT TRACK
 	
@@ -581,6 +618,12 @@ FD_STATUS1:
 	OR	A			; A ALREADY = $FF, JUST SET FLAGS
 	RET
 ;
+;
+;
+FD_RESET:
+	XOR	A		; ALWAYS OK
+	RET
+;
 ; FD_CLRDSKCHG
 ;
 FD_CLRDSKCHG:
@@ -674,8 +717,12 @@ FD_DRIVERESET:
 ;
 ;
 FD_SELECTUNIT:
+	PUSH	HL
+	PUSH	DE
+
 	LD	A,C
 	AND	0FH		; ISOLATE THE UNIT NIBBLE
+	LD	(FD_UNIT),A	; SAVE IT
 
 	; GOOD PLACE FOR AN INTEGRITY CHECK
 	CP	2
@@ -691,14 +738,30 @@ FD_SELECTUNIT:
 	LD	(FDDS_TRKADR),HL	; LOAD TRKADR
 	INC	HL			; SKIP TRK
 	LD	(FDDS_MEDIAADR),HL	; LOAD MEDIAADR
+	
+	POP	DE
+	POP	HL
 
+	XOR	A
 	RET
-	
+;
+;
+;
+FD_SEEK:
+	LD	(HSTSEC),DE		; RECORD HEAD/SECTOR
+	LD	(HSTTRK),HL		; RECORD TRACK
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+;
+;
 FD_READ:
+	LD	(FD_DSKBUF),HL		; SAVE DISK BUFFER ADDRESS
 	LD	A,DOP_READ
 	JR	FD_RUN
 ;
 FD_WRITE:
+	LD	(FD_DSKBUF),HL		; SAVE DISK BUFFER ADDRESS
 	LD	A,DOP_WRITE
 	JR	FD_RUN
 ;
@@ -706,11 +769,12 @@ FD_RUN:
 	LD	(FCD_DOP),A
 
 	; UPDATE DRIVE SELECTION
-	LD	A,(HSTDSK)		; GET THE NEW DRIVE SELECTION
-	AND	0FH
+	;LD	A,(HSTDSK)		; GET THE NEW DRIVE SELECTION
+	;AND	0FH
+	LD	A,(FD_UNIT)		; GET UNIT
 	LD	(FCD_DS),A		; UPDATE FCD_DS TO NEW VALUE
-	LD	C,A
-	CALL	FD_SELECTUNIT
+	;LD	C,A
+	;CALL	FD_SELECTUNIT
 	
 	; MAP HSTTRK TO FCD_H, FCD_C
 	LD	BC,(HSTTRK)
@@ -798,7 +862,7 @@ FD_RUN0:
 	; INITIATE SEEK TO NEW TRACK
 	CALL	FC_SEEK
 	JR	NZ,FD_RUNERR
-
+	
 	; WAIT FOR SEEK TO COMPLETE
 	CALL	FD_WTSEEK
 	JR	NZ,FD_RUNERR
@@ -872,44 +936,44 @@ FD_DSKY:
 ; ENTRY POINTS FOR FDC COMMANDS
 ;
 FC_READ:
-	LD	A,CMD_READ | 11100000B
+	LD	A,CFD_READ | 11100000B
 	CALL	FC_SETUPIO
 	JP	FOP
 
 FC_WRITE:
-	LD	A,CMD_WRITE | 11000000B
+	LD	A,CFD_WRITE | 11000000B
 	CALL	FC_SETUPIO
 	JP	FOP
 
 FC_READID:
-	LD	A,CMD_READID | 01000000B
+	LD	A,CFD_READID | 01000000B
 	CALL	FC_SETUPCMD
 	JP	FOP
 	
 FC_RECAL:
-	LD	A,CMD_RECAL | 00000000B
+	LD	A,CFD_RECAL | 00000000B
 	CALL	FC_SETUPCMD
 	JP	FOP		; FIX: DO WE NEED TO REMOVE HDS BITS FROM SECOND BYTE?
 
 FC_SENSEINT:
-	LD	A,CMD_SENSEINT | 00000000B
+	LD	A,CFD_SENSEINT | 00000000B
 	CALL	FC_SETUPCMD
 	LD	A,1		; GENERIC COMMAND, BUT JUST FIRST COMMAND CODE
 	LD	(FCP_LEN),A
 	JP	FOP
 
 FC_SPECIFY:
-	LD	A,CMD_SPECIFY | 00000000B
+	LD	A,CFD_SPECIFY | 00000000B
 	CALL	FC_SETUPSPECIFY
 	JP	FOP
 
 FC_DRVSTAT:
-	LD	A,CMD_DRVSTAT | 00000000B
+	LD	A,CFD_DRVSTAT | 00000000B
 	CALL	FC_SETUPCMD
 	JP	FOP
 
 FC_SEEK:
-	LD	A,CMD_SEEK | 00000000B
+	LD	A,CFD_SEEK | 00000000B
 	CALL	FC_SETUPSEEK
 	JP	FOP
 ;
@@ -1229,11 +1293,11 @@ FOP_X1:
 	LD	HL,FOP_RES
 	PUSH	HL
 	
-	CP	CMD_READ
+	CP	CFD_READ
 	JP	Z,FXR_READ
-	CP	CMD_WRITE
+	CP	CFD_WRITE
 	JP	Z,FXR_WRITE
-	CP	CMD_READID
+	CP	CFD_READID
 	JP	Z,FXR_NULL
 	RET				; RET ACTUALLY JUST JUMPS RIGHT TO FOP_RES
 ;
@@ -1318,7 +1382,7 @@ FOP_ERR:
 FOP_EVAL:
 	LD	A,(FCP_CMD)
 	; DRVSTAT IS WEIRD, HAS ONLY ST3, NOTHING TO EVAL
-	CP	CMD_DRVSTAT
+	CP	CFD_DRVSTAT
 	JR	Z,FOP_EXIT
 	; DO WE HAVE ST0?
 	LD	A,(FRB_LEN)
@@ -1339,7 +1403,7 @@ FOP_EVALST0:
 FOP_ABTERM:
 	; SENSEINT DOES NOT USE ST1
 	LD	A,(FCP_CMD)
-	CP	CMD_SENSEINT
+	CP	CFD_SENSEINT
 	JR	Z,FOP_ABTERM1
 	; DO WE HAVE ST1?
 	LD	A,(FRB_LEN)
@@ -1425,7 +1489,7 @@ FXR_NULL1:
 ; READ DATA
 ;	
 FXR_READ:
-	LD	HL,(DIOBUF)		; POINT TO SECTOR BUFFER START
+	LD	HL,(FD_DSKBUF)		; POINT TO SECTOR BUFFER START
 	LD	DE,(FCD_SECSZ)
 	; TIMEOUT COUNTER IS CPU MHZ / 4 (MAKING SURE IT IS AT LEAST 1)
 ;	LD	A,(CPUMHZ + 3) / 4
@@ -1465,7 +1529,7 @@ FXRR5:					; OUTER LOOP, REALLY ONLY HAPPENS WHEN WAITING FOR FIRST BYTE OR ABOR
 ; WRITE DATA
 ;
 FXR_WRITE:
-	LD	HL,(DIOBUF)		; POINT TO SECTOR BUFFER START
+	LD	HL,(FD_DSKBUF)		; POINT TO SECTOR BUFFER START
 	LD	DE,(FCD_SECSZ)
 	; TIMEOUT COUNTER IS CPU MHZ / 4 (MAKING SURE IT IS AT LEAST 1)
 ;	LD	A,(CPUMHZ + 3) / 4
@@ -1628,7 +1692,7 @@ FC_PRTRESULTS:
 	
 	; SPECIAL CASE, DON'T PRINT IF SENSEINT & INVCMD/DSK CHG/ABTERM
 	LD	A,(FCP_CMD)
-	CP	CMD_SENSEINT
+	CP	CFD_SENSEINT
 	JR	NZ,FCPR2
 	
 	LD	A,(FST_RC)
@@ -1769,3 +1833,8 @@ FCD_U1MEDIA	.DB	FDMEDIA		; MEDIA BYTE
 ;
 FDDS_TRKADR	.DW	0	; POINTER TO FDCUXTRK ABOVE
 FDDS_MEDIAADR	.DW	0	; POINTER TO FDCUXMEDIA ABOVE
+;
+; GENERAL WORKING STORAGE
+;
+FD_UNIT		.DB	0
+FD_DSKBUF	.DW	0
\ No newline at end of file
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index e11ca7a0..4b7d7fc3 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -674,7 +674,7 @@ HB_DISPATCH:
 	LD	A,B		; REQUESTED FUNCTION IS IN B
 	CP	BF_CIO + $10	; $00-$0F: CHARACTER I/O
 	JP	C,CIO_DISPATCH
-	CP	BF_DIO + $10	; $10-$1F: DISK I/O
+	CP	BF_DIO + $10	; $10-$1F: OLD DISK I/O
 	JP	C,DIO_DISPATCH
 	CP	BF_RTC + $10	; $20-$2F: REAL TIME CLOCK (RTC)
 	JP	C,RTC_DISPATCH
@@ -682,6 +682,8 @@ HB_DISPATCH:
 	JP	C,EMU_DISPATCH
 	CP	BF_VDA + $10	; $40-$4F: VIDEO DISPLAY ADAPTER
 	JP	C,VDA_DISPATCH
+	CP	BF_NDIO + $10	; $50-$5F: NEW DISK I/O
+	JP	C,VDA_DISPATCH
 	
 	CP	BF_SYS		; SKIP TO BF_SYS VALUE AT $F0
 	CALL	C,PANIC		; PANIC IF LESS THAN BF_SYS
@@ -791,86 +793,135 @@ CIO_GETINF1:
 	RET			; RETURN
 ;
 ;==================================================================================================
-;   DISK I/O DEVICE DISPATCHER
+; OLD STYLE DISK I/O DEVICE DISPATCHER
 ;==================================================================================================
 ;
 ; ROUTE CALL TO SPECIFIED DISK I/O DRIVER
 ;   B: FUNCTION
 ;   C: DEVICE/UNIT
-;   H:7: INDICATES LBA MODE
-;   CHS MODE: DE:HL==TT:HS
-;   LBA MODE: HL:DE==NN:NN (32 BIT ADDRESS)
 ;
 DIO_DISPATCH:
 	; GET THE REQUESTED FUNCTION TO SEE IF SPECIAL HANDLING
 	; IS NEEDED
 	LD	A,B
+	CP	BF_DIORD	; READ
+	JR	Z,DIO_READ	; GO TO READ SHIM
+	CP	BF_DIOWR	; WRITE
+	JR	Z,DIO_WRITE	; GO TO WRITE SHIM
+	CP	BF_DIOST	; STATUS
+	JR	Z,DIO_STAT	; GO TO STATUS SHIM
+	CP	BF_DIOMED	; MEDIA
+	JR	Z,DIO_MEDIA	; GO TO MEDIA SHIM
+	;CP	BF_DIOID	; IDENTIFY
+	;CALL	Z,DIOID		; WAS NEVER REALLY SUPPORTED
+	CP	BF_DIOGETBUF	; GET BUF
+	JR	Z,DIO_GETBUF	; GO TO GET BUF SHIM
+	CP	BF_DIOSETBUF	; SET BUF
+	JR	Z,DIO_SETBUF	; GO TO SET BUF SHIM
+	CP	BF_DIOGETCNT	; FUNCTION = DIOGETCNT?
+	JR	Z,DIO_GETCNT	; YES, HANDLE IT
+	CP	BF_DIOGETINF	; FUNCTION = DIOGETINF?
+	JR	Z,DIO_GETINF	; YES, HANDLE IT
+	CALL	PANIC		; UNSUPPORTED FUNCTION REQUEST
+;
+; DISK: SHIM FOR OLD STYLE READ CALL
+;
+DIO_READ:
+	LD	B,BF_NDIOREAD	; OVERLAY OLD FUNCTION ID WITH NEW ONE
+	JR	DIO_RW		; ... AND GO TO COMMON R/W ROUTINE
+;
+; DISK: SHIM FOR OLD STYLE WRITE CALL
+;
+DIO_WRITE:
+	LD	B,BF_NDIOWRITE	; OVERLAY OLD FUNCTION ID WITH NEW ONE
+	JR	DIO_RW		; ... AND GO TO COMMON R/W ROUTINE
+;
+; DISK: COMMON ROUTINE USED BY READ/WRITE SHIMS ABOVE
+; NEW FUNCTION ID IS EXPECTED TO BE IN B (NDIO_READ OR NDIO_WRITE)
+; THIS ROUTINE WILL TAKE THE OLD STYLE CALL AND PERFORM TWO CALLS TO
+; THE NEW INTERFACE (SEEK, THEN READ OR WRITE) WHICH EFFECTIVELY
+; REPLICATES THE FUNCTIONALITY OF THE OLD CALL.
+;
+DIO_RW:
+	PUSH	BC		; SAVE INCOMING FUNCTION, DEVICE/UNIT
+	EX	DE,HL           ; SWAP DE/HL TO XLAT FROM OLD TO NEW CALL
+	LD	B,BF_NDIOSEEK   ; SETUP FOR NEW SEEK CALL
+	CALL	NDIO_DISPATCH   ; DO IT
+	POP	BC              ; RESTORE INCOMING FUNCTION, DEVICE/UNIT
+	RET	NZ              ; ABORT IF SEEK RETURNED AN ERROR W/ ERROR IN A
+	LD	HL,(DIOBUF)     ; GET BUFFER ADDRESS
+	LD	DE,1            ; TRANSFER ONE SECTOR
+	JR	NDIO_DISPATCH   ; RETURN VIA DISPATCHER
+	
 ;
-	; DIO FUNCTIONS STARTING AT DIOGETBUF ARE COMMON FUNCTIONS
-	; AND DO NOT DISPATCH TO DRIVERS (HANDLED GLOBALLY)
-	CP	BF_DIOGETBUF	; TEST FOR FIRST OF THE COMMON FUNCTIONS
-	JR	NC,DIO_COMMON	; IF >= DIOGETBUF HANDLE AS COMMON DIO FUNCTION
-;
-	; HACK TO FILL IN HSTTRK AND HSTSEC
-	; BUT ONLY FOR READ/WRITE FUNCTION CALLS
-	; ULTIMATELY, HSTTRK AND HSTSEC ARE TO BE REMOVED
-	CP	BF_DIOST		; BEYOND READ/WRITE FUNCTIONS ?
-	JR	NC,DIO_DISPATCH1	; YES, BYPASS
-	LD	(HSTSEC),HL		; RECORD HEAD/SECTOR (OR LBA HIGH)
-	LD	(HSTTRK),DE		; RECORD TRACK (OR LBA LOW)
-;
-;	PUSH	BC
-;	CALL	NEWLINE
-;	PUSH	DE
-;	POP	BC
-;	CALL	PRTHEXWORD
-;	CALL	PC_COLON
-;	PUSH	HL
-;	POP	BC
-;	CALL	PRTHEXWORD
-;	POP	BC
-;
-	; HACK TO CONVERT INCOMING CHS TO LBA IFF HD ACCESS (NOT FLOPPY)
-	; FIRST CHECK FOR FLOPPY DEVICE AND BYPASS IF SO
-	LD	A,C			; GET REQUEST DEVICE/UNIT FROM C
-	AND	$F0			; ISOLATE THE DEVICE PORTION
-	CP	DIODEV_FD		; FLOPPY?
-	JR	Z,DIO_DISPATCH1		; YES, BYPASS
-;
-	; NOW CHECK IF INCOMING IS ALREADY LBA AND BYPASS IF SO
-	BIT	7,H			; TEST HIGH BIT OF HEAD/LBA
-	RES	7,H			; CLEAR LBA INDICATOR BIT
-	JR	NZ,DIO_DISPATCH1	; IF NZ, ALREADY LBA, BYPASS
+; DISK: SHIM FOR OLD STYLE STATUS CALL
 ;
-	; WE HAVE INCOMING HARDDISK CHS, CONVERT TO LBA
-	; DE=TRACK (0..N), H=HEAD (0..15), L=SECTOR (0..15)
-	; XLAT DE:HL (TT:HS) --> 32 BIT LBA (LBAHI:LBALO)
-	LD	A,H			; HEAD TO A
-	RLCA				; LEFT SHIFT TO HIGH NIBBLE
-	RLCA				; ... DEPENDS ON HIGH
-	RLCA				; ... NIBBLE BEING 0 SINCE
-	RLCA				; ... IT ROTATES INTO LOW NIBBLE
-	OR	L			; COMBINE WITH SECTOR (HIGH NIBBLE MUST BE ZERO)
-	LD	L,A			; THIS IS LBA LOW LSB
-	LD	H,E			; LBA LOW MSB, E -> H
-	LD	(HSTLBALO),HL		; SAVE FINAL LBA LOW
-	LD	L,D			; LBA HIGH LSB, D -> L
-	LD	H,0			; LBA HIGH MSB, ZERO FILL
-	LD	(HSTLBAHI),HL		; SAVE FINAL LBA HIGH
-;
-;	PUSH	BC
-;	CALL	PC_SPACE
-;	LD	BC,(HSTLBAHI)
-;	CALL	PRTHEXWORD
-;	CALL	PC_COLON
-;	LD	BC,(HSTLBALO)
-;	CALL	PRTHEXWORD
-;	POP	BC
-;
-DIO_DISPATCH1:
+DIO_STAT:
+	LD	B,BF_NDIOSTAT
+	JR	NDIO_DISPATCH
+;
+; DISK: SHIM FOR OLD STYLE MEDIA CALL
+;
+DIO_MEDIA:
+	LD	B,BF_NDIOGETPAR
+	CALL	NDIO_DISPATCH
+	LD	A,E
+	OR	A
+	RET
+;
+; DISK: GET BUFFER ADDRESS
+;
+DIO_GETBUF:
+	LD	HL,(DIOBUF)	; HL = DISK BUFFER ADDRESS
+	XOR	A		; SIGNALS SUCCESS
+	RET
+;
+; DISK: SET BUFFER ADDRESS
+;
+DIO_SETBUF:
+	LD	A,H		; TEST HL
+	OR	L		; ... FOR ZERO
+	JR	NZ,DIO_SETBUF1	; IF NOT, PROCEED TO SET BUF ADR
+	LD	HL,HB_BUF	; IF ZERO, SET TO DEFAULT ADR
+DIO_SETBUF1:
+	LD	(DIOBUF),HL	; RECORD NEW DISK BUFFER ADDRESS
+	XOR	A		; SIGNALS SUCCESS
+	RET
+;
+; DISK: GET DEVICE COUNT
+;
+DIO_GETCNT:
+	LD	A,(HCB + HCB_DDL - 1)	; GET DEVICE COUNT (FIRST BYTE OF LIST)
+	LD	B,A		; PUT IT IN B
+	XOR	A		; SIGNALS SUCCESS
+	RET
+;
+; DISK: GET DEVICE INFO
+;
+DIO_GETINF:
+	LD	HL,HCB + HCB_DDL - 1	; POINT TO DEVICE MAP ENTRY COUNT (FIRST BYTE OF LIST)
+	LD	B,(HL)		; ENTRY COUNT TO B
+	LD	A,C		; INDEX TO A
+	CP	B		; CHECK INDEX AGAINST MAX VALUE (INDEX - COUNT)
+	JR	NC,DIO_GETINF1	; IF INDEX TOO HIGH, ERR
+	INC	HL		; BUMP TO START OF DEV MAP ENTRIES
+	CALL	ADDHLA		; AND POINT TO REQUESTED INDEX
+	LD	C,(HL)		; DEVICE/UNIT TO C
+	XOR	A		; SIGNAL SUCCESS
+	RET			; DONE
+
+DIO_GETINF1:
+	OR	$FF		; SIGNAL ERROR
+	RET			; RETURN
+;
+;==================================================================================================
+; DISK I/O DEVICE DISPATCHER
+;==================================================================================================
+;
+NDIO_DISPATCH:
 	; START OF THE ACTUAL DRIVER DISPATCHING LOGIC
 	LD	A,C		; GET REQUESTED DEVICE/UNIT FROM C
-	LD	(HSTDSK),A	; TEMP HACK TO FILL IN HSTDSK
+	;LD	(HSTDSK),A	; TEMP HACK TO FILL IN HSTDSK
 	AND	$F0		; ISOLATE THE DEVICE PORTION
 ;
 #IF (MDENABLE)
@@ -911,64 +962,62 @@ DIO_DISPATCH1:
 #ENDIF
 	CALL	PANIC
 ;
-; HANDLE COMMON DISK FUNCTIONS (NOT DEVICE DRIVER SPECIFIC)
+; CONVERT AN HBIOS STANDARD HARD DISK CHS ADDRESS TO
+; AN LBA ADDRESS.  A STANDARD HBIOS HARD DISK IS ASSUMED
+; TO HAVE 16 SECTORS PER TRACK AND 16 HEADS PER CYLINDER.
 ;
-DIO_COMMON:
-	SUB	BF_DIOGETBUF	; FUNCTION = DIOGETBUF?
-	JR	Z,DIO_GETBUF	; YES, HANDLE IT
-	DEC	A		; FUNCTION = DIOSETBUF?
-	JR	Z,DIO_SETBUF	; YES, HANDLE IT
-	DEC	A		; FUNCTION = DIOGETCNT?
-	JR	Z,DIO_GETCNT	; YES, HANDLE IT
-	DEC	A		; FUNCTION = DIOGETINF?
-	JR	Z,DIO_GETINF	; YES, HANDLE IT
-	CALL	PANIC		; INVALID FUNCTION SPECFIED
+; INPUT:  HL=TRACK, D=HEAD, E=SECTOR
+; OUTPUT: DE:HL=32 BIT LBA ADDRESS (D:7 IS NOT SET IN THE RESULT)
 ;
-; DISK: GET BUFFER ADDRESS
-;
-DIO_GETBUF:
-	LD	HL,(DIOBUF)	; HL = DISK BUFFER ADDRESS
-	XOR	A		; SIGNALS SUCCESS
-	RET
+HB_CHS2LBA:
 ;
-; DISK: SET BUFFER ADDRESS
+	;; DEBUG: DUMP INCOMING TRACK:HEAD/SEC
+	;CALL	NEWLINE
+	;PUSH	BC
+	;PUSH	HL
+	;POP	BC
+	;CALL	PRTHEXWORD
+	;CALL	PC_COLON
+	;PUSH	DE
+	;POP	BC
+	;CALL	PRTHEXWORD
+	;POP	BC
 ;
-DIO_SETBUF:
-	LD	A,H		; TEST HL
-	OR	L		; ... FOR ZERO
-	JR	NZ,DIO_SETBUF1	; IF NOT, PROCEED TO SET BUF ADR
-	LD	HL,HB_BUF	; IF ZERO, SET TO DEFAULT ADR
-DIO_SETBUF1:
-	LD	(DIOBUF),HL	; RECORD NEW DISK BUFFER ADDRESS
-	XOR	A		; SIGNALS SUCCESS
-	RET
+	; WE HAVE INCOMING HARDDISK CHS, CONVERT TO LBA
+	; HL=TRACK (0..N), D=HEAD (0..15), E=SECTOR (0..15)
+	; XLAT HL:DE (TT:HS) --> 32 BIT LBA (LBAHI:LBALO)
+	;
+	;	D/E -> A	(COMBINE HEAD/SEC AND SAVE IN A)
+	;	0 -> D
+	;	H -> E
+	;	L -> H
+	;	A -> L
+	;
+	LD	A,D			; HEAD TO A
+	RLCA				; LEFT SHIFT TO HIGH NIBBLE
+	RLCA				; ... DEPENDS ON HIGH
+	RLCA				; ... NIBBLE BEING 0 SINCE
+	RLCA				; ... IT ROTATES INTO LOW NIBBLE
+	OR	E			; COMBINE WITH SECTOR (HIGH NIBBLE MUST BE ZERO)
+	LD	D,0
+	LD	E,H
+	LD	H,L
+	LD	L,A
 ;
-; DISK: GET DEVICE COUNT
+	;; DEBUG: DUMP RESULTING LBA (32 BIT)
+	;PRTS("-->$")
+	;PUSH	BC
+	;PUSH	DE
+	;POP	BC
+	;CALL	PRTHEXWORD
+	;PUSH	HL
+	;POP	BC
+	;CALL	PRTHEXWORD
+	;POP	BC
 ;
-DIO_GETCNT:
-	LD	A,(HCB + HCB_DDL - 1)	; GET DEVICE COUNT (FIRST BYTE OF LIST)
-	LD	B,A		; PUT IT IN B
-	XOR	A		; SIGNALS SUCCESS
+	XOR	A
 	RET
 ;
-; DISK: GET DEVICE INFO
-;
-DIO_GETINF:
-	LD	HL,HCB + HCB_DDL - 1	; POINT TO DEVICE MAP ENTRY COUNT (FIRST BYTE OF LIST)
-	LD	B,(HL)		; ENTRY COUNT TO B
-	LD	A,C		; INDEX TO A
-	CP	B		; CHECK INDEX AGAINST MAX VALUE (INDEX - COUNT)
-	JR	NC,DIO_GETINF1	; IF INDEX TOO HIGH, ERR
-	INC	HL		; BUMP TO START OF DEV MAP ENTRIES
-	CALL	ADDHLA		; AND POINT TO REQUESTED INDEX
-	LD	C,(HL)		; DEVICE/UNIT TO C
-	XOR	A		; SIGNAL SUCCESS
-	RET			; DONE
-
-DIO_GETINF1:
-	OR	$FF		; SIGNAL ERROR
-	RET			; RETURN
-;
 ;==================================================================================================
 ;   REAL TIME CLOCK DEVICE DISPATCHER
 ;==================================================================================================
@@ -1747,7 +1796,7 @@ IDLECOUNT	.DB	0
 ;		.DW	0		; LBA HIGH WORD
 ;
 ; DISK DEVICE/UNIT ID
-HSTDSK		.DB	0		; DISK DEVICE/UNIT ID
+;HSTDSK		.DB	0		; DISK DEVICE/UNIT ID
 ; FULL 32 BIT LBA
 HSTLBA		.EQU	$		; REFERS TO START OF 32-BIT LBA
 ; LBA LOW WORD -OR- TRACK
diff --git a/Source/HBIOS/hbios.inc b/Source/HBIOS/hbios.inc
index cbce248b..294127d6 100644
--- a/Source/HBIOS/hbios.inc
+++ b/Source/HBIOS/hbios.inc
@@ -22,6 +22,17 @@ BF_DIOSETBUF	.EQU	BF_DIO + 9	; DISK SET BUFFER ADR
 BF_DIOGETCNT	.EQU	BF_DIO + 10	; DISK DEVICE COUNT
 BF_DIOGETINF	.EQU	BF_DIO + 11	; DISK DEVICE INFO
 ;
+BF_NDIO		.EQU	$50
+BF_NDIOSEEK	.EQU	BF_DIO + 0	; DISK SEEK
+BF_NDIOREAD	.EQU	BF_DIO + 1	; DISK READ
+BF_NDIOWRITE	.EQU	BF_DIO + 2	; DISK WRITE
+BF_NDIOSTAT	.EQU	BF_DIO + 3	; DISK STATUS
+BF_NDIORESET	.EQU	BF_DIO + 4	; DISK RESET
+BF_NDIOCAP	.EQU	BF_DIO + 5	; GET DISK CAPACITY
+BF_NDIOGEOM	.EQU	BF_DIO + 6	; GET DISK GEOMETRY
+BF_NDIOGETPAR	.EQU	BF_DIO + 7	; GET DISK PARAMS
+BF_NDIOSETPAR	.EQU	BF_DIO + 8	; SET DISK PARAMS
+;
 BF_RTC		.EQU	$20
 BF_RTCGETTIM	.EQU	BF_RTC + 0	; GET TIME
 BF_RTCSETTIM	.EQU	BF_RTC + 1	; SET TIME
diff --git a/Source/HBIOS/hdsk.asm b/Source/HBIOS/hdsk.asm
index d0ed37b8..ba2ecacc 100644
--- a/Source/HBIOS/hdsk.asm
+++ b/Source/HBIOS/hdsk.asm
@@ -20,35 +20,6 @@ HDSKRC_OK	.EQU	0
 ;
 ;
 ;
-HDSK_DISPATCH:
-	LD	A,B		; GET REQUESTED FUNCTION
-	AND	$0F
-	JR	Z,HDSK_READ
-	DEC	A
-	JR	Z,HDSK_WRITE
-	DEC	A
-	JR	Z,HDSK_STATUS
-	DEC	A
-	JR	Z,HDSK_MEDIA
-	DEC	A
-	JR	Z,HDSK_CAP
-	DEC	A
-	JR	Z,HDSK_GEOM
-	CALL	PANIC
-;
-; HDSK_MEDIA
-;
-HDSK_MEDIA:
-	LD	A,C		; GET THE DEVICE/UNIT
-	AND	$0F		; ISOLATE UNIT
-	CP	HDSKCNT		; NUM UNITS
-	LD	A,MID_HD	; ASSUME WE ARE OK
-	RET	C		; RETURN
-	XOR	A		; NO MEDIA
-	RET			; AND RETURN
-;
-;
-;
 HDSK_INIT:
 	PRTS("HDSK: UNITS=$")
 	LD	A,HDSKCNT
@@ -62,11 +33,49 @@ HDSK_INIT:
 ;
 ;
 ;
+HDSK_DISPATCH:
+	; SAVE THE TARGET DEVICE/UNIT LOCALLY IN DRIVER
+	LD	A,C		; DEVICE/UNIT FROM C
+	AND	$0F		; ISOLATE UNIT NUM
+	CP	2		; CHECK FOR MAX UNIT EXCEEDED
+	LD	(HDSK_UNIT),A	; SAVE IT
+	CALL	NC,PANIC	; PANIC IF TOO HIGH
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
+	LD	A,B		; GET REQUESTED FUNCTION
+	AND	$0F		; ISOLATE SUB-FUNCTION
+	JP	Z,HDSK_SEEK	; SUB-FUNC 0: SEEK, USE HBIOS FOR NOW
+	DEC	A
+	JP	Z,HDSK_READ	; SUB-FUNC 1: READ
+	DEC	A
+	JP	Z,HDSK_WRITE	; SUB-FUNC 2: WRITE
+	DEC	A
+	JP	Z,HDSK_STATUS	; SUB-FUNC 3: STATUS
+	DEC	A
+	JP	Z,HDSK_RESET	; SUB-FUNC 4: RESET
+	DEC	A
+	JP	Z,HDSK_CAP	; SUB-FUNC 5: GET CAPACITY
+	DEC	A
+	JP	Z,HDSK_GEOM	; SUB-FUNC 6: GET GEOMETRY
+	DEC	A
+	JP	Z,HDSK_GETPAR	; SUB-FUNC 7: GET PARAMETERS
+	DEC	A
+	JP	Z,HDSK_SETPAR	; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC		; INVALID SUB-FUNCTION
+;
+;
+;
 HDSK_STATUS:
 	LD	A,(HDSK_STAT)	; LOAD STATUS
 	OR	A		; SET FLAGS
 	RET
 ;
+;
+;
+HDSK_RESET:
+	XOR	A		; ALWAYS OK
+	RET
+;
 ; GET DISK CAPACITY
 ;   RETURN DE:HL=BLOCK COUNT, BC=BLOCK SIZE
 ;   SLICE C/H/S = 65/16/16 OR 16,640 TOTAL SECTORS
@@ -79,26 +88,56 @@ HDSK_CAP:
 	XOR	A			; SIGNAL SUCCESS
 	RET
 ;
+;
+;
 HDSK_GEOM:
 	; FOR LBA, WE SIMULATE CHS ACCESS USING 16 HEADS AND 16 SECTORS
 	; RETURN HS:CC -> DE:HL, SET HIGH BIT OF D TO INDICATE LBA CAPABLE
-	CALL	HDSK_CAP			; GET TOTAL BLOCKS IN DE:HL, BLOCK SIZE TO BC
-	LD	L,H				; DIVIDE BY 256 FOR # TRACKS
-	LD	H,E				; ... HIGH BYTE DISCARDED, RESULT IN HL
-	LD	D,$80 | 16			; HEADS / CYL = 16, SET LBA BIT
-	LD	E,16				; SECTORS / TRACK = 16
-	XOR	A				; SIGNAL SUCCESS
+	CALL	HDSK_CAP		; GET TOTAL BLOCKS IN DE:HL, BLOCK SIZE TO BC
+	LD	L,H			; DIVIDE BY 256 FOR # TRACKS
+	LD	H,E			; ... HIGH BYTE DISCARDED, RESULT IN HL
+	LD	D,$80 | 16		; HEADS / CYL = 16, SET LBA BIT
+	LD	E,16			; SECTORS / TRACK = 16
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+;
+;
+HDSK_GETPAR:
+	LD	A,MID_HD		; HARD DISK MEDIA
+	LD	E,A			; VALUE TO E
+	XOR	A			; SIGNAL SUCCESS
+	RET
+;
+;
+;
+HDSK_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
 	RET
 ;
 ;
 ;
+HDSK_SEEK:
+	BIT	7,D		; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA	; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D		; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+	LD	BC,HSTLBA	; POINT TO LBA STORAGE
+	CALL	ST32		; SAVE LBA ADDRESS
+	XOR	A		; SIGNAL SUCCESS
+	RET			; AND RETURN
+;
+;
+;
 HDSK_READ:
+	LD	(HDSK_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
 	LD	A,HDSK_CMDREAD
 	JR	HDSK_RW
 ;
 ;
 ;
 HDSK_WRITE:
+	LD	(HDSK_DSKBUF),HL		; SAVE DISK BUFFER ADDRESS
 	LD	A,HDSK_CMDWRITE
 	JR	HDSK_RW
 ;
@@ -114,11 +153,11 @@ HDSK_RW:
 	; INIT IF NEEDED
 	LD	A,(HDSK_STAT)		; GET CURRENT STATUS
 	OR	A			; SET FLAGS
-	CALL	NZ,HDSK_RESET		; RESET IF NOT READY
+	CALL	NZ,HDSK_DSKRESET	; RESET IF NOT READY
 	
 	; SET DEVICE
-	LD	A,(HSTDSK)
-	AND	$0F
+	LD	A,(HDSK_UNIT)
+	;AND	$0F
 	LD	(HDSK_DEVICE),A
 	
 ;	; INCOMING TRK:SEC ACTUALLY REPRESENTS 32 BIT LBA
@@ -142,7 +181,7 @@ HDSK_RW:
 	LD	(HDSK_SEC),A		;   MAPS TO LSB OF HDSK SEC
 
 	; SET TRANSFER ADDRESS
-	LD	BC,(DIOBUF)
+	LD	BC,(HDSK_DSKBUF)
 	LD	(HDSK_DMA),BC
 
 	; EXECUTE COMMAND
@@ -180,12 +219,12 @@ HDSK_OK:
 ;
 ;
 ;
-HDSK_RESET:
+HDSK_DSKRESET:
 	LD	B,32
 	LD	A,HDSK_CMDRESET
-HDSK_RESET1:
+HDSK_DSKRESET1:
 	OUT	($FD),A
-	DJNZ	HDSK_RESET1
+	DJNZ	HDSK_DSKRESET1
 
 	XOR	A			; STATUS = OK
 	LD	(HDSK_STAT),A		; SAVE IT
@@ -256,7 +295,7 @@ HDSK_PRTRW:
 	LD	A,(HDSK_SEC)
 	CALL	PRTHEXBYTE
 	CALL	PC_SPACE
-	LD	BC,(HDSK_DMA)
+	LD	BC,(HDSK_DSKBUF)
 	CALL	PRTHEXWORD
 
 	CALL	PC_SPACE
@@ -305,9 +344,12 @@ HDSKSTR_RCUNK	.TEXT	"UNKNOWN ERROR$"
 HDSK_STAT	.DB	0
 HDSK_RC		.DB	0
 ;
+HDSK_UNIT	.DB	0
+HDSK_DSKBUF	.DW	0
+;
 HDSK_PARMBLK:
 HDSK_CMD	.DB	0	; COMMAND (HDSK_READ, HDSK_WRITE, ...)
 HDSK_DEVICE	.DB	0	; 0..7, HARD DISK UNIT
 HDSK_SEC	.DB	0	; 0..255 SECTOR
 HDSK_TRK	.DW	0	; 0..2047 TRACK
-HDSK_DMA	.DW	0	; DEFINES WHERE RESULT IS PLACED IN MEMORY
\ No newline at end of file
+HDSK_DMA	.DW	0	; DEFINES WHERE RESULT IS PLACED IN MEMORY
diff --git a/Source/HBIOS/ide.asm b/Source/HBIOS/ide.asm
index 2619eee3..545fe795 100644
--- a/Source/HBIOS/ide.asm
+++ b/Source/HBIOS/ide.asm
@@ -106,7 +106,7 @@
 ;   IDE2:	SECONDARY MASTER
 ;   IDE3:	SECONDARY SLAVE
 ;
-IDE_UNITCNT	.EQU	2			; ASSUME ONLY PRIMARY INTERFACE
+IDE_UNITCNT		.EQU	2		; ASSUME ONLY PRIMARY INTERFACE
 ;
 #IF (IDEMODE == IDEMODE_MK4)
 IDE_IO_BASE		.EQU	MK4_IDE
@@ -154,11 +154,11 @@ IDE_IO_DRVADR	.EQU 	$IDE_IO_BASE + $0F	; DRIVE ADDRESS REGISTER (R)
 ;
 ; COMMAND BYTES
 ;
-IDE_CMD_RECAL	.EQU	$10
-IDE_CMD_READ	.EQU	$20
-IDE_CMD_WRITE	.EQU	$30
-IDE_CMD_IDDEV	.EQU	$EC
-IDE_CMD_SETFEAT	.EQU	$EF
+IDE_CIDE_RECAL	.EQU	$10
+IDE_CIDE_READ	.EQU	$20
+IDE_CIDE_WRITE	.EQU	$30
+IDE_CIDE_IDDEV	.EQU	$EC
+IDE_CIDE_SETFEAT	.EQU	$EF
 ;
 ; FEATURE BYTES
 ;
@@ -242,9 +242,11 @@ IDE_INIT1:
 	RET				; DONE
 ;
 IDE_INIT2:
-	; DISPLAY DEVICE INFO
-	CALL	IDE_SELUNIT		; SELECT UNIT
-	RET	NZ			; ABORT ON ERROR
+;	; DISPLAY DEVICE INFO
+;	CALL	IDE_SELUNIT		; SELECT UNIT
+;	RET	NZ			; ABORT ON ERROR
+;
+	LD	(IDE_UNIT),A		; SET CURRENT UNIT
 ;
 	; CHECK FOR BAD STATUS
 	IDE_DPTR(IDE_STAT)		; GET STATUS ADR IN HL, AF TRASHED
@@ -290,41 +292,56 @@ IDE_INIT2:
 ;=============================================================================
 ;
 IDE_DISPATCH:
-	LD	A,C			; DEVICE/UNIT TO A
-	AND	$0F			; REMOVE DEVICE BITS LEAVING JUST UNIT ID
-	CALL	IDE_SELUNIT		; SELECT DESIRED UNIT
-	RET	NZ			; ABORT ON ERROR
+	; VERIFY AND SAVE THE TARGET DEVICE/UNIT LOCALLY IN DRIVER
+	LD	A,C			; DEVICE/UNIT FROM C
+	AND	$0F			; ISOLATE UNIT NUM
+	CP	IDE_UNITCNT
+	CALL	NC,PANIC		; PANIC IF TOO HIGH
+	LD	(IDE_UNIT),A		; SAVE IT
+	;CALL	IDE_SELUNIT		; SELECT DESIRED UNIT
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
 	LD	A,B			; GET REQUESTED FUNCTION
-	AND	$0F
-	JR	Z,IDE_READ
-	DEC	A
-	JR	Z,IDE_WRITE
-	DEC	A
-	JR	Z,IDE_STATUS
-	DEC	A
-	JR	Z,IDE_MEDIA
-	DEC	A
-	JR	Z,IDE_CAP
-	DEC	A
-	JR	Z,IDE_GEOM
-	CALL	PANIC
+	AND	$0F			; ISOLATE SUB-FUNCTION
+	JP	Z,IDE_SEEK		; SUB-FUNC 0: SEEK, USE HBIOS FOR NOW
+	DEC	A	
+	JP	Z,IDE_READ		; SUB-FUNC 1: READ
+	DEC	A	
+	JP	Z,IDE_WRITE		; SUB-FUNC 2: WRITE
+	DEC	A	
+	JP	Z,IDE_STATUS		; SUB-FUNC 3: STATUS
+	DEC	A	
+	JP	Z,IDE_RESET		; SUB-FUNC 4: RESET
+	DEC	A	
+	JP	Z,IDE_CAP		; SUB-FUNC 5: GET CAPACITY
+	DEC	A	
+	JP	Z,IDE_GEOM		; SUB-FUNC 6: GET GEOMETRY
+	DEC	A	
+	JP	Z,IDE_GETPAR		; SUB-FUNC 7: GET PARAMETERS
+	DEC	A	
+	JP	Z,IDE_SETPAR		; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC			; INVALID SUB-FUNCTION
 ;
 ;
 ;
 IDE_READ:
+	LD	(IDE_DSKBUF),HL		; SAVE DISK BUFFER ADDRESS
 #IF (IDETRACE == 1)
 	LD	HL,IDE_PRTERR		; SET UP IDE_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
 #ENDIF
+	CALL	IDE_SELUNIT		; HARDWARE SELECTION OF TARGET UNIT
 	JP	IDE_RDSEC
 ;
 ;
 ;
 IDE_WRITE:
+	LD	(IDE_DSKBUF),HL		; SAVE DISK BUFFER ADDRESS
 #IF (IDETRACE == 1)
 	LD	HL,IDE_PRTERR		; SET UP IDE_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
 #ENDIF
+	CALL	IDE_SELUNIT		; HARDWARE SELECTION OF TARGET UNIT
 	JP	IDE_WRSEC
 ;
 ;
@@ -338,12 +355,17 @@ IDE_STATUS:
 ;
 ; IDE_MEDIA
 ;
-IDE_MEDIA:
+IDE_GETPAR:
+	; THE ONLY WAY TO RESET AN IDE DEVICE IS TO RESET
+	; THE ENTIRE INTERFACE.  SO, TO HANDLE POSSIBLE HOT
+	; SWAP WE DO THAT, THEN RESELECT THE DESIRED UNIT AND
+	; CONTINUE.
 	LD	A,(IDE_UNIT)		; GET UNIT SELECTION
 	PUSH	AF			; SAVE UNIT SELECTION
 	CALL	IDE_RESET		; RESET ALL DEVICES ON BUS
 	POP	AF			; RECOVER UNIT SELECTION
-	CALL	IDE_SELUNIT		; RESELECT DESIRED UNIT
+	LD	(IDE_UNIT),A		; RESTORE UNIT SELECTION
+	;CALL	IDE_SELUNIT		; RESELECT DESIRED UNIT
 ;
 	IDE_DPTR(IDE_STAT)		; POINT TO UNIT STATUS
 	LD	A,(HL)			; GET STATUS
@@ -351,14 +373,31 @@ IDE_MEDIA:
 #IF (IDETRACE == 1)
 	CALL	IDE_PRTERR		; PRINT ANY ERRORS
 #ENDIF
-	LD	A,MID_HD		; ASSUME WE ARE OK
+	LD	E,MID_HD		; ASSUME WE ARE OK
 	RET	Z			; RETURN IF GOOD INIT
-	LD	A,MID_NONE		; SIGNAL NO MEDA
-	OR	A			; SET FLAGS
+	LD	E,MID_NONE		; SIGNAL NO MEDA
 	RET				; AND RETURN
 ;
 ;
 ;
+IDE_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
+	RET
+;
+;
+;
+IDE_SEEK:
+	BIT	7,D		; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA	; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D		; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+	LD	BC,HSTLBA	; POINT TO LBA STORAGE
+	CALL	ST32		; SAVE LBA ADDRESS
+	XOR	A		; SIGNAL SUCCESS
+	RET			; AND RETURN
+;
+;
+;
 IDE_CAP:
 	IDE_DPTR(IDE_CAPACITY)		; POINT HL TO CAPACITY OF CUR UNIT
 	CALL	LD32			; GET THE CURRENT CAPACITY DO DE:HL
@@ -397,7 +436,7 @@ IDE_SETFEAT:
 	OUT	(IDE_IO_FEAT),A		; SET THE FEATURE VALUE
 	DCALL	PC_SPACE
 	DCALL	PRTHEXBYTE
-	LD	A,IDE_CMD_SETFEAT	; CMD = SETFEAT
+	LD	A,IDE_CIDE_SETFEAT	; CMD = SETFEAT
 	LD	(IDE_CMD),A		; SAVE IT
 	JP	IDE_RUNCMD		; RUN COMMAND AND EXIT
 ;
@@ -412,7 +451,7 @@ IDE_IDENTIFY:
 	OUT	(IDE_IO_DRVHD),A
 	DCALL	PC_SPACE
 	DCALL	PRTHEXBYTE
-	LD	A,IDE_CMD_IDDEV
+	LD	A,IDE_CIDE_IDDEV
 	LD	(IDE_CMD),A
 	CALL	IDE_RUNCMD
 	RET	NZ
@@ -434,11 +473,11 @@ IDE_RDSEC:
 	DCALL	PC_SPACE
 	DCALL	PRTHEXBYTE
 	CALL	IDE_SETADDR		; SETUP CYL, TRK, HEAD
-	LD	A,IDE_CMD_READ
+	LD	A,IDE_CIDE_READ
 	LD	(IDE_CMD),A
 	CALL	IDE_RUNCMD
 	RET	NZ
-	LD	HL,(DIOBUF)
+	LD	HL,(IDE_DSKBUF)
 	JP	IDE_GETBUF
 ;
 ;
@@ -456,11 +495,11 @@ IDE_WRSEC:
 	DCALL	PC_SPACE
 	DCALL	PRTHEXBYTE
 	CALL	IDE_SETADDR		; SETUP CYL, TRK, HEAD
-	LD	A,IDE_CMD_WRITE
+	LD	A,IDE_CIDE_WRITE
 	LD	(IDE_CMD),A
 	CALL	IDE_RUNCMD
 	RET	NZ
-	LD	HL,(DIOBUF)
+	LD	HL,(IDE_DSKBUF)
 	JP	IDE_PUTBUF
 ;
 ;
@@ -535,7 +574,7 @@ IDE_GETBUF:
 	CALL	IDE_WAITDRQ		; WAIT FOR BUFFER READY
 	RET	NZ			; BAIL OUT IF TIMEOUT
 
-	;LD	HL,(DIOBUF)
+	;LD	HL,(IDE_DSKBUF)
 	LD	B,0
 
 #IF (IDE8BIT | (IDEMODE == IDEMODE_DIDE))
@@ -574,7 +613,7 @@ IDE_PUTBUF:
 	CALL	IDE_WAITDRQ		; WAIT FOR BUFFER READY
 	RET	NZ			; BAIL OUT IF TIMEOUT
 ;
-	;LD	HL,(DIOBUF)
+	;LD	HL,(IDE_DSKBUF)
 	LD	B,0
 
 #IF (IDE8BIT | (IDEMODE == IDEMODE_DIDE))
@@ -646,6 +685,9 @@ IDE_RESET:
 	XOR	A
 	CALL	FILL
 ;
+	LD	A,(IDE_UNIT)		; GET THE CURRENT UNIT SELECTION
+	PUSH	AF			; AND SAVE IT
+
 	; PROBE / INITIALIZE ALL UNITS
 	LD	B,IDE_UNITCNT		; NUMBER OF UNITS TO TRY
 	LD	C,0			; UNIT INDEX FOR LOOP
@@ -656,6 +698,9 @@ IDE_RESET1:
 	POP	BC
 	INC	C			; NEXT UNIT
 	DJNZ	IDE_RESET1		; LOOP AS NEEDED
+;
+	POP	AF			; RECOVER ORIGINAL UNIT NUMBER
+	CALL	IDE_SELUNIT		; ... AND SELECT IT
 ;
 	XOR	A			; SIGNAL SUCCESS
 	RET				; AND DONE
@@ -663,12 +708,20 @@ IDE_RESET1:
 ;
 ;
 IDE_INITUNIT:
+	LD	(IDE_UNIT),A		; SET ACTIVE UNIT
+
 	CALL	IDE_SELUNIT		; SELECT UNIT
 	RET	NZ			; ABORT IF ERROR
-
+	
 	CALL	IDE_PROBE		; DO PROBE
 	RET	NZ			; ABORT IF ERROR
-
+	
+	OR	$FF
+	OUT	(IDE_IO_COUNT),A	; ZERO KEY REGISTERS IN TESTED DEVICE
+	OUT	(IDE_IO_SECT),A		; ZERO KEY REGISTERS IN TESTED DEVICE
+	
+	;RET
+	
 	JP	IDE_INITDEV		; INIT DEVICE AND RETURN
 ;
 ; TAKE ANY ACTIONS REQUIRED TO SELECT DESIRED PHYSICAL UNIT
@@ -682,17 +735,20 @@ IDE_SELUNIT:
 	CP	IDE_UNITCNT		; CHECK VALIDITY (EXCEED UNIT COUNT?)
 	JP	NC,IDE_INVUNIT		; HANDLE INVALID UNIT
 ;
-	; NEW UNIT SELECTED, IMPLEMENT IT
-	LD	(IDE_UNIT),A		; RECORD NEW UNIT NUMBER
+;	; NEW UNIT SELECTED, IMPLEMENT IT
+;	LD	(IDE_UNIT),A		; RECORD NEW UNIT NUMBER
+;
 ;
 #IF (IDEMODE == IDEMODE_DIDE)
 	; SELECT PRIMARY/SECONDARY INTERFACE FOR DIDE HARDWARE
 #ENDIF
 ;
+	PUSH	HL			; SAVE HL
 	AND	$01			; LS BIT DETERMINES MASTER/SLAVE
 	LD	HL,IDE_DRVSEL
 	CALL	ADDHLA
 	LD	A,(HL)			; LOAD DRIVE/HEAD VALUE
+	POP	HL			; RECOVER HL
 ;
 	OUT	(IDE_IO_DRVHD),A	; SELECT DRIVE
 	LD	(IDE_DRVHD),A		; UPDATE SHADOW REGISTER
@@ -1060,6 +1116,7 @@ IDE_CMD		.DB	0			; PENDING COMMAND TO PROCESS
 IDE_DRVHD	.DB	0			; CURRENT DRIVE/HEAD MASK
 ;
 IDE_UNIT	.DB	0			; ACTIVE UNIT, DEFAULT TO ZERO
+IDE_DSKBUF	.DW	0			; ACTIVE DISK BUFFER
 ;
 ; UNIT SPECIFIC DATA STORAGE
 ;
diff --git a/Source/HBIOS/md.asm b/Source/HBIOS/md.asm
index ffa43899..8f99d34a 100644
--- a/Source/HBIOS/md.asm
+++ b/Source/HBIOS/md.asm
@@ -3,6 +3,8 @@
 ;   MD DISK DRIVER (MEMORY DISK)
 ;==================================================================================================
 ;
+MD_UNITCNT	.EQU	2
+;
 ;
 ;
 MD_INIT:
@@ -20,34 +22,44 @@ MD_INIT:
 ;
 ;
 MD_DISPATCH:
+	; VERIFY AND SAVE THE TARGET DEVICE/UNIT LOCALLY IN DRIVER
+	LD	A,C			; DEVICE/UNIT FROM C
+	AND	$0F			; ISOLATE UNIT NUM
+	CP	MD_UNITCNT
+	CALL	NC,PANIC		; PANIC IF TOO HIGH
+	LD	(MD_UNIT),A		; SAVE IT
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
 	LD	A,B		; GET REQUESTED FUNCTION
-	AND	$0F
-	JP	Z,MD_READ
+	AND	$0F		; ISOLATE SUB-FUNCTION
+	JP	Z,MD_SEEK	; SUB-FUNC 0: SEEK, USE HBIOS FOR NOW
+	DEC	A
+	JP	Z,MD_READ	; SUB-FUNC 1: READ
+	DEC	A
+	JP	Z,MD_WRITE	; SUB-FUNC 2: WRITE
+	DEC	A
+	JP	Z,MD_STATUS	; SUB-FUNC 3: STATUS
 	DEC	A
-	JP	Z,MD_WRITE
+	JP	Z,MD_RESET	; SUB-FUNC 4: RESET
 	DEC	A
-	JP	Z,MD_STATUS
+	JP	Z,MD_CAP	; SUB-FUNC 5: GET CAPACITY
 	DEC	A
-	JP	Z,MD_MEDIA
+	JP	Z,MD_GEOM	; SUB-FUNC 6: GET GEOMETRY
 	DEC	A
-	JP	Z,MD_CAP
+	JP	Z,MD_GETPAR	; SUB-FUNC 7: GET PARAMETERS
 	DEC	A
-	JP	Z,MD_GEOM
-	CALL	PANIC
+	JP	Z,MD_SETPAR	; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC		; INVALID SUB-FUNCTION
 ;
 ;
 ;
-MD_MEDIA:
-	LD	A,C		; DEVICE/UNIT IS IN C
-	AND	$0F		; ISOLATE UNIT NUM
-	CP	2		; CHECK FOR MAX UNIT EXCEEDED
-	CALL	NC,PANIC	; PANIC IF TOO HIGH
-	ADD	A,MID_MDROM	; SET CORRECT MEDIA VALUE
+MD_STATUS:
+	XOR	A		; ALWAYS OK
 	RET
 ;
 ;
 ;
-MD_STATUS:
+MD_RESET:
 	XOR	A		; ALWAYS OK
 	RET
 ;
@@ -92,7 +104,35 @@ MD_GEOM1:
 ;
 ;
 ;
+MD_GETPAR:
+	LD	A,C		; DEVICE/UNIT IS IN C
+	ADD	A,MID_MDROM	; SET CORRECT MEDIA VALUE
+	LD	E,A		; VALUE TO E
+	XOR	A		; SIGNAL SUCCESS
+	RET
+;
+;
+;
+MD_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
+	RET
+;
+;
+;
+MD_SEEK:
+	BIT	7,D		; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA	; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D		; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+	LD	BC,HSTLBA	; POINT TO LBA STORAGE
+	CALL	ST32		; SAVE LBA ADDRESS
+	XOR	A		; SIGNAL SUCCESS
+	RET			; AND RETURN
+;
+;
+;
 MD_READ:
+	LD	(MD_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
 	CALL	MD_IOSETUP	; SETUP FOR MEMORY COPY
 #IF (MDTRACE >= 2)
 	LD	(MD_SRC),HL
@@ -118,6 +158,7 @@ MD_READ:
 ;
 ;
 MD_WRITE:
+	LD	(MD_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
 	LD	A,C		; DEVICE/UNIT IS IN C
 	AND	$0F		; ISOLATE UNIT NUM
 	LD	A,1		; PREPARE TO RETURN FALSE
@@ -186,7 +227,7 @@ MD_IOSETUP:
 	RL	H			;   FULL WORD
 	LD	C,H			; BANK NUMBER FROM H TO C
 	; GET BANK NUM TO A AND SET FLAG Z=ROM, NZ=RAM
-	LD	A,(HSTDSK)		; DEVICE/UNIT TO A
+	LD	A,(MD_UNIT)		; DEVICE/UNIT TO A
 	AND	$01			; ISOLATE LOW BIT, SET ZF
 	LD	A,C			; BANK VALUE INTO A
 	PUSH	AF			; SAVE IT FOR NOW
@@ -195,7 +236,7 @@ MD_IOSETUP:
 	LD	H,L			; MOVE MSB TO H WHERE IT BELONGS
 	LD	L,0			;   AND ZERO L SO HL IS NOW BYTE OFFSET
 	; LOAD DESTINATION AND COUNT
-	LD	DE,(DIOBUF)		; DMA ADDRESS IS DESTINATION
+	LD	DE,(MD_DSKBUF)		; DMA ADDRESS IS DESTINATION
 	LD	BC,512			; ALWAYS COPY ONE SECTOR
 	; FINISH UP
 	POP	AF			; GET BANK AND FLAGS BACK
@@ -255,6 +296,9 @@ MD_PRT:
 ;
 ;
 ;
+MD_UNIT		.DB	0
+MD_DSKBUF	.DW	0
+;
 MD_SRCBNK	.DB	0
 MD_DSTBNK	.DB	0
 MD_SRC		.DW	0
diff --git a/Source/HBIOS/ppide.asm b/Source/HBIOS/ppide.asm
index 83c1f0f9..07d9bb45 100644
--- a/Source/HBIOS/ppide.asm
+++ b/Source/HBIOS/ppide.asm
@@ -152,7 +152,7 @@ PPIDE_REG_DRVADR	.EQU 	PPIDE_CTL_CS3FX | $07	; DRIVE ADDRESS REGISTER (R)
 ;   PPIDE2:	SECONDARY MASTER
 ;   PPIDE3:	SECONDARY SLAVE
 ;
-PPIDE_UNITCNT	.EQU	2		; ASSUME ONLY PRIMARY INTERFACE
+PPIDE_UNITCNT		.EQU	2	; ASSUME ONLY PRIMARY INTERFACE
 ;
 ; COMMAND BYTES
 ;
@@ -233,9 +233,11 @@ PPIDE_INIT1:
 	RET				; DONE
 ;
 PPIDE_INIT2:
-	; DISPLAY DEVICE INFO
-	CALL	PPIDE_SELUNIT		; SELECT UNIT
-	RET	NZ			; ABORT ON ERROR
+;	; DISPLAY DEVICE INFO
+;	CALL	PPIDE_SELUNIT		; SELECT UNIT
+;	RET	NZ			; ABORT ON ERROR
+;
+	LD	(PPIDE_UNIT),A		; SET CURRENT UNIT
 ;
 	; CHECK FOR BAD STATUS
 	PPIDE_DPTR(PPIDE_STAT)		; GET STATUS ADR IN HL, AF TRASHED
@@ -281,28 +283,40 @@ PPIDE_INIT2:
 ;=============================================================================
 ;
 PPIDE_DISPATCH:
-	LD	A,C			; DEVICE/UNIT TO A
-	AND	$0F			; REMOVE DEVICE BITS LEAVING JUST UNIT ID
-	CALL	PPIDE_SELUNIT		; SELECT DESIRED UNIT
-	RET	NZ			; ABORT ON ERROR
+	; VERIFY AND SAVE THE TARGET DEVICE/UNIT LOCALLY IN DRIVER
+	LD	A,C			; DEVICE/UNIT FROM C
+	AND	$0F			; ISOLATE UNIT NUM
+	CP	PPIDE_UNITCNT
+	CALL	NC,PANIC		; PANIC IF TOO HIGH
+	LD	(PPIDE_UNIT),A		; SAVE IT
+	;CALL	PPIDE_SELUNIT		; SELECT DESIRED UNIT
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
 	LD	A,B			; GET REQUESTED FUNCTION
-	AND	$0F
-	JR	Z,PPIDE_READ
-	DEC	A
-	JR	Z,PPIDE_WRITE
-	DEC	A
-	JR	Z,PPIDE_STATUS
-	DEC	A
-	JR	Z,PPIDE_MEDIA
-	DEC	A
-	JR	Z,PPIDE_CAP
-	DEC	A
-	JR	Z,PPIDE_GEOM
-	CALL	PANIC
+	AND	$0F			; ISOLATE SUB-FUNCTION
+	JP	Z,PPIDE_SEEK		; SUB-FUNC 0: SEEK, USE HBIOS FOR NOW
+	DEC	A	
+	JP	Z,PPIDE_READ		; SUB-FUNC 1: READ
+	DEC	A	
+	JP	Z,PPIDE_WRITE		; SUB-FUNC 2: WRITE
+	DEC	A	
+	JP	Z,PPIDE_STATUS		; SUB-FUNC 3: STATUS
+	DEC	A	
+	JP	Z,PPIDE_RESET		; SUB-FUNC 4: RESET
+	DEC	A	
+	JP	Z,PPIDE_CAP		; SUB-FUNC 5: GET CAPACITY
+	DEC	A	
+	JP	Z,PPIDE_GEOM		; SUB-FUNC 6: GET GEOMETRY
+	DEC	A	
+	JP	Z,PPIDE_GETPAR		; SUB-FUNC 7: GET PARAMETERS
+	DEC	A	
+	JP	Z,PPIDE_SETPAR		; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC			; INVALID SUB-FUNCTION
 ;
 ;
 ;
 PPIDE_READ:
+	LD	(PPIDE_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
 #IF (PPIDETRACE == 1)
 	LD	HL,PPIDE_PRTERR		; SET UP PPIDE_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
@@ -312,6 +326,7 @@ PPIDE_READ:
 ;
 ;
 PPIDE_WRITE:
+	LD	(PPIDE_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
 #IF (PPIDETRACE == 1)
 	LD	HL,PPIDE_PRTERR		; SET UP PPIDE_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
@@ -329,7 +344,7 @@ PPIDE_STATUS:
 ;
 ; PPIDE_MEDIA
 ;
-PPIDE_MEDIA:
+PPIDE_GETPAR:
 	; THE ONLY WAY TO RESET AN IDE DEVICE IS TO RESET
 	; THE ENTIRE INTERFACE.  SO, TO HANDLE POSSIBLE HOT
 	; SWAP WE DO THAT, THEN RESELECT THE DESIRED UNIT AND
@@ -338,7 +353,8 @@ PPIDE_MEDIA:
 	PUSH	AF			; SAVE UNIT SELECTION
 	CALL	PPIDE_RESET		; RESET ALL DEVICES ON BUS
 	POP	AF			; RECOVER UNIT SELECTION
-	CALL	PPIDE_SELUNIT		; RESELECT DESIRED UNIT
+	LD	(PPIDE_UNIT),A		; RESTORE UNIT SELECTION
+	;CALL	PPIDE_SELUNIT		; RESELECT DESIRED UNIT
 ;
 	PPIDE_DPTR(PPIDE_STAT)		; POINT TO UNIT STATUS
 	LD	A,(HL)			; GET STATUS
@@ -346,14 +362,31 @@ PPIDE_MEDIA:
 #IF (PPIDETRACE == 1)
 	CALL	PPIDE_PRTERR		; PRINT ANY ERRORS
 #ENDIF
-	LD	A,MID_HD		; ASSUME WE ARE OK
+	LD	E,MID_HD		; ASSUME WE ARE OK
 	RET	Z			; RETURN IF GOOD INIT
-	LD	A,MID_NONE		; SIGNAL NO MEDA
-	OR	A			; SET FLAGS
+	LD	E,MID_NONE		; SIGNAL NO MEDA
 	RET				; AND RETURN
 ;
 ;
 ;
+PPIDE_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
+	RET
+;
+;
+;
+PPIDE_SEEK:
+	BIT	7,D		; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA	; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D		; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+	LD	BC,HSTLBA	; POINT TO LBA STORAGE
+	CALL	ST32		; SAVE LBA ADDRESS
+	XOR	A		; SIGNAL SUCCESS
+	RET			; AND RETURN
+;
+;
+;
 PPIDE_CAP:
 	PPIDE_DPTR(PPIDE_CAPACITY)	; POINT HL TO CAPACITY OF CUR UNIT
 	CALL	LD32			; GET THE CURRENT CAPACITY DO DE:HL
@@ -443,7 +476,7 @@ PPIDE_RDSEC:
 	LD	(PPIDE_CMD),A
 	CALL	PPIDE_RUNCMD
 	RET	NZ
-	LD	HL,(DIOBUF)
+	LD	HL,(PPIDE_DSKBUF)
 	JP	PPIDE_GETBUF
 ;
 ;
@@ -465,7 +498,7 @@ PPIDE_WRSEC:
 	LD	(PPIDE_CMD),A
 	CALL	PPIDE_RUNCMD
 	RET	NZ
-	LD	HL,(DIOBUF)
+	LD	HL,(PPIDE_DSKBUF)
 	JP	PPIDE_PUTBUF
 ;
 ;
@@ -549,7 +582,7 @@ PPIDE_GETBUF:
 	LD	D,A			; D := READ ASSERTED
 ;
 	; LOOP SETUP
-	;LD	HL,(DIOBUF)		; LOCATION OF BUFFER
+	;LD	HL,(PPIDE_DSKBUF)	; LOCATION OF BUFFER
 	LD	B,0			; 256 ITERATIONS
 	LD	C,PPIDE_IO_DATALO	; SETUP C WITH IO PORT (LSB)
 ;
@@ -608,7 +641,7 @@ PPIDE_PUTBUF:
 	LD	D,A			; D := WRITE ASSERTED
 ;
 	; LOOP SETUP
-	;LD	HL,(DIOBUF)		; LOCATION OF BUFFER
+	;LD	HL,(PPIDE_DSKBUF)	; LOCATION OF BUFFER
 	LD	B,0			; 256 ITERATIONS
 	LD	C,PPIDE_IO_DATALO	; SETUP C WITH IO PORT (LSB)
 ;
@@ -700,6 +733,9 @@ PPIDE_RESET:
 	LD	BC,PPIDE_UDLEN
 	XOR	A
 	CALL	FILL
+;
+	LD	A,(PPIDE_UNIT)		; GET THE CURRENT UNIT SELECTION
+	PUSH	AF			; AND SAVE IT
 ;
 	; PROBE / INITIALIZE ALL UNITS
 	LD	B,PPIDE_UNITCNT		; NUMBER OF UNITS TO TRY
@@ -711,6 +747,9 @@ PPIDE_RESET1:
 	POP	BC
 	INC	C			; NEXT UNIT
 	DJNZ	PPIDE_RESET1		; LOOP AS NEEDED
+;
+	POP	AF			; RECOVER ORIGINAL UNIT NUMBER
+	CALL	PPIDE_SELUNIT		; ... AND RESELECT IT
 ;
 	XOR	A			; SIGNAL SUCCESS
 	RET				; AND DONE
@@ -718,12 +757,22 @@ PPIDE_RESET1:
 ;
 ;
 PPIDE_INITUNIT:
+	LD	(PPIDE_UNIT),A		; SET ACTIVE UNIT
+
 	CALL	PPIDE_SELUNIT		; SELECT UNIT
 	RET	NZ			; ABORT IF ERROR
-
+	
 	CALL	PPIDE_PROBE		; DO PROBE
 	RET	NZ			; ABORT IF ERROR
-
+	
+	OR	$FF
+	CALL	PPIDE_OUT
+	.DB	PPIDE_REG_COUNT
+	CALL	PPIDE_OUT
+	.DB	PPIDE_REG_SECT
+	
+	;RET
+	
 	JP	PPIDE_INITDEV		; INIT DEVICE AND RETURN
 ;
 ; TAKE ANY ACTIONS REQUIRED TO SELECT DESIRED PHYSICAL UNIT
@@ -738,7 +787,9 @@ PPIDE_SELUNIT:
 	JP	NC,PPIDE_INVUNIT	; HANDLE INVALID UNIT
 ;
 	; NEW UNIT SELECTED, IMPLEMENT IT
-	LD	(PPIDE_UNIT),A		; RECORD NEW UNIT NUMBER
+	;LD	(PPIDE_UNIT),A		; RECORD NEW UNIT NUMBER
+;
+	PUSH	HL			; SAVE HL, IT IS DESTROYED BELOW
 ;
 	AND	$01			; LS BIT DETERMINES MASTER/SLAVE
 	LD	HL,PPIDE_DRVSEL
@@ -752,6 +803,7 @@ PPIDE_SELUNIT:
 ;
 	; SPEC REQUIRES 400NS DELAY BEFORE CHECKING STATUS REGISTER
 ;
+	POP	HL			; RECOVER HL
 	XOR	A
 	RET
 ;
@@ -1180,6 +1232,7 @@ PPIDE_CMD	.DB	0			; PENDING COMMAND TO PROCESS
 PPIDE_DRVHD	.DB	0			; CURRENT DRIVE/HEAD MASK
 ;
 PPIDE_UNIT	.DB	0			; ACTIVE UNIT, DEFAULT TO ZERO
+PPIDE_DSKBUF	.DW	0			; ACTIVE DISK BUFFER
 ;
 ; UNIT SPECIFIC DATA STORAGE
 ;
diff --git a/Source/HBIOS/ppp.asm b/Source/HBIOS/ppp.asm
index d0ede301..7d8fa521 100644
--- a/Source/HBIOS/ppp.asm
+++ b/Source/HBIOS/ppp.asm
@@ -121,11 +121,18 @@ PPP_INITPPP:
 ;
 ;
 PPP_DETECT:
-	LD	BC,4000			; TRY FOR ABOUT 4 SECONDS
+	LD	BC,6000			; TRY FOR ABOUT 6 SECONDS
 PPP_DETECT1:
 	LD	DE,64			; 1 MS
 	CALL	VDELAY
+
+	IN	A,(PPP_CTL)
+	BIT	5,A
+	JR	Z,PPP_DETECT1
+
 	IN	A,(PPP_IO)
+	;CALL	PC_SPACE
+	;CALL	PRTHEXBYTE
 	CP	$AA
 	RET	Z			; RETURN IF MATCH
 	DEC	BC
@@ -198,9 +205,10 @@ PPP_SNDCMD1:
 ;
 PPP_PUTBYTE:
 	PUSH	AF
+PPP_PUTBYTE1:
 	IN	A,(PPP_CTL)
 	BIT	7,A
-	JR	Z,PPP_PUTBYTE
+	JR	Z,PPP_PUTBYTE1
 	POP	AF
 	OUT	(PPP_IO),A
 	RET
@@ -262,6 +270,7 @@ PPPCON_IN:
 	LD	D,PPP_CMDKBDRD		; CMD = KEYBOARD READ
 	CALL	PPP_SNDCMD		; SEND COMMAND
 	CALL	PPP_GETBYTE		; GET CHARACTER READ
+	LD	E,A			; PUT IN E
 	XOR	A			; CLEAR A (SUCCESS)
 	RET				; AND RETURN
 ;
@@ -284,7 +293,7 @@ PPPCON_OUT:
 	JR	Z,PPPCON_OUT		; WAIT IF NECESSARY
 	LD	D,PPP_CMDVIDOUT		; CMD = VIDEO OUTPUT
 	CALL	PPP_SNDCMD		; SEND COMMAND
-	LD	A,E
+	LD	A,E			; MOVE TO A
 	CALL	PPP_PUTBYTE		; SEND IT
 	RET				; RETURN
 ;
@@ -330,7 +339,9 @@ PPPSD_STWRTPROT	.EQU	-10		; ATTEMPT TO WRITE TO WRITE PROTECTED MEDIA
 PPPSD_INIT:
 	; REINITIALIZE THE CARD HERE
 	CALL	PPPSD_INITCARD
-	RET	NZ
+#IF (PPPSDTRACE < 2)
+	JP	NZ,PPPSD_PRTSTAT	; IF ERROR, SHOW IT
+#ENDIF
 ;
 	CALL	NEWLINE
 	PRTS("PPPSD:$")
@@ -358,28 +369,40 @@ PPPSD_INIT:
 ;
 ;
 PPPSD_DISPATCH:
-	LD	A,C			; DEVICE/UNIT TO A
-	AND	$0F			; REMOVE DEVICE BITS LEAVING JUST UNIT ID
-	CALL	PPPSD_SELUNIT		; SELECT DESIRED UNIT
-	RET	NZ			; ABORT ON ERROR
-	LD	A,B			; GET REQUESTED FUNCTION
-	AND	$0F	
-	JP	Z,PPPSD_READ		; READ
-	DEC	A	
-	JP	Z,PPPSD_WRITE		; WRITE
-	DEC	A	
-	JP	Z,PPPSD_STATUS		; STATUS
-	DEC	A	
-	JP	Z,PPPSD_MEDIA		; MEDIA ID
+	; VERIFY AND SAVE THE TARGET DEVICE/UNIT LOCALLY IN DRIVER
+	LD	A,C			; DEVICE/UNIT FROM C
+	AND	$0F			; ISOLATE UNIT NUM
+	CP	PPPSD_UNITCNT
+	CALL	NC,PANIC		; PANIC IF TOO HIGH
+	LD	(PPPSD_UNIT),A		; SAVE IT
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
+	LD	A,B		; GET REQUESTED FUNCTION
+	AND	$0F		; ISOLATE SUB-FUNCTION
+	JP	Z,PPPSD_SEEK	; SUB-FUNC 0: SEEK, USE HBIOS FOR NOW
+	DEC	A
+	JP	Z,PPPSD_READ	; SUB-FUNC 1: READ
+	DEC	A
+	JP	Z,PPPSD_WRITE	; SUB-FUNC 2: WRITE
+	DEC	A
+	JP	Z,PPPSD_STATUS	; SUB-FUNC 3: STATUS
+	DEC	A
+	JP	Z,PPPSD_RESET	; SUB-FUNC 4: RESET
+	DEC	A
+	JP	Z,PPPSD_CAP	; SUB-FUNC 5: GET CAPACITY
 	DEC	A
-	JP	Z,PPPSD_CAP
+	JP	Z,PPPSD_GEOM	; SUB-FUNC 6: GET GEOMETRY
 	DEC	A
-	JP	Z,PPPSD_GEOM
-	CALL	PANIC
+	JP	Z,PPPSD_GETPAR	; SUB-FUNC 7: GET PARAMETERS
+	DEC	A
+	JP	Z,PPPSD_SETPAR	; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC		; INVALID SUB-FUNCTION
 ;
 ; READ AN LBA BLOCK FROM THE SD CARD
 ;
 PPPSD_READ:
+	LD	(PPPSD_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
+
 #IF (PPPSDTRACE == 1)
 	LD	HL,PPPSD_PRTERR		; SET UP PPPSD_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
@@ -401,17 +424,15 @@ PPPSD_READ:
 	CALL	PPP_SNDCMD		; SEND COMMAND
 	RET	NZ
 
-	LD	DE,$FFFF
-	LD	HL,$FFFF
-	LD	BC,HSTLBA
-	CALL	ST32
-
 	CALL	PPPSD_SENDBLK		; SEND THE LBA BLOCK NUMBER
 	CALL	PPP_GETBYTE		; GET READ RESULT
+	LD	(PPPSD_DSKSTAT),A	; SAVE IT
+
 #IF (PPPSDTRACE >= 3)
 	CALL	PC_SPACE
 	CALL	PRTHEXBYTE
 #ENDIF
+
 	OR	A			; SET FLAGS
 	JR	Z,PPPSD_READ1
 
@@ -427,7 +448,7 @@ PPPSD_READ1:
 
 	; READ THE SECTOR DATA
 	LD	BC,512
-	LD	HL,(DIOBUF)
+	LD	HL,(PPPSD_DSKBUF)
 PPPSD_READ2:
 	CALL	PPP_GETBYTE
 	LD	(HL),A
@@ -443,6 +464,8 @@ PPPSD_READ2:
 ; WRITE AN LBA BLOCK TO THE SD CARD
 ;
 PPPSD_WRITE:
+	LD	(PPPSD_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
+
 #IF (PPPSDTRACE == 1)
 	LD	HL,PPPSD_PRTERR		; SET UP PPPSD_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
@@ -466,7 +489,7 @@ PPPSD_WRITE:
 
 	; SEND OVER THE SECTOR CONTENTS
 	LD	BC,512
-	LD	HL,(DIOBUF)
+	LD	HL,(PPPSD_DSKBUF)
 PPPSD_WRITE1:
 	LD	A,(HL)
 	INC	HL
@@ -482,10 +505,13 @@ PPPSD_WRITE1:
 	RET	NZ
 	CALL	PPPSD_SENDBLK		; SEND THE LBA BLOCK NUMBER
 	CALL	PPP_GETBYTE
+	LD	(PPPSD_DSKSTAT),A	; SAVE IT
+
 #IF (PPPSDTRACE >= 3)
 	CALL	PC_SPACE
 	CALL	PRTHEXBYTE
 #ENDIF
+
 	OR	A			; SET FLAGS
 	RET	Z			; DONE IF NO ERRORS
 
@@ -500,23 +526,46 @@ PPPSD_STATUS:
 	OR	A
 	RET
 ;
+;
+;
+PPPSD_RESET:
+	XOR	A		; ALWAYS OK
+	RET
+;
 ; SETUP FOR SUBSEQUENT ACCESS
 ; INIT CARD IF NOT READY OR ON DRIVE LOG IN
 ;
-PPPSD_MEDIA:
+PPPSD_GETPAR:
 	; REINITIALIZE THE CARD HERE TO DETERMINE PRESENCE
 	CALL	PPPSD_INITCARD
 #IF (PPPSDTRACE == 1)
 	CALL	PPPSD_PRTERR		; PRINT ANY ERRORS
 #ENDIF
-	LD	A,MID_HD		; ASSUME SUCCESS, SETUP MEDIA ID
+	LD	E,MID_HD		; ASSUME WE ARE OK
 	RET	Z			; RETURN IF GOOD INIT
-	LD	A,MID_NONE		; SIGNAL NO MEDA
-	OR	A			; SET FLAGS
+	LD	E,MID_NONE		; SIGNAL NO MEDA
 	RET				; AND RETURN
 ;
 ;
 ;
+PPPSD_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
+	RET
+;
+;
+;
+PPPSD_SEEK:
+	BIT	7,D		; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA	; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D		; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+	LD	BC,HSTLBA	; POINT TO LBA STORAGE
+	CALL	ST32		; SAVE LBA ADDRESS
+	XOR	A		; SIGNAL SUCCESS
+	RET			; AND RETURN
+;
+;
+;
 PPPSD_CAP:
 	LD	HL,PPPSD_BLKCNT		; GET BLOCK COUNT
 	CALL	LD32			; GET THE CURRENT CAPACITY DO DE:HL
@@ -541,8 +590,6 @@ PPPSD_GEOM:
 ; UNIT IS SPECIFIED IN A
 ;
 PPPSD_SELUNIT:
-	CP	PPPSD_UNITCNT		; CHECK VALIDITY (EXCEED UNIT COUNT?)
-	JP	NC,PPPSD_INVUNIT	; HANDLE INVALID UNIT
 	XOR	A			; SIGNAL SUCCESS
 	RET				; DONE
 ;
@@ -554,15 +601,32 @@ PPPSD_INITCARD:
 	LD	BC,PPPSD_UNITDATALEN
 	XOR	A
 	CALL	FILL
-;
+
+#IF (PPPSDTRACE >= 3)
+	CALL	PPPSD_PRTPREFIX
+	PRTS(" RESET$")
+#ENDIF
+
 	; RESET & STATUS DISK
 	LD	D,PPP_CMDDSKRES		; COMMAND = DSKRESET
 	CALL	PPP_SNDCMD
 	RET	NZ
-	CALL	PPP_GETBYTE
-	LD	(PPPSD_STAT),A		; SAVE UPDATED STATUS
+	CALL	PPP_GETBYTE		; GET STATUS
+	LD	(PPPSD_DSKSTAT),A	; SAVE STATUS
+
+#IF (PPPSDTRACE >= 3)
+	CALL	PC_SPACE
+	CALL	PRTHEXBYTE
+#ENDIF
+
 	OR	A
-	RET	NZ			; BAIL OUT ON ERROR
+	JR	Z,PPPSD_INITCARD1
+	
+	; HANDLE ERROR
+	CALL	PPPSD_GETDSKSTAT	; GET FULL ERROR CODE
+	JP	PPPSD_ERRCMD		; HANDLE ERRORS
+
+PPPSD_INITCARD1:
 
 #IF (PPPSDTRACE >= 3)
 	; GET CSD IF DEBUGGING
@@ -720,6 +784,10 @@ PPPSD_SENDBLK:
 	LD	B,4
 PPPSD_SENDBLK1:
 	LD	A,(HL)
+
+	;CALL	PC_SPACE
+	;CALL	PRTHEXBYTE
+
 	INC	HL
 	CALL	PPP_PUTBYTE
 	DJNZ	PPPSD_SENDBLK1
@@ -913,6 +981,9 @@ PPPSD_STR_TYPESDXC	.TEXT	"SDXC$"
 ; DATA STORAGE
 ;=============================================================================
 ;
+PPPSD_UNIT		.DB	0
+PPPSD_DSKBUF		.DW	0
+;
 PPPSD_UNITDATA:
 PPPSD_STAT		.DB	0
 PPPSD_DSKSTAT		.DB	0
diff --git a/Source/HBIOS/prp.asm b/Source/HBIOS/prp.asm
index c4fc208f..812dd6d1 100644
--- a/Source/HBIOS/prp.asm
+++ b/Source/HBIOS/prp.asm
@@ -226,8 +226,8 @@ PRPSD_STINVUNIT	.EQU	-1		; INVALID UNIT
 PRPSD_STRDYTO	.EQU	-2		; TIMEOUT WAITING FOR CARD TO BE READY
 PRPSD_STINITTO	.EQU	-3		; INITIALIZATOIN TIMEOUT
 PRPSD_STCMDTO	.EQU	-4		; TIMEOUT WAITING FOR COMMAND RESPONSE
-PRPSD_STCMDERR	.EQU	-5		; COMMAND ERROR OCCURRED (REF SD_RC)
-PRPSD_STDATAERR	.EQU	-6		; DATA ERROR OCCURRED (REF SD_TOK)
+PRPSD_STCMDERR	.EQU	-5		; COMMAND ERROR OCCURRED (REF PRPSD_RC)
+PRPSD_STDATAERR	.EQU	-6		; DATA ERROR OCCURRED (REF PRPSD_TOK)
 PRPSD_STDATATO	.EQU	-7		; DATA TRANSFER TIMEOUT
 PRPSD_STCRCERR	.EQU	-8		; CRC ERROR ON RECEIVED DATA PACKET
 PRPSD_STNOMEDIA	.EQU	-9		; NO MEDIA IN CONNECTOR
@@ -238,7 +238,9 @@ PRPSD_STWRTPROT	.EQU	-10		; ATTEMPT TO WRITE TO WRITE PROTECTED MEDIA
 PRPSD_INIT:
 	; REINITIALIZE THE CARD HERE
 	CALL	PRPSD_INITCARD
-	RET	NZ
+#IF (PRPSDTRACE < 2)
+	JP	NZ,PRPSD_PRTSTAT	; IF ERROR, SHOW IT
+#ENDIF
 ;
 	CALL	PRPSD_PRTPREFIX
 ;
@@ -265,28 +267,40 @@ PRPSD_INIT:
 ;
 ;
 PRPSD_DISPATCH:
-	LD	A,C			; DEVICE/UNIT TO A
-	AND	$0F			; REMOVE DEVICE BITS LEAVING JUST UNIT ID
-	CALL	PRPSD_SELUNIT		; SELECT DESIRED UNIT
-	RET	NZ			; ABORT ON ERROR
-	LD	A,B			; GET REQUESTED FUNCTION
-	AND	$0F			; ISOLATE SUB-FUNCTION BITS
-	JP	Z,PRPSD_READ
+	; VERIFY AND SAVE THE TARGET DEVICE/UNIT LOCALLY IN DRIVER
+	LD	A,C			; DEVICE/UNIT FROM C
+	AND	$0F			; ISOLATE UNIT NUM
+	CP	PRPSD_UNITCNT
+	CALL	NC,PANIC		; PANIC IF TOO HIGH
+	LD	(PRPSD_UNIT),A		; SAVE IT
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
+	LD	A,B		; GET REQUESTED FUNCTION
+	AND	$0F		; ISOLATE SUB-FUNCTION
+	JP	Z,PRPSD_SEEK	; SUB-FUNC 0: SEEK, USE HBIOS FOR NOW
 	DEC	A
-	JP	Z,PRPSD_WRITE
+	JP	Z,PRPSD_READ	; SUB-FUNC 1: READ
 	DEC	A
-	JP	Z,PRPSD_STATUS
+	JP	Z,PRPSD_WRITE	; SUB-FUNC 2: WRITE
 	DEC	A
-	JP	Z,PRPSD_MEDIA
+	JP	Z,PRPSD_STATUS	; SUB-FUNC 3: STATUS
 	DEC	A
-	JP	Z,PRPSD_CAP
+	JP	Z,PRPSD_RESET	; SUB-FUNC 4: RESET
 	DEC	A
-	JP	Z,PRPSD_GEOM
-	CALL	PANIC
+	JP	Z,PRPSD_CAP	; SUB-FUNC 5: GET CAPACITY
+	DEC	A
+	JP	Z,PRPSD_GEOM	; SUB-FUNC 6: GET GEOMETRY
+	DEC	A
+	JP	Z,PRPSD_GETPAR	; SUB-FUNC 7: GET PARAMETERS
+	DEC	A
+	JP	Z,PRPSD_SETPAR	; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC		; INVALID SUB-FUNCTION
 ;
 ;
 ;
 PRPSD_READ:
+	LD	(PRPSD_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
+
 #IF (PRPSDTRACE == 1)
 	LD	HL,PRPSD_PRTERR		; SET UP PRPSD_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
@@ -316,7 +330,7 @@ PRPSD_READ:
 
 	LD	C,PRPSD_DSKIO
 	LD	B,0
-	LD	HL,(DIOBUF)
+	LD	HL,(PRPSD_DSKBUF)
 	INIR
 	INIR
 
@@ -326,8 +340,10 @@ PRPSD_READ:
 ;
 ;
 PRPSD_WRITE:
+	LD	(PRPSD_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
+
 #IF (PRPSDTRACE == 1)
-	LD	HL,PRPSD_PRTERR		; SET UP SD_PRTERR
+	LD	HL,PRPSD_PRTERR		; SET UP PRPSD_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
 #ENDIF
 
@@ -350,7 +366,7 @@ PRPSD_WRITE:
 
 	LD	C,PRPSD_DSKIO
 	LD	B,0
-	LD	HL,(DIOBUF)
+	LD	HL,(PRPSD_DSKBUF)
 	OTIR
 	OTIR
 
@@ -372,22 +388,45 @@ PRPSD_STATUS:
 	OR	A
 	RET
 ;
-; PRPSD_MEDIA
 ;
-PRPSD_MEDIA:
+;
+PRPSD_RESET:
+	XOR	A		; ALWAYS OK
+	RET
+;
+; PRPSD_GETPAR
+;
+PRPSD_GETPAR:
 	; REINITIALIZE THE CARD HERE
 	CALL	PRPSD_INITCARD
 #IF (PRPSDTRACE == 1)
 	CALL	PRPSD_PRTERR		; PRINT ANY ERRORS
 #ENDIF
-	LD	A,MID_HD		; ASSUME SUCCESS, SETUP MEDIA ID
+	LD	E,MID_HD		; ASSUME WE ARE OK
 	RET	Z			; RETURN IF GOOD INIT
-	LD	A,MID_NONE		; SIGNAL NO MEDA
-	OR	A			; SET FLAGS
+	LD	E,MID_NONE		; SIGNAL NO MEDA
 	RET				; AND RETURN
 ;
 ;
 ;
+PRPSD_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
+	RET
+;
+;
+;
+PRPSD_SEEK:
+	BIT	7,D		; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA	; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D		; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+	LD	BC,HSTLBA	; POINT TO LBA STORAGE
+	CALL	ST32		; SAVE LBA ADDRESS
+	XOR	A		; SIGNAL SUCCESS
+	RET			; AND RETURN
+;
+;
+;
 PRPSD_CAP:
 	LD	HL,PRPSD_BLKCNT		; POINT TO BLOCK COUNT
 	CALL	LD32			; GET THE CURRENT CAPACITY TO DE:HL
@@ -412,8 +451,6 @@ PRPSD_GEOM:
 ; UNIT IS SPECIFIED IN A
 ;
 PRPSD_SELUNIT:
-	CP	PRPSD_UNITCNT		; CHECK VALIDITY (EXCEED UNIT COUNT?)
-	JP	NC,PRPSD_INVUNIT	; HANDLE INVALID UNIT
 	XOR	A			; SIGNAL SUCCESS
 	RET				; DONE
 ;
@@ -884,6 +921,9 @@ PRPSD_STR_TYPESDXC	.TEXT	"SDXC$"
 ;
 PRP_FWVER		.DB	$00, $00, $00, $00	; MMNNBBB (M=MAJOR, N=MINOR, B=BUILD)
 ;
+PRPSD_UNIT		.DB	0
+PRPSD_DSKBUF		.DW	0
+;
 PRPSD_UNITDATA:
 PRPSD_STAT		.DB	0
 PRPSD_DSKSTAT		.DB	0
diff --git a/Source/HBIOS/rf.asm b/Source/HBIOS/rf.asm
index 62cfa367..500d2cf4 100644
--- a/Source/HBIOS/rf.asm
+++ b/Source/HBIOS/rf.asm
@@ -28,31 +28,50 @@ RF_INIT:
 ;
 ;
 RF_DISPATCH:
+	; VERIFY AND SAVE THE TARGET DEVICE/UNIT LOCALLY IN DRIVER
+	LD	A,C		; DEVICE/UNIT FROM C
+	AND	$0F		; ISOLATE UNIT NUM
+	CP	2		; CHECK FOR MAX UNIT EXCEEDED
+	LD	(RF_UNIT),A	; SAVE IT
+	CALL	NC,PANIC	; PANIC IF TOO HIGH
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
 	LD	A,B		; GET REQUESTED FUNCTION
-	AND	$0F
-	JR	Z,RF_READ
+	AND	$0F		; ISOLATE SUB-FUNCTION
+	JP	Z,RF_SEEK	; SUB-FUNC 0: SEEK, USE HBIOS FOR NOW
 	DEC	A
-	JR	Z,RF_WRITE
+	JP	Z,RF_READ	; SUB-FUNC 1: READ
 	DEC	A
-	JR	Z,RF_STATUS
+	JP	Z,RF_WRITE	; SUB-FUNC 2: WRITE
 	DEC	A
-	JR	Z,RF_MEDIA
+	JP	Z,RF_STATUS	; SUB-FUNC 3: STATUS
 	DEC	A
-	JP	Z,RF_CAP
+	JP	Z,RF_RESET	; SUB-FUNC 4: RESET
 	DEC	A
-	JP	Z,RF_GEOM
-	CALL	PANIC
-;
-; RF_MEDIA
-;
-RF_MEDIA:
-	LD	A,C		; GET THE DEVICE/UNIT
-	AND	$0F		; ISOLATE UNIT
-	CP	RFCNT		; NUM UNITS
-	LD	A,MID_RF	; ASSUME WE ARE OK
-	RET	C		; RETURN
-	XOR	A		; NO MEDIA
-	RET			; AND RETURN
+	JP	Z,RF_CAP	; SUB-FUNC 5: GET CAPACITY
+	DEC	A
+	JP	Z,RF_GEOM	; SUB-FUNC 6: GET GEOMETRY
+	DEC	A
+	JP	Z,RF_GETPAR	; SUB-FUNC 7: GET PARAMETERS
+	DEC	A
+	JP	Z,RF_SETPAR	; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC		; INVALID SUB-FUNCTION
+;
+;
+;
+RF_GETPAR:
+	LD	A,C		; DEVICE/UNIT IS IN C
+	ADD	A,MID_RF	; SET CORRECT MEDIA VALUE
+	LD	E,A		; VALUE TO E
+	XOR	A		; SIGNAL SUCCESS
+	RET
+;
+;
+;
+RF_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
+	RET
 ;
 ;
 ;
@@ -62,6 +81,12 @@ RF_STATUS:
 ;
 ;
 ;
+RF_RESET:
+	XOR	A		; ALWAYS OK
+	RET
+;
+;
+;
 RF_CAP:
 	LD	A,C		; DEVICE/UNIT IS IN C
 	AND	$0F		; ISOLATE UNIT NUM
@@ -88,10 +113,22 @@ RF_GEOM:
 ;
 ;
 ;
+RF_SEEK:
+	BIT	7,D		; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA	; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D		; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+	LD	BC,HSTLBA	; POINT TO LBA STORAGE
+	CALL	ST32		; SAVE LBA ADDRESS
+	XOR	A		; SIGNAL SUCCESS
+	RET			; AND RETURN
+;
+;
+;
 RF_READ:
+	LD	(RF_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
 	CALL	RF_SETIO
 	CALL	RF_SETADR
-	LD	HL,(DIOBUF)
+	LD	HL,(RF_DSKBUF)
 	LD	B,0
 	LD	A,(RF_IO)
 	OR	RF_DAT
@@ -104,6 +141,7 @@ RF_READ:
 ;
 ;
 RF_WRITE:
+	LD	(RF_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
 	CALL	RF_SETIO
 	LD	A,(RF_IO)
 	OR	RF_ST
@@ -113,7 +151,7 @@ RF_WRITE:
 	LD	A,1			; PREPARE TO RETURN FALSE (ERROR)
 	RET	NZ			; WRITE PROTECTED!
 	CALL	RF_SETADR
-	LD	HL,(DIOBUF)
+	LD	HL,(RF_DSKBUF)
 	LD	B,0
 	LD	A,(RF_IO)
 	OR	RF_DAT
@@ -126,7 +164,7 @@ RF_WRITE:
 ;
 ;
 RF_SETIO:
-	LD	A,(HSTDSK)	; GET DEVICE/UNIT
+	LD	A,(RF_UNIT)	; GET DEVICE/UNIT
 	AND	$0F		; ISOLATE UNIT NUM
 	JR	NZ,RF_SETIO1
 	LD	A,RF_U0IO
@@ -157,4 +195,7 @@ RF_SETADR:
 ;
 ;
 ;
-RF_IO	.DB	0
\ No newline at end of file
+RF_IO	.DB	0
+;
+RF_UNIT		.DB	0
+RF_DSKBUF	.DW	0
diff --git a/Source/HBIOS/sd.asm b/Source/HBIOS/sd.asm
index f10f6e2d..7ba184c4 100644
--- a/Source/HBIOS/sd.asm
+++ b/Source/HBIOS/sd.asm
@@ -321,7 +321,9 @@ SD_INIT1:
 ;
 ; INITIALIZE UNIT DESIGNATED IN ACCUM
 ;
-SD_INITUNIT:
+SD_INITUNIT
+	LD	(SD_UNIT),A		; SET CURRENT UNIT
+;
 	CALL	SD_SELUNIT		; SELECT UNIT
 	RET	NZ			; ABORT ON ERROR
 ;
@@ -404,42 +406,61 @@ SD_INITUNIT2:
 ;=============================================================================
 ;
 SD_DISPATCH:
-	LD	A,C			; DEVICE/UNIT TO A
-	AND	$0F			; REMOVE DEVICE BITS LEAVING JUST UNIT ID
-	CALL	SD_SELUNIT		; SELECT DESIRED UNIT
-	RET	NZ			; ABORT ON ERROR
+	; VERIFY AND SAVE THE TARGET DEVICE/UNIT LOCALLY IN DRIVER
+	LD	A,C			; DEVICE/UNIT FROM C
+	AND	$0F			; ISOLATE UNIT NUM
+	CP	SD_UNITCNT
+	CALL	NC,PANIC		; PANIC IF TOO HIGH
+	LD	(SD_UNIT),A		; SAVE IT
+	;CALL	SD_SELUNIT		; SELECT DESIRED UNIT
+;
+	; DISPATCH ACCORDING TO DISK SUB-FUNCTION
 	LD	A,B			; GET REQUESTED FUNCTION
-	AND	$0F			; ISOLATE SUB-FUNCTION BITS
-	JP	Z,SD_READ
-	DEC	A
-	JP	Z,SD_WRITE
-	DEC	A
-	JP	Z,SD_STATUS
-	DEC	A
-	JP	Z,SD_MEDIA
-	DEC	A
-	JR	Z,SD_CAP
-	DEC	A
-	JR	Z,SD_GEOM
-	CALL	PANIC
+	AND	$0F			; ISOLATE SUB-FUNCTION
+	JP	Z,SD_SEEK		; SUB-FUNC 0: SEEK, USE HBIOS FOR NOW
+	DEC	A	
+	JP	Z,SD_READ		; SUB-FUNC 1: READ
+	DEC	A	
+	JP	Z,SD_WRITE		; SUB-FUNC 2: WRITE
+	DEC	A	
+	JP	Z,SD_STATUS		; SUB-FUNC 3: STATUS
+	DEC	A	
+	JP	Z,SD_RESET		; SUB-FUNC 4: RESET
+	DEC	A	
+	JP	Z,SD_CAP		; SUB-FUNC 5: GET CAPACITY
+	DEC	A	
+	JP	Z,SD_GEOM		; SUB-FUNC 6: GET GEOMETRY
+	DEC	A	
+	JP	Z,SD_GETPAR		; SUB-FUNC 7: GET PARAMETERS
+	DEC	A	
+	JP	Z,SD_SETPAR		; SUB-FUNC 8: SET PARAMETERS
+	CALL	PANIC			; INVALID SUB-FUNCTION
+;
+;
 ;
 SD_READ:
+	LD	(SD_DSKBUF),HL		; SAVE DISK BUFFER ADDRESS
 #IF (SDTRACE == 1)
 	LD	HL,SD_PRTERR		; SET UP SD_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
 #ENDIF
+	CALL	SD_SELUNIT
 	; READ A SECTOR
 	LD	C,SD_CMD_READ_SNGL_BLK	; SET READ_SINGLE_BLOCK COMMAND
 	JP	SD_SECTIO		; DO SECTOR I/O
 ;
+;
+;
 SD_WRITE:
+	LD	(SD_DSKBUF),HL		; SAVE DISK BUFFER ADDRESS
 #IF (SDTRACE == 1)
 	LD	HL,SD_PRTERR		; SET UP SD_PRTERR
 	PUSH	HL			; ... TO FILTER ALL EXITS
 #ENDIF
-	; WRITE A SECTOR
+	CALL	SD_SELUNIT
 	CALL	SD_CHKWP		; CHECK FOR WRITE PROTECT
 	JP	NZ,SD_WRTPROT		; HANDLE IT IF SO
+	; WRITE A SECTOR
 	LD	C,SD_CMD_WRITE_BLOCK	; SET WRITE_BLOCK COMMAND
 	JP	SD_SECTIO		; DO SECTOR I/O
 ;
@@ -450,18 +471,46 @@ SD_STATUS:
 	OR	A			; SET FLAGS
 	RET				; AND RETURN
 ;
-SD_MEDIA:
+;
+;
+SD_RESET:
+	XOR	A		; ALWAYS OK
+	RET
+;
+;
+;
+SD_GETPAR:
+	CALL	SD_SELUNIT		; SET CUR UNIT
 	; RE-INITIALIZE THE SD CARD TO ACCOMMODATE HOT SWAPPING
 	CALL	SD_INITCARD		; RE-INIT SELECTED UNIT
 #IF (SDTRACE == 1)
 	CALL	SD_PRTERR		; PRINT ANY ERRORS
 #ENDIF
-	LD	A,MID_HD		; ASSUME SUCCESS, SETUP MEDIA ID
+	LD	E,MID_HD		; ASSUME WE ARE OK
 	RET	Z			; RETURN IF GOOD INIT
-	LD	A,MID_NONE		; SIGNAL NO MEDA
-	OR	A			; SET FLAGS
+	LD	E,MID_NONE		; SIGNAL NO MEDA
 	RET				; AND RETURN
 ;
+;
+;
+SD_SETPAR:
+	; NOT IMPLEMENTED
+	XOR	A
+	RET
+;
+;
+;
+SD_SEEK:
+	BIT	7,D		; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA	; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D		; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+	LD	BC,HSTLBA	; POINT TO LBA STORAGE
+	CALL	ST32		; SAVE LBA ADDRESS
+	XOR	A		; SIGNAL SUCCESS
+	RET			; AND RETURN
+;
+;
+;
 SD_CAP:
 	SD_DPTR(SD_CAPACITY)		; POINT HL TO CAPACITY OF CUR UNIT
 	CALL	LD32			; GET THE CURRENT CAPACITY DO DE:HL
@@ -469,6 +518,8 @@ SD_CAP:
 	XOR	A			; SIGNAL SUCCESS
 	RET				; AND DONE
 ;
+;
+;
 SD_GEOM:
 	; FOR LBA, WE SIMULATE CHS ACCESS USING 16 HEADS AND 16 SECTORS
 	; RETURN HS:CC -> DE:HL, SET HIGH BIT OF D TO INDICATE LBA CAPABLE
@@ -794,7 +845,7 @@ SD_SECTIO:
 	CALL	SD_EXECCMD		; EXECUTE COMMAND
 	RET	NZ			; ABORT ON ERROR
 
-	LD	HL,(DIOBUF)
+	LD	HL,(SD_DSKBUF)
 	LD	BC,512			; LENGTH TO READ
 	LD	A,(SD_CMD)		; GET THE COMMAND
 	CP	SD_CMD_READ_SNGL_BLK	; READ_SINGLE_BLOCK?
@@ -1156,7 +1207,7 @@ SD_SELUNIT:
 	JP	NC,SD_INVUNIT		; HANDLE INVALID UNIT
 ;
 	; NEW UNIT SELECTED, IMPLEMENT IT
-	LD	(SD_UNIT),A		; SAVE CURRENT UNIT NUMBER
+	;LD	(SD_UNIT),A		; SAVE CURRENT UNIT NUMBER
 #IF (SDMODE == SDMODE_DSD)
 	; SELECT REQUESTED UNIT
 	OUT	(SD_SELREG),A		; ACTUALLY SELECT THE CARD
@@ -1559,6 +1610,7 @@ SD_RC		.DB	0		; RETURN CODE FROM CMD
 SD_TOK		.DB	0		; TOKEN FROM DATA XFR
 ;
 SD_UNIT		.DB	0		; ACTIVE UNIT, DEFAULT TO ZERO
+SD_DSKBUF	.DW	0		; ACTIVE DISK BUFFER
 ;
 ; UNIT SPECIFIC DATA STORAGE
 ;