HP Precision Bus SCSI/Parallel Host Adapter, Technical Data
   For HP 9000 Series 800 HP-PB Computers Product Number 28655A
The HP 28655A is an HP Precision Bus (HP-PB) system host adapter that
delivers the Small Computer Systems Interface (SCSI) and Centronics
(parallel) functionality in a single-board solution. These two
industry-standard connections provide HP 9000 Series 800 HP-PB
customers the capability to connect to a wide range of peripherals that
implement these two widely accepted standards.

SCSI
The HP 28655A implements a SCSI solution which is fully compatible with
the ANSI SCSI-2 specification. It provides a standard 8-bit SCSI bus
and is capable of performing 32-bit DMA transfers to system backplanes.
When connected with any of HP's SCSI peripheral devices, it provides a
complete solution for direct access or backup storage. Each host
adapter can support up to 7 SCSI peripheral devices, although
performance and cable restrictions will apply.

SCSI Features
o Industry-standard interface
o Fully ANSI SCSI-2 Compliant
-  support of bus arbitration
-  parity across the interface
-  single-ended transceivers
-  disconnect/reconnect
o High-speed throughput:
-  asynchronous (3.0 Mbits/s) or synchronous (5.0 Mbits/s) mode
-  32-bit DMA transfers
   Note:  System level performance is application dependent and may not
reflect the higher I/O rate achievable with SCSI.
o Connects up to 7 devices per adapter
-  1 meter cable ships with the adapter card
-  Cable uses 50-pin, high-density male connector on one end; 50-pin,
    low-density male on the other end.
o Up to 6 meters connectivity distance
o Compatible with HP SCSI peripheral devices. Refer to "HP 9000
  Series 800 Configuration Guide".

Parallel
The parallel connection implements the widely accepted 8-bit Centronics
specification intended primarily for printer connections. By achieving
compatibility with a wide range of handshaking schemes, the HP 28655A
is able to connect to a large selection of printers that implement the
Centronics standard.

Parallel Features
o Industry-standard interface
o Asynchronous data transfer
o 64-byte FIFO
o 330 Kbyte/s burst transfer rate
o Compatible with HP's LaserJet printer family
o 36-pin parallel connector on peripheral side
o Up to 2 meters connectivity

Functional Specifications
Software
   The SCSI drivers provided in the HP-UX kernel implement the Common
Command Set and Message Set outlined in the SCSI-2-ANSI publication.
   Message Set
   The SCSI drivers implement a SCSI-2-compatible message set.
   Command Set
   In addition to all SCSI-2 mandatory commands, the 28655A driver
includes many SCSI-2 optional commands.

Warranties and Disclaimers
Standard HP 90-day warranty with purchase of the product.
   HP fully supports the 28655A for use with HP peripherals. Use of the
product with non-HP peripherals is at the user's own risk and is not
HP supportable. Hardware and/or software may require modification for
system/peripheral compatibility. Upon modification of the software,
HP waives all responsibility for proper operation including transaction
accuracy and data integrity. Modification of software should only be
taken on by users experienced with HP-UX drivers and SCSI
implementations.
   HP specifically disclaims the implied warranties of merchantability
and fitness for a particular purpose. In addition, HP specifically
disclaims all responsibility for the operation of the SCSI interface
software with non-HP products, and for results or data loss in
connection with use of the software.

Power Requirements
   Power Consumption:  3.75 watts (typical) at 5.0 volts
   Input Voltage Operating Range:  +4.75 to +5.25 volts
   Termpower:  The card supplies SCSI bus termination power and meets
SCSI specifications (0.9 amps max at +5 volts)

Environmental Characteristics
   Operating Temperature:  0 degrees C to +55 degrees C (+32 degrees F
      to +131 degrees F)
   Storage Temperature:  -40 degrees C to +70 degrees C (-40 degrees F
      to +158 degrees F)
   Relative Humidity:  15% to 95% noncondensing
   MTTR:  Less than one hour for failure isolation and card replacement

Physical Characteristics
   Dimensions:
      Height:  24.13 cm (9.50 in)
      Width:  12.95 cm (5.10 in)
      Thickness:  3.16 cm (1.25 in)

Related Products
Sister Products from HP's Peripherals Group include:  Winchester disks,
Optical disks, DDS Cartridge Tape, 9-Track Tape, and CD-ROM.

Ordering Information
   The HP 28655A includes:
      28655-60001 SCSI/Parallel Host Adapter with active SCSI
         termination circuits
      28655-90001 Installation Quick Start Guide
      1252-3920 SCSI active peripheral terminator
      5062-3383 SCSI 1-meter shielded twisted-pair cable with 50-pin,
         high density connector to 50-pin, low density connector
      5180-0010 2-meter parallel cable with 36-pin connector on
         peripheral side
   Note:  SCSI cable length may not exceed 6 meters in a daisy-chain
configuration. For cable extension, female to male cables are available
through Direct Marketing Division.
      28655A Accessories:  5061-6565 Loopback Hood

From HP Networking Communications Specifications Guide,
   5091-3821E, 9205, p 072
Associated files: none
HP Precision Bus SCSI/Parallel Host Adapter, Technical Data