.Page
;++
;--

TimIt	.Equ *
	Lda	#5				; Time 6 pulses
	Sta	Temp2
	Clc					; Should stay clear unless explicitly set
	Jsr	WtZero				; Look for low, then first high
	Bcs	RsOut				; 2,3	10	No edge within timeout period
	Jsr	RsEdge				; 8	8	Now at known locationo
	Bcs	RsOut				; 2,3	10	No edge within timeout period
	Lda	#0				; 2	12
	Sta	RangeL				; 3	15
	Sta	RangeH				; 3	18	Zero both bytes of counter

;++
;	WtZero & RsEdge both have 36 cycles (18.0 uSec) per tick of RangeL:H
;--

$20	Jsr	WtZero				; Look for low
	Bcs	RsOut				; 2,3
	Jsr	RsEdge				; Wait for next edge on pulse
	Bcs	RsOut				; 2,3
	Dec	Temp2				; 5		When less than zero then exit
	Bpl	$20				; 2,3	15*(2+@+%+#) = 180 cycles

RsOut	.Equ *
	Rts					; 6		Common exit point

WtZero	.Equ *
	Bit	K000				; 3		ccV set to Zero
	Bvc	RsEd				; 3	6

RsEdge	.Equ *					;		Look for a rising edge
	Bit	K0FF				; 3	3	ccV eq 0 == low, ccV eq 1 == high
	Bvs	ReEd				; 3	6
RsEd	.Equ *
	Ldy	#00				; 2	8
	Ldx	#0A0				; 2	10	Constant timeout for pulse counting

$10	Dey					; 2	2
	Bne	$20				; 2,3	4,5
	Dex					; 2	6
	Bne	$30				; 2,3	8,9
	Sec					; 2	10	When X-reg = 0 then return error
	Rts

$20	Nop					; 2	7
	Nop					; 2	9	Waste time

$30	Inc	RangeL				; 5	14
	Bne	$40				; 2,3	16,17
	Inc	RangeH				; 5	21
	Bne	$50				; 3	24	Always taken ??

$40	Pha					; 3	20	Waste more time
	Pla					; 4	24

$50	Lda	Q7L				; 4		Bit7=0 ==>tach low, else tach high
	Bvc	$70				; 2,3	30,31	ccV ==> look for low
	Bpl	$90				; 2,3	32,33	If high then fall thru & exit
	Nop					; 2	34
$60	Rts					; 6

$70	Bpl	$60				; 2,3	33,34	If low then exit

$90	Bcc	$10				; 3	36	Always taken?? -- 18.0 uSec loop

ChkLrg	.Equ *
	Lda	#Lrge				; 5
	Sta	Temp1				; For speed adjustment
	Lda	#WLow
	Beq	ChkComm

ChkSml	.Equ *
	Lda	#Smal				; 1
	Sta	Temp1
	Lda	#TLow

;++
;  ChkComm
;     if H < TL
;       then AdjPlus
;     else if H > TL
;       then TstHih
;     else  if L < Tl
;       then AdjPlus
;     else if L = TL
;       then OK
;  TstHih
;     If H > Th
;        then AdjMinus
;     else if H <> Th
;        then OK
;     else if L <= TH
;        then OK
;     else AdjMinus
;--

ChkComm	.Equ *
	Sta	InxPtrL			; Ptr to which constraints ( low of high )
	Lda	CurClass			; Current track class
	Asl	A			; *2 to address word array
	Tay
	Lda	RangeH
	Cmp	@InxPtrL,y		; High must be greater than or equal to lowtable,y
	Bcc	AdjPlus			; High byte low, must spin slower
	Bne	TsHih			; High byte greater -- must see if w/in high boundary
	Inc
	Lda	RangeL
	Cmp	@InxPtrL,y		; Must be greater than or equal to table,y
	Bcc	AdjPlus			; High bytes = and low byte low - slow it down
	Beq	ChkOK			; Both bytes are equal so within range
	Clc
TsHih	.Equ *				; ccC=1 if branched to here so add +1 for not 'Iny'
	Tya
	Adc	#TblJmp			; 9.
	Tay				; Index now points at high side of range
	Lda	@InxPtrL,y
	Cmp	RangeH			; High byte must be <= high boundary
	Bcc	AdjMinus			; High byte is too high, spin disk faster
	Bne	ChkOK			; If <> then low byte must be w/in range
	Iny				; Point @ low byte of boundary value
	Lda	@InxPtrL,y
	Cmp	RangeL			; Low byte is too high, spin disk faster

ChjkOK	.Equ *
	Clc
	Rts

AdjPlus	.Equ *				; ccC = 0 already
	Ldy	CurClass
	Lda	MSpdTbl,y
	Adc	TEmp1			; Add adjustment value
	Sta	MSpdTbl,y
	Sec
	Rts

AdjMinus	.Equ *
	Ldy	CurClass
	Lda	MSpdTbl,y
	Sec
	Sbc	Temp1
	Sta	MSpdTbl,y
	Sec
	Rts

SpdChk	.Equ *				; Main entry point for speed check
	Lda	#WHih			; '11'x
	Sta	InxPtrH
	Jsr	SetTach			; Make sure in Tach sense mode
	Jsr	TimIt			; Time 6 pulses & abort on timeout
	Bcs	SpdErr
	Jsr	ChkLrg			; Must be within +/- 2%
	Bcc	SpdDone
	Lda	#101.			; 100 times total for attempts to adjust
	Sta	Counter

$10	Dec	Counter
	Beq	SpdErr			; Try for 100 times and abort upon inability to adjust
	Jsr	SetSpeed
	Lda	ScDly
	Jsr	Wait
	Jsr	Timit
	Bcs	SpdErr
	Jsr	ChkLrg
	Bcs	$10			; Loop until speed within +/- 2%

$32	Sec				; Make sure error flag is set
	Dec	Counter
	Beq	SpdErr			; Try for 100 times and abort upon inability to adjust
	Jsr	ChkSml			; Now loop until within +/- .5%
	Bcc	SpdDone
	Jsr	SetSpeed
	Lda	ScDelay
	Jsr	Wait
	Jsr	TimIt
	Bcc	$32

SpdErr	.Equ*
	Lda	#SErrTmt

SpdDone	.Equ *
	Rts