* SPICE netlist
A1 N001 2 1 1 1 1 N003 1 SCHMITT Vt=0 Vh=1m
R1 N001 1 5K
R2 5 N001 5K
R3 8 5 5K
S1 1 7 N012 1 D
A2 N006 N003 1 1 1 1 N004 1 SRFLOP Trise=100n tripdt=10n
A3 6 5 1 1 1 1 N006 1 SCHMITT Vt=0 Vh=1m
S2 8 3 N010 1 O
S3 3 1 1 N010 O
A6 1 N013 1 N004 1 1 N012 1 OR Ref=.5 Vlow=-1 Trise=100n
R7 8 1 4K
R10 6 1 1G
A4 1 N004 1 N013 1 N010 1 1 OR Ref=.5 Vlow=-1 Trise=100n
A5 4 1 1 1 1 N013 1 1 SCHMITT Vt=.7 Vh=1m
I1 8 4 .4m load
D1 4 1 DR
R9 2 1 1G

* LTspice schematic (.asc)
Version 4
SHEET 1 1696 1040
WIRE -832 -520 -848 -520
WIRE -832 -456 -848 -456
WIRE -832 -344 -848 -344
WIRE -832 -88 -848 -88
WIRE -832 88 -848 88
WIRE -832 120 -848 120
WIRE -832 328 -848 328
WIRE -832 520 -848 520
WIRE -800 328 -832 328
WIRE -800 376 -800 328
WIRE -800 520 -832 520
WIRE -800 520 -800 456
WIRE -768 -344 -832 -344
WIRE -768 -232 -768 -344
WIRE -768 520 -800 520
WIRE -768 520 -768 -152
WIRE -720 -456 -832 -456
WIRE -720 -440 -720 -456
WIRE -720 520 -768 520
WIRE -720 520 -720 -376
WIRE -656 -456 -720 -456
WIRE -656 -440 -656 -456
WIRE -656 -344 -768 -344
WIRE -656 -344 -656 -360
WIRE -656 -232 -656 -344
WIRE -656 120 -832 120
WIRE -656 120 -656 -152
WIRE -656 168 -656 120
WIRE -656 296 -656 248
WIRE -656 392 -656 296
WIRE -656 520 -720 520
WIRE -656 520 -656 472
WIRE -608 296 -656 296
WIRE -560 296 -608 296
WIRE -560 328 -800 328
WIRE -560 520 -656 520
WIRE -560 520 -560 344
WIRE -448 -168 -448 -248
WIRE -448 520 -560 520
WIRE -448 520 -448 -168
WIRE -416 -344 -656 -344
WIRE -416 -168 -448 -168
WIRE -400 -248 -448 -248
WIRE -400 -248 -400 -296
WIRE -400 -216 -400 -248
WIRE -352 -264 -352 -296
WIRE -352 -248 -352 -264
WIRE -352 -216 -352 -248
WIRE -320 88 -832 88
WIRE -320 376 -320 88
WIRE -320 520 -448 520
WIRE -320 520 -320 456
WIRE -272 -520 -832 -520
WIRE -272 -344 -336 -344
WIRE -272 -344 -272 -520
WIRE -272 -168 -336 -168
WIRE -272 -168 -272 -344
WIRE -240 88 -320 88
WIRE -240 120 -656 120
WIRE -240 520 -320 520
WIRE -240 520 -240 136
WIRE -112 296 -496 296
WIRE -112 296 -112 136
WIRE -80 88 -176 88
WIRE -80 136 -112 136
WIRE -32 88 -80 88
WIRE -32 136 -80 136
WIRE -32 520 -240 520
WIRE -32 520 -32 168
WIRE 96 -264 -352 -264
WIRE 144 520 -32 520
WIRE 144 520 144 -248
WIRE 208 -296 160 -296
WIRE 208 88 64 88
WIRE 208 88 208 -296
WIRE 272 -264 160 -264
WIRE 272 56 272 -264
WIRE 336 56 272 56
WIRE 336 88 208 88
WIRE 400 56 336 56
WIRE 400 88 336 88
WIRE 416 520 144 520
WIRE 416 520 416 104
WIRE 512 56 464 56
WIRE 576 -88 -832 -88
WIRE 592 56 512 56
WIRE 592 56 592 -40
WIRE 640 8 640 -40
WIRE 688 -88 656 -88
WIRE 688 8 640 8
WIRE 688 8 688 -88
WIRE 688 520 416 520
WIRE 688 520 688 8
WIRE 720 -264 272 -264
WIRE 784 520 688 520
WIRE 784 520 784 -248
WIRE 848 -456 -656 -456
WIRE 848 -296 784 -296
WIRE 848 -296 848 -456
FLAG -832 520 1
FLAG -832 120 5
FLAG -832 -344 8
FLAG -832 -88 7
FLAG 512 56 N012
FLAG -608 296 N001
FLAG -80 88 N006
FLAG -80 136 N003
FLAG 336 88 N004
FLAG -832 88 6
FLAG -832 -520 3
FLAG -352 -248 N010
FLAG 336 56 N013
FLAG -832 -456 4
FLAG -832 328 2
SYMBOL Digital\\diffschmitt -560 248 R0
SYMATTR InstName A1
SYMATTR Value Vt=0 Vh=1m
SYMBOL res -672 376 R0
SYMATTR InstName R1
SYMATTR Value 5K
SYMBOL res -672 152 R0
SYMATTR InstName R2
SYMATTR Value 5K
SYMBOL res -672 -248 R0
SYMATTR InstName R3
SYMATTR Value 5K
SYMBOL sw 672 -88 M270
SYMATTR InstName S1
SYMATTR Value D
SYMBOL Digital\\srflop 16 40 R0
SYMATTR InstName A2
SYMATTR Value Trise=100n tripdt=10n
SYMBOL Digital\\diffschmitt -240 40 R0
SYMATTR InstName A3
SYMATTR Value Vt=0 Vh=1m
SYMBOL sw -432 -344 R270
SYMATTR InstName S2
SYMATTR Value O
SYMBOL sw -320 -168 R90
SYMATTR InstName S3
SYMATTR Value O
SYMBOL Digital\\or 432 8 R0
SYMATTR InstName A6
SYMATTR Value Ref=.5 Vlow=-1 Trise=100n
SYMBOL res -784 -248 R0
SYMATTR InstName R7
SYMATTR Value 4K
SYMBOL res -336 360 R0
SYMATTR InstName R10
SYMATTR Value 1G
SYMBOL Digital\\or 128 -344 M0
SYMATTR InstName A4
SYMATTR Value Ref=.5 Vlow=-1 Trise=100n
SYMBOL Digital\\diffschmitt 784 -344 M0
SYMATTR InstName A5
SYMATTR Value Vt=.7 Vh=1m
SYMBOL current -656 -360 M180
SYMATTR InstName I1
SYMATTR Value .4m
SYMATTR SpiceLine load
SYMBOL diode -704 -440 M0
SYMATTR InstName D1
SYMATTR Value DR
SYMBOL res -784 360 M0
SYMATTR InstName R9
SYMATTR Value 1G