Radio Shack TRS-80 Service Manual page 14

All and more about Sharp PC-1500 at http:l/www.PC-1500.info
Read/write timings for 1/0 port
A0 - 1$
::x ________ _,
c
MREQ°'t
_
_,
.,
..
---- -------
lli' AlT* --~
u o-1 - - ---c===)--
(a) Data read f rom
1/0
port
A0-1 5 :JC _ __ _ _ _ __
~x:::
RJ •---~ , .__
___
~ r--
WAI~
00- 1
--c=======>-
(b) Data w rit e to 1/0 port
Do not sale this PDF
!!!
NOT!>:
Clock ¢ is furnished to the
i\()S
input of t he
1 /0 port. MREQ•
is
an
inversion of
ME RQ of Z·80 and
furni1hed to
the MEO
of
the 1/0
port.
WAIT•
is
an
inversion of
WAIT
of
the 1/0
port
and furnished
to
the
W AJT
input
of Z·SO.
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