// PrintSlot.bcpl - SLOT printing code

// errors 3100

get "PDInternals.d"

//outgoing procedures
external
	[
	PSlot
	SLOTInit
	]

//incoming procedures
external
	[ 
//OS
	Zero;MoveBlock;StartIO
//PRINT
	PrintError
//PRINTDISK
	PrintDiskInit
	PrintDiskRead
	PrintDiskCheck
	PrintDiskStop
	]

//incoming statics
external
	[ 
	invertMode
	ScanMarginAdjust		//Adjustments to add to user input
	BitMarginAdjust
	SLOTScanLength			//To give to 3100 interface
	SLOTDouble
	SLOTTimeOut
	]

// S L O T   Definitions:

structure RS [
	blank		byte
	Spare2		bit
	Wait		bit		//complement signal
	PaperJam	bit		//complement signal
	AddPaper	bit		//complement signal
	SelectB		bit
	Ready		bit
	LineSync	bit
	PageSync	 bit		//complement signal
	]
manifest
	[
	NormalizeStatus = #161  //use to uncomplement above signals
	readyMask = #164
	readyValue = #4
	]

structure SCB [
	blank		bit	14
	COM		bit	2	//	Command Beam On		#0
					//	Command	 Status		#1
					//	Command Reset		#2
					//	Command Print		#3
	BlowUp		bit		// Make-one-bit-into-four; true select option
	LastPage	bit		// Marks this command as the last page if true
	invert		bit		// inverts the page
	bitsPerLine	bit	13	// Servo Count for number of bits per line
	bitMargin	word		// Bottom Margin  (bits)
	scanLineWc	word		// Double Word Count
	scanMargin	word		// Left Margin (bits before print in portrait)
	scansPerPage	word		// Total number of Scan Lines per page
	bufferPtr	word		// Print Buffer Base Address (first loc.)
	scanLineWcInc	word		// Print Buffer Scan Line Increment
	scansPerBuff	word		// Print-mode Buffer Length
	currentBuff	word		// Current Buffer Address
	currentLine	word		// Current Scan Address
	SW		word = @RS	// Return Status Word
	]


manifest
	[
	lSCB = size SCB/16
	SCBloc=#720
	slotSIObit=4

	BeamOnCommand=0
	StatusCommand=1
	ResetCommand=2
	PrintCommand=3
	]

manifest 
	[
	RTC=#430
	Active=#453
	parityInterruptBit=1
	WakeupsWaiting=#452
	]

let SLOTInit() be
[
	SLOTCommand(ResetCommand)
	SLOTCommand(BeamOnCommand)
	let FailCode=SLOTStatus()
	if FailCode eq 0 then return
	PrintError(FailCode)
] repeat

and PSlot(pg, last, firstAdr, lastAdr) be
[
//Disable parity interrupts
	let oldActive=@Active
	@Active=oldActive&(not parityInterruptBit)

[Retry
	let bandWidth=pg>>PageG.BandWidth
	let numBands=pg>>PageG.LastBand-pg>>PageG.FirstBand+1
	let scanLength=pg>>PageG.BitWc*16

//Initialize band buffers and fill them
	let FirstBuf=nil
	let nBuffers=PrintDiskInit(pg, firstAdr, lastAdr, lv FirstBuf)
	let nR,nC=nil,nil
	for i=1 to nBuffers do nR=PrintDiskRead()
	nC=PrintDiskCheck() repeatuntil nC eq nR

	let scb=vec lSCB
	scb=SetSCB(scb)
	scb>>SCB.COM = PrintCommand
	scb>>SCB.LastPage = last
	scb>>SCB.bitMargin = pg>>PageG.BitMargin + BitMarginAdjust
	scb>>SCB.scanLineWc = pg>>PageG.BitWc/2
	scb>>SCB.scanMargin = pg>>PageG.FirstBand*bandWidth + ScanMarginAdjust
	scb>>SCB.scansPerPage = numBands*bandWidth
	let currentBuff = FirstBuf
	scb>>SCB.bufferPtr = currentBuff
	scb>>SCB.currentBuff = currentBuff
	scb>>SCB.scanLineWcInc = pg>>PageG.BitWc
	scb>>SCB.scansPerBuff = bandWidth
	@SCBloc = scb

SlotStart:
	let startTime=@RTC
	let PrintFail=0
	StartIO(slotSIObit)
		[
		if scb>>SCB.currentBuff ne currentBuff then  //started next buff
			[
			let onR=nR
			nR=PrintDiskRead()
			if onR ne nR then currentBuff=currentBuff!-1
			]
		nC=PrintDiskCheck()
		if nC-nR ge nBuffers-1 then PrintFail=3105	//disk behind
		if scb>>SCB.SW then break
		if @RTC-startTime ge SLOTTimeOut*27 then [ PrintFail=3106; break ]
		] repeat

	PrintDiskStop()

	let FailCode=SLOTStatus()
	if last then [ MsWait(6000); SLOTCommand(ResetCommand) ]
	if (PrintFail%FailCode) eq 0 then break	//Successful printing

// Error while printing this page. Reset and try again
	SLOTCommand(ResetCommand)
	PrintError((FailCode? FailCode,PrintFail))
	SLOTInit()			//Fuss until printer is ready
]Retry repeat

   @WakeupsWaiting=@WakeupsWaiting&(not parityInterruptBit)
   @Active=oldActive
 ]


// SLOT Procedures

// Test status of SLOT card and return a failure code (0= ready)

and SLOTStatus() = valof
[
	let scb=vec lSCB
	scb=SetSCB(scb)
	scb>>SCB.COM = StatusCommand
	scb>>SCB.SW = NormalizeStatus
	@SCBloc = scb
	StartIO(slotSIObit)
	MsWait(20)		//give microcode long enough to see the new command
	if scb>>SCB.SW eq NormalizeStatus then PrintError(3100)
	scb>>SCB.SW = scb>>SCB.SW xor NormalizeStatus
	if (scb>>SCB.SW & readyMask) eq readyValue then resultis 0
	if scb>>SCB.Wait then resultis 3101
	if scb>>SCB.PaperJam then resultis 3102
	if scb>>SCB.AddPaper then resultis 3103
	resultis 3104
]

// Issue a command to the SLOT

and SLOTCommand(comm) be
[
	let scb=vec lSCB
	scb=SetSCB(scb)
	scb>>SCB.COM=comm
	@ SCBloc = scb
	StartIO(slotSIObit)
	for i = 0 to 30000 do if scb>>SCB.SW then break
	if scb>>SCB.SW eq 0 then PrintError(3100)	//No response
	if comm eq BeamOnCommand then MsWait(1000)
]

and SetSCB(scb) = valof
[
	scb=(scb+1)&(-2)
	Zero(scb, lSCB)
	scb>>SCB.invert = invertMode
	scb>>SCB.bitsPerLine=SLOTScanLength
	scb>>SCB.BlowUp=SLOTDouble
	resultis scb
]

and MsWait(ms) be
[
	let startTime = @RTC
	until @RTC-startTime ge ms/37 do [ ]
]
(635)\39f1 1f0