.PS
# TTLnand.m4
cct_init
up_
Q3: bi_tr
"\sf Q3" at Q3.E above ljust
dot(at Q3.C); reversed(`diode',up_ dimen_/2)
Q4: bi_tr with .E at Here
"\sf Q4" at Q4.E above ljust
resistor(up_ dimen_ from Q4.C); rlabel(,`130\,\mathrm{\Omega}')
V: dot
line left_ dimen_*0.75 from Q4.B; dot
line left_ dimen_*0.75 from Q3.B; dot
Q2: bi_tr(up_ Q4.B.y-Q3.B.y) with .E at Here
"\sf Q2" at 1/2 between Q2.E and Q2.C ljust
resistor(from Q2.C to (Q2.C,V)); rlabel(,`1.6\,\mathrm{k\Omega}'); dot
resistor(from Q2.E down_ dimen_); llabel(,`1\,\mathrm{k\Omega}')
line to (Q4.E,Here)
G: dot
line to Q3.E
line left_ dimen_/4 from Q2.B
right_
Q1: bi_trans(,,BCdE2BU) with .C at Here
"\sf Q1" at Q1.Bulk above rjust
resistor(up_ from Q1.B to (Q1.B,V)); rlabel(,`4\,\mathrm{k\Omega}')
line to V
line left dimen_ from Q1.E2
X1: dot; "$X1$" rjust above at last [].w
X2: dot(at (X1,Q3.C)); "$X2$" rjust at last [].w
AA: line invis right dimen_ from X2
line from X2 to Intersect_(AA,Q1.Em1) then to Q1.E1
X3: dot(at 2 between X1 and X2); "$X3$" rjust below at last [].w
AA: line invis right dimen_ from X3
line from X3 to Intersect_(AA,Q1.Em0) then to Q1.E0
W: X2+(dimen_/2,0)
N: V+(0,dimen_/4)
S: (N.x,N.y-2*(N.y-W.y))
line from V to 2 between V and N
Vcc:dot; "$+5\,\hbox{V}$" ljust at last [].e
line from G to (G,S)
ground
line from N to (W,N) then to (W,S) then to S
arc rad N.y-W.y ccw to N with .c at 1/2 between N and S
line right (N.y-S.y)/2+dimen_/2 from Q3.C
Z: dot; "$Z = \overline{X1\cdot X2\cdot X3}$" ljust
.PE