Technical data

1-21
General Information
Model 743 and Model 744 VME Board Computers
AUI LAN LAN circuits use the Ethernet/IEEE 802.3 standard interface. Only the Attach-
ment Unit Interface (AUI) version is used; no BNC connector is provided for ThinLAN. The
AUI connector enables connections to an external MAU using the HP A4303A adapter cable.
Table 1-15 summarizes the LAN AUI interface specifications.
Single-Ended SCSI The 8-bit single-ended implementation is compatible with the current
Series 700 products and supports 5 MB/sec data transfer rates.
The SCSI bus is terminated to 3.3 volts through 127 ohms on the system board. If the board
computer is used in a VME chassis having internal mass storage devices, all devices except
the last one must have their terminator removed. If an external disk drive is used, an active
terminator must be used on the last drive’s uncabled connector.
Table 1-16 summarizes the specifications for the single-ended SCSI interface.
Table 1-15 LAN AUI Specifications
Connector type 15-pin MDSM
Controller Intel 82596CA compatible megacell
Data rate 10 Mbits/sec
Electrical interface AUI
Type IEEE 802.3, Ethernet 1.0
Table 1-16 Single-Ended SCSI Interface Specifications
Controller NCR 53C710 compatible macrocell, Rev D
Connector type SCSI-II, ALT-1 50-pin high-density thumbscrew
Data rate Asynchronous, 1.5 MBs/second
Synchronous, 5 MB/second
Device limits
7 internal and/or external devices plus the host controller
a
Maximum external
cable length
4 meters (13.1 feet)
Type SCSI-II (ANSI X3.131-1986), 8-bit, single-ended
a.The board computer is the host controller.