Appendix B

Specifications

Main Unit

16-bit CPU

Main memory

Coprocessor

Read Only Memory (ROM)

Direct Memory

Access (DMA)

8088 microprocessor; 4.77MHz. or 10MHz clockrate; switch selectable

640KB

8087 microprocessor (optional)

16KB

Programmable DMA controller with four channels-two on the mother board (one for refreshing and one for floppy disk controller), two available for user peripherals including a hard disk controller

Interrupt (8259)

Timer/counter (8253-5)

Clock/calendar RAM

Parallel interface

Serial interface

Speaker interface

Option slots

Programmable interrupt controllers, 8 interrupt levels

Three programmable timer/counters

Real-time clock, calendar, and 50-byte CMOS RAM for configuration, battery back-up

Standard 8-bit parallel, DB-25 female connector; programmable

RS-232C, asynchronous, DB-25 male connector; programmable

Internal, controlled by timer/counter

Five IBM-compatible input-output expansion slots

E l