Black Box IC496A-R2 User manual

CUSTOMER
SUPPORT
INFORMATION
Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOX
FREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax [phone]
Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018
Web site: www.blackbox.com • E-mail: [email protected]
OCTOBER 2001
IC496A-R2 IC496AE-R2
IC497A IC497AE
IC498A IC498AE
IC499A IC499AE
SCSI Repeaters
SCSI REPEATER

1
FCC/IC RFI STATEMENTS
FEDERAL COMMUNICATIONS COMMISSION AND INDUSTRY CANADA
RADIO-FREQUENCY INTERFERENCE STATEMENTS
Class B Digital Device. This equipment has been tested and found to comply with
the limits for a Class B computing device pursuant to Part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against harmful
interference in a residential installation. However, there is no guarantee that
interference will not occur in a particular installation. This equipment generates,
uses, and can radiate radio frequency energy, and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio
communications. If this equipment does cause harmful interference to radio or
telephone reception, which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference by one of the following
measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which
the receiver is connected.
• Consult an experienced radio/TV technician for help.
Caution:
Changes or modifications not expressly approved by the party
responsible for compliance could void the user’s authority to operate
the equipment.
To meet FCC requirements, you should use shielded cables and power cords to
connect this device to a personal computer or other Class B certified device.
This digital apparatus does not exceed the Class A limits for radio noise emission from digital
apparatus set out in the Radio Interference Regulation of Industry Canada.
Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant les limites
applicables aux appareils numériques de la classe A prescrites dans le Règlement sur le
brouillage radioélectrique publié par Industrie Canada.

2
SCSI REPEATERS
NORMAS OFICIALES MEXICANAS (NOM)
ELECTRICAL SAFETY STATEMENT
INSTRUCCIONES DE SEGURIDAD
1. Todas las instrucciones de seguridad y operación deberán ser leídas antes de
que el aparato eléctrico sea operado.
2. Las instrucciones de seguridad y operación deberán ser guardadas para
referencia futura.
3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de
operación deben ser respetadas.
4. Todas las instrucciones de operación y uso deben ser seguidas.
5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo, cerca
de la tina de baño, lavabo, sótano mojado o cerca de una alberca, etc.
6. El aparato eléctrico debe ser usado únicamente con carritos o pedestales que
sean recomendados por el fabricante.
7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea
recomendado por el fabricante.
8. Servicio—El usuario no debe intentar dar servicio al equipo eléctrico más allá
a lo descrito en las instrucciones de operación. Todo otro servicio deberá ser
referido a personal de servicio calificado.
9. El aparato eléctrico debe ser situado de tal manera que su posición no
interfiera su uso. La colocación del aparato eléctrico sobre una cama, sofá,
alfombra o superficie similar puede bloquea la ventilación, no se debe colocar
en libreros o gabinetes que impidan el flujo de aire por los orificios de
ventilación.
10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor
como radiadores, registros de calor, estufas u otros aparatos (incluyendo
amplificadores) que producen calor.
11. El aparato eléctrico deberá ser connectado a una fuente de poder sólo del
tipo descrito en el instructivo de operación, o como se indique en el aparato.

3
12. Precaución debe ser tomada de tal manera que la tierra fisica y la polarización
del equipo no sea eliminada.
13. Los cables de la fuente de poder deben ser guiados de tal manera que no
sean pisados ni pellizcados por objetos colocados sobre o contra ellos,
poniendo particular atención a los contactos y receptáculos donde salen del
aparato.
14. El equipo eléctrico debe ser limpiado únicamente de acuerdo a las
recomendaciones del fabricante.
15. En caso de existir, una antena externa deberá ser localizada lejos de las lineas
de energia.
16. El cable de corriente deberá ser desconectado del cuando el equipo no sea
usado por un largo periodo de tiempo.
17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean
derramados sobre la cubierta u orificios de ventilación.
18. Servicio por personal calificado deberá ser provisto cuando:
A: El cable de poder o el contacto ha sido dañado; u
B: Objectos han caído o líquido ha sido derramado dentro del aparato; o
C: El aparato ha sido expuesto a la lluvia; o
D: El aparato parece no operar normalmente o muestra un cambio en su
desempeño; o
E: El aparato ha sido tirado o su cubierta ha sido dañada.
EUROPEAN UNION DECLARATION OF CONFORMITY
This equipment complies with the requirements of the European EMC Directive
89/336/EEC.
NOM STATEMENT, EU DECLARATION OF CONFORMITY

4
SCSI REPEATERS
Contents
Chapter Page
1. Specifications ............................................................................................. 5
2. Introduction ............................................................................................... 8
2.1 Overview .............................................................................................. 8
2.2 Features ............................................................................................... 9
3. Installation ................................................................................................ 10
3.1 The Complete Package ..................................................................... 10
3.2 Placement .......................................................................................... 10
3.3 The Installation Procedure .............................................................. 11
3.3.1 Attaching the AC Power Supply ............................................. 11
3.3.2 Connecting the SCSI Repeater to the SCSI Bus ................... 11
3.3.3 Ensuring Proper Termination ............................................... 12
3.3.4 Powering Up the System ........................................................ 12
4. Operation and Troubleshooting ............................................................ 13
4.1 Monitoring the LED ......................................................................... 13
4.2 Contacting Black Box ....................................................................... 13
4.3 Shipping and Packaging ................................................................... 14
Appendix A: Pinouts ....................................................................................... 15
A.1 50-Pin Narrow Single-Ended SCSI Ports
(IC496 and IC497 Models) ............................................................ 15
A.2 68-Pin Wide Single-Ended SCSI Ports (IC498 Models) .................. 16
A.3 68-Pin LVD SCSI Ports (IC499A) ..................................................... 17
A.4 Power Connector .............................................................................. 18
Appendix B: SCSI Technical Information .................................................... 19
B.1 SCSI Basics ......................................................................................... 19
B.2 SCSI Installation Tips ....................................................................... 21
B.3 SCSI Signal Descriptions .................................................................. 22
B.4 Device and Distance Support By Bus Type ...................................... 23

5
CHAPTER 1: Specifications
1. Specifications
Compliance — CE; FCC Part 15 Subpart J Class B, IC Class/classe B
Standards — ANSI X3.131 and X3T9.2
Interfaces — IC496 and IC497 models: Narrow SCSI-1 and SCSI-2
single-ended;
IC498 models: Wide SCSI-2 and Ultra SCSI (SCSI-3)
single-ended;
IC499 models: Wide Ultra2 SCSI LVD
Protocol — Synchronous or asynchronous
Maximum
Data Rate — IC496 and IC497 models: 20 MBps;
IC498 models: 40 MBps;
IC499 models: 80 MBps
Maximum
Signal Delay — IC499 models: 10 ns;
All other models: 15 ns
Maximum
Signal Slew — 3 ns
Maximum
Distance — IC496 and IC497 models:
From each port to the most distant directly attached
device:
6 m (19.7 ft.) at 5 MBps,
3 m (9.8 ft.) at 10 MBps, or
1.5 m (4.9 ft.) at 20 MBps;
Up to 3 units can be installed on one bus to extend
total bus length up to 24 m (78.7 ft.), 12 m (39.4 ft.),
or 6 m (19.7 ft.) respectively;

6
SCSI REPEATERS
Maximum
Distance (cont’d) — IC498 models:
From each port to the most distant directly attached
device:
6 m (19.7 ft.) at 10 MBps,
3 m (9.8 ft.) at 20 MBps or (with four or fewer
devices) at 40 MBps, or
1.5 m (4.9 ft.) with more than four devices at
40 MBps;
Up to 3 units can be installed on one bus to extend
total bus length up to 24 m (78.7 ft.), 12 m (39.4 ft.),
or 6 m (19.7 ft.) respectively;
IC499 models:
Point-to-point (only two other devices on the bus):
82 ft. (25 m) from each port to each directly
attached device;
Multipoint (more than two other devices on the bus):
39.4 ft. (12 m) from each port to the most distant
directly attached device;
Up to 2 units can be installed on one bus to extend
total bus length up to 246 ft. (75 m) or 118 ft. (36 m)
respectively
SCSI ID — None required
Termination — Active internal or external (user-selectable)
Internal Terminator
Power — 1 amp; internal resettable fuse will provide 5 VDC at
1 amp
User Controls —(2) Side-mounted slide switches: Internal vs. external
termination
Indicator — (1) Unlabeled Power/Activity LED
Connectors — All models: (1) 5-pin mini-DIN female power jack;
IC496 models: (2) 50-pin Centronics®female;
IC497 models: (2) Micro D50 (50-pin high-density)
female;
IC498 models and IC499A: (2) Micro D68 (68-pin high-
density) female

7
CHAPTER 1: Specifications
Power — IC496A-R2, IC497A, and IC498A:
From wallmount power supply:
Optimal Input: 115 VAC, 60 Hz;
Input Range: 103.5 to 126.5 VAC, 48 to 65 Hz;
Input Current Rating: 0.25 amps;
Output: 12 VDC at up to 1 amp;
IC496AE-R2, IC497AE, and IC498AE:
From desktop power supply:
Optimal Input: 220 VAC, 50 Hz;
Input Range: 198 to 242 VAC, 48 to 65 Hz;
Input Current Rating: 0.25 amps;
Output: 12 VDC at up to 1 amp;
IC499A:
From wallmount power supply:
Optimal Input: 115 VAC, 60 Hz;
Input Range: 103.5 to 126.5 VAC, 48 to 65 Hz;
Input Current Rating: 0.25 amps;
Output: 6 to 12 VDC at up to 1.3 amps
IC499AE:
From desktop power supply:
Optimal Input: 230 VAC, 50 Hz;
Input Current Rating: 110 mA
Output: 12 VDC at up to 1 amp
MTBF — 50,000 hours
Temperature
Tolerance — 32 to 131˚F (0 to 55˚C)
Humidity
Tolerance — Up to 90% noncondensing
Size — 1.1"H x 3.4"W x 4.7"D (2.8 x 8.6 x 11.9 cm)
Weight — 1 lb. (0.5 kg)

8
SCSI REPEATERS
2. Introduction
NOTE
If you’re not very familiar with how SCSI works or with the
characteristics of its different varieties, please read the technical
information in Appendix B. It might help you (a) confirm that you have
the proper Repeater and (b) prevent installation and operation problems.
2.1 Overview
Your new SCSI Repeater gives you the freedom to extend the distance of any LVD
SCSI bus (IC499 models) or single-ended SCSI bus (all other models) beyond the
standard distance limits. It’s a low-cost data repeater that plugs in-line on a SCSI
chain, regenerating and reconditioning the data signal, doubling the distance your
data can travel, and giving you the flexibility to install your SCSI peripherals
wherever you need them most (see Figure 2-1).
Figure 2-1. One SCSI Repeater doubles the distance of a SCSI bus.
In fact, you can link as many as three IC496, IC497, or IC498 model SCSI
Repeaters to a single SCSI-1, SCSI-2, or Ultra SCSI (SCSI-3) bus in order to place
disk drives, tape peripherals, CD-ROM drives, or laser printers up to 24 m (78.7 ft.)
away from the host computer (see Figure 2-2 on the next page). Or you can link as
many as two SCSI LVD Repeaters (IC499 models) to an Ultra2 SCSI bus to place
one such devices as much as 246 ft. (75 m) from the host computer, or two or
more such devices as much as 118 ft. (36 m) from the host computer.
NOTE
The maximum distance attainable in an IC496, IC497, or IC498 model
SCSI Repeater system depends on whether the bus is narrow or wide,
how many devices are on it, and how high the data rate is. See
Section 3.3.2 and Section B.4.
At 5 MBps, single-ended SCSI bus extended to as
much as 12 m (39.4 ft.) with a single Repeater
Multipoint LVD SCSI bus extended to as
much as 24 m (78.7 ft.) with a single Repeater
Computer with
SCSI host adapter
SCSI Repeater
SCSI
storage
devices

9
Figure 2-2. Daisychain SCSI Repeaters for more distance (DOS/Windows®
drive-letter assignments shown).
Three basic types of the SCSI Repeater are available. One supports “narrow” (8-bit)
single-ended SCSI devices, the second supports “wide” (16-bit) single-ended SCSI
devices, and the third supports low-voltage differential (LVD) SCSI devices. All
three Repeater types can double the distance of your SCSI bus.
2.2 Features
• Doubles SCSI-bus distance.
• Maximum data rate of 20 (narrow single-ended), 40 (wide single-ended), or
80 (LVD) Mbps.
• Compatible with synchronous and asynchronous applications.
• User-installable.
• Transparent to SCSI controllers and peripherals.
• Internal active bus termination.
• No software required.
• IC496 and IC497 models are compatible with SCSI-1 and SCSI-2; IC498 models
are compatible with SCSI-2 and Ultra SCSI (SCSI-3); and IC499 models are
compatible with Ultra2 SCSI.
• Conforms to ANSI X3.131 and X3T9.2 SCSI specifications.
CHAPTER 2: Introduction
Multipoint LVD SCSI bus extended to as much as 36 m
(118.1 ft.) or single-ended SCSI bus extended to as much
as 18 m (59.1 ft.) with two Repeaters—a third Repeater
could extend the single-ended range to the maximum
24 m (78.7 ft.)
Tape
drive
(D:)
Zip®
drive
(B:)
Computer with
3.5" drive (A:)
and hard drive
(C:)
Tape
drive (E:)
DVD-ROM
drive (G:)
CD-ROM
tower
(F:)

10
SCSI REPEATERS
3. Installation
3.1 The Complete Package
The complete SCSI Repeater package you should have received includes the SCSI
Repeater itself, its AC power supply, and this manual. If you didn’t receive
everything, or if anything arrived damaged, call Black Box immediately.
3.2 Placement
Your SCSI Repeater, shown in Figure 3-1, requires no additional software to
operate. The only thing necessary to operate it is a nearby working AC outlet.
You can install the SCSI Repeater in any position and any location that is
convenient for you. The only exception is that you should not install the unit near
any devices that generate (a) excessive heat, such as desk lamps or radiators, or
(b) excessive electrical noise, such as motors, fluorescent lights, or compressors.
Figure 3-1. Top view of the SCSI Repeater, showing connections.
SCSI cable to
computer
(or peripheral or
other Repeater)
SCSI cable to
peripheral
(or computer or
other Repeater)
DC power plug
(with flat side facing
forward)
Single-ended SCSI cables can be up to 6 m
(19.7 ft.) long depending on the data rate;
LVD SCSI cables can be up to 25 m (82 ft.) long
regardless of the data rate

11
3.3 The Installation Procedure
3.3.1 A TTACHING THE AC P OWER S UPPLY
The first step in installing your SCSI Repeater is to connect its power supply.
Depending on which model of the Repeater you ordered, it will be shipped with
either a 115- or 230-VAC supply. Both supplies have an attached 6-ft. (1.8-m)
output cord terminated with a 5-pin mini-DIN DC plug.
The shape of this DC plug is “keyed” so that it will only fit the DC socket on the
SCSI Repeater if it’s positioned properly. If the plug doesn’t seat easily, check to
make sure it’s positioned properly. Do not use excessive force to seat the plug.
Refer to Appendix A for the pinout of this plug.
Next, plug the Repeater’s power supply (115-VAC models) or its input cord
(230-VAC models) into a working AC outlet. The red Power/Activity LED on the
right side of the SCSI Repeater will light to indicate when the unit is powered ON.
3.3.2 C ONNECTING THE SCSI R EPEATER TO THE SCSI B US
CAUTION!
Turn OFF any computers and peripherals attached to the SCSI bus
before connecting the SCSI Repeater to the bus.
Don’t ever attach the Repeater to a SCSI bus containing high-voltage
differential (HVD) devices. This will damage or destroy the Repeater.
You may install the SCSI Repeater at any point on the SCSI bus. The Repeater has
two SCSI connectors with locking tabs or screw locks for secure connections. These
ports are not computer- or peripheral-specific, so you can connect cable from a
computer or SCSI peripheral to either one.
Use good cable for your SCSI bus. High-quality shielded SCSI cables will provide
a link with the greatest noise immunity, and across the greatest distance, between
the SCSI Repeater and your other SCSI devices. No matter how good the cable is,
however, no cable connected to the SCSI Repeater may be longer than the
maximum for your bus type and data rate:
• 6 m (19.7 ft.) for single-ended SCSI at 5 MBps (narrow) or 10 MBps (wide);
• 3 m (9.8 ft.) for single-ended SCSI at 10 MBps (narrow), 20 MBps (wide), or
40 MBps (wide with four or fewer devices);
•
1.5 m (4.9 ft.) for single-ended SCSI at 20 MBps (narrow) or 40 MBps (wide
with five or more devices);
• 25 m (82 ft.) for point-to-point LVD SCSI; or
• 12 m (39.4 ft.) for multipoint LVD SCSI.
CHAPTER 3: Installation

12
SCSI REPEATERS
3.3.3 E NSURING P ROPER T ERMINATION
All SCSI buses must be properly terminated at each end. But because the SCSI
Repeater essentially ties together two SCSI chains that can each be as long as an
entire bus, there has to be extra termination on each side of the Repeater in
addition to the standard terminators at each end of the bus.
That’s a total of four terminators—two on each side of the SCSI Repeater.
Figure 3-2 shows the locations of the required terminators. Be careful, though—
your system will fail if more than two terminators are installed on either side of the
SCSI Repeater.
Figure 3-2. Termination in a SCSI Repeater system.
Your SCSI Repeater comes standard with active-type internal terminators that
provide the necessary termination on each side of the Repeater. However, your
application or peripherals might require that you use external device terminators
with the Repeater, in which case you must disable the internal terminators before
attaching external ones. (The SCSI Repeater contains an internal resettable fuse
that can provide power—1 amp at 5 volts—to an external terminator. Note that the
SCSI Repeater contains internal protection and will not be affected if other SCSI
devices provide terminator power.)
Select which type of termination you’re going to use with the two slide switches
on the right side of the SCSI Repeater. Switch “A” controls the internal terminators
on the Repeater’s Port A; switch “B” controls those on Port B. When the switches
are in the “down” position, the Repeater’s internal terminators are ON. For
normal operation, leave the switches in the “down” (ON) position and install an
additional terminator at each end of the SCSI bus.
3.3.4 P OWERING U P THE S YSTEM
Once you’ve connected the SCSI Repeater to your properly terminated SCSI bus,
power up the SCSI peripherals on the bus, then the host computer.
This completes your SCSI Repeater installation. The Repeater system should be
ready for continuous operation.
Computer
T
T
T*T* Peripherals
SCSI Repeater
T = required terminators that you must make sure are present
T* = required terminators that are already there (internal to the Repeater)

13
CHAPTER 4: Operation and Troubleshooting
4. Operation and Troubleshooting
4.1 Monitoring the LED
While the SCSI Repeater is working normally, boosting and regenerating SCSI data
signals as they pass through it, the red Power/Activity LED on the right side of the
Repeater will blink. If data communication is not getting from one side of the
Repeater to the other, check your cable connections, your termination, and this
LED. If the LED is dark even though the Repeater is plugged in and turned ON,
there is a problem with either the unit or the site’s electricity. If the LED is
constantly lit (does not flicker) when you are trying to communicate with a device
on the other side of the Repeater, even though your cable connections are secure
and termination is properly set up, the Repeater is not working properly (see the
next section).
4.2 Contacting Black Box
If you determine that your SCSI Repeater is malfunctioning, do not attempt to alter or
repair the unit. It contains no user-serviceable parts. Call Black Box Technical
Support at [phone].
Before you do, make a record of the history of the problem. We will be able to
provide more efficient and accurate assistance if you have a complete description,
including:
• the nature and duration of the problem;
• when the problem occurs;
• the components (host computer, host adapter, SCSI devices and cables, etc.)
involved in the problem;
• any particular application that, when used, appears to create the problem or
make it worse; and
• the results of any testing you’ve already done.

14
SCSI REPEATERS
4.3 Shipping and Packaging
If you need to transport or ship your SCSI Repeater:
• Package it carefully. We recommend that you use the original container.
• If you are shipping the Repeater for repair, make sure you include its power
supply. If you are returning the Repeater, make sure you include its manual as
well. Before you ship, contact Black Box to get a Return Authorization (RA)
number.

15
APPENDIX A: Pinouts
Appendix A: Pinouts
A.1 50-Pin Narrow Single-Ended SCSI Ports (IC496 and IC497 Models)
The “narrow” single-ended SCSI ports on the IC496 and IC497 versions of the SCSI
Repeater are pinned as shown in Table A-1.
Table A-1. Pinout chart for narrow single-ended SCSI connectors.
SIGNAL NAME PIN NUMBER SIGNAL NAME PIN NUMBER
GROUND 1 –DB(0) 26
GROUND 2 –DB(1) 27
GROUND 3 –DB(2) 28
GROUND 4 –DB(3) 29
GROUND 5 –DB(4) 30
GROUND 6 –DB(5) 31
GROUND 7 –DB(6) 32
GROUND 8 –DB(7) 33
GROUND 9 –DB(P) 34
GROUND 10 GROUND 35
GROUND 11 GROUND 36
GROUND 12 GROUND 37
OPEN 13 TERMPWR 38
GROUND 14 GROUND 39
GROUND 15 GROUND 40
GROUND 16 –ATN 41
GROUND 17 GROUND 42
GROUND 18 –BSY 43
GROUND 19 –ACK 44
GROUND 20 –RST 45
GROUND 21 –MSG 46
GROUND 22 –SEL 47
GROUND 23 –C/D 48
GROUND 24 –REQ 49
GROUND 25 –I/O 50

16
SCSI REPEATERS
A.2 68-Pin Wide Single-Ended SCSI Ports (IC498 Models)
The “wide” single-ended SCSI ports on the IC498 versions of the Repeater are
pinned as shown in Table A-2.
Table A-2. Pinout chart for wide single-ended SCSI connectors.
SIGNAL NAME PIN NUMBER SIGNAL NAME PIN NUMBER
GROUND 1 –DB(12) 35
GROUND 2 –DB(13) 36
GROUND 3 –DB(14) 37
GROUND 4 –DB(15) 38
GROUND 5 –DB(P1) 39
GROUND 6 –DB(0) 40
GROUND 7 –DB(1) 41
GROUND 8 –DB(2) 42
GROUND 9 –DB(3) 43
GROUND 10 –DB(4) 44
GROUND 11 –DB(5) 45
GROUND 12 –DB(6) 46
GROUND 13 –DB(7) 47
GROUND 14 –DB(P) 48
GROUND 15 GROUND 49
GROUND 16 GROUND 50
TERMPWR 17 TERMPWR 51
TERMPWR 18 TERMPWR 52
RESERVED 19 RESERVED 53
GROUND 20 GROUND 54
GROUND 21 –ATN 55
GROUND 22 GROUND 56
GROUND 23 –BSY 57
GROUND 24 –ACK 58
GROUND 25 –RST 59
GROUND 26 –MSG 60
GROUND 27 –SEL 61
GROUND 28 –C/D 62
GROUND 29 –REQ 63
GROUND 30 –I/O 64
GROUND 31 –DB(8) 65
GROUND 32 –DB(9) 66
GROUND 33 –DB(10) 67
GROUND 34 –DB(11) 68

17
A.3 68-Pin LVD SCSI Ports (IC499 Models)
The low-voltage differential (LVD) SCSI ports on the IC499 versions of the
Repeater are pinned as shown in Table A-3.
Table A-3. Pinout chart for LVD SCSI connectors.
SIGNAL NAME PIN NUMBER SIGNAL NAME PIN NUMBER
+DB(12) 1 -DB(12) 35
+DB(13) 2 -DB(13) 36
+DB(14) 3 -DB(14) 37
+DB(15) 4 -DB(15) 38
+DB(P1) 5 -DB(P1) 39
+DB(0) 6 -DB(0) 40
+DB(1) 7 -DB(1) 41
+DB(2) 8 -DB(2) 42
+DB(3) 9 -DB(3) 43
+DB(4) 10 -DB(4) 44
+DB(5) 11 -DB(5) 45
+DB(6) 12 -DB(6) 46
+DB(7) 13 -DB(7) 47
+DB(P) 14 -DB(P) 48
GROUND 15 GROUND 49
DIFFSENS 16 GROUND 50
TERMPWR 17 TERMPWR 51
TERMPWR 18 TERMPWR 52
RESERVED 19 RESERVED 53
GROUND 20 GROUND 54
+ATN 21 -ATN 55
GROUND 22 GROUND 56
+BSY 23 -BSY 57
+ACK 24 -ACK 58
+RST 25 -RST 59
+MSG 26 -MSG 60
+SEL 27 -SEL 61
+C/D 28 -C/D 62
+REQ 29 -REQ 63
+I/O 30 -I/O 64
+DB(8) 31 -DB(8) 65
+DB(9) 32 -DB(9) 66
+DB(10) 33 -DB(10) 67
+DB(11) 34 -DB(11) 68
APPENDIX A: Pinouts

18
SCSI REPEATERS
A.4 Power Connector
The DC power-input port common to all versions of the SCSI Repeater, illustrated
in Figure A-1, is pinned as shown in either Table A-4 or Table A-5.
Figure A-1. The 5-pin mini-DIN power connector.
Table A-4. The pinout of the power connector on the IC499 models.
Table A-5. The pinout of the power connector on all other models.
PIN NUMBER DESCRIPTION
1 +5 VDC
2 +12 VDC
3 Ground
4 +12 VDC
5 Ground
Shell No connection
PIN NUMBER DESCRIPTION
1 No connection
2 +6 to +12 VDC
3 Ground
4 +6 to +12 VDC
5 Ground
Shell No connection

19
APPENDIX B: SCSI Technical Information
Appendix B:
SCSI Technical Information
B.1 SCSI Basics
This section briefly discusses some of the major topics involved with the SCSI
(Small Computer Systems Interface).
SCSI-l
The original specification supported data transfers up to 5 MBps on an 8-bit-wide
parallel data bus. However, the SCSI-1 standards did not solve certain
incompatibility problems between host adapters and peripheral devices. The need
to improve compatibility, increase transfer rates, and add other features for better
performance prompted a review of this specification.
SCSI-2
Improved compatibility and higher transfer rates were provided in this
enhancement. The addition of “Wide SCSI” permitted 16 or 32 bits to be
transferred in parallel, the latter requiring two cables. “Fast SCSI,” which doubled
previous maximum data rates, was also added. The new specifications made it
possible to achieve synchronous data transfers at up to 10 MBps for 8-bit buses,
20 MBps for 16-bit buses, and 40 MBps for 32-bit buses.
Ultra SCSI (SCSI-3)
The most significant additions in this enhancement were the ability to address up
to 32 devices, a 16-bit single-cable data bus, and a serial SCSI protocol. In the Ultra
SCSI standard, various aspects of the interface have their own subsidiary standards,
including the SCSI Parallel Interface (SPI), which is a hardware specification, and
the SCSI Interlocked Protocol (SIP), which is a software-link protocol.
Ultra2 SCSI
In this version of the SCSI specification, the Low-Voltage Differential (LVD) bus
was added, which supports the distance and noise resistance of differential SCSI
but uses the low power levels typical of single-ended SCSI (see the Signal Wiring
section on the next page). The maximum data rate was also doubled again, to
80 MBps.