Tektronix 5440 Instruction Manual page 51

Decimal-point locatio n
e
n-
cod ed
d
u rin g t h is time-slot
-- no
d
isp lay
Decimal
p
oint
locatio n No . 3
(col u m n 3)
F
irst
p
ossible c haracte r
d
is-
played on
C
RT at th is loca-
tio n
Decimal p
oint
locatio n No . 4
(col u mn 4)
F
irst number of meas ure-
m ent n ormally
d
isplaye d at
th is locatio n
Deci m al
p
oint
location No . 5
(col u m n 5)
Decimal
p
oint
location No . 7
(column 7)
Decimal p
oint
locatio n No . 6
(colu mn 6)
1260-44
F
ig . 3-9 .
R
eadout wor d relating 10 possible c h aracter locatio n s
to th e decimal point instructio n s th at can
b
e enco d e d , an d th e
resultant C R T
d
isplay .
Wh en decimal- p oint data is enco d e d , t h e crt is υπ -
blan k ed so α rea d out dis p lay is presente d .
H
owever, si n ce
row 7 does
n
ot activate any of t h e five c h aracter
generators, t h e crt beam is not d eflecte d but instead
remai n s in α fixed
p
ositio n to dis p lay α decimal
p
oi n t
between t h e c h aracter alo n g t h e bottom line of t h e rea d out
wor d . After t h e d ecimal
p
oint is p ro d uce d in t h e addressed
location, t h e crt beam retur n s to t h e location indicated by
t h e c h aracter
p
osition cou n ter to
p
roduce t h e remainder
of t h e dis p lay .
Circuit Descri p tion-5440
F
ormat Ge n erator .
T
h e Χ an d Υ deflection sig n als
p
ro d uced by t h e c h aracter generator stage, are connected
to
p
ins 2 a n d 7, respectively, of
F
ormat Generator
U
1100 .
T h e wor d address co d e from t h e word counter is also
connecte d to
p
ins 1, 8, a n d 15 of t h is stage . T h e wor d
address co d e
d
irects t h e
F
ormat Ge n erator to ad d current
to t h e Χ an d Υ sig n als to deflect t h e crt beam to t h e area of
t h e crt t h at is associate d wit h
t
h e
p
lug-in c h annel t h at
originate d
t
h e i n formation (see
F
ig . 3-1) .
In a d ditio n , t h e c h aracter p ositio n current from t h e
d ecimal
p
oint logic and c h aracter position stage is added
to t h e Χ ( h orizo n tal) in p ut signal to space t h e c h aracters
h orizontally on t h e crt (see
p
revious discussion) . T h e
c h an n el switc h OFF signal at
p
in 13 activates t h is stage
w h en α
c
h aracter is to be d isplaye d on t h e crt . V ertical
s p acing a d j ustment,
R
118, sets t h e se p aratio n between
t h e u p per and lower readout dis p lays .
Υ -Out p ut Amplifier .
T
h e Υ -Out p ut Amplifier at
p
in 6 of
U
1100 is connecte d to t h e Υ -Out p ut Am p lifier Q1100 . T h is
stage
p
rovi d es α low im p edance loa d for t h e format
generator w h ile
p
roviding isolatio n betwee n
t
h e rea d out
system a n d
t
h e vertical am p lifier .
Χ -Out p ut Amplifier .
T
h e Χ -Out p ut Amplifier Q1110
o p erates similarly to t h e Υ -Out p ut Amplifier . It
p
rovi d es
t h e
h
orizontal d eflection from t h e rea d out signal available
at p in 4 of
U
1100 .
H
orizontal
p
osition is controlle d by
R
1110, w h ic h
c
h a n ges t h e emitter current of 01110 .
H
orizontal c h an n el switc h U 1130 normally passes
sig n als from t h e
h
orizo n tal p lug-in connector to t h e
h
orizo n tal am p lifier wit h unity gain . Wh e n
t
h e c h a n nel
switc h OFF signal is generate d by timer
U
1000, t h e
c h annel switc h substitutes t h e h
orizontal readout sig n al
for t h e
h
orizontal
p
lug-in co nn ector signal .