1-18 Technical Information
SYSTEM VIDEO
The system's LCD operates using the Chips and Technologies 65550A1 VGA Controller.
Video signals travel from the controller through the system's 15-pin D-SUB connector us-
ing 5 volts.
System video integrates a PCI-bus interface. The system ships with 2 MB Video RAM
(VRAM). It supports video modes up to 1024 x 768 with 64K colors in LCD mode.
See Appendix B for a list of Video modes.
PARALLEL INTERFACE
The system' s parallel interface integrates National Semiconductor’s PC87338 chip with a
25-pin D-subconnector. The port is located on the system's rear panel.
The modes of operation available for a PC87338 chip are:
compatibility mode
nibble mode
byte mode
Extended Capabilities Port (ECP)
Enhanced Parallel Port (EPP).
The user selects between three parallel interface modes using Auto Setup. These include
unidirectional, bidirectional or enhanced. Unidirectional mode sends data output from the
standard ISA port only. Bidirectional mode sends data using the standard ISA port or PS/2
technology. Enhanced mode enables high speed data transmission to occur using either the
unidirectional or bidirectional modes.
The default parallel port address is 378h and the interrupt level is IRQ07. Pin locations for
the parallel interface are listed in Appendix A.