10·14
Reference
Information
Portable
PLUS
Computer
U17
is
a dual-trigger monostable muItivibrator.
It
determines the EPROM
burn-in
time for
data
at
each address (50 to 55 ms). U17 is triggered
when
the EPROM chip select is low,
and
is asserted.
The
second multivibrator is
used
to generate a 5-MHz
DEN*
signal to clock the D-type flip-flop U18. U18
generates a READY* signa\. The flip-flop is triggered
when
U17 asserts
the
PGM*
line.
The
output
of
flip-flop U18 is connected to
FET
Q5 to pull the open drain READY signal low.
Table 10·2. Diagnostic Module Replaceable Parts
Reference
HP
Description
Quantity
Designation
Part Number
C1-C18
0160-5332
CAPACITOR, 0.1
JLF
20% 50V
18
C19
0180-0269
CAPACITOR, 1
JLF
150V
1
C20 0180-0291
CAPACITOR, 1
JLF
35V
1
C21
0160-4787
CAPACITOR,
22
pF 5%
1
CRl,
CR2 1901-1098
DIODE, switch 1N4150
2
J2
1251-6978
CONNECTOR, housing AMP 1
V2
1
Ql
1854-0477 TRANSISTOR,
NPN
2N2222
1
Q2 1854-0215 TRANSISTOR,
NPN
2N3904
1
Q3, Q4
1853-0036
TRANSISTOR,
PNP
2N3906
2
Q5
1855-0556 TRANSISTOR, VN2222L
1
R1,
R2
1810-0281
RESISTOR,
lOOK
x 9
2
R3,
R9,
RIO
,
0683-2235
RESISTOR,
22K
5% I/.W 5
Rll,
R12
R4
0683-2225 RESISTOR, 2.2K 5%
v.W
1
R5
0698-3440
RESISTOR, 196f! 1%
VsW
1
R6
0757-0394
RESISTOR,
5Uf!
1%
1
R7
0699-0208
RESISTOR, If! 1
R8
0757-0421
RESISTOR, 25f!
1
R13
0683-4725
RESISTOR, 4.
7K
1
R14
2100-3253
RESISTOR, variable 50K 10%
1
R15
0683-3935
RESISTOR, 39K 5% I/.W
1
R16
0683-1025
RESISTOR, lK 5% I/.W
1
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