Appendix B

Specifications

Main Unit

 

16-bit CPU

8088-1 microprocessor; 4.77 or

 

 

10 MHz clockrate; switch selectable

Main memory

640KB

Coprocessor

8087-1, 10 MHz microprocessor

 

 

(optional)

Read Only Memory

16KB (ROM BIOS)

(ROM)

 

Direct

Memory

Programmable DMA controller with

Access

(DMA)

four channels-two on the

 

 

motherboard (one for refreshing and

 

 

one for diskette controller), two

 

 

available for user peripherals

 

 

including a hard disk controller

Interrupt (8259)

Programmable interrupt controllers,

 

 

8 interrupt levels

Timer/counter

Three programmable timer/counters

(8253-S)

 

Clock/calendar/RAM

Real-time clock, calendar, and

 

 

SO-byteCMOS RAM for

 

 

configuration, battery back-up

Parallel interface

Standard 8-bit parallel, DB-25

 

 

female connector; programmable

Serial

interface

RS-232C, asynchronous, DB-25

 

 

male connector; programmable

Specifications B-1