Vga Controller; Parallel Interface; Keyboard Controller - NEC VERSA 6050MH Service Manual

VGA Controller

The Chips and Technologies 65550A1 is a PCI 64-bit Graphics Accelerator. The integrated
programmable linear address feature accelerates the graphics user interface (GUI) perform-
ance. The controller also supports Hardware Multimedia and VESA interface standards.
The controller provides advanced power management that helps to minimize power usage
in:
T
normal operation
T
Standby (sleep) mode
T
panel off power saving modes.

Parallel Interface

The PC87338VLJ chip is a 100-pin Thin Quad Flat Plastic (TQFP) chip. The controller
changes 8-bit parallel data into serial data and writes the data to the diskette. Conversely,
the serial data is transmitted from the diskette into parallel data, where it remains until the
read operation takes place.
Additional PC87338VLJ chip operations include:
T
ISA compatibility
T
low-power CMOS with enhanced power-down mode

Keyboard Controller

The keyboard controller (M38813E) supports a PS/2-style keyboard, mouse and password
security feature. Refer to Appendix A for keyboard interface connector pin assignments.
When data is written to the output buffer, the controller generates an interrupt, and requests
the CPU to receive the data. The controller automatically adds an even parity bit to the data
sent and waits for a response. The device must acknowledge that the data was successfully
received by sending a response to the controller for each byte of data received.
Technical Information 1-21