Digital Equipment DEC 3000 Series Service Information page 17

System Overview,
Continued
Addresses generated by DMA devices in the I/O system may be
translated by a scatter/gather map. The scatter/gather map can
map 32 Kbyte pages. This translation is an option, enabled on a
device-by-device basis.
Serial Lines: The serial line interface supports the following
equipment:
Equipment
Keyboard
Mouse
Printer
Communication
port
Ethernet Interface: The Ethernet interface can connect to the
local area network (LAN) by using an attachment unit interface
(AUI, or thickwire) or 10BaseT twisted-pair cable. The selection
(thickwire or twisted pair) is software-controllable.
SCSI Interface: The SCSI interface consists of two separate
channels using two SCSI controller chips. These controller chips
connect to the TURBOchannel through an ASIC. The ASIC
buffers data to and from the SCSI controllers, providing 16-
longword DMA bursts across the TURBOchannel for increased
bus efficiency.
ISDN and Audio In/Out: An AMD 79C30A controller chip
provides an ISDN interface and telephone-quality audio input
and output. Jacks and connectors in the front of the unit provide
connections for a microphone and headphones.
Battery Backed-Up TOY: A battery backed-up time-of-year
(TOY) chip provides a time reference when the unit is powered
off.
Function
Connects to a 15-pin D-sub connector.
Shares 15-pin D-sub connector with keyboard.
Connects to a 6-pin MMJ and is DEC–423
compliant.
Connects to a 25-pin D-sub connector and
supports full modem control.
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