Appendix B
Specifications
Main Unit
16-bit CPU
Main memory
Coprocessor
Read Only Memory (ROM)
Direct Memory
Access (DMA)
Interrupt (8259)
Timer/counter (8253-5)
Clock/calendar RAM
Parallel interface
Serial interface
Speaker interface
Option slots
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
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 expan-
sion slots
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