Epson MX-80 Technical Manual page 29

(5) 8049
The LSI "8049" functions as the main controller of the MX-80. The 8049 executes all
instructions according to the data stored in the 2716 (or 2332).
The data stored in the 2716 (or 2332) are latched into the 74LS175 by the signal ALE
(pin No. 11) of the 8049 and are taken into the 8049 through the address data bus lines,
for decoding. The basic clock of the 8049 is generated by a 6 MHz crystal oscillator.
Accordingly, the pulse spacing of signal ALE is approx. 2.5 /xsec as shown in Fig. 2.12.
2.5 fjLS
Fig. 2.1 2 Signal ALE
Fig. 2.13 shows the 8049 and program memory circuits.
REV. A
(MHt OCPI
lOP jCO
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ACO
OC)
8049.
8039
i! jiI
u
XL.
El lilllili |l!}i
° IMl! II 11' ; ' : I 1" I! 11 iI njT-
•SUMMMMi
r t m
ws
rrt! I I ' '
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Fig. 2.13 8049 and Program Memory Circuits
2-16
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