SCSI and ESPSD Driver Cleaning

- Improved error handling flow - Simplified ESPSD I/O timeout handling
2 months ago · 5014a47a64
4 changed files with 162 additions and 174 deletions
--- a/Source/HBIOS/espsd.asm
+++ b/Source/HBIOS/espsd.asm
@ -288,8 +288,9 @@ ESPSD_INIT5:
 	CALL	ESPSD_INITDEV		; INITIALIZE DEVICE
 #IF (ESPSDTRACE < 2)
 	JP	NZ,ESPSD_PRTSTAT
-#ENDIF
+#ELSE
 	RET	NZ
+#ENDIF
 ;
 	CALL	ESPSD_PRTPREFIX		; TAG FOR ACTIVE DEVICE
 ;
@ -345,7 +346,7 @@ ESPSD_READ:
 	;;;LD	A,'R'
 	;;;CALL	COUT
 	;;;CALL	PRTHEXWORDHL
-	LD	A,ESPSD_CMD_READ	; SETUP FOR BLOCK READ CMD
+	LD	E,ESPSD_CMD_READ	; SETUP FOR BLOCK READ CMD
 	JP	ESPSD_IO		; CONTINUE TO GENERIC IO ROUTINE
 ;
 ;
@ -356,7 +357,7 @@ ESPSD_WRITE:
 	;;;LD	A,'W'
 	;;;CALL	COUT
 	;;;CALL	PRTHEXWORDHL
-	LD	A,ESPSD_CMD_WRITE	; SETUP FOR BLOCK WRITE CMD
+	LD	E,ESPSD_CMD_WRITE	; SETUP FOR BLOCK WRITE CMD
 	JP	ESPSD_IO		; CONTINUE TO GENERIC IO ROUTINE
 ;
 ;
@ -501,15 +502,23 @@ ESPSD_INITDEV1:
 ; COMMON SECTOR I/O
 ;
 ESPSD_IO:
-	LD	(ESPSD_CMDVAL),A	; SAVE THE COMMAND
-	LD	(ESPSD_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
-;
-	; CHECK FOR ERROR STATUS AND REINIT?
 ;
 #IF (ESPSDTRACE == 1)
-	LD	HL,ESPSD_PRTERR		; SET UP SD_PRTERR
-	PUSH	HL			; ... TO FILTER ALL EXITS
+	PUSH	HL
+	LD	HL,ESPSD_PRTERR		; SET UP ESPSD_PRTERR
+	EX	(SP),HL			; ... TO FILTER ALL EXITS
 #ENDIF
+;
+	PUSH	DE
+	PUSH	HL
+	CALL	ESPSD_CHKERR		; CHECK FOR ERR STATUS AND RESET IF SO
+	POP	HL
+	POP	DE
+	RET	NZ			; BAIL OUT ON ERROR
+;
+	LD	A,E			; COMMAND TO ACCUM
+	LD	(ESPSD_CMDVAL),A	; SAVE THE COMMAND
+	LD	(ESPSD_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
 ;
 	; SELECT PRI/SEC DEVICE
 	CALL	ESPSD_SELECT		; SELECT DEVICE
@ -532,7 +541,7 @@ ESPSD_IO:
 ESPSD_IO2:
 	CALL	ESPSD_BLKWRITE		; DO THE WRITE
 ESPSD_IO3:
-	JP	NZ,ESPSD_ERR		; ON ERROR, RECORD AND BAIL OUT
+	JR	NZ,ESPSD_IO4		; IF ERROR, SKIP INCREMENT
 ;
 	; INCREMENT LBA
 	LD	A,ESPSD_LBA		; LBA OFFSET
@ -544,11 +553,24 @@ ESPSD_IO3:
 	INC	(HL)			; BUMP DMA BY
 	INC	(HL)			; ... 512 BYTES
 ;
-	; CLEAN UP
-	LD	HL,(ESPSD_DSKBUF)	; CURRENT DMA TO HL
 	XOR	A			; SIGNAL SUCCESS
+ESPSD_IO4:
+	LD	HL,(ESPSD_DSKBUF)	; CURRENT DMA TO HL
+	OR	A			; SET FLAGS
+	RET	Z			; DONE IF NO ERROR
+	LD	A,ERR_IO		; SIGNAL IO ERROR
+	OR	A			; SET FLAGS
 	RET				; AND DONE
 ;
+; CHECK CURRENT DEVICE FOR ERROR STATUS AND ATTEMPT TO RECOVER
+; VIA RESET IF DEVICE IS IN ERROR.
+;
+ESPSD_CHKERR:
+	LD	A,(IY+ESPSD_STAT)	; GET STATUS
+	OR	A			; SET FLAGS
+	CALL	NZ,ESPSD_RESET		; IF ERROR STATUS, RESET BUS
+	RET
+;
 ;=============================================================================
 ; COMMAND PROCESSING
 ;=============================================================================
@ -568,11 +590,9 @@ ESPSD_INITCARD:
 ;
 	; GET CAPACITY
 	LD	E,ESPSD_CMD_CAP		; GET CAPACITY COMMAND
-	CALL	ESPSD_CMD_SLOW		; SEND IT
+	CALL	ESPSD_CMD		; SEND IT
 	RET	NZ			; HANDLE ERROR
 ;
-
-
 	LD	A,ESPSD_MEDCAP		; OFFSET TO CAPACITY FIELD
 	CALL	LDHLIYA			; HL := IY + A, REG A TRASHED
 	LD	A,4			; START AT END FOR LITTLE ENDIAN
@ -582,7 +602,7 @@ ESPSD_INITCARD:
 ESPSD_INITCARD1:
 	DEC	HL			; DEC POINTER
 	PUSH	BC			; SAVE LOOP CONTROL
-	CALL	ESPSD_GETBYTE_SLOW	; FIRST BYTE (MSB)
+	CALL	ESPSD_GETBYTE		; FIRST BYTE (MSB)
 	POP	BC			; RESTORE LOOP CONTROL
 	RET	NZ			; HANDLE ERROR
 	LD	(HL),E			; SAVE IT
@ -594,18 +614,18 @@ ESPSD_INITCARD1:
 ;
 ESPSD_FWVER:
 	LD	E,ESPSD_CMD_FWVER	; FWVER COMMAND
-	CALL	ESPSD_CMD_SLOW		; SEND IT
+	CALL	ESPSD_CMD		; SEND IT
 	RET	NZ			; HANDLE ERROR
-	CALL	ESPSD_GETBYTE_SLOW	; GET BOARD ID
+	CALL	ESPSD_GETBYTE		; GET BOARD ID
 	RET	NZ			; HANDLE ERROR
 	LD	D,E			; SAVE IN D
-	CALL	ESPSD_GETBYTE_SLOW	; GET VER MAJOR
+	CALL	ESPSD_GETBYTE		; GET VER MAJOR
 	RET	NZ			; HANDLE ERROR
 	LD	H,E			; PUT IN H
-	CALL	ESPSD_GETBYTE_SLOW	; GET VER MINOR
+	CALL	ESPSD_GETBYTE		; GET VER MINOR
 	RET	NZ			; HANDLE ERROR
 	LD	L,E			; PUT IN H
-	CALL	ESPSD_GETBYTE_SLOW	; GET RESULT
+	CALL	ESPSD_GETBYTE		; GET RESULT
 	RET	NZ			; HANDLE ERROR
 	LD	A,E			; RESULT TO ACCUM
 	LD	E,D			; BOARD ID BACK TO E
@ -626,10 +646,10 @@ ESPSD_SELECT:
 ;
 ESPSD_RUNCMD:
 	LD	E,A			; PUT IN E
-	CALL	ESPSD_CMD_SLOW		; SEND COMMAND
+	CALL	ESPSD_CMD		; SEND COMMAND
 	RET	NZ			; HANDLE ERROR
 ESPSD_GETRESULT:
-	CALL	ESPSD_GETBYTE_SLOW	; GET RESULT
+	CALL	ESPSD_GETBYTE		; GET RESULT
 	RET	NZ			; HANDLE ERROR
 	LD	A,E			; RESULT TO ACCUM
 	OR	A			; SET FLAGS
@ -644,7 +664,7 @@ ESPSD_GETRESULT:
 ;
 ESPSD_SETLBA:
 	LD	E,ESPSD_CMD_SETLBA	; SETLBA COMMAND
-	CALL	ESPSD_CMD_SLOW		; SEND IT
+	CALL	ESPSD_CMD		; SEND IT
 	RET	NZ			; HANDLE ERROR
 	LD	A,4			; LITTLE ENDIAN
 	CALL	ADDHLA			; BUMP TO END OF LBA BYTES
@ -654,12 +674,12 @@ ESPSD_SETLBA1:
 	DEC	HL			; DEC POINTER
 	LD	E,(HL)			; GET NEXT BYTE TO SEND
 	PUSH	BC			; SAVE LOOP CONTROL
-	CALL	ESPSD_PUTBYTE_SLOW	; SEND BYTE
+	CALL	ESPSD_PUTBYTE		; SEND BYTE
 	POP	BC			; RESTORE LOOP CONTROL
 	RET	NZ			; HANDLE ERROR
 	DJNZ	ESPSD_SETLBA1		; LOOP AS NEEDED
 ;
-	CALL	ESPSD_GETBYTE_SLOW	; GET RESULT
+	CALL	ESPSD_GETBYTE		; GET RESULT
 	RET	NZ			; HANDLE ERROR
 	LD	A,E			; RESULT TO ACCUM
 	OR	A			; SET FLAGS
@ -672,7 +692,7 @@ ESPSD_SETLBA1:
 ;
 ESPSD_BLKREAD:
 	LD	E,ESPSD_CMD_READ
-	CALL	ESPSD_CMD_SLOW
+	CALL	ESPSD_CMD
 	RET	NZ
 ;
 	LD	B,0			; LOOP COUNTER
@ -680,13 +700,13 @@ ESPSD_BLKREAD:
 #IF FALSE
 ESPSD_BLKREAD1:
 	PUSH	BC
-	CALL	ESPSD_GETBYTE_SLOW
+	CALL	ESPSD_GETBYTE
 	POP	BC
 	RET	NZ
 	LD	(HL),E
 	INC	HL
 	PUSH	BC
-	CALL	ESPSD_GETBYTE_SLOW
+	CALL	ESPSD_GETBYTE
 	POP	BC
 	RET	NZ
 	LD	(HL),E
@ -699,14 +719,13 @@ ESPSD_BLKREAD1:
 	CALL	ESPSD_BLKREAD2		; DO SECOND 256 BYTES
 #ENDIF
 ;
-	CALL	ESPSD_GETBYTE_SLOW	; GET RESULT
+	CALL	ESPSD_GETBYTE		; GET RESULT
 	RET	NZ			; HANDLE ERROR
 	LD	A,E			; RESULT TO ACCUM
 	OR	A			; SET FLAGS
-	RET	Z			; GOOD RETURN
-	LD	A,ESPSD_STIOERR		; CALL THIS AN IO ERROR
-	OR	A			; SET FLAGS
-	RET				; DONE
+	JP	NZ,ESPSD_IOERR		; HANDLE AS IO ERROR
+	XOR	A			; SIGNAL SUCCESS
+	RET				; AND DONE
 ;
 ESPSD_BLKREAD2:
 	; READ BYTES FAST (NO TIMEOUT CHECK)
@ -726,7 +745,7 @@ ESPSD_BLKREAD2A:
 ;
 ESPSD_BLKWRITE:
 	LD	E,ESPSD_CMD_WRITE
-	CALL	ESPSD_CMD_SLOW
+	CALL	ESPSD_CMD
 	RET	NZ
 ;
 	LD	B,0			; LOOP COUNTER
@ -736,13 +755,13 @@ ESPSD_BLKWRITE1:
 	LD	E,(HL)
 	INC	HL
 	PUSH	BC
-	CALL	ESPSD_PUTBYTE_SLOW
+	CALL	ESPSD_PUTBYTE
 	POP	BC
 	RET	NZ
 	LD	E,(HL)
 	INC	HL
 	PUSH	BC
-	CALL	ESPSD_PUTBYTE_SLOW
+	CALL	ESPSD_PUTBYTE
 	POP	BC
 	RET	NZ
 	DJNZ	ESPSD_BLKWRITE1
@ -753,14 +772,13 @@ ESPSD_BLKWRITE1:
 	CALL	ESPSD_BLKWRITE2		; DO SECOND 256 BYTES
 #ENDIF
 ;
-	CALL	ESPSD_GETBYTE_SLOW	; GET RESULT
+	CALL	ESPSD_GETBYTE		; GET RESULT
 	RET	NZ			; HANDLE ERROR
 	LD	A,E			; RESULT TO ACCUM
 	OR	A			; SET FLAGS
-	RET	Z			; GOOD RETURN
-	LD	A,ESPSD_STIOERR		; CALL THIS AN IO ERROR
-	OR	A			; SET FLAGS
-	RET				; DONE
+	JP	NZ,ESPSD_IOERR		; HANDLE AS IO ERROR
+	XOR	A			; SIGNAL SUCCESS
+	RET				; AND DONE
 ;
 ESPSD_BLKWRITE2:
 	; WRITE BYTES FAST (NO TIMEOUT CHECK)
@ -791,126 +809,103 @@ ESPSD_CMD:
 	RET	NZ
 	JR	ESPSD_PUTBYTE
 ;
-; SEND COMMAND BYTE IN E TO ESP32
-;
-ESPSD_CMD_SLOW:
-	PUSH	DE
-	LD	E,$33			; COMMAND PREFIX BYTE
-	CALL	ESPSD_PUTBYTE_SLOW
-	POP	DE
-	RET	NZ
-	JR	ESPSD_PUTBYTE_SLOW
-;
 ; WRITE BYTE IN E TO ESP32
 ; RETURN STATUS IN A (0=SUCCESS)
+; BC IS DESTROYED
 ;
 ESPSD_PUTBYTE:
 #IF (ESPSDTRACE >= 3)
 	CALL	PC_GT
 #ENDIF
-	LD	B,0
+
+	PUSH	HL			; PRESERVE HL
 	LD	C,(IY+ESPSD_IOBASE)
-ESPSD_PUTBYTE1:
+	LD	HL,100 * CPUMHZ		; SETUP OUTER LOOP COUNTER
+;
+ESPSD_PUTBYTE1:	; OUTER LOOP
+	LD	B,0			; SETUP INNER LOOP COUNTER
+;
+ESPSD_PUTBYTE2:	; INNER LOOP
 #IF (PLATFORM == PLT_SZ180)
 	IN	A,(C)			; EXTRA READ FOR Z180 STABILITY
 #ENDIF
-	IN	A,(C)
-	BIT	0,A
-	JR	Z,ESPSD_PUTBYTE2
-	DJNZ	ESPSD_PUTBYTE1
-	LD	A,ESPSD_STTO
-	OR	A
-	RET
-ESPSD_PUTBYTE2:
-	; NOPS NEEDED FOR RELIABILITY
+	IN	A,(C)			; READ STATUS
+	BIT	0,A			; ISOLATE SENDACT (TXF)
+	JR	Z,ESPSD_PUTBYTE3	; IF NOT ACTIVE, GO TO SEND BYTE
+	DJNZ	ESPSD_PUTBYTE2		; LOOP SOME MORE
+;
+	DEC	HL			; DEC OUTER LOOP COUNTER
+	LD	A,H			; TEST COUNTER
+	OR	L			; ... FOR ZERO
+	JR	NZ,ESPSD_PUTBYTE1	; IF NOT ZERO, LOOP MORE
+;
+	; HANDLE TIMEOUT
+	POP	HL			; RECOVER HL
+	JP	ESPSD_TO		; RETURN VIA ERROR HANDLER
+;
+ESPSD_PUTBYTE3:
+	POP	HL			; RECOVER HL
+	; SEND THE DATA BYTE
+	; NOPS NEEDED FOR RELIABILITY???
 	;NOP \ NOP \ NOP \ NOP \ NOP \ NOP
-	INC	C
-	OUT	(C),E
+	INC	C			; BUMP TO DATA PORT
+	OUT	(C),E			; SEND IT
 ;
 #IF (ESPSDTRACE >= 3)
 	LD	A,E
 	CALL	PRTHEXBYTE
 #ENDIF
 ;	
-	XOR	A
-	RET
-;
-; WRITE BYTE TO ESP32 FROM E WITH EXTRA LONG TIMEOUT
-;
-ESPSD_PUTBYTE_SLOW:
-	PUSH	HL
-	LD	HL,100 * CPUMHZ		; CPU SPEED SCALED TIMEOUT
-ESPSD_PUTBYTE_SLOW1:
-	PUSH	HL
-	CALL	ESPSD_PUTBYTE
-	POP	HL
-	JR	Z,ESPSD_PUTBYTE_SLOW_Z
-	DEC	HL
-	LD	A,H
-	OR	L
-	JR	NZ,ESPSD_PUTBYTE_SLOW1
-	LD	A,ESPSD_STTO
-ESPSD_PUTBYTE_SLOW_Z:
-	;CALL	PC_SPACE		; *DEBUG*
-	;CALL	PRTHEXWORDHL		; *DEBUG*
-	POP	HL
-	OR	A			; SET FLAGS
-	RET
+	XOR	A			; SIGNAL SUCCESS
+	RET				; DONE
 ;
 ; READ BYTE FROM ESP32 INTO E
 ; RETURN STATUS IN A (0=SUCCESS)
+; BC IS DESTROYED
 ;
 ESPSD_GETBYTE:
 #IF (ESPSDTRACE >= 3)
 	CALL	PC_LT
 #ENDIF
-	LD	B,0
+
+	PUSH	HL			; PRESERVE HL
 	LD	C,(IY+ESPSD_IOBASE)
-ESPSD_GETBYTE1:
+	LD	HL,100 * CPUMHZ		; SETUP OUTER LOOP COUNTER
+;
+ESPSD_GETBYTE1:	; OUTER LOOP
+	LD	B,0			; SETUP INNER LOOP COUNTER
+;
+ESPSD_GETBYTE2:	; INNER LOOP
 #IF (PLATFORM == PLT_SZ180)
 	IN	A,(C)			; EXTRA READ FOR Z180 STABILITY
 #ENDIF
-	IN	A,(C)
-	JP	M,ESPSD_GETBYTE2
-	DJNZ	ESPSD_GETBYTE1
-	LD	A,ESPSD_STTO
-	OR	A
-	RET
-ESPSD_GETBYTE2:
-	; NOPS NEEDED FOR RELIABILITY
+	IN	A,(C)			; READ STATUS
+	JP	M,ESPSD_GETBYTE3	; IF RCV READY, GO TO GET BYTE
+	DJNZ	ESPSD_GETBYTE2		; LOOP SOME MORE
+;
+	DEC	HL			; DEC OUTER LOOP COUNTER
+	LD	A,H			; TEST COUNTER
+	OR	L			; ... FOR ZERO
+	JR	NZ,ESPSD_GETBYTE1	; IF NOT ZERO, LOOP MORE
+;
+	; HANDLE TIMEOUT
+	POP	HL			; RECOVER HL
+	JP	ESPSD_TO		; RETURN VIA ERROR HANDLER
+;
+ESPSD_GETBYTE3:
+	POP	HL			; RECOVER HL
+	; NOPS NEEDED FOR RELIABILITY???
 	;NOP \ NOP \ NOP \ NOP \ NOP \ NOP
-	INC	C
-	IN	E,(C)
+	INC	C			; BUMP TO DATA PORT
+	IN	E,(C)			; GET DATA BYTE
 ;
 #IF (ESPSDTRACE >= 3)
 	LD	A,E
 	CALL	PRTHEXBYTE
 #ENDIF
 ;	
-	XOR	A
-	RET
-;
-; READ BYTE FROM ESP32 INTO E WITH EXTRA LONG TIMEOUT
-;
-ESPSD_GETBYTE_SLOW:
-	PUSH	HL
-	LD	HL,100 * CPUMHZ		; CPU SPEED SCALED TIMEOUT
-ESPSD_GETBYTE_SLOW1:
-	PUSH	HL
-	CALL	ESPSD_GETBYTE
-	POP	HL
-	JR	Z,ESPSD_GETBYTE_SLOW_Z
-	DEC	HL
-	LD	A,H
-	OR	L
-	JR	NZ,ESPSD_GETBYTE_SLOW1
-	LD	A,ESPSD_STTO
-ESPSD_GETBYTE_SLOW_Z:
-	;CALL	PC_SPACE		; *DEBUG*
-	;CALL	PRTHEXWORDHL		; *DEBUG*
-	POP	HL
-	OR	A			; SET FLAGS
-	RET
+	XOR	A			; SIGNAL SUCCESS
+	RET				; DONE
 ;
 ;=============================================================================
 ; ERROR HANDLING AND DIAGNOSTICS
--- a/Source/HBIOS/scsi.asm
+++ b/Source/HBIOS/scsi.asm
@ -167,7 +167,11 @@ SCSI_INIT3:
 	CALL	PRTDEC8			; DISPLAY IT
 ;
 	CALL	SCSI_INITDEV		; INITIALIZE DEVICE
+#IF (SCSITRACE < 2)
 	JP	NZ,SCSI_PRTSTATSTR	; IF ERROR, EXIT VIA PRINT
+#ELSE
+	RET	NZ
+#ENDIF
 ;
 	; PRINT STORAGE CAPACITY (BLOCK COUNT)
 	PRTS(" BLOCKS=0x$")		; PRINT FIELD LABEL
@ -230,14 +234,14 @@ SCSI_DEFMED:
 ;
 SCSI_READ:
 	CALL	HB_DSKREAD		; HOOK HBIOS DISK READ SUPERVISOR
-	LD	A,SCSI_CMD_READ		; SETUP READ COMMAND
+	LD	E,SCSI_CMD_READ		; SETUP READ COMMAND
 	JP	SCSI_IO			; DO THE IO
 ;
 ;
 ;
 SCSI_WRITE:
 	CALL	HB_DSKWRITE		; HOOK HBIOS DISK WRITE SUPERVISOR
-	LD	A,SCSI_CMD_WRITE	; SETUP WRITE COMMAND
+	LD	E,SCSI_CMD_WRITE	; SETUP WRITE COMMAND
 	JP	SCSI_IO			; DO THE IO
 ;
 ;
@ -362,8 +366,23 @@ SCSI_INITDEV:
 ;
 ;
 SCSI_IO:
+;
+#IF (ESPSDTRACE == 1)
+	PUSH	HL
+	LD	HL,SCSI_PRTERR		; SET UP ESPSD_PRTERR
+	EX	(SP),HL			; ... TO FILTER ALL EXITS
+#ENDIF
+;
 	LD	(SCSI_DSKBUF),HL	; SAVE DISK BUFFER ADDRESS
+	PUSH	DE			; SAVE COMMAND BYTE
+	PUSH	HL			; SAVE BUFFER ADDRESS
+	CALL	SCSI_CHKERR		; CHECK FOR ERR STATUS AND RESET IF SO
+	POP	HL			; RESTORE BUFFER ADDRESS
+	POP	DE			; RESTORE COMMAND BYTE
+	RET	NZ			; BAIL OUT ON ERROR
+;
 	; SETUP SCSI COMMAND
+	LD	A,E
 	LD	(SCSI_S_CDB),A		; SET SCSI COMMAND
 	; SETUP DISK BUFFER POINTERS
 	LD	(SCSI_BUF_OUT),HL	; INPUT BUFFER
@ -386,12 +405,7 @@ SCSI_IO:
 	LD	A,(IY+SCSI_LBA+0)	; LBA MID
 	LD	(SCSI_CUR_LBN+1),A	; PUT IN CDB
 	; DO THE SCSI TRANSACTION
-	PUSH	IX			; SAVE IX
-	LD	IX,SCSI_S_IOT		; SET POINTER
 	CALL	SCSI_GO			; DO THE SCSI TRANSACTION
-	POP	IX			; RESTORE IX
-	AND	%00111110		; IGNORE RESERVED BITS OF STATUS
-	CALL	NZ,SCSI_IOERR		; DIAGNOSE/RECORD ERRORS
 	JR	NZ,SCSI_IO1		; IF ERROR, SKIP INCREMENT
 	; INCREMENT LBA
 	LD	A,SCSI_LBA		; LBA OFFSET
@ -410,12 +424,14 @@ SCSI_IO1:
 	OR	A			; SET FLAGS
 	RET				; AND DONE
 ;
-; CHECK FOR DEVICE EXISTENCE
+; CHECK CURRENT DEVICE FOR ERROR STATUS AND ATTEMPT TO RECOVER
+; VIA RESET IF DEVICE IS IN ERROR.
 ;
-SCSI_TSTRDY:
-	XOR	A			; SIGNAL SUCCESS
+SCSI_CHKERR:
+	LD	A,(IY+SCSI_STAT)	; GET STATUS
+	OR	A			; SET FLAGS
+	CALL	NZ,SCSI_RESET		; IF ERROR STATUS, RESET BUS
 	RET
-
 ;
 ; ISSUE SCSI INQUIRY COMMAND
 ; ON INPUT, HL POINTS TO OUTPUT DATA BUFFER
@ -434,13 +450,7 @@ SCSI_INQUIRY:
 	RRCA				; ...
 	LD	(SCSI_INQ_LUN),A	; PUT IN INQ CDB
 	; DO THE SCSI TRANSACTION
-	PUSH	IX			; SAVE IX
-	LD	IX,SCSI_S_IOT		; SET POINTER
-	CALL	SCSI_GO			; DO THE SCSI TRANSACTION
-	POP	IX			; RESTORE IX
-	AND	%00111110		; IGNORE RESERVED BITS OF STATUS
-	JP	NZ,SCSI_IOERR		; HANDLE ERROR
-	RET				; DONE
+	JP	SCSI_GO			; DO THE SCSI TRANSACTION
 ;
 ; ISSUE SCSI CAPACITY COMMAND AND CAPTURE
 ; RESULTS AS DEVICE CAPACITY
@ -460,12 +470,8 @@ SCSI_CAPACITY:
 	RRCA				; ...
 	LD	(SCSI_CAP_LUN),A	; PUT IN INQ CDB
 	; DO THE SCSI TRANSACTION
-	PUSH	IX			; SAVE IX
-	LD	IX,SCSI_S_IOT		; SET POINTER
 	CALL	SCSI_GO			; DO THE SCSI TRANSACTION
-	POP	IX			; RESTORE IX
-	AND	%00111110		; IGNORE RESERVED BITS OF STATUS
-	JP	NZ,SCSI_IOERR		; HANDLE ERROR
+	RET	NZ			; ABORT ON ERROR
 ;
 	; RETURNED LBA IS BIG ENDIAN.  CONVERT TO A STANDARD 32-BIT
 	; INTEGER IN DE:HL
@ -501,35 +507,22 @@ SCSI_CAPACITY:
 ; COMMAND PROCESSING
 ;=============================================================================
 ;
-;----------------------------------------------------------------
-;WRITE LOGICAL BLOCK TO DISK
-;CUR_TID,CUR_LUN,CUR_LBN ALREADY SET
-;EXIT WITH ZERO STATUS IF OK
-;----------------------------------------------------------------
+; WRAPPER FOR HBIOS INVOCATION
 ;
-WR_PHY:
-	LD A,0AH		;WRITE COMMAND
-	JR PHY_COM		;FINISH SAME AS READ
-
-;----------------------------------------------------------------
-;READ LOGICAL BLOCK FROM DISK
-;CUR_TID,CUR_LUN,CUR_LBN ALREADY SET
-;EXIT WITH ZERO STATUS IF OK
-;----------------------------------------------------------------
+SCSI_GO:
+	PUSH	IX			; PRESERVE IX
+	LD	IX,SCSI_S_IOT		; POINT TO IO TABLE
+	CALL	SCSI_GO1		; RUN THE TRANSACTION
+	POP	IX			; RESTORE IX
+	AND	%00111110		; IGNORE RESERVED BITS OF STATUS
+	JP	NZ,SCSI_IOERR		; HANDLE ERROR
+	RET				; DONE
 ;
-RD_PHY:
-	LD A,8			;READ COMMAND
-PHY_COM:
-	LD (SCSI_S_CDB),A		;SET IN COMMAND BLOCK
-	LD IX,SCSI_S_IOT		;POINT TO IO TABLE
-	CALL SCSI_GO
-	AND 02H			;MASK TO ERROR BIT
-	RET
 ;-------------------------------------------------------------------------------
 ;DO SCSI TRANSACTION
-; IX=SCSI IO BLOCK
 ;-------------------------------------------------------------------------------
-SCSI_GO:
+;
+SCSI_GO1:
 	LD A,$FF	;PRESET ERROR STATUS
 	LD L,(IX+4)	;POINT TO STATUS ADDRESS
 	LD H,(IX+5)	;POINT TO STATUS ADDRESS
--- a/Source/ver.inc
+++ b/Source/ver.inc
@ -2,7 +2,7 @@
 #DEFINE	RMN	6
 #DEFINE	RUP	0
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.6.0-dev.46"
+#DEFINE BIOSVER	"3.6.0-dev.47"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP
--- a/Source/ver.lib
+++ b/Source/ver.lib
@ -3,5 +3,5 @@ rmn	equ	6
 rup	equ	0
 rtp	equ	0
 biosver	macro
-	db	"3.6.0-dev.46"
+	db	"3.6.0-dev.47"
 	endm