Introduction
3
Counter/
Timers
Interrupt
Controller
RS-232-C
Serial
RS-232-C/
RS-422/485
Serial
Centronics
Printer
I/O
32K RAM
(Optional
Battery
Backup)
Clock
Slowdown
and
Halt/
Restart
AC/DC
Power-
Fail
Real-time
Clock
V20
CPU
256K RAM & 256K ROM
or
384K RAM & 128K ROM
(RAM Optionally
Battery-backed)
Optional
Battery
Backup
ZT 8809A
Figure 1–1. ZT 8809A Functional Block Diagram.
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