C	PROGRAM MOVSTG.FT
C	-----------------------
C
C
C	P. LEMKIN
C	NIH
C	BETHESDA, MD 20014
C
C	DEC 22, 1977
C
C
C
C	PURPOSE
C	-------
C	MOVE THE STAGE IN A TOP DOWN LEFT-RIGHT-LEFT-RIGHT...RASTER
C	PATTERN.
C	1. ENTER THE NUMBER OF ROWS IP
C	2. ENTER THE NUMBER OF COLUMNS IQ
C
C	NOTE: THE SIZE OF THE STAGE PATTERN IS A PXQ STEP
C	PATTERN WHICH SHOULD BE CHANGED TO THE DESIRED
C	PATTERN.
C	AS THE STAGE SCANS, STOP WHEN THE DENSITY > A
C	SET THRESHOLD (THIS LOGIC MAY BE INCOMPLETE).
C
C	NOTE: CHECK TO SEE THE MSTAG PATTERN OF YOUR
C	STAGE!!! (IT WILL PROBABLY BE DIFFERENT SO THAT THE BIT
C	PATTERNS MUST BE CHANGED).
C
C
C	PDP8E OPCODE DEFINITIONS
C	------------------------
C	THE FOLLOWING DEVICE CODES ARE UNIQUE
C	TO OUR RTPP. YOU SHOULD CHANGE (MSTAGE,STEP) TO WHATEVER
C	IS USED ON YOUR PDP12.
C
C	THE A/D SPECIFIED HERE IS THE AD8E WITH 16 CHANNEL
C	MULTIPLEXOR. THIS CODE SHOULD BE REWRITTEN FOR YOUR PDP12.
C
S	OPDEF	MSTAG	6366 /LOAD STEPPING MOTOR REGISTER
C				AS FOLLOWS:
C				BIT	FUNCTION
C				---	--------
C				8	+Y
C				9	-Y
C				10	+X
C				11	-X
S	OPDEF	STEP	6305 /MOVE THE STAGE ACCORDING TO MSTAG REG.
C
C       Analogue to Digital 16  channel  converter
C       (DEC  AD8-ea/AM8-ea)  with an input voltage
C       range of +/- 1 volt, 0-30 KHZ bandwidth, 10
C       bit resolution, 200 nsec. apperature time.
S       OPDEF ADCL 6530 /Clear AD done and timing error flags.
C	Clear enable, mux and status register.
S       OPDEF ADLM 6531 /LOAD mux register from AC[8:11],
C	clear AC.
S       OPDEF ADST 6532 /CLear AD done and timing error flags.
C	Start AD converter. Channel to
C	be converted is to be determined by
C	mux register.
S       OPDEF ADRB 6533 /CLear AD done flag. Contents of
C	AD buffer ==>ac[0:11].
S       SKPDF ADSK 6534 /SKIp next instruction if AD done=1.
C	Do not clear flag.
S       SKPDF ADSE 6535 /Skip next instruction if 
C	timing error=1.
C	Do not clear flag.
S       OPDEF ADLE 6536 /LOad enable register from AC[2:5].
S       OPDEF ADRS 6537 /REAd AD status/enable register and
C	mux into AC[0:11].
C
C       A/D Status register
C	Bit     function
C	----    --------
C       0       Conversion done
C       1       error
C       2       done interrupt enable
C       3       error interrupt enable
C       4       external start enable
C       5       auto increment enable
C       6-7     not used
C       8-11    contents of mux register
C
C
C	[1] DEFINE THE MAXIMUM X AND Y
402	READ(1,400)IP,IQ
400	FORMAT(' # ROWS?=',I5,/,' # COLUMNS?=',I5)
C
C	IF IP OR IQ=0
C		THEN ASK THE QUESTION AGAIN;
	IF(IP)402,402,403
403	IF(IQ)402,402,404
404	CONTINUE
C
C
C	[1.1] SET THE STAGE TO MOVE IN THE +X DIRECTION
	IXDIRECTION=0
	MXPATTERN=2
C
C
C	[2] MOVE THE STAGE IN THE RASTER
	DO 200 IY=1,IQ
C
	WRITE(1,101)IY
101	FORMAT(' DOING LINE:',I5)
C
	DO 201 IX=1,IP
C
C	[2.1] CALL THE CLOCK TO WAIT 5 MSEC
S	JMS CLOCK
C
C
C	[2.2] MOVE THE STAGE IN THE +X DIRECTION
S	TAD \MXPATTERN /+X BIT PATTERN
S	JMS MOVSTAGE /BITS==>STAGE
C

C	[2.3] CALL THE A/D TO SEE IF YOU STOP
C	LET THE PHOTOMETER BE ON A/D CHANNEL 0
C	AND A - SATURATION SIGNAL WILL STOP IT!
	IZ=0
C@@@@	JMS SAMPLE
	IF(IZ)221,220,220
221	READ(1,1221)JUNK
1221	FORMAT(' FOUND ONE!')
220	CONTINUE
C
	ICHAN=0
201	CONTINUE
C
C	INCREMENT Y STAGE
S	TAD (0010 /+Y DIRECTION
S	JMS MOVSTAGE
C
C
C	FINISHED X LINE, NOW MOVE THE STAGE BACK
C	BY TOGGLING THE X DIRECTION
	IXDIRECTION=1-IXDIRECTION
	IF(IXDIRECTION)210,211,210
210	MXPATTERN=1
	GOTO 200
211	MXPATTERN=2
200	CONTINUE
C
C
C	[3] DONE!
	WRITE(1,103)
103	FORMAT(' DONE!')
	CALL EXIT
C	************************************************
C	*SUBROUTINE   M O V S T A G E
C	************************************************************
C	MOVE THE STAGE ACCORDING TO THE BIT PATTERN IN THE AC
C
S	CPAGE 3
S RMOVSTAGE,	JMP I MOVSTAGE
S MOVSTAGE,	0 /ENTRY
C
S	MSTAG /LOAD THE STAGE REGISTER
S	STEP /SEND A PULSE TO LOAD THE REGISTER
C
C	SETUP THE 100 USEC DELAY
S	CLA
	ICOUNT=-40
S WAIT,	ISZ \ICOUNT /COUNT DOWN 100 USEC
S	JMP WAIT
S	CLA
S	MSTAG /ZERO THE STAGE REGISTER
C
S	JMP RMOVSTAGE
C       *********************************************
C       *SUBROUTINE     S A M P L E	*
C       *********************************************
C	SUBROUTINE SAMPLE SAMPLES THE  A/D  CHANNEL
C       IN ICHAN AND PUT THE RESULT IN IZ.
C
S       CPAGE 3
S RSAMPLE,      JMP I SAMPLE
S SAMPLE,       0 /ENTRY
C       [AD.1] SET UP THE CHANNEL WHICH IS PASSED
C       THROUGH ICHAN.
S       ADCL
S       TAD \ICHAN /CHANNEL #
S       AND (0017 /ONLY 0 TO 17
S       ADLM /LOAD THE MUX SELECTOR
C
C
C       [AD.2] START THE A/D
S       ADST
S ADFIN,ADSK
S       JMP ADFIN /NOT FINISHED.
C
C
C       [AD.3] GET THE DATA 
S       ADRB
S	TAD (1000 /ADD +512 SO -1 TO +1 VDC ==>[0:1777]
S       DCA \IZ
S       JMP RSAMPLE
C
C
C	******************************************************
C	*SUBROUTINE   C L O C K
C	*******************************************************
C	WAIT 5 MSEC
C
S	CPAGE 3
S RCLOCK,	JMP I CLOCK
S CLOCK,	0 /ENTRY
C
1556	DO 1555 MSEC=1,5
	DO 1555 IUSEC=1,50
C	WASTE SOME TIME
S	ISZ \JUNK
S	CLA
1555	CONTINUE
S	JMP RCLOCK /RETURN
	END
 