NEC VERSA P, Service Manual

Page: 31 / 177

1-16 Technical Information
Diskette Controller, Serial Interface, Parallel Interface
The PC87332VLJ chip is a 100-pin plastic Thin Quad Flat Plastic (TQFP) chip. The con-
troller changes 8-bit parallel data into serial data and writes the data to the diskette. Con-
versely, the serial data is transmitted from the diskette into parallel data, where it remains
until the read operation takes place.
Additional PC87334VJG chip operations include:
n
compatibility with ISA, EISA, and Micro channel architectures
n
low-power CMOS with enhanced power-down mode
n
supports new 2 Mbps tape drives
Keyboard Controller
The keyboard controller (M38802M2-001HP) supports a PS/2-style keyboard, mouse and
security features such as keyboard hot keys and password. Refer to Appendix A for key-
board interface connector pin assignments.
When data is written to the output buffer, the controller generates an interrupt (IRQ01 or
IRQ12) 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.
PCMCIA Controller
The controller (CL-PD6720-B-2) interfaces with the ISA bus, PCMCIA card socket and
configuration registers to provide:
n
memory address mapping, I/O address mapping
n
power management for each PCMICA card socket, controlled through power and
RESETDRV control registers
n
the elimination of interrupt conflicts using interrupt steering.
For a list of PCMCIA drivers and utilities, see Section 3, Options. They can also be found in
the CARDSOFT directory on the C: drive.