supermario/base/SuperMarioProj.1994-02-09/OS/IoPrimitives/ClockPRAMPrimitives.a

;
;	File:		ClockPRAMPrimitives.a
;
;	Contains:	low-level routines for accessing the realtime clock and parameter RAM
;
;	Written by:	Steve Christensen 
;
;	Copyright:	© 1991-1993 by Apple Computer, Inc.  All rights reserved.
;
;   This file is used in these builds: ROM
;
;	Change History (most recent first):
;
;	  <SM14>	12/13/93	PN		Roll in KAOs and Horror changes to support Malcom and AJ
;									machines.
;	  <SM13>	 6/23/93	RC		Go back to the Ludwig roll-in since PDM reallly needs this code
;									from Cyclone - stay tuned for further fixes/changes from Kurt
;	  <SM12>	 6/21/93	kc		Roll out SM10 so that Quadras would wake up with the right time.
;	  <SM11>	 6/14/93	kc		Roll in Ludwig.
;	   <LW3>	 1/14/93	GS		(RBM)  Fix the occassional hang at boot.  When outputing from
;									the VIA to Cuda, the interrupt will occur prior to the rising
;									edge of CB1.  Delay long enough for the edge to occur before
;									acknowledging the shift register interrupt.
;	  <SM10>	 5/20/93	RM		EgretReadTime should not call _EgretDispatch. The lowmem global
;									'Time' is self correcting for Egret/Caboose/Cuda. The one second
;									interrupt handler for Egret / Caboose / Cuda maintains the
;									lowmem global 'Time' in a self correcting manner.  This routine
;									need only return the lowmem 'Time'.  A call to _EgretDispatch
;									will cause the AutoPoll timer within Egret / Caboose / Cuda to
;									reset, resulting in deferring ADB auto polling.  If an
;									application calls ReadTime in a tight loop, ADB polling could be
;									deferred indefinitely (making the mouse/keyboard appear to hang
;									or respond intermittently).  Since 'Time' is self correcting,
;									the routine just returns 'Time' as the result placed into
;									'GetParam'.
;	   <SM9>	12/11/92	fau		Backed out <SM8> cause it broke Cyclone.
;	   <SM8>	12/10/92	GS		This patch bypasses the physical read of Egret Chip when reading
;									the time. The time is automatically updated in the background,
;									therefore the low mem global always reflects the accurate time.
;									This patch pertains to all Egret Chip based firmware in
;									Egret8/9, Caboose, and Cuda.
;	   <SM7>	11/30/92	SWC		Rolled in the rest of the Horror changes, except for HcMac code.
;									Added the build conditionals back in.
;		<H6>	  9/3/92	SWC		Fixed a couple of bugs in the RTC-based routines (you mean no
;									one had any problems until now?). Thanks, Helder.
;	   <SM6>	10/21/92	fau		Cleaned up a MMCExists that was there from Pandora's timeframe:
;									comment P5.  Cuda works now, so we don't need to bypass stuff.
;	   <SM5>	 6/26/92	GS		(RBM)  Rewrite of 'CudaRdXByte' & 'CudaWrXByte' to avoid looking
;									for collisions. This is possible because a 'SyncAck' cycle
;									occurs immediately after 'InitVias' and disables all
;									asynchronous message sources within Cuda. These routines are
;									being used after the Cuda manager is installed which will cause
;									a loss of data from Cuda so I also made the routine dispatch to
;									a trap based function using the Cuda manager once the Cuda
;									manager is installed. This is not a particularly clean
;									implementation and needs to be looked at further!!!
;	   <SM4>	 5/28/92	kc		Add ClkNoMem.
;	   <SM3>	 5/25/92	RB		Removed a forCyclone conditional. This WAS the last one left. A
;									check for MMC is used instead to skip over RTCClkNoMem.
;	   <SM2>	 5/21/92	RB		Making changes for Cyclone. Original comments below: <P6>
;									2/10/92 GS Changed the PRAM IOPrimitives to use the full word of
;									a register to set up the address to R/W. <P5> 1/30/92 RMP
;									Temporarly disabled RTCClock read/write PRAM since Cuda isn't
;									working (I know it doesn't make sense but it's 2:13 in the
;									morning). <P4> 1/16/92 GS Updated the PRAMIO routine to use a
;									full word as the address to Read/Write <P4> 1/16/92 GS Update
;									VIA control bit var names. <P3> 1/16/92 GS Update to include the
;									new file CudaMgr Clock and PRAM routines. <P2> 01/14/92 jmp
;									(SWC,H5) Fixed PMgrWrXByte (registers were getting trashed).
;		 <1>	 5/17/92	kc		first checked in
;	   <SM0>	  5/2/92	kc		Roll in Horror. Comments follow:
;		<H5>	 1/13/92	SWC		Fixed PMgrWrXByte (registers were getting trashed).
;		<H4>	11/25/91	CCH		Used standardized equates for VIA pins.
;		<H3>	 11/7/91	SWC		Re-wrote the Egret code. It was working on an emulator but
;									stopped working when the Mac was running stand-alone. Converted
;									existing implementations to use a "standard" PramIO routine that
;									calls implementation specific read/write PRAM byte routines so
;									there's one less routine to write for new PRAM models that can
;									use it.
;		<H2>	 11/6/91	SWC		Re-wrote PMGRXPRamIO to fix problems too numerous to mention.
;		<H1>	10/15/91	SWC		Adding this file into the build.


			PRINT	OFF
			LOAD	'StandardEqu.d'
			INCLUDE	'HardwarePrivateEqu.a'
			INCLUDE	'UniversalEqu.a'
		IF hasPwrControls THEN
			INCLUDE	'PowerPrivEqu.a'
		ENDIF
		IF hasEgret THEN
			INCLUDE	'EgretEqu.a'
		ENDIF
			INCLUDE	'IOPrimitiveEqu.a'
			PRINT	ON
			PRINT	NOMDIR
			MACHINE	MC68020



ClockPRAMPrimitives	PROC	EXPORT

;————————————————————————————————————————————————————————————————————————————————————————
;
;	Clock/PRAM primitives vector table
;
;	Tables pointed to by the universal ProductInfo record (ClockPRAMPtr) for low-level
;	clock and PRAM routines dependent on the hardware.  There should be a table for each
;	supported ProductInfo.  Note that if a machine has a combination of the "standard"
;	PRAM and clock models, it should have a machine-specific table added below


		IF hasVIAClock THEN
			EXPORT	RTCClockPRAM
			DC.W	0									; flags
			DC.W	(RTCTableEnd-RTCClockPRAM)/4		; number of entries
RTCClockPRAM
			DC.L	RTCInitHW-RTCClockPRAM				; initialize the hardware (RAM-less)
			DC.L	RTCWrProtOff-RTCClockPRAM			; write-enable PRAM (RAM-less)
			DC.L	RTCWrProtOn-RTCClockPRAM			; write-protect PRAM (RAM-less)
			DC.L	RTCRdXByte-RTCClockPRAM				; read PRAM byte (RAM-less)
			DC.L	RTCWrXByte-RTCClockPRAM				; write PRAM byte (RAM-less)
			DC.L	StandardXPramIO-RTCClockPRAM		; read/write PRAM byte[s] (no traps)		<H3>
			DC.L	RTCXParam-RTCClockPRAM				; read/write PRAM byte[s] (trap-based)
			DC.L	RTCReadTime-RTCClockPRAM			; read the clock (uses RAM)
			DC.L	RTCWriteTime-RTCClockPRAM			; write to the clock (uses RAM)
RTCTableEnd
		ENDIF


		IF hasPwrControls THEN
			EXPORT	PMGRClockPRAM
			DC.W	0									; flags
			DC.W	(PMGRTableEnd-PMGRClockPRAM)/4		; number of entries
PMGRClockPRAM
			DC.L	0									; not used
			DC.L	0									; not used
			DC.L	0									; not used
			DC.L	PMGRRdXByte-PMGRClockPRAM			; read PRAM byte (RAM-less)
			DC.L	PMGRWrXByte-PMGRClockPRAM			; write PRAM byte (RAM-less)
			DC.L	StandardXPramIO-PMGRClockPRAM		; read/write PRAM byte[s] (no traps)		<H3>
			DC.L	PMGRXParam-PMGRClockPRAM			; read/write PRAM byte[s] (trap-based)
			DC.L	PMGRReadTime-PMGRClockPRAM			; read the clock (uses RAM)
			DC.L	PMGRWriteTime-PMGRClockPRAM			; write to the clock (uses RAM)
PMGRTableEnd
		ENDIF


		IF hasEgret THEN
			EXPORT	EgretClockPRAM
			DC.W	0									; flags
			DC.W	(EgretTableEnd-EgretClockPRAM)/4	; number of entries
EgretClockPRAM
			DC.L	0									; not used
			DC.L	0									; not used
			DC.L	0									; not used
			DC.L	EgretRdXByte-EgretClockPRAM			; read PRAM byte (RAM-less)
			DC.L	EgretWrXByte-EgretClockPRAM			; write PRAM byte (RAM-less)
			DC.L	StandardXPramIO-EgretClockPRAM		; read/write PRAM byte[s] (no traps)		<H3>
			DC.L	EgretXParam-EgretClockPRAM			; read/write PRAM byte[s] (trap-based)
			DC.L	EgretReadTime-EgretClockPRAM		; read the clock (uses RAM)
			DC.L	EgretWriteTime-EgretClockPRAM		; write to the clock (uses RAM)
EgretTableEnd

			EXPORT	CudaClockPRAM
			DC.W	0									; flags
			DC.W	(CudaTableEnd-CudaClockPRAM)/4		; number of entries
CudaClockPRAM
			DC.L	0									; not used
			DC.L	0									; not used
			DC.L	0									; not used
			DC.L	CudaRdXByte-CudaClockPRAM			; read PRAM byte (RAM-less)
			DC.L	CudaWrXByte-CudaClockPRAM			; write PRAM byte (RAM-less)
			DC.L	StandardXPramIO-CudaClockPRAM		; read/write PRAM byte[s] (no traps)		<H5>
			DC.L	EgretXParam-CudaClockPRAM			; read/write PRAM byte[s] (trap-based)
			DC.L	EgretReadTime-CudaClockPRAM			; read the clock (uses RAM)
			DC.L	EgretWriteTime-CudaClockPRAM		; write to the clock (uses RAM)
CudaTableEnd
		ENDIF


		IF hasProtectedPRAM THEN
			EXPORT	NoPRAMClockPRAM
			DC.W	0									; flags
			DC.W	(NoPRAMTableEnd-NoPRAMClockPRAM)/4	; number of entries
NoPRAMClockPRAM
			DC.L	0									; not used
			DC.L	0									; not used
			DC.L	0									; not used
			DC.L	NoPRAMRdXByte-NoPRAMClockPRAM		; read PRAM byte (RAM-less)
			DC.L	NoPRAMWrXByte-NoPRAMClockPRAM		; write PRAM byte (RAM-less)
			DC.L	NoPRAMXPramIO-NoPRAMClockPRAM		; read/write PRAM byte[s] (no traps)
			DC.L	NoPRAMXParam-NoPRAMClockPRAM		; read/write PRAM byte[s] (trap-based)
			DC.L	NoPRAMReadTime-NoPRAMClockPRAM		; read the clock (uses RAM)
			DC.L	NoPRAMWriteTime-NoPRAMClockPRAM		; write to the clock (uses RAM)
NoPRAMTableEnd
		ENDIF



		IF hasVIAClock | hasPwrControls | hasEgret | hasPowerMgr THEN	;							<H3>
;________________________________________________________________________________________
;
; Routine:	StandardXPramIO
;
; Inputs:	A0	-	pointer to table of base addresses
;			A1	-	pointer to ProductInfo record for this machine
;			A3	-	pointer to PRAM I/O buffer
;			D1	-	flags indicating which external features are valid
;			D3	-	[r/w (bit 31)][number of PRAM bytes to read/write][starting PRAM address]
;
; Outputs:	none
;
; Trashes:	A0,A1,A2,A3,D0,D1,D2,D3
;
; Function:	Reads/writes byte[s] from paramter RAM before traps are set up.  This calls
;			the implementation-specific RdXByte and WrXByte routines to read or write
;			each PRAM byte.
;________________________________________________________________________________________

			IMPORT	ClkWPOff,RdXByte,WrXByte

StandardXPramIO
			MOVEM.L	D7/A4-A6,-(SP)

			MOVEA.L	DecoderInfo.VIA1Addr(A0),A2	; get VIA 1's base address

			BCLR	#31,D3					; read or write?
			BEQ.S	@StartRead				; -> read

			;BigBSR6	ClkWPOff,A5				; write-enable PRAM
			BRA.S	@StartWrite

@WriteLoop	
			MOVE	SR,-(SP)				; save the status register
			ORI		#$0700,SR				; and disable all interrupts
			BigBSR6	ClkWPOff,A5				; write-enable PRAM
			SWAP	D3						; get the PRAM address
			MOVE.W	D3,D1					; move entire address into D1
			MOVE.B	(A3)+,D2				;  and a data byte from the caller's buffer
			MOVE.L	A3,D7					; (save the buffer pointer)
			BigBSR6	WrXByte,A5				; write a byte to PRAM
			MOVEA.L	D7,A3					; (restore the buffer pointer)
			ADDQ.W	#1,D3					; next byte
			MOVE	(SP)+,SR				; restore the status register
			bsr.l	StdXPRAM2Patch			; call the patch
@StartWrite	
			SWAP	D3						; get the count
			DBRA	D3,@WriteLoop			; -> keep looping until done
			MOVEA.L	A1,A6					; point to this machine's product info
			ADDA.L	ProductInfo.ClockPRAMPtr(A6),A6	;  and get the address of its clock/PRAM table
			MOVE.L	4*cpWrProtOn(A6),D0		; get the offset to the write-protect routine
			BEQ.S	@Done					; -> it's not supported for this implementation
			;ADDA.L	D0,A6					; calculate the routine's address
			;LEA		@Done,A5				; (simulate a BSR5)
			;JMP		(A6)					;  and call it to turn on PRAM write-protect
			bra.s	@Done					; we're done

@ReadLoop	SWAP	D3						; get the PRAM address
			MOVE.W	D3,D1					; move entire address into D1
			MOVE.L	A3,D7					; (save the buffer pointer)
			BigBSR6	RdXByte,A5				; read a byte from PRAM
			MOVEA.L	D7,A3					; (restore the buffer pointer)
			MOVE.B	D1,(A3)+				;  and save it in the caller's buffer
			ADDQ.W	#1,D3					; next byte
@StartRead	SWAP	D3						; get the count
			DBRA	D3,@ReadLoop			; -> keep looping until done

@Done		MOVEM.L	(SP)+,D7/A4-A6
			RTS
		ENDIF



		IF hasVIAClock THEN
;••••••••••••••••••••••••••••••••••••••••• RTC ••••••••••••••••••••••••••••••••••••••••••

			IMPORT	ReadTime

;________________________________________________________________________________________
;
; Routine:	RTCReadTime
;
; Inputs:	none
;
; Outputs:	D0	-	result code
;			"GetParam" contains the 32-bit time value read from the clock
;
; Trashes:	A0,A2,A3,D1,D2,D4,D5, 8 bytes at "GetParam"
;
; Function:	reads the time from the realtime clock
;________________________________________________________________________________________

RTCReadTime	MOVEM.L	A5/A6,-(SP)
			MOVEA.L	VIA,A2					; get the VIA 1 base address for RTCClkNoMem

			MOVEQ	#2-1,D4					; try reading twice in case the time rolls over
@RetryLoop	MOVEQ	#$9D-256,D5				; command to read the high byte of the time
			LEA		GetParam,A0				; use clock utility storage
			MOVEA.L	A0,A3					;  and save a copy for later

@ReadLoop	MOVE.B	D5,D1					; get the command into D1
			BSR5	RTCClkNoMem				; read a byte of the time
			MOVE.B	D1,(A0)+				;  and save it
			SUBQ.B	#4,D5					; next byte
			BMI.S	@ReadLoop				; -> keep looping until all 8 bytes are read

			MOVE.L	(A3)+,D0				; do the two reads of the time match?
			SUB.L	(A3)+,D0
			DBEQ	D4,@RetryLoop			; -> keep looping if not, or for two tries
			BEQ.S	@Done					; -> no error

			MOVEQ	#ClkRdErr,D0			; note the problem
@Done		MOVEM.L	(SP)+,A5/A6
			RTS


;________________________________________________________________________________________
;
; Routine:	RTCWriteTime
;
; Inputs:	"Time" contains the 32-bit value to write to the clock
;
; Outputs:	D0	-	result code
;
; Trashes:	A0,D1,D2,D3,D4,D5
;
; Function:	writes a new time value to the realtime clock
;________________________________________________________________________________________

RTCWriteTime
			MOVEM.L	D6/A2/A5/A6,-(SP)
			MOVEA.L	VIA,A2					; get the VIA 1 base address for RTCClkNoMem

			BSR5	RTCWrProtOff			; write-enable the clock chip

			MOVEQ	#2-1,D5					; give it two tries
			MOVE.L	Time,D3					; get the time to write

@RetryLoop	MOVEQ	#$01,D6					; command to write the low byte of the time
			MOVEQ	#4-1,D4
@WriteLoop	MOVE.L	D3,D1					; put the byte to write into the upper word
			SWAP	D1
			MOVE.B	D6,D1					;  and the command in the lower word
			BSR5	RTCClkNoMem				; write a byte of the time
			ADDQ.B	#4,D6					; address the next register
			ROR.L	#8,D3					; get the next byte
			DBRA	D4,@WriteLoop

			BIGJSR	ReadTime,A0				; read the time to verify it was written correctly
			BNE.S	@Done
			CMP.L	Time,D3 				; do they match?
			DBEQ	D5,@RetryLoop			; -> keep looping if not, or for two tries
			BEQ.S	@Done					; -> they match so we're done
			MOVEQ	#ClkWrErr,D0			; note the error

@Done		MOVE.L	D0,D3					; save the result code
			BSR5	RTCWrProtOn				; turn write-protect back on							<H6>
			MOVE.L	D3,D0					; restore the result code
			MOVEM.L	(SP)+,D6/A2/A5/A6
			RTS


;________________________________________________________________________________________
;
; Routine:	RTCXParam
;
; Inputs:	A0	-	pointer to user's buffer
;			D0	-	[number of bytes to transfer][starting PRAM address]
;			D1	-	bit 12: 1=read, 0=write
;
; Outputs:	D0	-	result code
;
; Trashes:	A0,A1,A2,A3,D1,D2,D3
;
; Function:	reads/writes byte[s] from RTC-based paramter RAM
;________________________________________________________________________________________

RTCXParam	MOVEA.L	A0,A3					; get the pointer to the caller's buffer
			MOVEA.L	UnivInfoPtr,A1			; point to the ProductInfo table						<H3>
			MOVEA.L	A1,A0					;  and to the decoder table								<H3>
			ADDA.L	ProductInfo.DecoderInfoPtr(A0),A0
			MOVE.L	D0,D3					; get the starting PRAM address and count
			BTST	#12,D1					; is it a read or write?
			BNE.S	@ItsRead
			BSET	#31,D3					; mark it as a write

@ItsRead	BSR.S	StandardXPramIO			; go transfer the PRAM bytes							<H3>

			MOVEQ	#0,D0					; always return "no error"
			RTS


;________________________________________________________________________________________
;
; Routine:	RTCRdXByte
;
; Inputs:	D1	-	address of PRAM byte to read
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	D1	-	byte read from PRAM
;
; Trashes:	D0,D2,A5,A6
;
; Function:	reads a byte from RTC-based PRAM without using RAM
;________________________________________________________________________________________

RTCRdXByte	ANDI.W	#$00FF,D1				;  [oooo oooo 7654 3210]
			ASL.W	#3,D1					;  [oooo o765 4321 0ooo]
			ROR.B	#1,D1					;  [oooo o765 o432 10oo]
			ROR.W	#8,D1					;  [o432 10oo oooo o765]
			ORI.B	#$B8,D1					;  [o432 10oo ioii i765]

			BSR5	RTCClkNoMem				; read the PRAM byte

			ANDI.W	#$00FF,D1				; zero-extend the byte
			JMP		(A3)


;________________________________________________________________________________________
;
; Routine:	RTCWrXByte
;
; Inputs:	D1	-	address of PRAM byte to write
;			D2	-	byte to write to PRAM
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	none
;
; Trashes:	D0,D1,D2,A5,A6
;
; Function:	writes a byte to RTC-based PRAM without using RAM
;________________________________________________________________________________________

RTCWrXByte	SWAP	D1						; copy the byte to write
			MOVE.B	D2,D1					;  to the upper word of D1
			SWAP	D1

			ANDI.W	#$00FF,D1				;  [oooo oooo 7654 3210]
			ASL.W	#3,D1					;  [oooo o765 4321 0ooo]
			ROR.B	#1,D1					;  [oooo o765 o432 10oo]
			ROR.W	#8,D1					;  [o432 10oo oooo o765]
			ORI.B	#$38,D1					;  [o432 10oo ooii i765]

			MOVEA.L	A3,A5					; (fake out the return address)
			BRA.S	RTCClkNoMem				; write the PRAM byte


;________________________________________________________________________________________
;
; Routine:	RTCInitHW
;
; Inputs:	A1	-	pointer to ProductInfo record for this machine
;			A6	-	return address (BSR6)
;
; Outputs:	none
;
; Trashes:	D0,D1,D2,A0,A2,A5,A6
;
; Function:	initializes the RTC by taking it out of test mode
;________________________________________________________________________________________

RTCInitHW	MOVEA.L	A6,A0					; save the return address
			MOVEA.L	A1,A2					; point to the decoder info
			ADDA.L	ProductInfo.DecoderInfoPtr(A2),A2
			MOVEA.L	DecoderInfo.VIA1Addr(A2),A2	; get VIA 1's base address							<H6>

			BSR5	RTCWrProtOff			; write-enable the clock chip

			MOVEQ	#(0<<16)+($31<<0),D1 	; write zero to test bit in clock chip
			BSR5	RTCClkNoMem

			MOVEA.L	A0,A5					; restore the return address


;________________________________________________________________________________________
;
; Routine:	RTCWrProtOn						[RTC utility routine]
;
; Inputs:	A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A5	-	return address (BSR5)
;
; Outputs:	none
;
; Trashes:	D0,D1,D2,A6
;
; Function:	write-protects RTC-based PRAM when we're done modifying it
;________________________________________________________________________________________

RTCWrProtOn	MOVE.L	#($D5<<16)+($35<<0),D1 	; use 'set write protect' command
			BRA.S	RTCClkNoMem				; write it to the clock chip


;________________________________________________________________________________________
;
; Routine:	RTCWrProtOff					[RTC utility routine]
;
; Inputs:	A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A5	-	return address (BSR5)
;
; Outputs:	none
;
; Trashes:	D0,D1,D2,A6
;
; Function:	write-enables RTC-based PRAM so we can write bytes to it
;________________________________________________________________________________________

RTCWrProtOff
			MOVE.L	#($55<<16)+($35<<0),D1 	; use 'reset write protect' command
*			BRA.S	RTCClkNoMem				; write it to the clock chip


;________________________________________________________________________________________
;
; Routine:	RTCClkNoMem						[RTC utility routine]
;
; Inputs:	D1	-	[x] [byte to write] [<extended command>] [command (bit 7: 1=read, 0=write)]
;			A2	-	VIA1 base address
;			A5	-	return address (BSR5)
;
; Outputs:	D1	-	data byte read
;
; Trashes:	D0,D1,D2,A6
;
; Function:	reads or writes one 8-bit clock register
;________________________________________________________________________________________

RTCClkNoMem	MOVE	SR,D2					; save the SR
			ORI		#HiIntMask,SR			;  and disable interrupts
			SWAP	D2

			MOVE.B	D1,D2					; save a copy of the command

			BCLR	#vRTCEnb,vBufB(A2)		; enable the clock

			MOVEQ	#$78,D0					; mask off the code bits
			AND.B	D1,D0
			CMPI.B	#$38,D0					; is this an extended command?
			BNE.S	@NotExtended			; -> nope

			BSR6	SendToClk				; send the first command byte
			LSR.W	#8,D1					; move the second command byte into position

@NotExtended
			TST.B	D2						; is this a read or write command?
			BMI.S	@ItsRead				; -> read

			BSR6	SendToClk				; send the command byte
			SWAP	D1						; get the data byte
			BSR6	SendToClk				;  and send it
			BRA.S	@Done

@ItsRead	BSR6	SendToClk				; send the command byte
			BSR6	ReadFrClk				;  and read the data byte

@Done		BSET	#vRTCEnb,vBufB(A2)		; disable the clock
			SWAP	D2
			MOVE	D2,SR					; re-enable interrupts
			RTS5


;________________________________________________________________________________________
;
; Routine:	SendToClk						[RTC utility routine]
;
; Inputs:	D1	-	command/data byte to write to RTC
;			A2	-	VIA1 base address
;			A6	-	return address (BSR6)
;
; Outputs:	none
;
; Trashes:	D0,D1
;
; Function:	writes a command or data byte to the RTC (assumes interrupts masked to $2700)
;________________________________________________________________________________________

SendToClk	MOVEQ	#8-1,D0					; shifting out 8 bits
	
@ShiftLoop	SWAP	D0						; save the count
			MOVE.B	vBufB(A2),D0			; get the VIA register's contents
			ROR.B	#1,D0					; shift the bits to position the RTC data bit (bit 0)
			ADDX.B	D1,D1					; shift the next data bit into the extend bit
			ADDX.B	D0,D0					; shift the data bit from the extend bit to the RTC data bit
			MOVE.B	D0,VBufB(A2)			; stuff it back into the VIA register
			BCLR	#vRTCClk,vBufB(A2)		;  and clock the bit out
			BSET	#vRTCClk,vBufB(A2)
			SWAP	D0						; get the bit counter back
			DBRA	D0,@ShiftLoop			; -> keep looping until all bits are shifted out
			RTS6


;________________________________________________________________________________________
;
; Routine:	ReadFrClk						[RTC utility routine]
;
; Inputs:	A2	-	VIA1 base address
;			A6	-	return address (BSR6)
;
; Outputs:	D1	-	data byte read from RTC
;
; Trashes:	D0
;
; Function:	reads a data byte from the RTC (assumes interrupts masked to $2700)
;________________________________________________________________________________________

ReadFrClk	BCLR	#vRTCData,vDirB(A2)   	; set the RTC data bit's direction to input
			MOVEQ	#1,D1					; initialize the result with a flag bit

@ShiftLoop	BCLR	#vRTCClk,vBufB(A2)		; clock the next bit in
			BSET	#vRTCClk,vBufB(A2)
			MOVE.B	vBufB(A2),D0			; read the register
			LSR.B	#vRTCData+1,D0			; shift the RTC data bit into the carry/X
			ADDX.B	D1,D1					; shift in the new bit towards the msb
			BCC.S	@ShiftLoop				; -> keep looping until the flag bit shifts out

			BSET	#vRTCData,vDirB(A2)   	; restore the RTC data bit's direction to output
			RTS6


		ENDIF								; {hasVIAClock}



		IF hasPwrControls THEN
;••••••••••••••••••••••••••••••••••••• Power Manager ••••••••••••••••••••••••••••••••••••
			WITH	PMCommandRec

			IMPORT	USTPmgrSendCommand, USTPMgrSendByte, USTPMGRRecvByte

;________________________________________________________________________________________
;
; Routine:	PMGRReadTime
;
; Inputs:	none
;
; Outputs:	D0	-	result code
;			"GetParam" contains the 32-bit time value read from the clock
;
; Trashes:	A0
;
; Function:	reads the time from the realtime clock
;________________________________________________________________________________________

PMGRReadTime
			PEA		GetParam				;  pmRBuffer
			MOVE.L	(SP),-(SP)				;  pmSBuffer (not used)
			CLR.W	-(SP)					;  pmLength = 0
			MOVE.W	#TimeRead,-(SP)			;  pmCommand = read time
			MOVE.L	SP,A0					; point to the parameter block
			_PmgrOp							; read the time
			LEA		pmRBuffer+4(SP),SP		; clean up the stack
			RTS


;________________________________________________________________________________________
;
; Routine:	PMGRWriteTime
;
; Inputs:	"Time" contains 32-bit quantity to write to clock
;
; Outputs:	D0	-	result code
;
; Trashes:	A0
;
; Function:	writes a new time value to the realtime clock
;________________________________________________________________________________________

PMGRWriteTime
			PEA		Time					;  pmRBuffer (not used)
			MOVE.L	(SP),-(SP)				;  pmSBuffer
			MOVE.W	#4,-(SP)				;  pmLength = 4 bytes of time
			MOVE.W	#TimeWrite,-(SP)		;  pmCommand = write time
			MOVE.L	SP,A0					; point to the parameter block
			_PmgrOp							; read the time
			LEA		pmRBuffer+4(SP),SP		; clean up the stack
			RTS


;________________________________________________________________________________________
;
; Routine:	PMGRXParam
;
; Inputs:	A0	-	pointer to user's buffer
;			D0	-	[number of bytes to transfer][starting PRAM address]
;			D1	-	bit 12: 1=read, 0=write
;
; Outputs:	D0	-	result code
;
; Trashes:	A0,A1,A2,D1,D2,D3
;
; Function:	reads/writes byte[s] from PMGR-based parameter RAM
;________________________________________________________________________________________

PMGRXParam	MOVEA.L	SP,A2					; point to the current top of stack
			MOVE.L	D0,D2					; 
			SWAP	D2						; D2.L=[starting PRAM address][count]
			ADDQ.W	#2+1,D2					; make space on the stack for a buffer and 2 parameter bytes
			BCLR	#0,D2					;  and round up to the next word
			SUBA.W	D2,SP
			MOVEA.L	SP,A1

			MOVE.L	A0,-(SP)				;  pmRBuffer
			MOVE.L	A1,-(SP)				;  pmSBuffer

			MOVE.B	D0,(A1)+				; put the PRAM address
			SWAP	D0
			MOVE.B	D0,(A1)+				;  and count at the start of the send buffer

			MOVEQ	#xPramRead,D3			; assume it's a read
			MOVEQ	#2,D2					; 
			BTST	#12,D1					; is this a write command?
			BNE.S	@NoWrBuffer				; -> no
			MOVEQ	#xPramWrite,D3
			ADD.W	D0,D2					; adjust the count to include the bytes to be written
			BRA.S	@StartCopy
@CopyLoop	MOVE.B	(A0)+,(A1)+				; copy the write buffer into the stack buffer
@StartCopy	DBRA	D0,@CopyLoop

@NoWrBuffer	MOVE.W	D2,-(SP)				;  pmLength
			MOVE.W	D3,-(SP)				;  pmCommand
			MOVEA.L	SP,A0
			_PMgrOp							; have the PMGR read/write PRAM

			MOVEA.L	A2,SP					; restore the stack pointer
			RTS


;________________________________________________________________________________________
;
; Routine:	PMGRWrXByte
;
; Inputs:	D1	-	address of PRAM byte to write
;			D2	-	byte to write to PRAM
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	none
;
; Trashes:	A0,A3,A4,A5,A6,D0,D1,D2
;
; Function:	writes a byte to PMGR-based PRAM without using RAM
;________________________________________________________________________________________

PMGRWrXByte	MOVEA.L	A3,A4					; save the return address

			EXG		D3,D1					; save D3 in D1, put PRAM address in the upper word of D3
			SWAP	D3
			EXG		D4,D2					; save D4 in D2, put data byte in the upper word of D4
			SWAP	D4
			MOVE.L	D6,D0					; save D6

			MOVE.W	#(xPramWrite<<0)|\		; pmCommand
					 (-1<<8),D3				; pmLength = -1 (just send command byte)

			MOVEA.L	A1,A0					; point to the decoder table
			ADDA.L	ProductInfo.DecoderInfoPtr(A0),A0
			BigBSR6	USTPmgrSendCommand,A5	; send the command to the PMGR
			BNE.S	@PMgrDone				; -> error

			MOVE.B	#3,D3					; send pmLength = 3 (address, count, data)
			BigBSR5	USTPMgrSendByte,A6
			BNE.S	@PMgrDone				; -> error

			SWAP	D3						; send the PRAM address
			BigBSR5	USTPMgrSendByte,A6
			BNE.S	@PMgrDone				; -> error

			MOVEQ	#1,D3					; send the PRAM byte count
			BigBSR5	USTPMgrSendByte,A6
			BNE.S	@PMgrDone				; -> error

			MOVE.L	D4,D3					; send the PRAM data byte
			SWAP	D3
			BigBSR5	USTPMgrSendByte,A6

@PMgrDone	MOVE.L	D1,D3					; restore registers
			MOVE.L	D2,D4
			MOVE.L	D0,D6
			JMP		(A4)


;________________________________________________________________________________________
;
; Routine:	PMGRRdXByte
;
; Inputs:	D1	-	address of PRAM byte to read
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	D1	-	byte read from PRAM
;
; Trashes:	A0,A3,A4,A5,A6,D0,D2
;
; Function:	reads a byte from PMGR-based PRAM without using RAM
;________________________________________________________________________________________

PMGRRdXByte	MOVEA.L	A3,A4					; save the return address

			EXG		D3,D1					; save D3 in D1, put command/data bytes in D3
			MOVE.L	D4,D0					; save other registers
			MOVE.L	D6,D2

			ANDI.L	#$000000FF,D3			; mask the PRAM address and build the command:
			ORI.L	#(xPramRead<<16)|\		;  pmCommand
					 (2<<24)|\				;  pmLength
					 (1<<8),D3				;  count = 1 byte
			SWAP	D3						; D1.L=[count][addr][pmLength][pmCommand]

			MOVEA.L	A1,A0					; point to the decoder table
			ADDA.L	ProductInfo.DecoderInfoPtr(A0),A0
			BigBSR6	USTPmgrSendCommand,A5	; send the command to the PMGR
			BNE.S	@PMgrError				; -> error

			BigBSR5	USTPMGRRecvByte,A6		; read a byte back
			BNE.S	@PMgrError				; -> error
			CMPI.B	#xPramRead,D3			; is it the reply byte?
			BNE.S	@NoReplyByte			; -> no, new protocol

			BigBSR5	USTPMGRRecvByte,A6		; read the count byte
			BNE.S	@PMgrError				; -> error
@NoReplyByte
			BigBSR5	USTPMGRRecvByte,A6		; read the PRAM byte
			BEQ.S	@PMgrDone				; -> got it

@PMgrError	MOVEQ	#0,D3					; return a zero if an error occurs
@PMgrDone	EXG		D1,D3					; restore D3, return PRAM byte in D1
			MOVE.L	D0,D4					; restore other registers
			MOVE.L	D2,D6

			TST.B	D1						; set up the CCR if anybody cares
			JMP		(A4)


			ENDWITH							; {PMgrRec}
		ENDIF								; {hasPwrControls}



		IF hasEgret THEN
;••••••••••••••••••••••••••••••••••••••••• Egret ••••••••••••••••••••••••••••••••••••••••
			WITH	EgretPB

;________________________________________________________________________________________
;
; Routine:	EgretReadTime
;
;	The one second interrupt handler for Egret/Caboose/Cuda maintains the lowmem global		<sm10>
;	'Time' in a self correcting manner.  This routine need only return the lowmem 'Time'.
;	A call to _EgretDispatch will cause the AutoPoll timer within Egret/Caboose/Cuda to
;	reset, resulting in deferring ADB auto polling.  If an application calls ReadTime
;	in a tight loop, ADB polling could be deferred indefinitely (making the mouse/keyboard
;	appear to hang or respond intermittently).  Since 'Time' is self correcting, the
;	routine just returns 'Time' as the result placed into 'GetParam'.
;
; Inputs:	none
;
; Outputs:	D0	-	result code
;			"GetParam" contains the 32-bit time value read from the clock
;
; Trashes:	A0
;
; Function:	reads the time from the realtime clock
;________________________________________________________________________________________

EgretReadTime
			clr.l	d0						; result code = noErr					<sm10>
			move.l	Time,GetParam			; return current time					<sm10>
;			CLR.L	-(SP)					;  pbCompletion = nil					<sm12>
;			LEA		pbCmdType-pbCompletion(SP),SP ; 								<sm12>
;			MOVE.W	#(pseudopkt<<8)+\		;  pbCmdType = pseudo type				<sm12>
;					 (RdTime<<0),(SP)		;  pbCmd = read time					<sm12>
;			MOVEA.L	SP,A0					; point to the parameter block			<sm12>
;			_EgretDispatch					; call Egret to read the time			<sm12>
;			MOVE.L	pbParam(A0),GetParam	; move the time into a temporary buffer	<sm12>
;			LEA		EgretPBSize(SP),SP		; clean up the stack					<sm12>

			RTS


;________________________________________________________________________________________
;
; Routine:	EgretWriteTime
;
; Inputs:	"Time" contains 32-bit quantity to write to clock
;
; Outputs:	D0	-	result code
;
; Trashes:	A0
;
; Function:	writes a new time value to the realtime clock
;________________________________________________________________________________________

EgretWriteTime
			CLR.L	-(SP)					;  pbCompletion = nil
			LEA		pbParam-pbCompletion(SP),SP
			MOVE.L	Time,(SP)				;  pbParam = current time

			MOVE.W	#(pseudopkt<<8)+\		;  pbCmdType = pseudo type
					+(WrTime<<0),-(SP)		;  pbCmd = write time
			MOVEA.L	SP,A0					; point to the parameter block
			_EgretDispatch					; call Egret to read the time
			LEA		EgretPBSize(SP),SP		; clean up the stack
			RTS


;________________________________________________________________________________________
;
; Routine:	EgretXParam
;
; Inputs:	A0	-	pointer to user's buffer
;			D0	-	[number of bytes to transfer][starting PRAM address]
;			D1	-	bit 12: 1=read, 0=write
;
; Outputs:	D0	-	result code
;
; Trashes:	A0
;
; Function:	reads/writes byte[s] from Egret-based parameter RAM
;________________________________________________________________________________________

EgretXParam	CLR.L	-(SP)					;  pbCompletion = nil
			SUBQ.W	#pbCompletion-pbBufPtr,SP
			MOVE.L	A0,(SP)					;  pbBufPtr = pointer to user's buffer
			SWAP	D0
			MOVE.W	D0,-(SP)				;  pbByteCnt = number of PRAM bytes to read/write
			SUBQ.W	#pbByteCnt-pbParam,SP
			SWAP	D0
			ADDI.W	#$0100,D0				;• convert PRAM address to 6805 address (temporary?)
			MOVE.W	D0,(SP)					;  pbParam = starting PRAM address
			MOVE.W	#(pseudopkt<<8)+\		;  pbCmdType = pseudo type
					 (Rd6805Addr<<0),-(SP)	;  pbCmd = read PRAM
			BTST	#12,D1					; is this a write command?
			BNE.S	@NotWrite				; -> no
			MOVE.W	#(pseudopkt<<8)+\		;  pbCmdType = pseudo type
					 (Wr6805Addr<<0),(SP)	;  pbCmd = write PRAM
@NotWrite	MOVEA.L	SP,A0					; point to the parameter block
			_EgretDispatch					; call Egret to read/write PRAM
			LEA		EgretPBSize(SP),SP		; clean up the stack
			RTS


;________________________________________________________________________________________
;
; Routine:	EgretWrXByte
;
; Inputs:	D1	-	address of PRAM byte to write
;			D2	-	byte to write to PRAM
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	none
;
; Trashes:	D0,D1,D2,A5,A6
;
; Function:	writes a byte to Egret-based PRAM without using RAM
;________________________________________________________________________________________

EgretWrXByte
			SWAP	D1
			MOVE.B	D2,D1					; save the byte to send
			SWAP	D1
			BSET	#15,D1					; mark this as a write
			;  fall into EgretRdXByte

;________________________________________________________________________________________
;
; Routine:	EgretRdXByte
;
; Inputs:	D1	-	address of PRAM byte to read
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	D1	-	byte read from PRAM
;
; Trashes:	D0,D2,A5,A6
;
; Function:	reads a byte from Egret-based PRAM without using RAM
;________________________________________________________________________________________

EgretRdXByte
			BCLR	#vSysSesbit,vBufB(A2)	; pending transaction?
			BEQ.S	@NotPending				; -> no
			BSR5	EgretDelay				; wait a bit
			BCLR	#vViaFullBit,vBufB(A2)	; de-assert VIA full
			BSR5	EgretDelay				; wait some more
			BRA.S	@NotPending

@Abort		BSR6	EgretReadByte			; too many bytes being returned so
			BEQ.S	@Abort					;  keep throwing them out until there are no more,
			BRA.S	@Reset					; then start over

@DisposePacket
			BSR5	EgretDelay				; wait for the interrupt to occur
			TST.B	vSR(A2)					;  then read the ATTN byte to clear the interrupt

@Reset		BCLR	#vSysSesbit,vBufB(A2)	; turn off SYS session
			BCLR	#vViaFullBit,vBufB(A2)	;  and de-assert VIA full
			BCLR	#SRdir,vACR(A2)			; define shift direction = FROM Egret
			BSR5	EgretDelay				; wait
			BRA.S	@CheckXCVR

@ThrowAway	BSET	#vSysSesbit,vBufB(A2)	; set SYS session
			BSR6	EgretReadByte			; read a byte to throw away
@CheckXCVR	BTST	#vXcvrSesBit,vBufB(A2)	; is XCVR session asserted (active low)?
			BEQ.S	@ThrowAway				; -> yes, throw away the byte
			BSR5	EgretDelay				; wait

@NotPending	ORI.B	#ACRMode++(1<<SRdir),vACR(A2)	; set VIA shift register to shift out with external clock
			BTST	#vXcvrSesBit,vBufB(A2)	; is XCVR session asserted (active low)?
			BEQ.S	@DisposePacket			; -> yes, dispose of the packet

			BSET	#vSysSesbit,vBufB(A2)	; assert sys session signal
			MOVEQ	#pseudopkt,D0			; packet type
			BSR6	EgretSendByte
			BMI.S	@Reset					; -> Egret's hung, so try to reset

			BTST	#vXcvrSesBit,vBufB(A2)	; is XCVR session asserted (active low)?
			BEQ.S	@Reset					; -> yes, throw out the packet

			MOVEQ	#rdPram,D0				; assume we're doing a read
			TST.W	D1						; are we?
			BPL.S	@SendCmd
			MOVEQ	#wrPram,D0				; no, we're writing
@SendCmd	BSR6	EgretSendByte			; send the command byte
			MOVEQ	#0,D0
			BSR6	EgretSendByte			; send the MSB of the PRAM address
			MOVE.B	D1,D0
			BSR6	EgretSendByte			; send the LSB of the PRAM address
			TST.W	D1						; are we writing?
			BPL.S	@SendDone
			MOVE.L	D1,D0					; yes, get the data byte
			SWAP	D0
			BSR6	EgretSendByte			;  and send it

@SendDone	BCLR	#SRdir,vACR(A2)			; define shift direction = FROM Egret
			BCLR	#vSysSesbit,vBufB(A2)	; turn off SYS session

@WaitForIRQ	BTST	#ifSR,vIFR(A2)			; wait for shift to complete
			BEQ.S	@WaitForIRQ
			BTST	#vXcvrSesBit,vBufB(A2)	; is XCVR session asserted (active low)?
			BNE.S	@WaitForIRQ				; -> no, keep polling until it is

			TST.B	vSR(A2)					; read the ATTN byte to clear the interrupt
			BSR5	EgretDelay				; wait
			BSET	#vSysSesbit,vBufB(A2)	; assert sys session again

			BSR6	EgretReadByte			; read the response packet type
			BNE.S	@Reset					; -> XCVR session turned off early, so try again

			BSR6	EgretReadByte			; read the response packet flag
			BNE.S	@Reset					; -> XCVR session turned off early, so try again

			TST.W	D1						; is this a read or write?
			BPL.S	@FinishRead				; -> read

			BSR6	EgretReadByte			; read the "command was" byte
			BEQ.S	@Abort					; -> XCVR session is still on, so try again
			CMPI.B	#wrPram,D0				; is this the correct packet?
			BNE.S	@Reset					; -> no, try again

			BCLR	#vSysSesbit,vBufB(A2)	; turn off SYS session
			BCLR	#vViaFullBit,vBufB(A2)	;  and de-assert VIA full
			BSR5	EgretDelay				; delay to let Egret see the lines change state
			JMP		(A3)


@FinishRead	BSR6	EgretReadByte			; read the "command was" byte
			BNE.S	@Reset					; -> XCVR session turned off early, so try again
			SUBQ.B	#rdPram,D0				; is this the correct packet?
			BNE.S	@Reset					; -> no, try again

			BSR6	EgretReadByte			; read the PRAM data byte
			BCLR	#vSysSesbit,vBufB(A2)	; turn off SYS session

@Wait4XCVR	BTST	#vXcvrSesBit,vBufB(A2)	; wait for XCVR session to turn off
			BEQ.S	@Wait4XCVR
			BCLR	#vViaFullBit,vBufB(A2)	; de-assert VIA full

			BSR5	EgretDelay				; delay to let Egret see the lines change state
			MOVE.B	D0,D1					; return the byte in D1
			JMP		(A3)


;________________________________________________________________________________________
;
; Routine:	EgretSendByte					[Egret utility routine]
;
; Inputs:	D0	-	byte to send to Egret
;			A2	-	VIA1 base address
;			A6	-	return address (BSR6)
;
; Outputs:	none
;
; Trashes:	D2,A5
;
; Function:	sends a byte to Egret
;________________________________________________________________________________________

EgretSendByte
			MOVEA.L	A6,A5					; save the return address
			MOVE.B	D0,vSR(A2)				; load byte into shift register
			BSET	#vViaFullBit,vBufB(A2)	; indicate shift register is full
			MOVE.W	#32767,D0				; set a 42msec timeout
@Wait4Shift	BTST	#ifSR,vIFR(A2)			; wait for shift to complete
			DBNE	D0,@Wait4Shift
			BEQ.S	EgretSendTO				; -> timed out
			TST.B	vSR(A2)					; clear the interrupt
			BCLR	#vViaFullBit,vBufB(A2)	; then negate VIA full bit

;  delay a bit so Egret can keep up...

EgretDelay	MOVEQ	#104,D2					; delay 125µs minimum (we actually delay 134µsec)
@wait		TST.B	(A2)					; sync to VIA clock (about 1.28µsec/access)
			DBRA	D2,@wait				; delay at least 100 us (very rough)
EgretSendTO	TST.W	D0						; set CCR: BMI if send timeout, BPL if OK
			RTS5


;________________________________________________________________________________________
;
; Routine:	EgretReadByte					[Egret utility routine]
;
; Inputs:	A2	-	VIA1 base address
;			A6	-	return address (BSR6)
;
; Outputs:	D0	-	byte read
;
; Trashes:	D2,A5
;
; Function:	reads a byte from Egret
;________________________________________________________________________________________

EgretReadByte
			BCLR	#vViaFullBit,vBufB(A2)	; de-assert VIA full
@Wait4Shift	BTST	#ifSR,vIFR(A2)			; wait for shift to complete
			BEQ.S	@Wait4Shift
			BSET	#vViaFullBit,vBufB(A2)	; acknowlege byte
			MOVE.B	vSR(A2),D0				; read the byte
			BSR5	EgretDelay				; give Egret time to see it
			BTST	#vXcvrSesBit,vBufB(A2)	; return with the state of XCVR session
			RTS6


;________________________________________________________________________________________
;
; Routine:	CudaRdXByte
;
; Inputs:	D1	-	address of PRAM byte to read
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	D1	-	byte read from PRAM
;
; Trashes:	D0,D2,A5,A6
;
; Function:	reads a byte from Egret-based PRAM without using RAM
;
;			This routine can only be executed after a SyncAck cycle.  The SyncAck cycle,
;			which is executed immediately after InitVia will disable all asynchronous
;			message sources within Cuda.  This allows the following routine to be written
;			without regard to detecting collisions between command packets and response
;			packets.  AT NO TIME SHOULD AN ASYNCHRONOUS MESSAGE SOURCE BE ENABLED PRIOR
;			TO USE OF THIS ROUTINE.  ASYNCHRONOUS MESSAGE SOURCES SHOULD ONLY BE ENABLED
;			AFTER THE CUDA MANAGER HAS BEEN INSTALLED.
;________________________________________________________________________________________

CudaRdXByte	cmp.l	#$8000,sp						; is there any stack yet?
			ble.s	@5								; no, use register based
			cmp.w	#0,EgretBase
			bne.s	@5
			movec	VBR,d2							; get the contents of VBR
			tst.l	d2								; check for zero
			bne.s	@5

;	This code allows the low level routines to be used after the Cuda manager is installed
;	by constructing a parameter block on the stack and issuing a call to CudaDispatch.  This
;	is absolutely necessary because the low level routines do not detect collisions which can
;	occur once the Cuda manager is installed.  Further, it is almost impossible to determine
;	how to to synchronize Cuda after an asynchronous re-boot has occurred.

			movem.l	a0-a6/d0/d2-d7,-(sp)
			suba.l	#EgretPBSize,sp					; make room on the stack for Cuda parameter block
			move.b	#pseudoPkt,pbCmdType(sp)		; set packet type
			move.b	#RdPram,pbCmd(sp)				; set packet command
			move.w	d1,pbParam(sp)					; set pram address
			move.w	#1,pbByteCnt(sp)				; 1 byte to send
			move.l	sp,pbBufPtr(sp)
			add.l	#pbParam+2,pbBufPtr(sp)			; point to our data buffer
			move.b	#0,pbFlags(sp)
			move.w	#0,pbResult(sp)
			move.l	#0,pbCompletion(sp)				; execute synchronously
			move.l	sp,a0							; parameter block in a0
			_EgretDispatch							; (this is actually the Cuda A-Trap)
			move.w	pbParam+2(sp),d1				; get pram data
			adda.l	#EgretPBSize,sp					; remove parameter block from stack
			movem.l	(sp)+,a0-a6/d0/d2-d7
			jmp 	(a3)

;
;	The following code is executed only when the Cuda manager is not installed.
;	AT NO TIME SHOULD AN ASYNCHRONOUS MESSAGE SOURCE BE ENABLED PRIOR TO USE OF THIS ROUTINE.
;	ASYNCHRONOUS MESSAGE SOURCES SHOULD ONLY BE ENABLED AFTER THE CUDA MANAGER HAS BEEN INSTALLED.
;
@5
			ori.b	#ACRmode,vacr(a2)				; else initialize via mode
			bset.b	#SRdir,vACR(a2)					; set output mode
			move.b	#pseudopkt,vSR(a2)				; send packet type & clear any pending shift irq
			bclr.b	#TIP,vBufB(a2)					; start the transaction
@10 			
			btst.b	#ifSR,vIFR(a2)					; Wait for shift register IRQ to indicate byte was read
			beq.s	@10
			
;________________________________________________________________________________________________
;	When outputing from the VIA to Cuda, the interrupt will occur prior to the rising edge
;	of CB1.  Delay long enough for the edge to occur before acknowledging the shift
;	register interrupt.	(R. Montagne	1/11/93)
;________________________________________________________________________________________________
			moveq	#10,d2							; delay for 10µS min.							<LW3><VIA rbm>
@m7dly												;												<LW3><VIA rbm>
			tst.b	vBufB(a1)						; hardware access is 1.2µS						<LW3><VIA rbm>
			sub.b	#1,d2							; can only trash low byte						<LW3><VIA rbm>
			bne.s	@m7dly							; wait long enough for CB1 to rise (10µS delay)	<LW3><VIA rbm>
			tst.b	vSR(a2) 						; Clear the shift register IRQ

			moveq	#rdpram,d2						; Send the command byte
			BSR6	CudaWriteByte
			move.l	d1,d2
			lsr.l	#8,d2							; Send PRAM address MSB
			BSR6	CudaWriteByte
			move.l	d1,d2							; Send PRAM address LSB
			BSR6	CudaWriteByte

			bclr.b	#SRdir,vACR(a2)					; Define direction FROM Cuda
			btst.b	#SRdir,vACR(a2)
@69up
			bne.s	@69up
			
			ori.b	#((1<<vCudaTIP)|\
				(1<<vCudaByteAck)),vBufB(a2)		; terminate current command transaction
@Wait4Attn
			btst.b	#ifSR,vIFR(a2)					; Wait for attention IRQ
			beq.s	@Wait4Attn
			tst.b	vSR(a2)							; Read attn byte from VIA (clears IRQ)
			
			bclr.b	#vCudaTIP,vBufB(a2)				; assert TIP to begin response transaction
	
			BSR6	CudaReadByte					; Read a byte - response packet type
			BSR6	CudaReadByte					; next byte - response packet flag
			BSR6	CudaReadByte					; next byte - "cmd was" byte
			BSR6	CudaReadByte					; finally!	PRAM data in d2
			
			ori.b	#((1<<vCudaTIP)|\
				(1<<vCudaByteAck)),vBufB(a2)		; terminate current response transaction
@Wait4CudaDone
			btst.b	#vCudaTReq,vBufB(a2)			; Wait for TReq to negate
			beq.s	@Wait4CudaDone
@Wait4IdleIRQ 		
			btst.b	#ifSR,vIFR(a2)					; Wait for idle state IRQ
			beq.s	@Wait4IdleIRQ
			tst.b	vSR(a2) 						; Read idle state byte (clears IRQ)
			move.l	d2,d1							; return data in d1
			jmp 	(a3)							; return to caller


;________________________________________________________________________________________
;
; Routine:	CudaWrXByte
;
; Inputs:	D1	-	address of PRAM byte to write
;			D2	-	byte to write to PRAM
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	none
;
; Trashes:	D0,D1,D2,A5,A6
;
; Function:	writes a byte to Egret-based PRAM without using RAM
;
;			This routine can only be executed after a SyncAck cycle.  The SyncAck cycle,
;			which is executed immediately after InitVia will disable all asynchronous
;			message sources within Cuda.  This allows the following routine to be written
;			without regard to detecting collisions between command packets and response
;			packets.  AT NO TIME SHOULD AN ASYNCHRONOUS MESSAGE SOURCE BE ENABLED PRIOR
;			TO USE OF THIS ROUTINE.  ASYNCHRONOUS MESSAGE SOURCES SHOULD ONLY BE ENABLED
;			AFTER THE CUDA MANAGER HAS BEEN INSTALLED.
;________________________________________________________________________________________

CudaWrXByte	cmp.l	#$8000,sp						; is there any stack yet?							<SM5>(rbm)<2> begin {
			ble.s	@5								; no, use register based
			cmp.w	#0,EgretBase
			bne.s	@5
			movec	vbr,d5							; get a copy of VBR
			tst.l	d5								; is it zero?
			bne.s	@5

;	This code allows the low level routines to be used after the Cuda manager is installed
;	by constructing a parameter block on the stack and issuing a call to CudaDispatch.  This
;	is absolutely necessary because the low level routines do not detect collisions which can
;	occur once the Cuda manager is installed.  Further, it is almost impossible to determine
;	how to to synchronize Cuda after an asynchronous re-boot has occurred.

			movem.l	a0-a6/d0/d3-d7,-(sp)
			suba.l	#EgretPBSize,sp					; make room on the stack for Cuda parameter block
			move.b	#pseudoPkt,pbCmdType(sp)		; set packet type
			move.b	#WrPram,pbCmd(sp)				; set packet command
			move.w	d1,pbParam(sp)					; set pram address
			move.w	d2,pbParam+2(sp)				; set pram data
			move.w	#1,pbByteCnt(sp)				; 1 byte to send
			move.l	sp,pbBufPtr(sp)
			add.l	#pbParam+2,pbBufPtr(sp)			; point to our data buffer
			move.b	#0,pbFlags(sp)
			move.w	#0,pbResult(sp)
			move.l	#0,pbCompletion(sp)				; execute synchronously
			move.l	sp,a0							; parameter block in a0
			_EgretDispatch							; (this is actually the Cuda A-Trap)
			adda.l	#EgretPBSize,sp					; remove parameter block from stack
			movem.l	(sp)+,a0-a6/d0/d3-d7
			jmp 	(a3)

;	The following code is executed only when the Cuda manager is not installed.
;	AT NO TIME SHOULD AN ASYNCHRONOUS MESSAGE SOURCE BE ENABLED PRIOR TO USE OF THIS ROUTINE.
;	ASYNCHRONOUS MESSAGE SOURCES SHOULD ONLY BE ENABLED AFTER THE CUDA MANAGER HAS BEEN INSTALLED.

@5			move.l	d2,d5							; Save the write data

			ori.b	#ACRmode,vacr(a2)				; else initialize via mode
			bset.b	#SRdir,vACR(a2)					; set output mode
			move.b	#pseudopkt,vSR(a2)				; send packet type & clear any pending shift irq
			bclr.b	#TIP,vBufB(a2)					; start the transaction
@10 			
			btst.b	#ifSR,vIFR(a2)					; Wait for shift register IRQ to indicate byte was read
			beq.s	@10
;________________________________________________________________________________________________
;	When outputing from the VIA to Cuda, the interrupt will occur prior to the rising edge
;	of CB1.  Delay long enough for the edge to occur before acknowledging the shift
;	register interrupt.	(R. Montagne	1/11/93)
;________________________________________________________________________________________________
			move.b	#10,d2							; mode 7 interrupt occurs at falling edge CB1	<LW3><VIA rbm>
@m7dly												;												<LW3><VIA rbm>
			tst.b	vBufB(a1)						; hardware access is 1.2µS						<LW3><VIA rbm>
			sub.b	#1,d2							; can only trash low byte						<LW3><VIA rbm>
			bne.s	@m7dly							; wait long enough for CB1 to rise (10µS delay)	<LW3><VIA rbm>
			tst.b	vSR(a2) 						; Clear the shift register IRQ

	 		moveq	#wrpram,d2						; Send the command byte
			BSR6	CudaWriteByte
			move.l	d1,d2
			lsr.l	#8,d2							; Send PRAM address MSB
			BSR6	CudaWriteByte
			move.l	d1,d2							; Send PRAM address LSB
			BSR6	CudaWriteByte
			move.l	d5,d2							; Send the write data
			BSR6	CudaWriteByte
	
			bclr.b	#SRdir,vACR(a2)					; Define direction FROM Cuda
			
			ori.b	#((1<<vCudaTIP)|\
					(1<<vCudaByteAck)),vBufB(a2)	; terminate current transaction
			
@40 		btst.b	#ifSR,vIFR(a2)					; Wait for attention byte shift register IRQ
			beq.s	@40
	
			btst.b	#vCudaTReq,vBufB(a2)			; Is TReq asserted? (active low)
			bne.s	@40 							; continue polling if TReq is not asserted
			
			tst.b	vSR(a2) 						; Read attn byte from VIA (clears IRQ)
			bclr.b	#vCudaTIP,vBufB(a2)				; assert TIP to begin response transaction
@20 			
			btst.b	#ifSR,vIFR(a2)					; Wait for shift register IRQ to indicate byte was read
			beq.s	@20
			tst.b	vSR(a2) 						; Clear the shift register IRQ

			ori.b	#((1<<vCudaTIP)|\
					(1<<vCudaByteAck)),vBufB(a2)	; terminate the response transaction
			
@41 		btst.b	#ifSR,vIFR(a2)					; Wait for idle state IRQ
			beq.s	@41
			tst.b	vSR(a2) 						; Read idle state byte (clears IRQ)
			jmp 	(a3)
			
;---------------------------------------------------------------------------

			EXPORT	CudaWriteByte
CudaWriteByte
			move.b	d2,vSR(a2)					; Put data in VIA data reg
			eori.b	#1<<vCudaByteAck,vBufB(a2)	; indicate data moved into VIA
@10 			
			btst.b	#ifSR,vIFR(a2)				; Wait for shift register IRQ to indicate byte was read
			beq.s	@10
;________________________________________________________________________________________________
;	When outputing from the VIA to Cuda, the interrupt will occur prior to the rising edge
;	of CB1.  Delay long enough for the edge to occur before acknowledging the shift
;	register interrupt.	(R. Montagne	1/11/93)
;________________________________________________________________________________________________
			move.b	#10,d2						; mode 7 interrupt occurs at falling edge CB1	<LW3><VIA rbm>
@m7dly											;												<LW3><VIA rbm>
			tst.b	vBufB(a1)					; hardware access is 1.2µS						<LW3><VIA rbm>
			sub.b	#1,d2						; can only trash low byte						<LW3><VIA rbm>
			bne.s	@m7dly						; wait long enough for CB1 to rise (10µS delay)	<LW3><VIA rbm>
			tst.b	vSR(a2) 					; Clear the shift register IRQ
			RTS6

;---------------------------------------------------------------------------

			EXPORT	CudaReadByte
CudaReadByte
			btst.b	#ifSR,vIFR(a2)				; Wait for IRQ
			beq.s	CudaReadByte
			move.b	vSR(a2),d2					; Read data from VIA (clears IRQ)
			and.w	#$00FF,d2					; isolate the byte
			eori.b	#1<<vCudaByteAck,vBufB(a2)	; handshake the byte
			btst.b	#vCudaTReq,vBufB(a2)		; Return with state of TReq Session				<SM5>(rbm)<2> end }
			RTS6


			ENDWITH							; {EgretPB}
		ENDIF								; {hasEgret}



		IF hasProtectedPRAM THEN
; •••••••••••••••••••••••• PRAM in VRAM, clock is someplace else ••••••••••••••••••••••••
			WITH	ProductInfo, VideoInfo

;________________________________________________________________________________________
;
; Routine:	NoPRAMReadTime
;
; Inputs:	none
;
; Outputs:	D0	-	result code
;			"GetParam" contains the 32-bit time value read from the clock
;
; Trashes:	TBD
;
; Function:	Would read the time from the clock if we knew what kind it was.  This routine
;			is provided as an aid to the person who has to code for this case.
;________________________________________________________________________________________

NoPRAMReadTime
			MOVEQ	#dsCoreErr,D0			; just die so we know something didn't happen
			_SysError
			MOVEQ	#clkRdErr,D0			;  and leave this as a clue to why
			RTS


;________________________________________________________________________________________
;
; Routine:	NoPRAMWriteTime
;
; Inputs:	"Time" contains 32-bit quantity to write to clock
;
; Outputs:	D0	-	result code
;
; Trashes:	TBD
;
; Function:	Would write the time to the clock if we knew what kind it was.  This routine
;			is provided as an aid to the person who has to code for this case.
;________________________________________________________________________________________

NoPRAMWriteTime
			MOVEQ	#dsCoreErr,D0			; just die so we know something didn't happen
			_SysError
			MOVEQ	#clkWrErr,D0			;  and leave this as a clue to why
			RTS


;________________________________________________________________________________________
;
; Routine:	NoPRAMXParam
;
; Inputs:	A0	-	pointer to user's buffer
;			D0	-	[number of bytes to transfer][starting PRAM address]
;			D1	-	bit 12: 1=read, 0=write
;
; Outputs:	D0	-	result code
;
; Trashes:	A0,A1,A2,D1,D2,D3
;
; Function:	reads/writes byte[s] from parameter RAM that hides in unused video RAM
;			(assumes that traps and the MMU are set up)
;________________________________________________________________________________________

NoPRAMXParam
			MOVEA.L	A0,A2					; save the pointer to the user's buffer,
			MOVE.L	D0,D3					;  and the starting PRAM address and count

			MOVEQ	#true32b,D0				; switch into 32-bit addressing mode
			_SwapMMUMode

			MOVEA.L	UnivInfoPtr,A1			; point to this machine's product info,
			ADDA.L	VideoInfoPtr(A1),A1		;  which leads to video info,
			MOVEA.L	VRAMPhysAddr(A1),A1		;   which leads to the base address of video,
			LEA		-256(A1),A1				;    which leads to PRAM in unused video memory
			ADD.W	D3,A1					; index into start of desired PRAM
			SWAP 	D3						; get the number of bytes to transfer
			BTST	#12,D1					; is it a write?
			BNE.S	@StartCopy				; -> no
			EXG		A1,A2					; yes, exchange source and destination pointers
			BRA.S	@StartCopy
			
@CopyPRAM	MOVE.B	(A1)+,(A2)+				; move the bytes
@StartCopy	DBRA	D3,@CopyPRAM

			_SwapMMUMode					; restore the addressing mode
			MOVEQ	#0,D0					; never an error
			RTS


;________________________________________________________________________________________
;
; Routine:	NoPRAMXPramIO
;
; Inputs:	A0 -- pointer to table of base addresses
;			A1 -- pointer to ProductInfo record for this machine
;			A3 -- pointer to PRAM I/O buffer
;			D1 -- flags indicating which external features are valid
;			D3 -- [r/w (bit 31)][number of PRAM bytes to read/write][starting PRAM address]
;
; Outputs:	none
;
; Trashes:	A2,A3,D3
;
; Function:	reads/writes byte[s] from parameter RAM that hides in unused video RAM
;			before traps (or the MMU) are set up
;________________________________________________________________________________________

NoPRAMXPramIO
			MOVEA.L	A1,A2					; point to this machine's product info,
			ADDA.L	VideoInfoPtr(A2),A2		;  which leads to video info,
			MOVEA.L	VRAMPhysAddr(A2),A2		;   which leads to the base address of video,
			LEA		-256(A2),A2				;    which leads to PRAM in unused video memory
			ADD.W	D3,A2					; index into start of desired PRAM
			SWAP 	D3						; get the number of bytes to transfer
			BCLR	#15,D3					; is it a write?
			BEQ.S	@StartCopy				; -> no
			EXG		A2,A3					; yes, exchange source and destination pointers
			BRA.S	@StartCopy
			
@CopyPRAM	MOVE.B	(A2)+,(A3)+				; move the bytes
@StartCopy	DBRA	D3,@CopyPRAM
			RTS


;________________________________________________________________________________________
;
; Routine:	NoPRAMRdXByte
;
; Inputs:	D1	-	address of PRAM byte to read
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	D1	-	byte read from PRAM
;
; Trashes:	A0,D0
;
; Function:	reads a byte from parameter RAM that hides in unused video RAM without using RAM
;________________________________________________________________________________________

NoPRAMRdXByte
			MOVEA.L	A1,A0					; point to this machine's product info,
			ADDA.L	VideoInfoPtr(A0),A0		;  which leads to video info,
			MOVEA.L	VRAMPhysAddr(A0),A0		;   which leads to the base address of video,
			LEA		-256(A0),A0				;    which leads to PRAM in unused video memory
			MOVEQ	#0,D0
			MOVE.B	D1,D0					; zero-extend the byte number to make an index
			MOVE.B	0(A0,D0),D1				;  and get the byte
			JMP		(A3)


;________________________________________________________________________________________
;
; Routine:	NoPRAMWrXByte
;
; Inputs:	D1	-	address of PRAM byte to write
;			D2	-	byte to write to PRAM
;			A1	-	pointer to ProductInfo record for this machine
;			A2	-	VIA1 base address
;			A3	-	return address
;
; Outputs:	none
;
; Trashes:	A0,D0
;
; Function:	writes a byte to parameter RAM that hides in unused video RAM without using RAM
;________________________________________________________________________________________

NoPRAMWrXByte
			MOVEA.L	A1,A0					; point to this machine's product info,
			ADDA.L	VideoInfoPtr(A0),A0		;  which leads to video info,
			MOVEA.L	VRAMPhysAddr(A0),A0		;   which leads to the base address of video,
			LEA		-256(A0),A0				;    which leads to PRAM in unused video memory
			MOVEQ	#0,D0
			MOVE.B	D1,D0					; zero-extend the byte number to make an index
			MOVE.B	D2,0(A0,D0)				;  and write the byte
			JMP		(A3)


			ENDWITH							; {ProductInfo, VideoInfo}
		ENDIF								; {hasProtectedPRAM}


; ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••


;________________________________________________________________________________________
;
; Routine:	ClkNoMem
;
; Inputs:	A1	-	VIA 1 base address
;			A5	-	return address (BSR5)
;			D1	-	clock chip command byte (bit 7: 0=write, 1=read)
;			D2	-	data byte to write
;
; Outputs:	D2	-	data byte read
;
; Trashes:	A0,A1,A5,A6,D1,D3
;
; Function:	support for the jClkNoMem vector (do we still need this?)
;________________________________________________________________________________________

			EXPORT	ClkNoMem
ClkNoMem	RTS5
;________________________________________________________________________________________			<H9>thru next <H9>
; These patches change the behavior of StandardXPramIO so that during a multi-byte
; write to PRAM, interrupts are disabled and re-enabled around the write of each byte,
; and the RTC is write-enabled and then write-protected again during the time that
; interrupts are off.  This fixes a problem where the Reliability Manager's interrupt
; task, which calls this routine to write to PRAM every 5 minutes, interrupts during
; this loop, resulting in PRAM being left write-protected; when control returns to the
; foreground, remaining bytes to be written to PRAM don't get written.
;
; Monte Benaresh - 7/2/93
;________________________________________________________________________________________

StdXPRAM2Patch								; patch for StandardXPramIO
			MOVEA.L	A1,A6					; point to this machine's product info
			ADDA.L	ProductInfo.ClockPRAMPtr(A6),A6	;  and get the address of its clock/PRAM table
			MOVE.L	4*cpWrProtOn(A6),D0		; get the offset to the write-protect routine
			BEQ.S	@Done					; -> it's not supported for this implementation
			ADDA.L	D0,A6					; calculate the routine's address
			movea.l	(sp)+,A5				; simulate a BSR5 which returns to our caller
			JMP		(A6)					; and call it to turn on PRAM write-protect
@Done
			rts								;														<H9>

			END