Tektronix 4921 User manual

TEKTRONIX
R
4921/ 4922
FLEXIBLE
DISC
MEMORY
For
4010 -
Series
Term inal
USERS
INSTRUCTION
MANUAL
Tekt ronix ,
Inc.
P.O.
Box
500
Beavert on
,
Oregon
97077
Serial
Num ber
070-1758-00
First
Print ing
JAN
1975

WARRANTY
All Tekt ronix
product s
are
warrant ed
against defect ive
m at erials
and
workm anship
for one
year .
Addit ionally ,
TEKTRONIX
Com put er Term inals , Calculat ors and relat ed peri pheral
equi pm ent
are fully
warrant ed
against any
trouble for
the first
90
days
. Any
equi pm ent
trouble
occurring
to
those
TEKTRONIX
product s during
the 90 day
peri od will be
repaired by
TEKTRONIX personnel at no charge . Quest ions regarding this
warrant y
should be
discussed
wit h your
TEKTRONIX
sales
represent at ive .
3
Specifications and price change privileges reserved .
U.S.A. and foreign TEKTRONIX product s covered by U.S. and
foreign pat ents and / or pat ents pending .
TEKTRONIX is a regist ered t radem ark of Tekt ronix , Inc.
Copyright  1975 by Tekt ronix , Inc. , Beavert on , Oregon . Printed
in the Unit ed States of Am eri ca . All rights reserved . Cont ents of
this publicat ion m ay not be reproduced in any form wit hout
perm i ssion of
Tekt ronix , Inc.

4921/ 4922 Users
TABLE
OF
CONTENTS
SECTION 1
Page Page
1-1
1-1
1-1
1-2
2-1
2-1
2-2
2-3
2-3
1-2
DESCRIPTION
INTRODUCTION
Standard Accessories
Opt ional
Accessories
CHARACTERISTICS
Flexible Disc Mem ory Tim e
Charact erist ics
Flexible Disc
Cart ridge
Charact erist ics
Operat ing
Modes
Status Charact er
Error
Checki ng
Writ e Protect ion
Line Term inat or
Data Transfer Rat e
Special
Considerat ions
Ot her
Syst em Feat ures
CONTROLS
AND
INDICATORS
POWER Swit ch and Indicat or
START Swit ch
LOAD ADDRESS
Swit ch
TRACK BEGIN Swit ches
CURRENT TRACK Indicat ors
Swit ch 1
Swit ch 2
TERMINAL BUSY Indicat or
DISC BUSY Indicat or
FILE
UNSAFE
Indicat or
DISC ERROR Indicat or
RESET But t on
PROMPT MODE Swit ch
Manual -
Aut o Swit ch
CLOSE FILE
But t on
FILE OPEN Indicat or
DISC 1 / DISC 2 Swit ch
READY Indicat ors
PROTECT Indicat ors
DUPLICATE But t on
BUSY DUP Indicat or
Rear Panel
PHYSICAL DIMENSIONS
ENVIRONMENTAL
SPECIFICATION
2-3
2-5
2-5
2-7
2-8
2-10
2-10
SECTION 2 OPERATION
INSTALLATION
CARTRIDGE LOADING
CARTRIDGE CARE
DISC DRIVE CARE
OPERATING INTRODUCTION
TERMINAL OPERATING
CONSIDERATIONS
MANUAL OPERATION
Paper
Tape
Mode
Sect or Mode
Transparent
Mode
Prom pt
Mode
Duplicate Mode
PROGRAM - CONTROLLED
OPERATION
General
Cont rol
Com m ands
Read / Writ e Com m ands
Addressing
Com m ands
Paper
Tape
Mode
Sect or Mode
Transparent Mode
Prom pt
Mode
Com put er and Com put er
Int erface Modes
1-2
1-3
1-4
1-4
1-5
1-5
1-5
1-6
1-6
1-7
1-7
1-7
1-7
1-7
1-7
1-8
1-8
1-8
1-8
1-8
1-8
1-8
1-8
1-8
1-8
1-8
1-8
1-8
1-9
1-9
1-9
1-9
1-9
2-10
2-10
2-10
2-12
2-15
2-15
2-17
2-18
2-20
2-20
SECTION 3 SUPPLEMENTAL INFORMATION
AC POWER REQUIREMENTS
3-1
AC
Power Cord and
Grounding
Requirem ent s
3-1
Line Volt age Selection
3-1
Changing
Frequency
Selection
3-2
FUSES
3-4
BELT REPLACEMENT
3-4
CLEANING
3-4
STRAPPABLE OPTIONS
3-5
APPENDIX
ASCII CODE CHART
1-9
CHANGE INFORMATION
i
REV
.
A ,
JAN .
1976

10
TRAE
-
ABAD
ADDRESS
ANONY
BTRAY
TEKTRONIX
U10
DOUCH
TEKTRONIX
CURRENT
TEXXX
NNNNNN
LOS
ADOS
--2
Oin
Fig . 1-1 . 4921
and 4922
Flexible
Disc
Mem ory
Unit s .
4921/ 4922
Users
@

4921/ 4922 Users
Sect ion 1
DESCRIPTION
INTRODUCTION
The 4921 and
4922 ( Fig . 1-1
) are
Flexible Disc
Mem ory
unit s that provide an alt ernat ive to tape cassett es , car
tridges , paper tapes , and card readers . On st andard unit s ,
inform at ion m ay be recorded from the t erm i nal , from the
com put er , or bot h . Data is st ored on a rotating disc ;
st orage and recovery are sim i lar to recording and playing
m agnet ic tape . The 4921 is a single disc drive unit , and the
4922 is a dual disc drive unit . Operat ions for bot h unit s are
ident ical except for the added capabilit ies of the dual disc
drive unit ; references to disc 2 do not apply to the 4921 .
which prot ect s it during handling , operat ion , and st orage .
The disc and envelope together are called the Flexible
Disc Cart ridge . The disc is vert ically m ount ed in the drive
unit during operat ion , and should be st ored vert ically in a
st orage envelope to
prevent dust and
soil from ac
cum ulat ing
on the
surface of the
disc . Wipe
cushions
bonded to the inside of the flexible plast ic envelope help to
keep the disc clean during operat ion .
This
m anual
provides
inform at ion on
operat ing the
4921/ 4922 in a 4010 - Series Term inal environm ent . In
addit ion , inform at ion on operat ing the device wit h the
Tekt ronix 31 Calculat or is found in the 4921/ 4922 ( Opt ion
4 ) Flexible Disc Mem ory for " 31 " Calculat or Envi ronm ent
Users
Manual
.
Each disc has 64 tracks ( 00-63 ) , wit h 32 sect ors ( 00-31 )
in each track . Each sect or cont ains 128 eight - bit byt es , for
a tot al disc capacit y of 262,144 byt es ( 2,097,152 bit s ) of
dat a st orage . During recording , inform at ion is inserted
int o a " file " , which m ay encom pass any num ber of sect ors
and tracks . ( A file is ident ified as all inform at ion between
the st art of a recording and an end - of - file com m and ; the
end - of - file
com m and m ay be
program m ed or
m anually
inserted . ) Data prot ect ion is provided in the unit ; recor
ding and playback error detect ion are st andard feat ures .
Service inform at ion on the Flexible Disc Mem ory is
divided int o two basic areas . These are the basic Flexible
Disc Mem ory unit ( including the st andard circuit boards ,
the drive unit , and power supply ) , and the int erfaces
between the Flexible Disc Mem ory and another device .
Therefore , to provide com plete service on the Flexible
Disc Mem ory , it is necessary to refer to the Flexible Disc
Mem ory Service Manual and to one or m ore of the
int erface m anuals , depending on the device ( s ) wit h which
it is being used . The m anuals are as follows :
The Flexible Disc Mem ori es operat e in three basic
m odes - Paper Tape , Sect or , and Transparent . In addi
tion , Prom pt Mode ( a subset of Paper Tape Mode ) can be
selected from the front panel . All m odes are fully explain
ed lat er in this m anual . The st andard Flexible Disc Mem ory
unit int erfaces to any Tekt ronix 4010 - Series t erm i nal , and
through the t erm i nal to a com put er ( Fig . 1-2 ) .
Standard Accessories
Users Manual for 4010 - Series Term inal Envi ronm ent
070-1758-00 4921/ 4922
Flexible
Disc
Mem ory
Unit
Service Manual 070-1825-00
1 Flexible Disc Cart ridge ( 119-0666-00 ) per drive unit
021-0144-00 4010 - Series Term inal Int erface
1 Writ e Protect tab ( 214-2207-00 ) per drive unit
for
4921/ 4922
Flexible Disc
Mem ory
Inst ruct ion Manual
070-1898-00
021-0156-00 " 31 " Calculat or Int erface
Opt ional
Accessories
4921/ 4922 Flexible Disc Mem ory Unit
for 4921/ 4922 ( Opt ion 4 ) Flexible Disc Mem ory
Inst ruct ion Manual
070-1829-00
Service Manual
070-1825-00
021-0144-00 4010 - Series Term inal Int erface
The Flexible Disc on which dat a is st ored is a flat disc
com posed of a Mylar base coated wit h a m agnet ic oxide . It
is perm anent ly encased in a flexible plast ic envelope ,
for 4921/ 4922 Flexible Disc Mem ory Unit
Inst ruct ion Manual
070-1898-00
1-1

Description
-
4921 /
4922
Users
TERMINAL
COMPUTER
OD
D1015
00
DUD
 
HITTI
I
19
nu
AS
FLEXIBLE
DISC MEMORY
DOLED
COBETO



fe
O
@
:::
.
33
Com m unicat ion
Link
Data
Com m unicat ions
Int erface
Term inal
to - Disc
Int erface
1758-1
Fig . 1-2 . Standard Flexible Disc Mem ory posit ion in a 4010 - series t erm i nal syst em .
Addit ional
Flexible
Disc
Cart ridges
TABLE
1-1
Tim e
Charact erist ics
Package
of 5
119-0666-01
Package
of
10
119-0666-02
Disc
Rot at ion
Speed
375 RPM
Tim e per Revolut ion
160
m s
Track to Track Access Tim e
15
m s ,
plus 5
m s head
sett ling
t im e
at the
ad
dressed track .
Maxim um Track
Access
Tim e
945 m s , plus
5 m s set
tling
t im e
Head Load Tim e
40 m s m inim um
Addit ional Writ e Protect Tabs
Package
of
20
214-2207-01
CHARACTERISTICS
TABLE 1-2
Cart ridge
Charact erist ics
Cart ridge
Size
Flexible Disc Mem ory Tim e Charact erist ics
Table 1-1 sum m ari zes the t im e characterist ics of the
Flexible
Disc
Mem ory
unit s
.
Disc Size
Tracks per Disc
Sect ors per Track
Sect or
Capacit y
Bytes per Disc
( 8 - bit byt es
)
Bits per Disc
Recording
Mode
Recording Densit y
8 inches x 8 inches
x 1/ 16
inch thick
7.5 inch di am eter
64
32
128 eight
- bit dat a
byt es
262,144
2,097,152
Frequency
Modulation
3100 bit s per inch
Flexible Disc Cart ridge Charact erist ics
Table 1-2 sum m ari zes the characterist ics of the disc
m edia used in the Flexible Disc Mem ory unit s . The
configurat ion of the disc is shown in Fig . 1-3 .
1-2
@

Description - 4921 / 4922 Users
Keying
not ch
Sect or
holes (
32 )
O
O
o
O
o
O
O
Index
/
Sect or
access
hole
Track 00
07
To
lo
.
01
Read / Writ e
head
opening
TO
1
1
10
01
!
10
Track 63
O
Opening
for
driving
hub
lo
Index hole
Plastic
envelope
1758-2
Fig . 1-3 . Disc
cart ridge
and disc
configurat ion
.
Writ e Operat ing
Modes
The three basic operat ing m odes are out lined in Table
1-3 . Details regarding these m odes can be found in the
Operat ion
Sect ion .
Writ e
File if
accessed
m anually ;
Writ e Sect or or File if accessed
from Program Cont rol , dependent
upon dat a cont ained
in
Writ e
com
m and
.
Writ e
can
be
int errupt ed
by
DC4 , which returns it to Writ e
Enable
Status
.
1
TABLE 1-3
Operat ing
Modes
Operat ion
Feat ures
Duplicate
Paper
Tape
Mode
Feat ure of 4922 only . Front Panel
Cont rolled .
Perm it s
m ak ing
iden
tical copy of disc 1 on disc 2 .
Em ulat es a Paper tape reader
perforat or ;
unit act s on
cont rol
com m ands cont ained in dat a be
ing processed .
Transparent
Mode
Provides
Read and Writ e
Operat ions of
Sect or or File
.
Read Enable
Perm it s
unit
to
read in
response to
Front
-
panel
START or
program
DC1 .
Read
Read
Accessed by any Read com m and .
Read to end of sect or or file ,
dependent
on
com m and
received .
Once ent ered , unit ignores com
m ands from out side sources ; reads
and
t ransm it s dat a wit hout
decoding
it until end
of
sect or or
file is reached .
Reads file if
accessed
m anually in
Paper Tape Mode
; reads eit her File
or
Sect or if accessed from
Program
Cont rol ,
dependent
upon
dat a cont ained in Read com m and .
Read
can
be
int errupt ed
by DC3 ,
which returns it to Read Enable
Status . Read
can also
be in
terrupt ed by
program m ed
CR if
Front Panel PROMPT MODE
swit ch is on . Read cont inues aft er
Prom pt Charact er is received .
Writ e
Accessed by any Writ e com m and .
Writ es until end of
sect or
if
Writ e
Sect or was sent , and then returns
to Transparent Mode . Writ es until
CLOSE FILE
but t on
on
unit is
pressed
or
until end
of
disc is
reached , if Writ e File was received .
Will not decode or ot herwise act on
dat a ( com m ands ) during Writ e
Operat ion .
Writ e Enable
Perm it s
unit to
write in
response to
Front -
Panel
START
or
program
DC2 .
1-3

Description 
4921 /
4922
Users
Sect or Mode
Read and
Writ e Operat ions
are
lim it ed to
one sect or at a
t im e ,
regardless
of
whet her
a file
or
sect or
com m and is
received .
Parit y Error . Each character is Parit y checked as it is
received from the Term inal or Com put er . Even though a
character cont ains an error , it is writt en on the disc and
( unless the sect or is rewrit t en ) the error will be read back
during
a
Read
rat ion . When an error is detect ed , the
parit y error
bit of the st at us
character
is set to one
.
Read
Sect or
Accessed by any Read com m and ;
once enabled ,
reads to
end of
sect or (
regardless
of
which
Read
Com m and
was
received
)
and
returns to Sect or Mode . Unit
t ransm it s all dat a and
ignores all
cont rol com m ands ( regardless of
source )
during
Read
Sect or
Operat ion .
Parit y Error
checking m ay be
set for even
parit y , odd
parit y , or disabled , and is cont rolled by a st rap on one of
the int erface cards . Refer to Strappable Opt ions in Sect ion
3 of this m anual for a descript ion of the operat ion of this
st rap in the various Flexible Disc Mem ory options .
Writ e
Sect or
Accessed by a Writ e com m and .
Once enabled , condit ion rem ai ns
until 128 characters are writt en
int o the
input
buffers
( end
of
sec
tor ) regardless of which Writ e
com m and was received , and the
file is then closed . Unit records all
dat a
wit hout
decoding
any
cont rol
com m ands during Writ e Sect or
Operat ion
Checksum Error . This error check occurs in Sect or or
Transparent Mode only . When enabled ( a cut - st rap on the
Disc - to - Term inal card can be cut to disable this check ) an
ent ire sect or of dat a ( 128 characters ) sent by the com put er
is checked . A seven - bit accum ulat or st arts a sect or set to
all zeros . As dat a is received , the 7 least significant bit s are
added to the accum ulat or using an end around carry . * The
128t h character m ust be a checksum , which will cause the
accum ulat or to be all ones . If the 128t h character does not
cause all ones in the accum ulat or , the parit y error bit of the
st at us character is set .
I Disc Error . Disc Error checking occurs during a Writ e
( to disc )
Operat ion or a Read ( from
disc )
Operat ion . These
errors m ay be caused by a defect in the disc , by a dam aged
disc , or by
dust or
im purit ies on the
Read / Writ e
head .
Status
Charact er
A st at us
character
is
sent by the
unit upon
receipt
of a
Send
Status com m and from
the
t erm i nal or
com put er
.
The
first six bit s of
that
character
cont ain
inform at ion
as
list ed
in Table 1-4 , Error bit s ( bit s 5 and 6 ) are reset aft er
t ransm ission .
Disc Error Checki ng m ay be disabled by st raps on the
Buffer Cont rol card to operat e at higher baud rat es ( see
the
Buffer
Cont rol card
st raps
) .
TABLE 1-4
Status
Charact er Bit
Assignm ent s
I
Charact er Bit Status Inform at ion indicat ed by True Bit
Bit
1
(
LSB )
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
Bit 8
Disc 1
Ready
Disc 1
Writ e -
prot ect ed
Disc
2
Ready (
4922
only )
Disc 2 Writ e
-
prot ect ed
(
4922 only )
Parit y Error or Checksum Error
Disc Error (
during
Read
or Writ e )
Redundant (
com plem ent of Bit 6
)
Not used
as
st at us
indicat or
(
Parit y
Bit )
During a Writ e Operat ion , the buffer cont ent s are
writt en on the
disc , but st ill rem ai n
in the buffer
. A Read
Aft er - Writ e sequence then occurs to com pare the dat a just
writt en on the disc to the dat a st ill in the buffer . If an erroris
detect ed during the Read - Aft er - Writ e sequence , the dat a
is writt en again and another Read - Aft er - Writ e occurs . If
the error persists , the dat a rem ai ns on the disc but the Disc
Error bit of the st at us character is set to one , and the DISC
ERROR light on the
front panel
light s .
Error
Checki ng
The
Flexible
Disc
Mem ory
unit s
accom pli sh two
types
of error checking . These are Received Data Error check
ing and Disc Error checking . Received Data Error check
ing includes Parit y Error checking and Checksum Error
checking
;
this
checks
dat a
as it arrives
from the
com put er
or
t erm i nal
.
Disc Error
checking checks for errors
during
Read and Writ e Operat ions wit hin the Flexible Disc drive
unit .
During a Read
Operat ion , the
error check occurs
aft er
the sect or being
read is placed
in the buffer
. If an error is
detect ed , the dat a is read and checked again , up to a tot al
of four t im es . If the error persists aft er the fourt h read , the
dat a is
t ransm it ted .
However , the
Disc Error
bit of
the
Status Charact er is set true and the front panel DISC
ERROR light
turns
on .
* In end - around addit ion , when two seven digit binary num bers
are added and the sum is an eight digit num ber ( i.e. , 0101010+
1101010 = 10010100 ) , the eight h digit is m oved to the first digit
colum n and is added there ( i.e. , 0101010 + 1101010 = 0010101 ) .
1-4
REV.A , JAN . 1976

Description 
4921
/
4922
Users
Read Operat ions . 6400 baud m axi m um ( average ) ,
cont inuous
asynchronous
.
Writ e - Protect ion
Writ e - Protect tabs m ay be at t ached to the disc car
tridge to prevent dat a on the disc from being writt en over ,
and thereby lost . When a write - prot ect ed disc is inserted in
a disc drive , the PROTECT indicat or light s and dat a
cannot be writt en from the buffer to the disc . An at t em pt ed
Writ e Operat ion to a write - prot ect ed disc will result in lost
dat a . The soft ware - act ivat ed st at us character cont ains
Writ e - Protect inform at ion for use by a program .
Flagged Operat ion . If the t erm i nal - to - com put er int er
face is flagged , the flagging cont rols the dat a transfer rat e .
Great ly
increased dat a
rat e m ay
be
obt ained by 1 )
disabling
disc error
checking
and 2 )
transferring
dat a
at
the
m inim um
rat e specified
in
Table
1-5 . If
the
dat a
transfer
is slower
than
specified in
the
Table , then
the
act ual
dat a
rat e will be
reduced .
However , the 4921
or 4922
will st ill
function
at
slow
rat es like 300
baud .
Line Term inat or
TABLE
1-5
The Line Term inat or is an out put from the Flexible Disc
Mem ory that not ifies the com put er when a disc function is
com pleted . It m ay be one or two characters , depending on
the requi rem ent s
of the
syst em in which
the unit is
used .
The availabilit y of the Line Term inat or and the m ethod of
det erm i ni ng the character ( s ) is described under Strap
pable Opt ions in Sect ion 3. The Line Term inat or is sent at
the following t im es :
Sect ors
per
Revolut ion
8 4
N
w
1
Mini m um
Baud
Rat e
(
to
achieve
m axi m um
dat a
transfer rat e ,
10
-
bit
byt es
)
1 ) Im m edi at ely
following the
Status
Charact er when
Disc Status has been request ed .
92,000
37,700 17,300 8,300
2 ) When reading dat a from the disc in Prom pt Mode
and a CR is read , CR is suppressed and the Line
Term inat or is sent .
Inst rum ent s wit h serial num bers beginning wit h B01
and BO2 are set , when shipped , for one sect or per
revolution .
Inst rum ent s wit h
serial
num bers
beginning
wit h BO3 are
set , when
shipped ,
for 8
sect ors per
revolution
.
3 ) At the end of a Disc - to - Term inal or Term inal - to
Disc transfer that was com m anded by the com
put er , and from which the com put er was excluded .
On a Term inal - to - Disc transfer ( from which the
com put er
was
excluded )
the Close
File
com m and
m ust be given
by the
operat or from
the
keyboard .
This closes the file and sends the Line Term inat or to
the com put er .
NOTE
Changing from
one sect or
per revolution
to 8 , 4 , or 2
sect ors per revolution causes incom pat ibili ty of dat a
discs because the dat a is located physically in
different locations on the disc cart ridge .
a
4 ) In the event the com put er com m ands another
peripheral to
write to the Disc
, the
peripheral m ust
com m and a Close File so that the Line Term inat ori s
sent . Ot herwise the com put er will have no way of
knowing that
the peripheral
has com pleted
writing
to the disc . If
the peripheral
cannot
com m and a
close file , the
operat or will
have to send
the Close
File com m and from the Term inal keyboard ; as is
done
following a Term inal -
to - Disc
transfer opera
tion
.
Convert ing
Data
From
One
Form at
To
Anot her
.
For
exam ple
, if you
have
a
num ber
of
disc cart ridges
that
have
been recorded
using a
one
sect or per
revolution
form at
and you
desire
to
convert the
dat a to the
8 sect or
per
revolution
form at , use the
following
procedure :
1 ) Use
a
4922 as it
cont ains Disc
1 and
Disc
2
operat ion .
Strap
Disc
1
Buffer
Cont rol
card
for
one
sect or
per
revolution
( the
present
form at of
the
dat a
on the dat a disc cart ridge ) .
5 ) At the
end of
every
Read File
Operat ion ,
unless the
End of Read File Term inat or Strap is cut .
2 ) Strap Disc 2 Buffer Cont rol card for 8 sect ors per
revolution ( the new dat a form at ) .
Data Transfer Rat e
Writ e
Operat ions . 1200
baud
m axi m um
, cont inuous
asynchronous .
3 )
Place a disc
cart ridge
recorded
wit h
the old
form at
in Disc 1 .
1-5
REV
. A
, JAN
.
1976

Description -
4921 /
4922
Users
4 )
Place a
blank Disc
cart ridge in
Disc 2 .
face
t ransm it s
one
character
(
unpredictable as to
which character ) prior to the Line Term inat or . The
soft ware
m ust
take
this
ext raneous
character int o
account
,
or else the
com put er will not
recognize
the
Line
Term inat or
.
5 )
Perform a
Duplicate
operat ion
.
6 ) Disc 2 now has the dat a st ored in the new form at .
7 )
Convert all ot her Discs
to the new
form at .
Ot her
Syst em
Feat ures
Echoplex
Suppression .
The 4921/ 4922 Status
character
is
sent
following a Send
Status
Cont rol com
m and ( ESC 7
1 ) . The
m eaning
of each of
the Status
character bit s is as follows :
8 ) Change the st raps on Disc 1 Buffer Cont rol card to 8
sect ors per
revolution ( the
new dat a
form at
) .
9 )
Conversion is now
com plete
. Use only
Disc
car
tridges wit h the 8 sect ors per revolution dat a form at .
Bit 1
Bit
2
Bit
3
Bit 4
Bit 5
Bit 6
Bit 7
Disc 1
Ready
Disc 1 Writ e - Protect ed
Disc 2
Ready
( in
4922 only
)
Disc
2
Writ e
-
Protect ed ( in
4922
only
)
Parit y or
Checksum
error .
Disc Error , Read or Writ e .
Redundant (
Com plem ent
of
Bit 6 )
The
4921/ 4922
will
issue the Line
Term inat or ( one or
two user -
definable
characters )
im m edi at ely
following the
Status
character
.
Special Considerat ions
1 ) If
the
user
wishes to
sequent ially
write
sect ors
wit h
few
characters
(
for
exam ple , 10
characters per
sect or ) , then special care m ust be taken not to
overflow
the
buffers
and
lose dat a .
Unless
in
Sect or
Mode ,
dat a
loss
m ay be
prevent ed by
request ing
st at us aft er
writing
in
a
sect or
.
The
st at us
character
will
not be
returned
until the
Writ e
Operat ion
is
com plete
.
It is then
safe to
write the next
sect or
.
a
The
Term inal - to - Disc
card will
prevent
the
Term inal
from displaying this Status character unless the Term inal
is in Graphic Plot m ode or the LOCAL swit ch is act ivat ed .
Only a Term inal Busy condit ion ( TBUSY ) will disable this
suppression .
TBUSY is
act ivat ed by any of
the
non
printing characters BEL , BS , CR , HT , LF , US or VT ; hence
one of these characters should be included in the Line
Term inat or .
Refer to
Sect ion 3 for
inform at ion
regarding
the sett ing of the Line Term inat or .
2 )
Data
transfer
rat es
higher
than
1200
baud
m ay be
used by
following
the
above
procedure ,
that
is
:
write one
sect or
,
request st at us ,
wait for st at us
to
be
returned ,
then
write
the
next
sect or ,
etc.
NOTE
3 )
When
using
the
Flexible
Disc
Mem ory
in
conjunc
tion
wit h
a
t erm i nal
that
has
a
TTY
port
int erface
,
the
following
m ust
be
considered
:
On a
Writ e
Operat ion
from
which the
com put er is
excluded
(
Term inal
Only
)
, a
Line
Term inat or is
norm ally
sent
to the
com put er at the
end
of
the
Writ e
Operat ion
.
In this
configurat ion
,
however , the
TTY port
int er
Local
Echo
or
Com put er
Echo of one
of the
above
characters
should
be
provided to
prevent
dat a
handling problem s .
1-6
REV . A , JAN . 1976

Description
-
4921 /
4922
Users
CONTROLS AND INDICATORS
When used wit h AUTO selected , the START swit ch
begins dat a transfer wit hout a DC1 or DC2 , if the com put er
or t erm i nal has previously given a Read or Writ e com
m and .
The function of the cont rols and indicat ors on the
Flexible Disc Mem ory front panel ( Fig . 1-4 ) are described
in the following sect ion . These descript ions apply to the
Flexible Disc Mem ory as it is used in com put er and
com put er
t erm i nal
environm ent s .
In the Duplicate m ode ( 4922 only ) , depressing the
START swit ch while the DUPLICATE swit ch is held on
init iat es
disc
duplicat ion .
POWER Swit ch and Indicat or
The POWER swit ch applies power . The POWER in
dicator illum inat es when power is applied to the unit .
LOAD ADDRESS Swit ch
With AUTO selected , the LOAD ADDRESS swit ch is
inactive .
START Swit ch
When MANUAL READ or MANUAL WRITE is selected ,
this swit ch st arts dat a transfer beginning at the track and
sect or address currently in the address regist er .
With MANUAL READ selected , the LOAD ADDRESS
swit ch
loads the
track address
selected by
the
TRACK
BEGIN lever swit ches . It also enables the read circuit ry so
that dat a transfer from the disc will begin ( im m edi at ely in
Sect or Mode or Transparent Mode , or when a DC1 is
received from the com put er or t erm i nal or the front panel
START swit ch is depressed , in Paper Tape Mode ) . Data
transfer
begins at
Sect or
00 of the
selected
track
.
TERMINAL
BUSY BUSY
2
CURRENT
TRACK
FILE
UNSAFE
RESET
DISC
ERROR
With
MANUAL WRITE
selected , LOAD
ADDRESS
loads the track address selected by the TRACK BEGIN
lever swit ches . It also enables the Writ e circuit ry so that
dat a transfer to the disc m ay begin ( im m edi at ely in
Transparent
or
Sect or
Modes
when a DC2 is
received
from
the com put er
or
t erm i nal , or when
the front panel
START
swit ch is depressed in Paper Tape Mode ) . Data transfer
begins
at
Sect or 00 of the
selected
track .
PROMPT
MODE OFF
TRACK BEGIN
63
MANUAL
READ
MANUAL
WRITE
AUTO
LOAD
ADDRESS
CLOSE
FILE
TRACK BEGIN Swit ches
FILE
OPEN
READY READY
These lever swit ches det erm i ne the st arting address for
a dat a transfer cont rolled from the front panel . The
address is accessed when the LOAD ADDRESS swit ch is
depressed . The track addresses which m ay be selected
are 00 to 63. If the lever swit ches are set to a num ber larger
than 63 , address 00 is accessed .
START
DISC DISC
1
2
PROTECT PROTECT
POWER
OFF
ON
DUPLICATE
BUSY
DUP
1758-3
CURRENT TRACK Indicat ors
The CURRENT TRACK indicat ors display the present
track address . Note that if no dat a disc is inst alled in the
disc drive unit , the Read / Writ e head will not access the
track , but will as
soon as a disc
is
inst alled
.
Fig . 1-4 . Flexible Disc Mem ory front panel .
REV . A , JAN . 1976
1-7

Description - 4921 / 4922 Users
Swit ch
1
Spare swit ch , available for specific requi rem ent s . Refer
to the Strappable Opt ions inform at ion in Sect ion 3 .
PROMPT MODE Swit ch
When placed in the PROMPT MODE posit ion , this
swit ch sets the
Flexible Disc
Mem ory
unit to
the Prom pt
Mode subset of the Paper Tape Mode . Prom pt Mode
operat es only during Read operat ions . Refer to the
Operat ion sect ion for a full descript ion of PROMPT
MODE .
Swit ch 2
Swit ch 2 is norm ally connect ed to enable Transparent
Mode , when depressed to the right ; it m ay be changed
depending on user requi rem ent s . Refer to the Strappable
Opt ions
in
Sect ion 3 .
Manual - Aut o Swit ch
TERMINAL
BUSY
Indicat or
The
TERMINAL BUSY
indicat or
illum inat es when the
com put er or t erm i nal is busy . The function of this
indicat or m ay be changed depending on user re
qui rem ent s . Refer to the Strappable Opt ions in Sect ion 3 .
This is a three - posit ion swit ch that det erm i nes whet her
a Read or Writ e Operat ion is to be cont rolled from the front
panel or under program cont rol . When the swit ch is placed
in the MANUAL READ posit ion , all rem ot e com m ands are
ignored except for DC1 ( st art read ) and DC3 ( st op read ) .
When
in
the
MANUAL
WRITE
posit ion
, the
only
program
com m ands that can be
accept ed
are DC2 (
st art write ) and
DC4 ( st op write ) . The AUTO posit ion allows program
com m ands from the com put er or t erm i nal to assum e full
cont rol
of
the
Flexible Disc
Mem ory .
DISC
BUSY Indicat or
The DISC
BUSY
indicat or
illum inat es
when
eit her
of
the disc drive
unit s is busy
wit h a Read or
Writ e
operat ion .
The
function
of
this
indicat or m ay
be
changed
depending
on user
requi rem ent s
. Refer
to the
Strappable
Opt ions
in
Sect ion 3
CLOSE
FILE
But t on
The CLOSE FILE But t on is used to t erm i nat e a Writ e
Operat ion . Any dat a that rem ai ns in the buffer is writt en
ont o the disc . Any unfilled posit ions in the dat a buffer are
writt en ont o the disc as NUL’s and the Writ e Operat ion is
t erm i nat ed . An end - of - file signal is aut om at ically record
ed on the disc . The CLOSE FILE but t on is enabled only
when MANUAL WRITE or Transparent Mode is selected .
FILE
UNSAFE
Indicat or
The FILE
UNSAFE indicat or
illum inat es as a result of a
disc drive fault . Data transfer is inhibit ed while the FILE
UNSAFE
indicat or
is
illum inat ed
; the
FILE
UNSAFE
condit ion m ay be
cleared by
pressing the front
panel
RESET
but t on
.
If the
FILE
UNSAFE
indicat or
illum inat es
repeatedly
during
at t em pt ed
Read or
Writ e
Operat ions , a
circuit ry
fai lure that requires repair m ay be indicat ed .
FILE OPEN Indicat or
This indicat or light s during Writ e Mode . Giving a
CLOSE FILE com m and t erm i nat es the Writ e Operat ion
and ext inguishes the indicat or . Note that in Paper Tape
Mode , the indicat or rem ai ns illum inat ed even aft er a DC4 ,
to indicat e that the file has not yet been properly
t erm i nat ed . In Sect or Mode and during a Paper Tape Mode
Writ e Sect or Operat ion , the light goes out aft er one sect or
is writt en .
DISC ERROR Indicat or
The DISC ERROR indicat or m ay light to indicat e that
an error occurred during a Read or Writ e Operat ion .
During eit her operat ion , the DISC ERROR light in
dicates that the
Disc Error bit of
the st at us
character
is set .
The condit ion m ay be reset by pressing the front panel
RESET but t on , by a program reset com m and , or by an
inquiry for st at us . When the Status Charact er is sent , the
Disc Error
bit of the
Status Charact er is reset
.
DISC 1 / DISC 2 Swit ch
On the 4922
, this
swit ch is used to
select which
drive
unit is to be used
when
perform ing a
MANUAL READ
or
MANUAL WRITE from the front panel . This swit ch is
disabled when the 4922 is in AUTO ; addressing is then
perform ed
by
soft ware
com m and
.
The DISC
1 / DISC
2
swit ch should always be in the DISC1 posit ion in the 4921 .
RESET
But t on
Pushing the front panel RESET but t on resets the
Flexible Disc
Mem ory to Paper
Tape Mode
unless
Transparent Mode is swit ch or st rap selected . In addit ion ,
any error condit ions ( Disc Error , File Unsafe , Parit y or
Checksum error , etc. ) will be reset when this but t on is
pressed
;
any
operat ion
currently in
process
ceases
.
READY Indicat ors
The READY indicat ors illum inat e when a disc cart ridge
is cont ained in the associat ed disc drive unit , the door is
closed , the buffer is not busy Reading or Writ ing to the
disc , and
the File
Unsafe
signal is
not
present .
1-8
REV . A , JAN . 1976

Description - 4921 / 4922 Users
PROTECT
Indicat ors
PHYSICAL DIMENSIONS
The PROTECT indicat ors illum inat e when the disc
cart ridge has a plast ic write prot ect tab at t ached .
The Physical Dim ensions of the 4921/ 4922 Flexible
Disc Mem ory unit are shown in Fig . 1-5 .
DUPLICATE But t on
The Int erconnect ing Cable for the Standard 4921/ 4922
is 15
feet in
length .
ENVIRONMENTAL SPECIFICATIONS
On the
4922
,
the
DUPLICATE
But t on
causes
every
sect or on Disc 1 to be read and then writt en to the
corresponding sect or of Disc 2 , providing two discs wit h
ident ical dat a in
ident ical
locations
.
The
transfer
begins
at
Track
00
,
Sect or 00 ; the
operat ion m ay be
t erm i nat ed
before the
ent ire disc
has
been
copied by
pressing the
RESET
but t on
. The
DUPLICATE
but t on
m ust
be held in
while the START but t on is depressed in order to init iat e
duplicat ion . The DUPLICATE but t on has no function in a
4921 .
The
environm ent in
which
the
4921/ 4922
is
to be used
is
specified in
Table 1-6 .
TABLE 1-6
Envi ronm ent al
Specifications
Specification
Operat ing
Storage
BUSY
DUP
Indicat or
60  F to 90 
F
20 % to
80 %
| --40  F to 140  F
90 % m axi m um
The
BUSY DUP
indicat or
illum inat es while
the 4922 is
busy wit h a Duplicate Operat ion . The Duplicate Operat ion
takes about 11 m inut es , unless t erm i nat ed earlier by the
RESET
but t on
.
Tem perat ure
Relat ive
Hum idit y
Wet
Bulb
Tem pera
ture
Alt itude
78  F m axi m um
25,000 feet m ax .
Rear Panel
The
st andard
inst rum ent has no
rear
panel
cont rols
.
* At
alt it udes
above
5000
feet ,
the
m axi m um
operat ing
t em perat ure should be reduced to 80  F .
eae
TEKTRONIX
CURRENT
TRACK NI
RESET
ERROR
PROMPT
MODE
OFF
TRAC
DEON
12 Inches
ctose
Fak
LOAD
ADORES
NEW
BEROY
STARY
DISC
m one
PROTECT
POWER
m ore
?
DUPLICATE
axe
1
25
2
Inches
.17
12 Inches
1758-4
Fig . 1-5 . Physical di m ensions .
1-9

4921/ 4922 Users
Sect ion 2
OPERATION
INSTALLATION
CAUTION
Inst alling the Flexible Disc Mem ory consist s basically
of
finding a
suit able
location near the
equi pm ent
wit h
which
it
is to be
used
, and
selecting the
proper line
volt age
sett ing
.
The unit m ay
then be
connect ed
to
any
4010
Series
Term inal
, as
described below .
( 1 )
Be
careful in
handling
disc
cart ridges
. A
dam ag
ed or dirty
disc m ay
dam age the
Flexible Disc
Mem ory
unit .
CAUTION
( 2 )
Prior to the
insertion of
previously
unused ( or
long - st ored ) cart ridges , you should check for
freedom of
m ovem ent
wit hin the
plast ic
jacket .
See
Cart ridge
Care .
The
bot t om
of
the
Flexible
Disc Mem ory
m ust
be
kept free for air flow , as the cooling is located in the
bot t om of the unit .
2.
Insert the
cart ridge ( see Fig
. 2-3 )
com pletely int o the
cart ridge
gui de
. Note that the
keying not ch
should be at
the
top
forward
edge .
Turn off
the
Term inal
power
swit ch
and
the
Flexible
Disc
Mem ory power swit ch .
At t ach the
int erconnect ing
cable
to
the
m ult i
- pin
connect or (
J1010 ) at the
upper left
corner of the
Flexible
Disc Mem ory
back
panel
(
Fig . 2-1 ,
and
inst all
the
ot her end of
the
cable
through the
access
opening in the rear of the t erm i nal pedest al . Inst all the
Term inal
-
to - Disc
card in one
of the
spare
connect ors in
the
Term inal
Mot her
Board , and
inst all
the
harm oni ca
connect ors on card
connect ors , J50 ,
351 , and
J52 , as
shown
in
Fig . 2-2
.
Connect the
cable shield
ground
spade
connect or to a
ground
lug
under
the
card rack
wit hin
the
t erm i nal
pedest al .
3.
Close
the
disc
drive door .
It m ay be necessary to inst all a Mot her Board ext ender
in the t erm i nal to provide room for the Flexible Disc
int erface card .
Refer
to the
t erm i nal
m anual
for
details
.
Securing
Screws
1010
CARTRIDGE
LOADING
The disc cart ridge should be handled carefully when
being inserted int o , or rem oved from , the disc drive unit .
The cart ridge m ay be loaded or unloaded from the disc
drive wit h all
power on and
the drive
rotating
; the
cart ridge
is inserted int o the cart ridge gui de as described in the
following
st eps
.
1758-5
1. Open the desired disc drive door ( the 4921 has only
one ) . Once com pletely open , the door is held by spring
tension
.
Fig . 2-1 . Connect or location .
2-1

Operat ion - 4921
/ 4922 Users
DI
DDDD
A
10000
J51
J50 .
52
1758-6
Fig . 2-2 .
Connect or placem ent .
CARTRIDGE
CARE
Writ e Protect Tab
Perform ance of
the
Flexible Disc
Mem ory can be
seriously degraded by im proper handling and care of the
unit and / or the disc cart ridges . Dust and ot her airborn
cont am inant s can dam age delicat e recording com
ponent s as well as the disc it self . The Flexible Disc
Mem ory uses a vert ical m ount ing to m inim i ze part icle
sett ling on the disc or the head . Ot her considerat ions in
the care and handling of the disc cart ridge are as follows :
1. Return the cart ridge to it s st orage envelope whenever it
is rem oved from the Flexible Disc Mem ory drive unit .
2. Store
cart ridges
vert ically
in their
envelopes
to
prevent
dust
sett ling on the disc .
Cart ridge Guide
1758-7
3. Keep cart ridges away from m agnet ic fields and from
ferro - m agnet ic m at erials
which m ight becom e
m agnet ized . Strong m agnet ic fields can dam age the
m agnet ically recorded dat a on the disc .
Fig . 2-3 .
Insert ing the
disc
cart ridge .
2-2

Operat ion
-
4921
/ 4922
Users
DISC DRIVE CARE 4.
Replace
st orage
envelopes
when they
becom e worn ,
cracked , or dist ort ed ; in such a condit ion they are no
longer able to prot ect the disc .
5. Do not write on the plast ic cart ridge wit h a lead pencil
or ball point - pen . Writ e gent ly using a felt - tip pen .
Major m ai nt enance of the disc drive unit , such as
cleaning the Read / Writ e Head when dat a errors ( Disc
Errors ) occur due to dirt and / or oxide accum ulat ion on the
Head , is detailed in the 4921/ 4922 Flexible Disc Mem ory
Unit Service Manual .
NOTE
6. Use caut ion wit h cigaret t es ( cigars , pipes ) around
cart ridges . Heat and cont am inat ion from a carelessly
dropped ash can dam age the disc and / or the
Read / Writ e Head .
The
frequency of head
cleaning operat ions
is
highly
dependant upon cart ridge care . When discs are kept
clean and
handled
properly
, head
cleaning
frequen
cy will be
kept to
a m inim um
.
7. Do not expose cart ridges to heat or st rong sunlight ;
eit her m ay warp the disc or jacket .
8. Do not touch or at t em pt to clean the disc surface ;
result ing abrasions m ay cause the loss of st ored dat a
and / or the loss of the ability to st ore dat a .
OPERATING INTRODUCTION
The
Flexible Disc Drive unit
can be
operat ed from the
front panel cont rols ( Manual Operat ion ) , from program
cont rol
com m ands
(
Program
-
Cont rolled
Operat ion
)
or
from a com bi nat ion of the two . All operat ions are sum
m arized in the Operat ing State Diagram in Fig . 2-5 . Before
proceeding , st udy the Operat ing State Diagram to obt ain
an
overall
understanding of
it .
9. Make certain that the disc m oves freely wit hin the
envelope - cart ridge prior to inserting it int o the drive
unit ; this is especially im port ant for new disc cart ridges
and those which have been inactive and st ored . This
m ay be done by inserting two fingers int o the disc
spindle hole and m oving the disc from side to side
wit hin the envelope ( Fig . 2-4 ) ; do not at t em pt to rotate
the disc . Failure to check for freedom of disc m ove
m ent m ay result in a drive belt being forced off of the
pulley , or m ay cause dam age to the spindle cont act
area
of
the
disc .
The following explanat ions are cat egorized under
Manual Operat ion and Program - Cont rolled Operat ion .
Operat ions involving a com bi nat ion of Manual and
Program com m ands are explained as necessary wit hin
those two cat egories . In addit ion , a First - Tim e operat ion
procedure is incorporated int o all explanat ions .
Insert
Up
Return
to
envelope
when
not
in
use
MEMOREX
TERMINAL OPERATING
CONSIDERATIONS
Data
Disc
FD
/
DZ
In Paper Tape Mode , the Flexible Disc Mem ory
responds to certain ASCII Cont rol Charact ers ( DC1 , DC2 ,
DC3 , and DC4 ) as st art and st op com m ands during a Read
or Writ e Operat ion . These are fully explained in the
Operat ion descript ions . These com m ands m ay be
generated from the 4010 - Series Term inal keyboard by
pressing the CTRL key in com bi nat ion wit h another key .
DC1 through DC4 are generated as follows , from the
t erm i nal
keyboard
.
Move disc
back and fort h
wit hin
envelope
1758-8
DC1 ( Start Read ) -CTRL Q
DC2 ( Start Writ e ) -CTRL R
DC3 ( Stop Read ) -CTRLS
DC4 ( Stop Writ e ) -CTRL T
Fig . 2-4 . Checki ng for freedom of disc m ovem ent .
2-3

Operat ion
 4921 / 4922
Users
SEND
STATUS
END
SECTOR ( F )
END
SECTOR
READ
SECTOR SECTOR
MODE
WRITE
SECTOR
READ
( E )
WRITE ( E )
FILE
OPEN
RESET
( D )
SECTOR
MODE
END
OF
DISC
RESET
RESET
(
D
)
( C )
PROMPT
MODE
END
OF
DISC
END
SECTOR.FILE
OR
DISC_
( F
) .
CLOSE
FILE
PROMPT
CR
SEND
STATUS
DC - 3
RESET
DC - 4
READ ( G )
DC - 1
START ( A )
..............
READ
ENABLE
READ ( E )
LOAD
ADDRESS
...........
PAPER
TAPE
MODE
CLOSE FILE
WRITE ( E )
LOAD ADDRESS
WRITE
ENABLE
DC - 2
START ( A )
WRITE ( G )
....
SEND
STATUS
CLOSE
SECTOR
FILE
OPEN
SEND
STATUS
:
START ( B )
START ( B )
DISC
END
DUPLICATE
..
STAR
RESET
132
TRANSPARENT
MODE
ON
..............
DUPLICATE
MODE
1.0.0.0
.........
TRANSPARENT
MODE
OFF
RESET
..................
CLOSE
FILE
READ
RESET
....
END ( F )
READ ( E )
LOAD
ADDRESS
.............
START ( B )
O
...
TRANSPARENT
MODE
WRITE
WRITE ( E )
LOAD ADDRESS
START
( B )
.......
SEND
STATUS
FILE
OPEN
A ... Start
always
available
.
B ... Start
available
only
in
MANUAL READ or
MANUAL
WRITE
.
C ...
PROMPT
MODE
swit ch
m ust
be
on .
D ...
Reset
always
returns
to
Paper
Tape
Mode
,
unless
Transparent
Mode
is
m anually
selected .
E ...
Read or
Writ e
Com m ands m ay
cont ain
a 3 -
character
address
,
or m ay st art
at the next
sequent ial sect or .
F ... Line
Term inat ors are sent
at the end
of Read
Operat ions
(
See
"
Line
Term inat or "
text ) .
G ...
Operat ions are of
sect or or file
length ,
dependent on the
Read
/
Writ e Com m and .
Only file
-
length
operat ions are
available
from the
front
panel
.
Dot - Dashed Lines ( - :-) are eit her soft ware or front panel com m ands
Dashed Lines (
--- ) are
aut om at ic
functions
Dot t ed Lines (
..... ) are front
panel
cont rols
Solid
Lines (
- ) are soft ware com m ands
All Soft ware com m ands are only available in the Aut o posit ion of the Read - Aut o
1758-9
Writ e
swit ch
Fig .
2-5 .
State
diagram .
2-4
@

Operat ion
-
4921 /
4922 Users
MANUAL
OPERATION
The Flexible Disc Mem ory m ay be m anually operat ed
from the front panel in Paper Tape Mode , Transparent
Mode , and Prom pt Mode . In addit ion , Sect or Mode m ay be
used from the front panel aft er ent ering Sect or Mode by
Program Cont rol Com m and . Duplicate Mode is available
only from the 4922 front panel .
When cont rolled from the front panel , Read and Writ e
Operat ions are lim it ed to lengths of one file . A file m ay be
any num ber of sect ors , but m ay not be less than one sect or
( 128 8 - bit byt es
) . However
, if short files (
less than 128
8 - bit
byt es ) are desired , the Flexible Disc Mem ory aut om at ical
ly fills the sect or wit h NUL characters when the file is
closed . On the 4922 , DISC 1 or DISC 2 m ay be selected .
NOTE
Part icular sect ors of a given track are not direct ly
accessible from the front panel . The Read or Writ e
Operat ion m ay be enabled at a part icular Track / Sect or
address by placing the Mode Cont rol in AUTO and using
the Read / Writ e Com m and sequence . MANUAL READ or
MANUAL WRITE m ay then be selected and operat ions
st arted wit h the front panel START but t on .
In order to close a file wit hin a part icular sect or when
writing a file in Paper Tape Mode , it is necessary to
issue the DC4 and Close File com m and ( or press the
CLOSE FILE but t on in m anual operat ion ) prior to
the 128t h character ( byt e ) . When the 128t h character
is issued , the file is aut om at ically cont inued int o the
next sect or .
Paper
Tape
Mode
Paper Tape Mode is the basic operat ing m ode of the
Flexible Disc Mem ory , when no ot her m ode is selected
( Fig . 2-6 ) .
Writ e Operat ions . MANUAL WRITE m ust be selected in
order to cont rol a Writ e Operat ion from the front panel .
RESET
(
D )
.
( C )
PROMPT
MODE
END
OF
DISC
END
FILE
OR
DISC
(
F
)
CLOSE
FILE
PROMPT
CR
SEND
STATUS
DC - 3
RESET
. - . - . - .
DC - 4
READ ( G )
DC - 1
START
( A )
..............
READ
ENABLE
PAPER
TAPE
MODE
WRITE
ENABLE
WRITE ( G )
LOAD
ADDRESS
..............
DC - 2
START ( A
)
..............
LOAD ADDRESS
)
SEND
STATUS
CLOSE
SECTOR
FILE
OPEN
SEND
STATUS
START ( B
)
TE
+
START ( B )
DUPLICATE
DISC
END
RESET
DUPLICATE
MODE
A ... Start always available .
B ... Start available only in MANUAL READ or MANUAL WRITE .
C ... PROMPT MODE swit ch m ust be on .
D ... Reset always returns to Paper Tape Mode , unless Transparent
Mode is m anually selected .
E ... Not applicable to Manual Operat ion
F ... Line Term inat ors are sent at the end of Read Operat ions ( See
" Line
Term inat or
"
text ) .
G ... Operat ions are of sect or or file length , dependent on the
Read / Writ e
Com m and
. Only file
- length
operat ions are
available
from
the front panel
.
Dot - Dashed Lines ( -.- ) are eit her soft ware or front panel com m ands
Dashed Lines ( --- ) are aut om at ic functions
Dot t ed Lines ( ..... ) are front panel cont rols
Solid
Lines (
-
) are
soft ware
com m ands
All Soft ware com m ands are only available in the Aut o posit ion of the Read - Aut o
Writ e swit ch
1758-10
Fig . 2-6 . Paper Tape Mode Manual Operat ion .
@
2-5

Operat ion - 4921 / 4922 Users
The
desired track ( 00-63
) is
selected by using
the
TRACK
BEGIN
lever
swit ches
,
then
pressing the
LOAD
ADDRESS but t on to
enable
a Writ e
Operat ion which will
st art at Sect or 00 of the selected track . The selected track
address will appear in the CURRENT TRACK display , and
the
FILE
OPEN
indicat or
will
light
.
If a Read Operat ion is t erm i nat ed by a DC3 , a soft ware
or Front Panel RESET is necessary before reading or
writing ot her files . If this does not occur , dat a rem ai ni ng in
the buffer will be m ixed wit h the dat a next read or writt en .
NOTE
Data
transfer
from the
t erm i nal or
com put er
begins
aft er the
START
but t on
is
depressed , or
aft er a DC2 is
received from the
t erm i nal or
com put er . Data
is
recorded ,
one sect or at a t im e , until the front panel CLOSE FILE
but t on is pressed . The dat a in the buffer at the t im e the
CLOSE
FILE
but t on is
pressed
is
transferred to
becom e
the last
sect or
in that
dat a file ;
unused
posit ions
in the
buffer are aut om at ically writt en as NUL’s .
DC1 m ay be used in place of the START but t on
during a m anual Read Operat ion . However , it s use is
lim it ed to rest arting an operat ion which was st opped
wit h a DC3 , or st arting an operat ion that was enabled
by a Load Address sequence from the front panel .
The Writ e Operat ion m ay be st opped prior to the end of
a file by a DC4 from the com put er or t erm i nal , and then
rest arted
by a
DC2 . Data in
the buffer at the
t im e of a DC4
rem ai ns
there
;
dat a between
DC4 and
DC2
is not
ent ered
.
In
addit ion , a
RESET
from
the
front
panel
will
st op and
disable the Writ e Operat ion . Data in the buffer at the t im e
of a reset
is lost and
no end - of -
file m ark
will be
inserted .
First
-
Tim e Manual
Operat ion
Paper
Tape Mode
1. Make certain that the unit is properly inst alled , that the
power is
connect ed
and
applied , and that
a
blank disc
cart ridge is
inserted in
the DISC 1
drive unit .
NOTE
DC2 m ay be used in place of the START but t on
during a m anual Writ e Operat ion . However , it s use is
lim it ed
to
rest arting
an
operat ion that was
st opped
by a DC4
( as
above
)
, or
st arting an
operat ion that
was
enabled by a
Load
address
sequence
from the
front
panel
.
2. Position the swit ches on the front panel as follows :
DISC
1 selected , MANUAL WRITE selected ,
Transparent Mode off ( SWITCH 2 depressed left on
st andard inst rum ent s ) , and PROMPT MODE swit ch to
the
OFF
posit ion .
3. Position the TRACK BEGIN lever swit ches to 30 , then
press the LOAD
ADDRESS but t on
.
Observe that the
CURRENT
TRACK
indicat or displays
a
30 ,
indicat ing
that track 30 has been accessed , and that the File Open
indicat or is on .
Read Operat ion . MANUAL READ m ust be selected in
order to
cont rol
a
Read
Operat ion from the
front panel .
The desired track ( 00-63 ) is selected by using the TRACK
BEGIN lever swit ches , then pressing the LOAD ADDRESS
but t on to enable a Read Operat ion to st art at Sect or 00 of
the
selected
track
. The
selected
track
address will
appear
in
the
CURRENT
TRACK
display
.
4. Press the START but t on , then send 128 characters ( 8
bit byt es ) from the t erm i nal or com put er . Note that
upon
receiving the
128t h character , the
DISC BUSY
indicat or light s
m om ent arily , as
the 128
characters are
writt en ont o the disc . The FILE OPEN indicat or
rem ai ns on , indicat ing that the next sect or of that file
m ay
be
writt en to
.
Pressing the START but t on allows dat a transfer to the
t erm i nal or com put er from the Flexible Disc Mem ory . Data
m ay then be transferred until an end - of - file m ark is
detect ed
in
the dat a
from the
disc ,
signifying the last
sect or of a file .
5. Enter another character st ring from the t erm i nal or
com put er , inserting a CR and LF ( Carriage Return ,
Line Feed ) aft er each group of about ten characters .
( This will be used lat er , when reading back in a Prom pt
Mode
Operat ion . )
A Read Operat ion m ay be st opped before the end of a
file by pressing the front panel RESET but t on , or by DC3
from the com put er or t erm i nal ; however , a DC3 does not
disable the Read operat ion , as does a RESET . A DC1 or a
front panel
START
will
st art the Read
again , from the
point
at which it st opped . Subsequent files m ay be read by
pressing START wit hout a LOAD ADDRESS ; the Read
Operat ion begins at the next sequent ial sect or .
6. Aft er writing about half of the sect or ( 64 or m ore
characters ) press the CLOSE FILE but t on . Observe
that the
DISC
BUSY
indicat or
light s
m om ent arily , as
Sect or 01 is writt en to the disc , and that the FILE OPEN
indicat or
is
ext inguished .
2-6
@