Service Precaution On The Cpu And Outer Rom Replacement - Sharp ER-1910 Service Manual

ER-2395
8. Service Precaution on the CPU and
Outer ROM Replacement
Basically the CPU SC1003C is so designed to operate by its own
program stored in the internal ROM. However, an outer ROM may
be used to improve the program instead of using the internal ROM
at the early stage of the implimentation.
Even if an outer ROM is used together with the CPU at the early
stage of the production, it'will finally be replaced with the internal
ROM, then the CPU can operate without any outer ROM.
Therefore, when replacing either the CPU or the outer ROM, or
replacing the CPU/outer ROM together to a new CPU, the following
care should be exercised and the each pees wire must be
connected or disconnected. . | o e
The CPU aan Outer ROM Version and the Jumper Wire Connection Table
(Refer to the Circuit Diagram OOZER2395CD1M on a 5)
The outer ROM.- | Jumperwires wires
| vit _. . Applicable
_used together with aE Terminal Name' a 1 | C-2 —— 1 | C-2 — 1 | C2
Sree
es Cece ke Scie
(Signal)
(+5V) | (A15) |(+5¥) | (A14) | (A15) | (C82) (GND)
(Until Feb. 1987) oe :
| VHISC1033C102 NETIC Teco 26 1 B ™
(From Mar. 1987) | .
VHISC1033C104 mottere
Jumper wire
(Until Mar. 1987) . = :
VHISC1033C102
-
connection
pe VHI27256R361A
VHISC1033C104
(From April. 1987)
VHISC1033C103
© :Tobe connected.
X :To be disconnected. _
"1: The ROM type VHI27256R281A had been used. for Jan. 1987 production except for Switzerland - A. : When J4is being connected, it may leave as itis.
model and has been changed to VHI27256R281B from Feb. 1987 production for all ER-1910 mp nes "ase |
and ER-1920.