ZiLOG Z80 User Manual

24
Step 10
Removeany solder ‘splats’ with a brush,such as an oldtoothbrush.
Visually inspect thesolderingfor dry joints andshorts.
Cleanthe flux off withsuitable cleaning materials.
Visually inspect again.
Beforefittingthe ICsor jumper shunts, plug the boardinto anRC2014 backplane
withno other boardsfitted. Powerthe backplane and performthe followingchecks
witha voltmeter:
 Check the supply voltage onthe PIOmodule,between, say, U1pin 10and U1
pin 20.This shouldbe 4.5 to5.5 volts, preferably 4.75to 5.25 volts.

Check
the
interrupt
enable
input
(IEI)
on
connector
P4
is
being
pulled
up
to
at
least 4.5 volts.
 Check eachaddressswitch input(Q2 toQ7)on U1 isbeing pulled up toat least
4.5 voltswhenthe appropriateswitch (SW1) isOff (open) anddropsto less
than 0.4 voltswhen the appropriateswitch (SW1) isOn (closed).
If all is well, powerdown andremovethe PIO module.

ZiLOG Z80 Specifications

General

Manufacturer	ZiLOG
Introduction Year	1976
Clock Speed	2.5 MHz to 20 MHz
Data Width	8-bit
Address Width	16-bit
Instruction Set	Z80
Transistor Count	8, 500
Package	40-pin DIP
Category	Microprocessor
Memory Address Space	64 KB
Voltage Supply	5V