Beehive International B100 User manual

:
maintenance manual
V' ' v' •
M ^ J
INTERNATIONAL.
COMPUTER
TERMINAL
4S10 Amelia Eanhant Drive
Box 25BBB • Salt Lake City, Utah B-4125
CS013 355-SGOO •TWX S10-925-5271

COMPUTER TERMINAL
Manual
AUGUST 1B7B
This Documant has b««n praoarad by Baahiva Madical Electronics and is
furnished on the condition that it will be used by the customer solely for the
purpose of supporting tha op«ratior^, service and maintenance of Beehive Tar-
minals. Tha rights of the customer with respect to this Document will be
governed by mutually acceptable provisions Of tha contract with Beehive Me
dical Electronics. This Documant shall not ba duplicated by the customer,
nor be ralessad, disclosed or used, in whole or In part, for any purpose other
than stated herein without the express written permission of said Beehive
Medical Electronics.
BEEHIVE IIMTERIMATIONAL
070 West SeOO South -Box 25B6S • Salt Lake City. Utah 0-4125* tBOD 972-6000 TWX aiO-0SS-5271
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Section
4-1
4-2
4-3
5-1
5-2
5-3
5-4
5-5
6-1
6-2
A.
Table
5-1
Figure
4-1
4-2
4-3
4-4
4-5
4-6
4-7
5-1
5-2
5-3
B100 Maintenance Manual
TABLE OF CONTENTS
SECTION IV - THEORY OF OPERATION
Introduction
General Function Description
Detailed Functional Description
SECTION V - MAINTENANCE
Introduction
Preventive Maintenance
Corrective Maintenance
Monitor Adjustment
Disassembly Procedure
SECTION VI - SCHEMATICS
8100 Board Assembly Drawing
8100 Schematics
APPENDIX
Monitor - General Information
TABLES
Troubleshooting Flow Diagrams
FIGURES
Basic Block Diagram
Basic Functional Flow Diagram
Basic Functional Flow Diagram
Power Supply Block Diagram
Character Dot Matrix
Timing Diagram
Timing Diagram
Echoplex Test Connector
Monitor Adjustments
Assembly Drawing 8100
Page
4-1
4-1
4-6
5-1
5-1
5-1
5-17
5-18
6-1
6-2 thru 6-17
Page
5-3-5-15
Page
4-2
4-3
4-4
4-5
4-8
4-9
4-10
5-2
5-16
5-18

SECTION IV
Theory of Operation
4.1
INTRODUCTION
This section contains the theory of operation for
the BEEHIVE B100 Terminal. This discussion is
presented as a functional description at adetailed
block diagram level referencing
appropriate func
tional blocks on the diagrams.
4.2
GENERAL FUNCTIONAL DESCRIPTION
The 8100 consists of four basic functional compo
nents, Power Supply, Monitor, Keyboard
and
iVIain Logic Board. Figure 4-3 shows the basic
functional flow diagram of the terminal. These
functions are briefly described in the following
paragraphs.
4.2.1
Power Supply
The PowerSupply provides the required, regula
ted DC voltages to the terminal. This assembly
will operate on 100, 115, 200 or 230 VAC power
(selectable at the factory).
4.2.2
Monitor
The Monitor Assembly includes a 12 inch (30.5
cm), diagonally measured, CRT and its support
ing solid-state circuitry. The Monitor is controlled
by the vertical and horizontal synchronization sig
nals, and the video signals generated on the logic
board. Afull screen of information consists of 12
4-1
lines of 80 characters ~ a two raster scan between
lines - or the optional feature of 24 lines of 80
characters each. Brightness and contrast adjust
ments are provided by external potentiometers
located on the rear panel, (see Figure 2-2, Section
II). Other monitor adjustments are discussed in
Section V and in Appendix A.
4.2.3
Keyboard
The keyboard isthe input device used by the opera
tor to communicate with the terminal. The key
board contains the switches and supporting circuitry
to generatethe appropriate control signals and
ASCII codes utilized in the B100 terminal. The key
board conforms to the proposed ANSI keyboard
standard for data keys, but has been expanded to
facilitate the capabilities of the B100.
4.2.4
Logic Board
The Logic Board containsthe major functionand
control circuits in the B100 terminal. It also
holds all of the DC voltage regulators to power
the unit. The basic operations accomplished by
the main logic boardare: Generation of data and
control
signals for the monitor, interactionwith
the keyboard, control of the data sent between
the B100 and any external device, and generation
of the basic timing signals essential for the opera
tion of the terminal.

ro
MAIN
POHT
CONKIC.
SELECTION
AUX
POHT
CONFIO
SELECTION
PORT
SELECTION
CIRCUIT
UART
RECEIVER
DATA
INPUT
BUFFER
OPERATION
SEQUENCE
INS
MODE
ILLEGAL
PROTECT
FORMAT
HUSY
MODE
ONFI
CRVSTAL
OSCILLATOR
DATA
UART
TRANSMITTER
MODE
DOT
POSITION
^ 7
DPC
BAUD
CLOCK
SELECTION
ROTARY
CHAK
POSITION
96
CPC
BAUD
CLOCK
CKT.
AUX
CLK
MAIN
CLK
f
SET/CLR
CHAR
HEIGHT
. 9
CilC
)
CURSOR
POS
<
CURSOR
LINE
ROLL
WRITE
BUNK
WRITE
PROT.
f
CURSOR
POS
BUSY
DATA
BEADY
0
SEQUENCE
COUNTER
I
SEQUENCE
VIDEO
CURSOR
GENERATION
CIRCUIT
CURSOR >
CURL
CURSOR
UNE
REC.
BCURL
buffered
CURSOR
LINE
OPERATION
REGISTER
CURSOR
LINE
ROLL
COUNTER
OPERATION
CIIAH
LINE
-
26
CLC
XIEMOHY
ADDRESS
MANIPULATION
]<J20 \ 1
lilT
HLINK
1920
X I
BIT
PROTECT
1920
\ 7
BITS
data
refresh
MEMORY
CURP
CURSOR
POSITION
REG.
protect
CURSOR
POSITION
BCURF
BUFFERED
CURSOR
POSITION
ROLL
FIGURE
4-1
BASIC
BLOCK
DIAGRAM
SYNC
viEN.
COX'I'.
>lii
iiiin
i.ii
III.IXK
LOW
Vll>i:
l>l<l\
Kl(
ciHCin
VIDEO
CURSOR
•OFF
SCREEN
CIRCUIT
f d RSOH
VIDEO
SHIf'T
HEUISTEII
CHARACTER
GENERATOR
LOWER
CASE
UPPER
CASE
INSERT/UELETI:;
CIRCUIT
ILLEGAL
KEYIIOARO
CONTROL
LOGIC
V
lll(l\
I.
M
liKU
L
VlliLO
M>'M
I. ;
KROV.
KEYItOAItU

ESCWAIT
UL!. IN
UFFEi
CO
JAVE
CU.-UOH
lOCAflON
C-lJ
CURSOR 10
UNF 23
SAVE
CURSOR
LOCATION
WRITE NULL
TO MEM.
1NCR.CUR.
POSITION
URSOR
ILLEGAL
CLEAR CUR
POSITION
\
INCR CUR
UNE
URSO
illegal
CLEAR
CURSOR
DECR.CUR
UNE
cuRSon
liSXiA
GO TO "BPT-
GO TO "RTN CURSOR"
GO TC "LF"
NULL CODE
TO
REG 2
CLEAR
STORED
CURSOR
UNE
PROTECTE
WRITE NULL
TO MEM.
INCR.CUR.
POSITION
cunsoR
CLEAR
CfRSOR
POSITION
GO TC "ADV
HOME
CURSOR
SAVE CUR.
LOCATION
GO TO "FPT"
GO TO "RTU CURSOR
CO TO "BKSF
NULL CODE
TO REG a
I
REG 2
BUS
CLEAR CUR.
POS. (•
UNE
HOME
CURSOR
CLEAR
WRITE ,
PROT
FLOP
SET
WRITE
PROT
FLOP
ENABLE
KEYBD.
DISABLE
KEYBD.
GO TO "FPT"
START
SEND-
UTERAL
BUS
FIRE
TIMER
TIME
SEND
1st BYTE
SEND
2nd BYTE
-SOM-
l
CLR. CUH.
POSITION
I
DECR.
STORED
CUR. UNE
MEMORY
BUS
DECR.
STORED
CURSOR
I
INCR. CUR
POSITION
FIGURE 4-2 BASIC FUNCTIONAL FLOW DIAGRAM
SETWRITE
BUNK FLO
DECR.
STORED
CURSOR
ILLEGAL
INCaCUR.
POSITION
URSOR
ILLEGAL
CURSOH^ V
ILLEGA
LEAR WR
LINK FLO
I
UTERAL
BUS
ROlErTE
SEND 1st
BYTE
END UNPRQI
SEND 2nd
BYTE
END UNPRa
SAVE
CURSOR
CLEAR
CUR. UNE
ENABLE
AUX
XMiT.
CO TO "FPT
CURSOR
SEND lat
BYTE
-EOL-
l
SEND 2nd
BYTE
-EOL-
CUR. LINE
I
CLR.CUR.
POSITION
I
INCLCUR.
UNE
SEND 1st
byte EOM
i
SEND 2nd
BYTE EOM
FIRE TIME
TIME
GO TO "IDLE
SAVE
CURSOR
CLEAR
STORED
CURSOR UNE
LOVtK
CASE
SAVE BYTE
UNDER CURSORI
I
WHITE VC
CODE TO MEM
!
LCCODE—•R2
SAVED BYTE
TO MEMORY
I
FIRE TIMER
TIME
OUT
SEND 1st BYTE
- STX -
SEND 2nd BYTE
- ESC-
SEND LC CODE
FROM B2
I
SEND 3rd BYTE
-ETX-
I FIRE TIMER j
TIME
OUT

4^
( )
NUU
j:
Dt^L.
IN
V s
^BUKI-tK
C
''"iJ
PROrVCTKU
ISCR
CUK.
POSITIO.S
ILUGAL
CUAR
CURSOR
POSITION
GOTO^U*
ILUGAL
TO
TO*Bn
'
CK
COOK
cu:ah
CURSOR
POSL
GO
T0>-PT
•
HOML
CURSOR
GO rO^KPT
GO
TO
lUU
^TN
cursor)
DECR
STORED
LINE
COUNT
DECR
STORED
POS.
COUNT
ILLEGAL
INCR
CUR.
POSITION
ILUGAL
LEAR
CURSOR
posmoN
INCH.
CUR.
UNE
decr.
stored
UNE
coura
DECR
STORED
POS.
COUNT
U'
CODl
l\ck.cur.
UN^
CURSOR
ILLKGAL
FMT
MODK
SAVE
CURSOR
POSITION
ROU
SCRKEN
ERASL
OOTTOM
UNL
CURSOR
TO
KlftST
POS.
LAST
UNE
GOTO
ITTN
CURSOR
GO
TO'FPT
*
eKSH
COOK
*BKSP
Dt:CH
CUR.
POS.
:URSOR
ILUGAL
CO
TOW
CURSOR
TO
POS.
79
GO TO*UP •
PROTECTED
<;o
TO
lOU
GO TO'BICSP •
HARDWARE
CUAR:
CURPOSmOA
CUR
UN£
WRITE
PROT
FORMAT
GOTO^EOS
UXLCOUt
HRK
KbPCR
GO
TOW
m
coD^
INCR
CUR.
POSmON
ILUGAL
PROTkCTED
CLKAR
CUR.
POSITION
INCR.
CUR.
UNK
ILUGAL
IIO.MK*
CUKs^OM
CiOTO
ix:i
com
SWi.
CLKSOX
CUAR
CURSOR
UNK
\
IXJ
TO
•STARr
SKND
GO
ro*AD\.
FIGURE
4-3
BASIC
FUNCTIONAL
FLOW
DIAGRAM
CLKAR
INI'l'T
UL
VhkM
SKT
SK05
i;0
l O
KSl-.*V»Air*
(
ikl:
cuui
INSIKf
S.\\>
m 11
LMIl
K
flR.
IN
Kli«
\
URin
NKV
CCMJK
LMJI-N
CCKSUH
irh>Kf^ll
Ot-K
I
ja\k
cur.
posi
rioN
I.NCR
CIR.
PUSH
ION
ILLEGAL
PROTKTKIJ
MKMUM\
REG.
KKG.;:
MEMOR\
UKItl
M.k
I K I
M)KR
I'l
KM)tr
U>
CLK.AH
CURdUK
iVainON
I
INCR.
CLH
POSITION
UO
ru
•irrx
CURSOR

4^
I
CJ1
115/230 vAC INPUT
TRANSFORMER
BLOCK
RECTIFIER
RECTIFIER
RECTIFIER
H
M
FIGURE 4-4 POWER SUPPLY BLOCK DIAGRAM
+5 V
REGULATOR
+15
REGULATOR
+12
REGULATOR
-12 V
REGULATOR
+5 vDC
>
>
+15vDC
>
+12vDC
j-12vDC

4.3 DETAILED FUNCTIONAL DESCRIPTION
A detailed discussion of the BEE HIVE B100 termi
nal operation is contained in the following para
graphs. The Subassembly components of the termi
nal are functionally interdependent, however, the
isolation of various functions to the responsible
subassembly is relatively simple. The function of
each subassembly is also described. Schematic
diagrams are provided in Section VI of this manual.
4.3.1
Power Supply
The Power Supply provides +5, +15, +12, and -12
VDC voltages to the circuitry from a 115 or 230
VAC source at 50 or 60 Hz. Figure 4-4 is a block
diagram of the Power Supply subassembly. The
DC regulators utilized are overcurrent and ther
mally protected.
The power applied to the Power Supply is step
ped down in voltage. The transformer output
voltages are rectified by three bridge circuits.
The
output from the rectifiers and filters pro
vides power to the +5, +15, +12, and -12 VDC
regulator circuits.
4.3.2
Monitor
The monitor displays data on the CRT in a pattern
determined by the vertical and horizontal syn
chronization signals, and the video information
driving signals. A +15 VDC voltage is applied by
the Power supply to the Monitor. Appendix A
presents general and detailed data on the Moni
tor Assembly.
a3.3
Vertical Synchronization
Vertical synchronization is applied to the verti
cal oscillator and triggers it at the vertical re
fresh rate deternmned by the driving logic. The
vertical frequency is stabilized by the vertical
frequency control, which determines the point
of oscillation. The output pulse of the vertical
oscillator is applied to the driver amplifier
which shapes the pulse and is controlled by the
vertical linearity control. The output of the
driver amplifier is applied to the vertical
driver by way of the height control. The verti
cal driver output pulse is applied to the yoke
of the CRT and causes vertical deflection. The
refresh rate is 50 - 60 Hz. switch selectable.
4-6
4.3.4 Horizontal Synchronization
The horizontal synchronization pulses are applied
to the horizontal amplifierwherethey are ampli
fied and applied to the horizontal driver. The out
put of the horizontal drive is applied through the
width coil to the yoke, where it causesthe horizon
tal deflection. The horizontal deflection signal is
also applied to the flyback transformer. The hori
zontaldeflection signal isstepped up to approxi
mately 12 KV where it isthen rectified, filtered
and applied to the anode cap of the CRT to pro
vide the high voltage required.
4.3.5 Video Information
The Video Information is applied to the video amp
lifierby way of the contrast control, external to
the monitor. The video information signal from the
videoamplifier isapplied to the cathode of the CRT
gun to causean On/Off condition corresponding
to light patterns of the screen. The brightness con
trol is external to the monitor and varies the vol
tage on the accelerating grid of the CRT.
4.3.6 Keyboard
The keyboardiscompatiblewith ANSI standards.
Figure3.2 defines the ASCII codes available.
Figure 1.2 shows the keyboard layout.
The keyboard enables the operator to manually
input information to the terminal. When a key is
depressed, the keyboard logicgenerates the corres
ponding7-bit ASCII code and presents the data
in parallel form to the keyboard data lines. After
a short delayfor debouncing, the strobe is driven
to its active level and held there as long as the key
is held down. For those keys which auto repeat,
the strobe lineis pulsed at a 15character per second
rate. The BREAKkey is not encoded, but is a func
tion line that is driven low for approximately 400
milliseconds when the key is depressed.The follow
ingkeyscause special 8-bit (non-ASCII) codes:
AUXSEND, 1 t , CLEAR/HOME,SEND,
EOS, EOL, and DELETE CHAR. Thesecodesare
used iplecnal to the CRT only and are not transmitted.
4.3.7 Display Organization
The main timing chain (oscillator, dot position
counter, character position counter, character
height counter, and character line counter)

defines the configuration of the display on the CRT.
There are 30 lines, 6 of which are used for vertical
retrace and 24 of which are used to display charac
ters . The 30 lines are composed of nine scans each.
Each scan being composed of 96 character times,
80 for display and 16 for horizontal retrace. Each
character block is composed of 7 x 9 dot matrix
field which contains a 5 x 7 character matrix for
the displayed character.
Oscillator The oscillator is crystal controlled with
a frequency of 10.8864 MHz. Two 74H04's are
connected in series by a lOOpf capacitor. Each
74H04 has a 1 Kohm feedback resistor around it.
A 10.8864 MHz crystal is connected from the
input of the first 74H04 to the output of the
second. The output of the oscillator is buffered,
inverted and fed to the Dot Position Counter.
Dot Position Counter This divide-by-seven coun
ter defines each of the seven dots required to
compose one character. The outputs of this four
stage counter are labeled DPC1, DPC2, DPC4,
and DPC8. The Counter actually presets to a
count of 10, counts up through the overflow
point at 15 to a count of zero, and presets then
back to a count of 10. The Dot Position coun
ter output, DPC8, drives the Character Position
Counter.
Character Position Counter The Character
Position Counter is composed of two binary-
type counters that define 96 character times,
each being seven dots wide. The output of the
Character Position Counter drives the Charac
ter Height Counter.
Character Height Counter The Character Height
Counter is a standard counter that defines 9
scans of 96 characters each, with each charac
ter being seven-dots wide. The output of the
Character Height Counter drives the Character
Line Counter.
Character Line Counter The Character Line
Counter is a binary counter that starts at a
count of zero and counts to a maximum of 29
for a total of 30 character lines. The final out
put of this counter runs at the vertical refresh
rate.
Horizontal and Vertical Drive The Horizontal
4-7
Drive is started when the Character Position Coun
ter leaves the video area of the scan and is active
for the following 40 character times. The high
active output of this flip-flop is sent to the moni
tor on pin 9 of connector J1.
The vertical drive is generated during the time that
the Character Line Counter is decoding 26.
4.3.8
Cursor Location Counter
The Cursor Location Counter identifies the loca
tion of the cursor. This is a count made from the
Cursor Line Counter, called CURL, and the Cur
sor Position Counter^ called CURP. These two
counters, in conjunction with the ROLL counter,
are used to address the memory to determine the
entry point of the next character. The cursor loca
tion counters are compared with the next character.
The cursor location counters are compared with
the Character Position Counter and the Character
Line Counter to generate the signal called CNTR
CURSOR. This signal is used to generate the cur
sor displayed on the CRT. Also associated with the
cursor location counters is the appropriate circuitry
to move the cursor up, down, right, left, home,etc.
A LINE FEED code causes the Cursor Line Counter
to increment by one. A CARRIAGE RETURN code
clears the Cursor Position Counter.
With the terminal operating in FORMAT MODE,
when the cursor is incremented off the bottom
line, the cursor automatically wraps around to the
top of the display, i.e., the Cursor Line Counter
is reset to zero. However, if the terminal is not in
FORMAT MODE, the display scrolls whenever the
cursor increments from a count of 23.
Ascroll is initiated by any of 3 functions if act
ivated when the cursor is on the last line of the
display and the terminal is not in FORMAT MODE:
a. LINE FEED or CTRL J
b. CURSOR DOWNorESCB
c. If the cursor is on the last position
of the last line.
1. Cursor right
2. Any displayable character
3. Space

SCAN 0
CHARACTER
DISPLAY
SCAN 8
DOT 0
BLANK
f
♦o o
o •
o •
o •
o •
o •
o •
•o o
♦o
CHARACTER
DISPLAY
A.
o o o
o o o
ooo
o o o
• • •
o o o
o o o
o o o
o o o
DOT «
BLANK
DOT 0
BLANK
o o
• o
• o
• o
• o
• o
• o
• o
o o
• o
o o
• o
o o
o o
o o
o o
o o
o o
o o
o o
(—
o o
o •
o •
o •
o •
o •
o •
o •
o o
o o
o o
o •
o •
o •
o •
o •
o •
o •
o o
o o
SCAN 9
FOR CURSOR
SCAN 0
♦o o o o o
CHARACTER
DISPLAY
SCAN 8
O •
o •
o •
o •
o •
o •
o •
>o o
SCAN 9 O
FOR CURSOR
o o o
o o o
• • •
o o o
o o o
o o o
o o o
ooo
FIGURE 4-5
CHARACTER DOT MATRIX
4-8
CHARACTER
DISPLAY
A.
o o o
• • •
o o o
o o o
• • •
o o o
o o o
o o o
o o o
o o o
o o o
o o o
o o o
o o o
• • •
o o o
ooo
o o o
o o o
o o o
DOT 6
BLANK
—\
o o
• o
o o
o o
o o
o o
o o
o o
o o
o o
o o
• o
• o
• o
• o
• o
• o
• o
o o
o o

cb
osc
DPC1
DPC2
DPC4
DPC8
j"ijajn_rLJ"ijn
nrui
—I
r-Lj—^
ru—^^—I
u1
CHAR
FREQ=
10.8864
MHz
DOT
POSITION
COUNTER
FREQ=
1.5552
MHz
CHARACTER
POSITION
COUNTER
CPC1
jTjmjTJumrmnjTJijmJiJinjinLriri^^
CPC2
CPC4
_
CPC8
CPC16 CPC32
CPC64
CPC80
j—^^—L_rn_r
FIGURE
4-6
TIMING
DIAGRAM

O
CHCl
CHC2
CHC4
CHC8
j—M—^ r
CLC2_| t_J L_l l_J L_J L I I—T"
CLC4 I I I 1 I I I
CLCB
CLC16
CLC32
cLci_n_in
CLC2
CLC4
CLC8
CLC16
CLC32
I
LJl
n_rLJ"iTTJ~m
1 r
FIGURE 4-7 TIMING DIAGRAM
CHARACTER HEIGHT
COUNTER
FREQ. = 1.800 KHz
CHARACTER LINE
COUNTER
(50 Hz OPERATION)
FREQ = 60 Hz
CHARACTER LINE
COUNTER
(60 Hz OPERATION)

4.3.9 Memory
The page memory is actually a 2048 byte memory.
Each byte consists of 9 bits: 7 for data, one for
protect, and one for blink. Of these 2048 bytes,
1920 are displayable. The program does not have
the capability of displaying or writing Into the
remaining 128. In order to write data into the
page memory from the receiver, the memory
address is muxed over to the cursor location
registers and the signal WRITE is generated. The
UART Is then reset and is capable of receiving
the next character. The page memory output
is sent to the character generator input buffer
at the proper time to generate the displayable
characters.
The program has the capability of
shutting down the screen refresh for any given
operation to increase
the program operating
time.
4.3.10 Character Generator
The Character Generator is a read-only memory
(ROM) that is addressed by the character (in
ASCII). The scan configuration and the charac
ter indicates the pattern desired on that scan,
-ive-bit dot patterns are generated which form
portion of acharacter. The output of the
character generator is applied to the parallel-
to-serial video shift register.
4.3.11 Video Shift Register
The paraliel-to-serial Video Shift Register is ^
loaded with data by the low-active signal, DPC8,
and is clocked by
the main oscillator output. The
dots are shifted out, mixed with cursor Informa
tion, and blanking signals, and applied to the
monitor through the CONTRAST control as
video information^
4.3.12 Input/Output Operations UART (Receiver)
Data can be received by the B100 from one of
three sources; from the I/O interface into the
receive side of the UART or from the keyboard
through the transmit side of the UART to the
receive side of the UART.
The UART is driven by a clock generated inter
nally off
the main counter chain. No separate
oscillator is required. Arotary switch located
4-11
on the back panel switches the clock rate for
operation from 75 to 19200 baud. The times 16
clock is then applied to the transmitter and re
ceiver of the UART.
The El A line receiver receives data at RS 232C
levels and gates them into the UART when the
B100 is on-line. Through the same gating, data
is brought.in from the transmit side of the UART.
The data is brought into the UART where it is
converted to parallel (seven bits) data.
4.3.13 UART (Transmit)
The keyboard data lines for bits 1 through 7 are
applied to the transmit input data lines along with
the seven BUS lines. Also coming from the key
board circuit is a load signal which triggers the
UART to initiate the transmission. As the UART
receives the character for transmission, it performs
the appropriate parity generation, provides one or
two stop bits, divides the XI6 clock to get the baud
rate, and transmits the character. The character is
applied through an EIA RS 232C interface to the
computer or modem. Also coming from the UART
is output data at a TTL level which is applied to
the receiver side of the UART through the previously
mentioned logic. The EIA interface includes a Data
Terminal Ready signal which indicates the status
of the B100 to the computer and a Request to Send
signal which indicates that the terminal has data to
send to the computer. The Clear-to-Send line coming
from the computer is monitored at the EIA RS 232C
interface levels. It is received by aline receiver which
converts it to TTL levels and applies it to the UART
clock control circuit to control transmission. An
optional times 8clock (TTL levels) is available as
part of the interface. The BREAK key is on the key
board and enables a timer which holds the transmit
data line in a spacing condition for a predetermined
length of time.
4.3.14
Block Send Circuit
The Block Send feature allows the operator to com
pose amessage on the terminal screen and then,
by depressing the SEND key, cause the terminal to
send the entire message to the computer at the selec
ted baud rate.
The sequence of operations is described in Figure 4-1.

The operation is as follows:
1. Raise Request-to-Send
2. When Clear-to-Send, send STX (002)
header.
3. Send data
4. If FORMAT and END OF PROTECTED
FIELD, send HT code (005).
5. If not FORMAT and END of LINE,
send CR/LF sequence.
6. When end of message, send ETX (003)
7. Time out and drop Request-to-Send.
4.3.15 Auxiliary Send Circuit
The Aux Send feature is identical to the Block
Send except for two points:
1. The message is transmitted out the AUX
Port instead of the Main I/O Port.
4-12
2, The delimiters sent at the start of mes
sage, end of unprotected field (135),end
of line (134), and ETX (003) are selected
from a different portion of the Block
Send ROM.
4.3.16 Special Function (F1-F16)
Sends a code sequence to the computer from the
terminal. The code is instigated by pressing any one
of the 16 function keys.
1. An STX is transmitted (002)
2. An Escape code (033)
3. Code character (see ASCII Code Chart
Table 3-2)
4. And ends with an ETX (003)

SECTION V
Maintenance
5.1
INTRODUCTION
This section contains information to aid in the
maintenance of the B100 Terminal. Preventive
and corrective maintenance procedures are
specified as well as troubleshooting aids and
techniques.
5.2 PREVENTIVE MAINTENANCE
No scheduled periodic maintenance is required.
However, several precautions can be taken
periodically to ensure proper operation. Care
should be exercised to see that there is proper
air circulation for the fan. The terminal should
not be placed on a shag carpet or other soft sur
face that could impede the air entrance to the
fan. Special care must be taken to ensure that
no paper or other loose articles are placed under
the terminal. The degree of dust density inthe
air should be considered in selecting the location
of the terminal.
The interior of the unit may be wiped free of
dust. Accumulation of dirt causes overheating and
component breakdown. Dirt acts as an insulating
blanket and prevents efficient heat dissipation. A
small brush is very useful for dislodging dirt; a cot
ton-tipped applicator isgood for narrow or hard
to get places.
The following isa list of the troubleshooting aids
that are provided in this manual to assist in the
troubleshooting of functional failures.
5-1
Circuit Schematics
Detail Block Diagram HSee Section IV,
Functional Flow Diagram Figures 1, 2 & 3)
Timing Diagrams (See Section IV,
Figures 6 & 7)
Glossary of Terms (See Appendix)
Troubleshooting Flow Diagrams
Disassembly/Assembly Procedures
Adjustment Procedures
Configuration/Strapping
Information
Character Dot Matrix
(See Section II)
(See Section IV,
Figure 5)
5.2.1
Troubleshooting Equipment
The following isa listof tools and standard equip
ment required to repair a B100 Terminal:
V/0 Multimeter
Oscilloscope
Assorted Electronic Hand Tools
5.3
CORRECTIVE MAINTENANCE
This section provides corrective maintenance
information to aid in servicing the B100 Terminal.
It issuggested that the configuration sheet and the
turn-on procedure be consulted before performing
the corrective maintenance described here. See
page 3-1.

5.3.1 Troubleshooting Preliminary Considerations
The most common problem occuring in B100 are
switch, control and operation^elated. A simple
procedure may be followed to help determine if
the problem is control and/or operation-related
or internal circuitry related by checking the
following:
Illegal Operation {Refer to Section II)
Improper Baud Rate Setting
Wrong Transmit or Receive Mode
Loose Interconnect Cable
5.3.2 Troubleshooting Flow Diagrams
A list of trouble-shooting flow diagrams is given
in Table 5-1. This index lists apparent failure
and refers the user to the proper flow diagram.
The Table is only intended to allow the user to
varify the component where trouble exists, and
not to indicate the specific problem. The user
is advised to swap the defective component and
have that component repaired or replaced by an
authorized service agent.
1. Find the apparent trouble in the Trou
bleshooting Flow Diagram Index.
2. Proceed to the specified Troubleshoot
ing Flow Diagram in the diagram section
and begin the troubleshooting procedure.
3. If an adjustment procedure is referen
ced in the Troubleshooting Flow Diagram,
perform the adjustment and return to the
flow diagram to complete the trouble
shooting process.
4. Reference is made to Timing diagrams
contained in (Section VI) this manual.
5.3.3 Full-DOplex Echoplex Test
A specially wired connector may be assembled
that will allow the operator to perform this test.
This connector tester allows the terminal to be
operated and tested independent of an external
data device. The connector mates with the Main
I/O Port. Set-up for the test is as follows:
FDX (Full
Duplex Mode)
Baud
Rate -- Any Setting
Test Connector Installed
in the I/O Port
5-2
Enter data from the keyboard as you would if
you were on-line to a computer. If data is dis
played on the screen properly, then the 8100
is transmitting and receiving data properly.
• The Test Connector is wired as follows:
(Refer to Figure 5.1.)
Connects Transmitted Data Line out of
the terminal to received data line into the
terminal. Pin 2 to Pin 3 of the I/O Port.
Pin 3
Pin 2
Jumper between
Pjn 2 and Pin 3
CD
0
Amphenol Male Type
Connector
Beehive Part No. 606-0011-25 AP
Amphenol Part No. 17-20250-1
Figure 5-1
ECHOPLEX TEST CONNECTOR

Table5-1. Troubleshooting Flow Diagram Index
Apparent Failure
Troubleshooting
Flow Diagram
GENERAL
No raster present >
5-1A
No raster present
5-1B
OFF LINE
Cursor either absent,multiplecursors, cursornot in homeposition or
screen filled with video blocks
5-2A
Nocharacter displayed when written,non cursor advance
5-2B
Wrong character displayed
5-2C
No escape functions
5-2D
No control functions
5-2E
ON LINE
No data being transmitted
5-3A
Transmits invalid data
5-3B
No reception
5-3C
Receives invalid data and/or improper parity
5-3D
DISPLAY
Alldisplayed characters out of focus
5-4A
Rolling display
5-4B
Display too tall/short for screen size
5-40
Height of displayed characters uneven
5-4D
Display too wide/narrow for screen size
5-4E
Display not centered
5-4F
Tilted display
5-4G
Others
A. Single vertical line
B. Physical damage
C. Dot in center of screen
D. Uneven intensity/focus
E. Burned phosphor
F. Uneven display dimensions
G. Excessive H.V. Arcing
5-4 H
5-3

START
IS KBD
PLUGGED
IN
YES
IS
•^BRIGHTNESS""
CONTROL
ADJ
YES
IS
MONITOR
PLUGGED
IN
YES
IS
15VDC
PRESENT
.MON PI2-6.
YES
IS
HORIZ
DRIVE SIGNAL
PRESEN
NO
PLUG
IN
KEYBOARD
ADJUST
BRIGHTNESS
CONTROL AT
REAR OF UNIT
NO
PLUG
MONITOR
IN
IS
PROBLEM
SOLVED
IS
PROBLEM
SOLVED
IS
PROBLEM
SOLVED
PRESENT
NO
^^^GIC CAR^^
1 YES
REPLACE WIRING
HARNESS FROM
LOGIC CARD TO
MONITOR
N
LOGIC
CARD
BOARD
YES
REPL
MON
ACE
ITOR
5-1A
(ZED
5-4