P H 4 4 0 N L X M o t h e r b o a r d U s e r G u i d e
The SMSC 37C677 Super IO controller provides standard I/O. This comprises the four functions
described below. It is packaged in a 100-pin PQFP and is PC98 and ACPI compliant.
Keyboard and Mouse
The keyboard and mouse controller uses the Phoenix Multikey version 1.40 firmware. PS/2 style
keyboard and mouse ports are provided on the rear panel. The ports are interchangeable.
Floppy Disk Interface
Standard 2-mode and 3-mode 3½" drives are supported.
The floppy disk drive signals are routed from the motherboard to the NLX riser and the floppy
disk drive connector is mounted on the NLX riser.
As per the NLX specification, all floppy disk input signals to the motherboard must be pulled up
on the NLX riser.
There are two standard COM ports, which are wired to two standard 9-way D-type connectors on
the rear panel. The maximum Baud rate is 115K bits per second.
This is EPP 1.7/1.9 and IEE1284 (ECP) compliant and is compatible with a standard (output
only) PC parallel port as well as a bi-directional (PS/2 style) parallel port. There is a 25-way D-
type connector on the rear panel.
IDE Disk Controller
Two UltraDMA33 IDE ports are provided with the controller integrated into the PIIX4e. This
allows for a maximum of four drives to be connected - two to each port. Normally the primary
port would be used for hard disk drives and the secondary port for CD-ROM or DVD drives.
120MB floppy drives have IDE interfaces.
Both IDE controllers are independent and both can bus-master data into memory for improved
performance. UltraDMA33 drives have a theoretical maximum transfer rate of 33MBs
interfaces are also, of course, compatible with standard ATA drives.
Universal Serial Bus (USB)
The motherboard supports two USB ports with the controller integrated into the PIIX4e. The
motherboard has a build option of a dual USB connector at the rear or with a single on the rear
and with the second port routed to the NLX riser to cater for an optional front USB connector.
The standard build is with a dual USB connector at the rear.
There is chassis intrusion detection available on motherboards with the Heceta II fitted. This is
capable of detecting an intrusion even when AC is disconnected (the logic is powered from the
3V lithium cell).
MITSUBISHI ELECTRIC MOTHERBOARD DIVISION
S e p t e m b e r 1 9 9 8
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