diff --git a/Source/config_n8_2511.asm b/Source/config_n8_2511.asm
index 59fc3e90..3e422c96 100644
--- a/Source/config_n8_2511.asm
+++ b/Source/config_n8_2511.asm
@@ -56,7 +56,7 @@ PPIDESLOW	.EQU	FALSE		; ADD DELAYS TO HELP PROBLEMATIC HARDWARE (TRY THIS IF PPI
 SDENABLE	.EQU	TRUE		; TRUE FOR SD SUPPORT
 SDTRACE		.EQU	1		; 0=SILENT, 1=ERRORS, 2=EVERYTHING (ONLY RELEVANT IF IDEENABLE = TRUE)
 SDCAPACITY	.EQU	64		; CAPACITY OF DEVICE (IN MB)
-SDMODE		.EQU	SDMODE_CSIO	; SDMODE_JUHA, SDMODE_CSIO, SDMODE_UART, SDMODE_PPI, SDMODE_DSD
+SDMODE		.EQU	SDMODE_N8	; SDMODE_JUHA, SDMODE_CSIO, SDMODE_UART, SDMODE_PPI, SDMODE_DSD
 SDCSIOFAST	.EQU	FALSE		; TABLE-DRIVEN BIT INVERTER
 ;
 PRPENABLE	.EQU	FALSE		; TRUE FOR PROPIO SD SUPPORT (FOR N8VEM PROPIO ONLY!)
diff --git a/Source/hbios.asm b/Source/hbios.asm
index f6357d6c..32c10351 100644
--- a/Source/hbios.asm
+++ b/Source/hbios.asm
@@ -193,11 +193,11 @@ IDLE:
 BIOS_DISPATCH:
 	LD	A,B		; REQUESTED FUNCTION IS IN B
 	CP	BF_CIO + $10	; $00-$0F: CHARACTER I/O
-	JR	C,CIO_DISPATCH
+	JP	C,CIO_DISPATCH
 	CP	BF_DIO + $10	; $10-$1F: DISK I/O
-	JR	C,DIO_DISPATCH
+	JP	C,DIO_DISPATCH
 	CP	BF_RTC + $10	; $20-$2F: REAL TIME CLOCK (RTC)
-	JR	C,RTC_DISPATCH
+	JP	C,RTC_DISPATCH
 	CP	BF_EMU + $10	; $30-$3F: EMULATION
 	JP	C,EMU_DISPATCH
 	CP	BF_VDA + $10	; $40-$4F: VIDEO DISPLAY ADAPTER
diff --git a/Source/makefile b/Source/makefile
index e60874b9..63cf9e03 100644
--- a/Source/makefile
+++ b/Source/makefile
@@ -186,7 +186,7 @@ zcprw.bin : zcprw.asm zcpr.asm
 zsdos.bin : zsdos.asm zsdos.lib zsdos-gp.z80
 	$(TASM) $(ASMOPT80) $< $@
 
-cbios.bin: cbios.asm fd_data.asm ide_data.asm ppide_data.asm sd_data.asm prp_data.asm ppp_data.asm uart.asm vdu.asm std.asm ver.inc build.inc
+cbios.bin: cbios.asm fd_dph.asm ide_dph.asm ppide_dph.asm sd_dph.asm prp_dph.asm ppp_dph.asm uart.asm vdu.asm std.asm ver.inc build.inc
 	$(TASM) $(ASMOPT80) -dBLD_SYS=SYS_$(SYS) $< $@
 
 dbgmon.bin: dbgmon.asm std.asm ver.inc build.inc
diff --git a/Source/makefile.linux b/Source/makefile.linux
index 14fd13e6..e5f1eaed 100644
--- a/Source/makefile.linux
+++ b/Source/makefile.linux
@@ -172,7 +172,7 @@ zcprw.bin : zcprw.asm zcpr.asm
 zsdos.bin : zsdos.asm zsdos.lib zsdos-gp.z80
 	$(TASM) $(ASMOPT80) $< $@
 
-cbios.bin: cbios.asm fd_data.asm ide_data.asm ppide_data.asm sd_data.asm prp_data.asm ppp_data.asm uart.asm vdu.asm std.asm ver.inc build.inc
+cbios.bin: cbios.asm fd_dph.asm ide_dph.asm ppide_dph.asm sd_dph.asm prp_dph.asm ppp_dph.asm uart.asm vdu.asm std.asm ver.inc build.inc
 	$(TASM) $(ASMOPT80) -dBLD_SYS=SYS_$(SYS) $< $@
 
 dbgmon.bin: dbgmon.asm std.asm ver.inc build.inc
diff --git a/Source/sd.asm b/Source/sd.asm
index 12251d45..2fad9eda 100644
--- a/Source/sd.asm
+++ b/Source/sd.asm
@@ -109,18 +109,18 @@ SD_DO		.EQU	%00000001	; RTC:0 IS DATA OUT (CARD -> CPU)
 ;
 ; SD CARD COMMANDS
 ;
-SD_CMD0		.EQU	$40 | 0		; GO_IDLE_STATE
-SD_CMD1		.EQU	$40 | 1		; SEND_OP_COND
-SD_CMD8		.EQU	$40 | 8		; SEND_IF_COND
-SD_CMD9		.EQU	$40 | 9		; SEND_CSD
-SD_CMD10	.EQU	$40 | 10	; SEND_CID
-SD_CMD16	.EQU	$40 | 16	; SET_BLOCKLEN
-SD_CMD17	.EQU	$40 | 17	; READ_SINGLE_BLOCK
-SD_CMD24	.EQU	$40 | 24	; WRITE_BLOCK
-SD_CMD55	.EQU	$40 | 55	; APP_CMD
-SD_CMD58	.EQU	$40 | 58	; READ_OCR
+SD_CMD0		.EQU	$40 | 0		; 0x40, GO_IDLE_STATE
+SD_CMD1		.EQU	$40 | 1		; 0x41, SEND_OP_COND
+SD_CMD8		.EQU	$40 | 8		; 0x48, SEND_IF_COND
+SD_CMD9		.EQU	$40 | 9		; 0x49, SEND_CSD
+SD_CMD10	.EQU	$40 | 10	; 0x4A, SEND_CID
+SD_CMD16	.EQU	$40 | 16	; 0x50, SET_BLOCKLEN
+SD_CMD17	.EQU	$40 | 17	; 0x51, READ_SINGLE_BLOCK
+SD_CMD24	.EQU	$40 | 24	; 0x58, WRITE_BLOCK
+SD_CMD55	.EQU	$40 | 55	; 0x77, APP_CMD
+SD_CMD58	.EQU	$40 | 58	; 0x7A, READ_OCR
 ; SD APPLICATION SPECIFIC COMMANDS
-SD_ACMD41	.EQU	$40 | 41	; SD_APP_OP_COND
+SD_ACMD41	.EQU	$40 | 41	; 0x69, SD_APP_OP_COND
 ;
 ; SD CARD TYPE
 ;
@@ -774,7 +774,7 @@ SD_INITCARD00:
 SD_INITCARD0:
 	CALL	SD_DONE
 
-	LD	A,$40
+	LD	A,0
 	LD	(SD_LCNT),A
 SD_INITCARD1:
 	; CALL SD_APP_OP_COND UNTIL CARD IS READY (NOT IDLE)
diff --git a/Source/ver.inc b/Source/ver.inc
index a45279dd..073a86ce 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -1,6 +1,6 @@
 #DEFINE	RMJ	2
 #DEFINE	RMN	5
 #DEFINE	RUP	0
-#DEFINE	RTP	2
-#DEFINE BIOSVER	"2.5 - Beta 2"
+#DEFINE	RTP	3
+#DEFINE BIOSVER	"2.5 - Beta 3"
 #DEFINE REVISION 412