Datum 5091-P8e Parts list manual

5091-P8e
MAGNETIC TAPE
SYSTEM
TECHNICAL DESCRIPTION
PUBLICATION NO. SM-06
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••••• ••••

DATUM INC.
1363 s. State College Blvd.
Anaheim, California 92806
5091-P8e
MAGNETIC TAPE
SYSTEM
TECHNICAL DESCRIPTION
PUBLICATION NO. SM-06

SERIES 5091
MAGNETIC TAPE
INPUT I OUTPUT
SYSTEMS
FOR
MINI-COMPUTERS
••••••••••••••••
••••• ••••

OPTIONS
SEVEN/NINE CHANNEL
The standard controller accommodates either seven (dual-density) or nine-channel,
magnetic tape recorders. This option offers both seven and nine-channel operation.
The device selection and command set is augmented to provide program selection
of low or high BPI recording density. Also, character parity (VRG) may be selected
by program control as even or odd parity (7-channel only).
CABINETS
Both single-bay and dual-bay cabinets are available.
TAPE UNIT ADDRESS SWITCH
The Series 5091 system may include from one to four tape recorders, designated
A, B, Cand D. Logically these are identified as 0,1,2 and 3. In the standard controller,
recorder A corresponds to logic unit 0, recorder B to logic unit 1, etc. This option
provides four front-panel switches allowing any recorder to be assigned any
logical identity.
TERMINATION CARD
By providing a single termination card, this option allows interchangeability of the
tape units at will in a multiple-tape unit system.
SPECIFICATIONS
Weight:
Power:
Number of Tracks:
Data Density:
Rewind Speed:
Reel Size:
Operating Temperature:
Mounting:
Single tape system-less than 100 Ibs.
117V 60 Hz single phase, regular outlet power, 300 watts
per tape unit.
7 or 9 IBM compatible.
9 track-800 BPI 9 track - 1600 BPI
7 track-800/556,
800/200,
556/200 BPI
150 IPS (10-1/2 inches)
50 IPS (7 inches)
10-1/2 inches
7 inches
35° to 122°F (10-1/2 inches)
41 ° to 113°F (7 inches)
User-supplied standard RETMA rack mount.
Optional cabinet can be supplied by DATUM, Inc.
Standard Series 5091 Systems, with software, are available forthe following
computers:
HP2114
PDP-9
Honeywell 124A
HP2115
PDP-9/l
Honeywell 316
HP2116
PDP-11
Honeywell 416
PDP-8 PDP-15
Honeywell 516
PDP-8E
IBM 1130
SDS CE16
PDP-8/l
Varian 620i SDS
CF16
PDP-8/1 CAl
816
Micro-Systems 810
Univac 1107 NOVA Univac 1616
Designs for other computers are being produced continually.

FEATURES
DATUM 5091-P8e
MAGNETIC TAPE SYSTEM DESCRIPTION
a. TCS8-compatible.
b. Stand-alone driver and diagnostics provided.
c. Controller mounts within the mainframe.
d.
Drives -- Rack Mount
1• Pertec
(a) Speeds of 12.5 ips to 75 ips
(b) Ree 1 sizes 7" to 10-1 /2"
(c) Read-after-write is standard (single gap optional).
2. Wangco
(a) Speeds of 12.5 ips to 75 ips
(b) Vacuum column available on 10-1/2" reel models at
25, 37.5, 45, or 75 ips
(c) Read-after-write is standard (single gap optional).
e. Write or read on-the-fly (continuous tape motion).
f. Edit mode (if transport is so equipped).
-1-

FEATURES (continued)
g. Memory extension.
h. Mixed 7- or 9-track.
i. Up to four drives.
j. Three-cycle data break.
-2-

SECTION I
GENERAL DESCRIPTION AND SPECIFICATIONS'
1• 1 rUNeT 10NAl OESCR I PT ION.
The DATUM pop8c Controller provides interfa~e between the DEC
PDP8e computer and 9-track, 800 BPI and/or 7-track 800/556/200 BPI tape
machines, cnabl ing computer;;,contro,l of ~/riting and reading IBM- or USACCI'-
compatible magnetic tapes.
All major operations are performed automatically under command of
the Controller. Individual selection and operation with up to four "Daisy-
Chained" tape transports is provided. Either single- or dual-gap machines
can be accommodated.
Tape
transport mot ion control, Cyc) ic Redundancy Check Character
(CRCC) and l.ongitudinit.1 Redundancy Check Character (LRCC) generation and
checking, inter-record-gap generation and status reporting.are included. All
Write clocks and delay times are derived from a crystal-control Jed oscillato.-.
No lIone-shots" or RC delays are utilized.
The unit plugs directly into th~ computer omnibus and uses
computer power.
"On the Fly" operation (continuous read or write at maximum
tape speed without stopping in each inter-record gap) is
provided.
The IBH"compatible fi Ie mark (7- or 9;'track formats) is
written and recognized.
1-1

The "Edit" .featllre (allows a record anywhere on a previously
recorded tape to be replaced with an updated record of e~ual
size) is provided.
No calibration or adjustment potentiometers in the Formatter.
All timing is derived from a crystal oscillator.
Compatible to entire 12.5 to 7S-ips tape-speed range without
changing crystals. A single field-changeable Jumper selects.
the frequencies needed for the tape speed.
~~
1.2 PHYSICAL DESCRIPTION
The DATUM Model 5091 NRZI Contro{ler~ complete on three large
circuit boards, is designed to be installed in the PDp8e computer mainframe.
Figure 1-1 shows ·this installation.
l' •3 . S Pi: CIF I CAT ION S
Inter-record gap (7 tra~k)
Inter-record gap (9 track)
Circui ts
Operat'ng Temperature
Storage Temperature
AI t i tude
Relative Humidity
Interface Voltages
(DTL 900 series or TTL
7L lOO ser ies compat ib Ie)
1-2
.75 inch nominal (.69 inch
minimum)
.6 inch nominal (.54 inch
minimum)
All s i I icon
0° to 50° C
_40
0
to +70
0 C
o to· 20,000 feet
10 to9~h (non-condensing)
low &: OV ±.4v
high &: 3.9V ±1.5V

THREE BOARDS; REQUIRES
FOUR SLOTS
TAPE
MACHINE
#1
CABLES TERMINATE
HERE
TAPE
MACHINE
#2
o
o
INTERCONNECT
ASSEMBLY
76258
Figl!re 1-1. I nsta11ation of Model 5091 NRZI Controller
1-2a

The i nterfncc i 5 des igncd 'such that an open ci rcu i tis i nter-
preted as Cl "h ;gh" signa 1•
Figure 1-3 illustrates the configuration for which the interface
has been designed.
1.4 MAGNET IC TAPE FORI1ATS
Figures 1-4 and 1-5 i11ustrate the IBM and USASCI I magnetic tape
formats for 7-track ~nd 9-track tapes, respectively.
1-3

r--------i r-----~------I
. CABLE
I I TERMINATION I
I I +5V I
I CABLE DRIVER I -CABLE RECEIVER I
I I 220n I
: ~J~--------------I----~~------~___ r- :
I I I I
L ________ ~ L ____________ J
DTL 84l~ or TTL 7416, 7J·~37. DTL 8XX Series; TTL 71 lXX Series
7438, 7~40 or equivalent or equivalent
Interface Circuits

BCD ~ FORWARD MOTION
_______ /~BiNARY ~~"_ ___ (_HE_A_\D_RtLATI"E TO TAPE) -:'/~ )
P C I·
\ 2 B 1
r:--~) ~~ :: \
I.
I
I
I
R::FERE~CE EDGE
~o~ ~.B.J ( I _____ ~_~_: __ ~_: _________ __'(
J h=-S-B, NO_TC-H-GA-,M'P_'I N-'.I-MU'M~:- __ DA_T_fJ. _____ .... _!: ~~RA:I~ ~T:~;~ECO~:l:_ NaT DATA "ECORD
v. PERIODS 0.75 INCH +.lL5
LRCC
-.0625
NOTES
1 .. TAPE SHOHN WITH OXIDE SIDE UP.
2. CHh~~ELS 2 THROUGH 7 CONTAIN DATA BITS IN DESCENDING ORDER OF SIGNIFICANCE.
3. CHA~~NEL P (P/~R.iTY) CONTAI NS COD DATA PARiTY FOR 5iNARY TAPES, OR EVEN PARiTY
FOR BCD TAPES.·
4. EACH BiT OF THE LRCC IS SUCf-l THAi THE TOTAL NUM8ER OF Ill" BITS IN THAT TRACK
(I;JClUDiNG THE LRCC) IS EVEN. IT IS POSSiBLE IN THE 7-TRACK FORt·1AT FOR THIS
CHARACTER TO BE ALL ZEROES, IN WHtCH CA~E A READ DATA STROBE WILL NOT 8E
5. A FILE t·:ARK IS A S!NGLE CHP\F\ACTER RECCRD HA'flNG 111" BITS IN CHANNelS 4,5,6
AND 7 FOR BOTH THE DATA CHAR.l\CTEF. I\ND TH~ LRCC. THE FI LE ~1.A.RK I S SEPARATED
BY NORMAL IRG's (.75 INCH) FROM THE PREVIOUS AND FOLLOWING RECORDS. OPTION-
ALLY, A 3.5-1NCH GAP CAN BE ERASED PRIOR TO WRIT!NG THE FILE MARK.
6. DATA PACKING DENSITY MAY BE 200, 555, O~ 800 BITS PER INCH.
Figure 1-4. 7-Track Format

I
~
n
r:C-= -AS'
~" I :.J
-- 1
fi
/'
~EFERENCE
--!::-o FORWARD MOTION (HEAD RELATI VE TO TAPE)I----::>-
CHAi\NEL 4
6
0
1
2
p
3
7
5
I
I
I
I
I
t
I
I
I
I
DATA
I '
t , i
I I
I I
I
I
I
f
I
I
I
J
I
,
f'
~
J
BOT GAP I'
EDGE
INCH M' Nl i1w:r~ ,
0.5
t
l
'.4 CHAR.'AC- 4 CHA. ?Jl.C_I
I
... '. '"
TER TER ~
--::"1< PERI ODS-r~PERI ooSt :1 NTER-RECORD J NEXT DATA RECOKD
CRCC
NOTES
1. TAPE SHO~N w!TH OXID~ SIDE UP.
, GAP
"0 •6 Hi CH +. -15
-. 10
LRC.c
2. CHA~NELS 0 THROUGH 7 CONTAIN DATA BITS iN DESCENDING ORDER OF SIGNIFICANCE.
3. CHAN~EL P (P~RITY) ALWAYS CONTAINS O~D DATA PARITY.
4. E.L;CH 3!T OF THE LRCC IS SUCH TnAT THE TOTAL NUriSER 0;:- "l!! SiTS IN THAT TRACK
(INCLUJING THE CRCC AND THE LRCC) IS EVE~. IN THE9-TRACK FORMAT THE LRCC
WILL n::VER BE A:\! ALL-ZEROES C!1P .. RACTEK.
5. IT 1S POSSIBLE FOR THiS CRCC CHARACTER TO ~E ALL ZEROES, IN WHICH CASE A
READ DATA STROBE WILL NOT 8E GE~ERATED.
6. A FILE l"'l\F:K IS A SINGLE CHARACTER RECORD HAVING "1" BITS IN CHANNELS 3, 6,
AND 7 FOR BOTH THE DATA CHA?-ACTER Ai~D THE LRCC. THE CRee CONTA I NS ALL
ZEROES. THE FILE MARK IS SEPARATED 3Y NORMAL IRGfs (.6 INCH) FROM THE
P?\~VIOUS AND FOLlOHi~~G RECO~DS. OPTlm~J\LLY, A 3.5 INCH GAP CAN BE E~ASEO
PR10R TO WRITING A FILE MARK.
Figure 1- 5. 9-Track Format
1071

SECTION II
INTERFACE
2.1 INTRODUCTION
There are two interfaces to the Cont '''0 11 er' Format ter sect ion, one
to the computer adapter section and one to the tape units (76232 AI, A2,
Cl and C2).
Individual, stranded, 22-26-gauge twisted-pair wires should be
used. Maximum length should be twenty feet (total) for .the tape-unit "Daisy-
Chain" bus.
The twisted-pair wire should have at least one twist per inch and
a
minimum insulation thickness of .01 inch.
The ground wire of each twisted pair should be terminated to
grqund as close to the origin or destination of the signal as possible
{within 6 inches maximum} to minimize ground-loop-current "crosstalk"
effects.
2.2
FORMATTER/TRANSPORT(s) INTERFACE
2.2.1
Formatter to Transport
Transport Address
SELECT A through SELECT D - Transport Select Lines. Four select
1ines to select one of the "daisy-chained" transports. Developed by decoding
CRI and CR2 from the command register.
2-)

2.2.1.2
Control
The control 1ines activate the selected transport when it is
"READY II and liON LINE".
SFC -Synchronous Forward Command. A levelwhich, when low,
causes the selected transport to "ramp" up to speed and drive forward
at the rated speed until the level goes back high. When switches to the
high ievel, the transport IIramps" down to halt.
SRC -SynchronoLis Reverse Command. A level which, when low,
causes the same action as SFC except in reverse. tape motion.
RWC -Rewind Command. A negative-going pulse which causes the
selected transport to rewind to load point.
OFC - Offl ine Command. A negat ive-going pul se which causes
the selected transport to revert to manual control. Transport must be
manually
placed liON LINEII before it can again be operated.
'.
The offline command can be transmitted to a tape transport that
is rewinding (even though the transport status indicates NOT READY).
SWS - Set Write Status. The level of this signal is inspected
within 20 microseconds after an SFC or SRC cOl11l1and is initiated to set the
.selected transport to the write or read mode. This mode is maintained
unt i1 . the next SFC or SRC command is in i t i ated.
The write nude within the transport is also switched to read
mode if:
a) An RWC or OFC command is received.
b) Loss of interlock occurs.
c) The transport is manually switched offl ine.
2-2

EDIT -(Over Write). - This signal is a level that causes the trans-
port write current enable/disable to Ilrampil on and off to minimize rate of
change of recorded inter block gap magnetism when rewriting a record in the
EDIT mode.
This signal level also causes the DC erase head current to be turned
off immediately after rewriting the new record (to keep from erasing the be-
ginning of the next record).
WARS - Write Amplifiers Reset. This signal controls the early ramp
down of write and early turn off of erase currents after rewriting a record
in the EDIT mode.
The
negative-going transition of this signal initiates the write cur-
rent ramp down. In NRZI transports, this signal also generates the LRC char-
ac te r.
DDS - Select High Density. Low = select high density (for NRZI For-
matter only) for 7-track transport.
2.2.1.3 Write Data
WDS - Write Data Strobe. This is a clock used to copy the write data
(WDP and WDO through WD7) into the selected transport write flip-flops. The
data levels must be static during WDS and the trailing e~e (positive-going)
of WDS is used to clock the flip-flops. The clock rate is at the character
rate for NRZ I.
WDP, WDO through WD7- Write Data. WDP is the parity bit, WDO is the
-- --
most significant bit, and WD7 is the least-significant bit. WDO and WDl are
not used for 7-track NRZI operation.
These signals are presented to the selected transport along with the
WDS clock. The write data is presented in a logic-level form (low = logic 1,
high = logic O).
2-3

2.2.2
Transport to Formdtter
2.2.2.1
Status Li nes.
ROY -Ready. A level that is low only when the selected trans-
port is:
a) Interlocked
b) Through the initial load or rewind-to-lo~d point sequence.
c) On I j ne
d)
Not rewinding
Note: A
transport may go NOT Ready for approximately .5-second
after reversing into load point and does not go Ready until approximately
.5-second after termination of a Rewind.
ONLINE - On I ine. A level that is low when the selected trans-
port is manually switched on I ine (to place it under remote control).
REWINDING -.Rewinding. A level that is low while the selected
transport is rewinding. The level remains low until the transport completes
the automatic "return to load point" sequence but the transport does' not
become Ready
until approximately .5 second after the R\JO signal terminates.
FPT - File Protect. A level that is low when the selected trans-
port has a supply reel of tape mountep that does not have a write-enable
ring ins tall ed.
lOP - Load Point. A level that is lo~ when the selected trans-
port's beginning-of-tape reflector is located under the photo sensor, inter-
locks are made, and the initial load or rewind sequence is completed.
EDT - End of Tape. A level that is low when the end-oF-tape
reflector is' under the photo sensor in the selected transport. This signal
is not staticic;ed and neither- the positive nor negative-going transition
is" c1ea nil •
2-4

SINGLE/DUAL - Head Stack. A level that reports the selected trans-
port head type. Low for single stack, high for dual stack Ilread while writing
ll
•
2.2.2.2
2.2.2.3
7 TRK/9 TRK ~ Transport Type
Low = 9-track
High = 7-track
001 -Data Density Indicator
Low = High Density Selected
High = Low Density Selected
Read Data & Read Clock
RDP, ROO through RD7 -Read Data
Read Data & Clock
The
read data is completely IIbuffered
ll
in a special register. The da-
ta is allowed to change until just before the leading edge of the read strobe
pulse (RSTROBE) and is static throughout RSTROBE and until a minimum of 1 ~s af-
ter RSTROBE.
2-5

SECTION I II
THEORY OF OPERATION
3.1 I NTRODUCTI ON
This section con~ains information on the operation of the NRZI Mag-
netic Tape Controller.
The information in thi~ section is divided into two major topics.
A discussion of the block diagram (Figure 3-1) is presented first, to provide
an overall functional description and to illustrate the .relationship between
the formatter portion, the adapter portion and a discussion of the command
execution, illustrated by timing diagrams, describes operation of the Con-
troller circuitry during execution of computer-originated instructions.
The Controller performs three basic functions. These are:
1. Control
2. Write
3. Read
The Controller provides control over the selected tape unit includ-
ing all timing necessary to perform automatically all Write, Read, Rewind,
Space Forward or Backward, and Rewind' commands.
Upon completion of the commanded operatio~, status is provided so that
the co~puter can ascertain whether the operation was performed correctly.
The Controller performs all the Write functions for erasing tape,
writing a file mark or writing a record of data. A 3.5-inch gap is automati-.
cally erased before the first record when starting from beginning of tape (BOT).
The correct timing delays for erasing the inter-record gap (IRG) are provided·
and the file-mark code is developed by the formatter portion of the Controller.

\N
I
-
OJ
"~Zl 7/9 j~;'C~
NRZI rOKI'.ATTE~
IT'"
\T':'?C:
;~;~
t:~'1 T
Ie
t';'~~:~ilC T.;?:: ":"VC;S?O"T r S'e~A ,... ____ ...., _------------ ________________ ... ________ -1 COMI'UTE~ AOAPTC~,
, • UNI. SELECT
Ii;'?:: 1-r;'PE !""'s;::;-1 k============ ________________________ -j
~!\IT liSIT~!" •• : I TA?E U"'T '*'
8 A _S lc~'~ SELECT , ~
i I SietJ S·,.' I TCHES FC:t:~ATTER
~ 3.~W @ AI)::lR SELECT 01
FAct
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1
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I 1 SFC C f'~'y T" ... <; "'O"'~ ;::::::: STATES I CO""""" k:::::::::;-:::=======CO~M~,MA~N='::l=S=============t
I l;i~ ~;;~1;2 C~-::~K;l"'Ob-d .,;"~:;~R 0nr V
I '1~;:FCJj;';i}J ':. REVAO ,J ~ I CO-;T?~L~E;"~t,;~y,:~1 STATES! ~6~~~~R l:= ~~~~o CLeCK
. t "VAll 0 CLOCK" j ANO ~AI N r.7'\ E STA-US .
I I
WRITE . cc~nROL '& I '
: : 7 • unml ll~~~R~cr ,.0_2_J~~.::::::::::::::::::::::::_~~~~~~V~A-l_t~O~C~l-O_C~K~~~~~~~~~:
:f STAiUS "
STR03t: C
REJECT
STAn;s
~. I ISTAT1.:s ~I ~~Gl STER @0F> 7 TRK
I I P.os T O£A. "'.O'E ~ JREA. STROSE
: ~~~~ A:~~~~~~~~.~~LI ______ --1- ___________ ......... ================== T. <EA> 'ArA
eb' "',- ..... ,,,_,;.R PARITY 000 PARITY ~1.._CPAC_NR_~~_O~ __ (,"";\~I~!-.-1 TR, 6 .
I p:,ql TY f" ~f<-- ~ ~EN ODt' ;>~~!:r
CHECK STATES (CR3)
WRITE
DATA
SELECT
CATES
PoAlT WRITE STORAGE
SH MTA RUilSTER @~ ..... ==========~
-'--'--~ ___ -r-_~~!:J _ CO;·\;'I\',:>
Ii2' FL';G ~
i C
RE:;ISTjJC.? .
7 Tit~ C------'l---~
r::~====== SET DATA FLAG CATA TAANSFE? OATA FLAG
~ =t STATES 1,/fR. ACK .' CONTR01l26\27/fi\I~---i W/~ ACKNC\ll!O::E
OdAY STATUS ~AlT . '. \!..;I"d JoI.A\.T
COU:HE:R(S'I - SPEED
.~~ CLOC;.:.K:.- ____ -.
~
L- ____ I __ _
~-:OL..---, 000 r \JR I TE
--- PARlTY CLOCK
~----I 7 TRK '------.
(5)
STATES
\!.V I r:ESET CC~I'.ANO
7 iRK
. 6·
HI OENSITY SELECT
(CR10)
I wDA~TIAl! )[ ~tl k:===~===~~===-:.-~-c~-~<?~ ..-- ___ .1.-_---,
1 7 } CRec GEN. - 1] READ _ IIt\TER-RECORO }--. U!;l.AY ~Eg~TER
Si
r.C:>'~S ::>;1 GAP DETECi IJ'4'I CC:;~iTEf\
\ (~ TAACK. ~ • ~~ \!..~ ~C CLOC!( HALT
I , ......s ~ I, C::LY)@t-
I-C
~ __________ ~
1 'J '~--'. ""~!!_E CLO !5 ______ . __
• t "':'F'.S r---.! RCSET '..:~ I ~E.!\~T.~_Jc~i~1~~~
II.. __ ..I..--....;.--~~·:<:. -----. ~-------_-=--=--=-- _-_--_-_-_.-_-~-[ '. ~:u ~ ~r~T.~'__ ... _._____ ~
L. _____ ... _________ . __ . ___ ... __ . _- ..... ---.-.-- .. -.---'==-=-:::-======!.--- ________ ~
SET DATA F:.AG