6. Mega-Midget Racer Installation in the Amiga A500
The CSA
Mega-Midget Racer
accelerator is designed to replace the 68000
m i c r o - p r o c e s s o r u n i t ( M P U ) i n s i d e t h e A m i g a A 5 0 0 w i t h a
68030/68881/882 combination. To install the CSA
Mega-Midget Racer
in
the A500, the following procedure must be followed:
WARNING! - THE INSTRUCTIONS IN THIS MANUAL ABOUT OPENING
T H E A M I G A A 5 0 0 S H O U L D B E U S E D A S A G U I D E O N LY. F O R
COMPLETE INFORMATION ABOUT THE A500, SEE THE AMIGA A500
USER’S MANUAL.
a. Turn off the power switch and disconnect all cables from the A500. Turn the unit
upside down.
b. Remove the expansion ram cover and expansion ram module, if present.
c. Remove six Torq sheet metal screws from the bottom of the A500 with a #T-10 Torq
wrench. Note that these screws have a special Torq drive head. An Allen wrench or
Phillips screwdriver will not work for these screws.
d. C a r e f u l l y t u r n t h e A 5 0 0 r i g h t - s i d e - u p , b e i n g c a r e f u l n o t t o d r o p t h e k e y b o a r d
assembly, which is now loose.
e. Unplug the keyboard cable from the A500 motherboard. Note that the black wire is
on your left as you face the front of the computer. This connector is not keyed, and
must be reassembled with the same cable orientation.
f. Remove four sheet metal screws which hold down the internal electrostatic shield.
g. Bend up four sheet metal hold-down tabs around the edge of the electrostatic shield.
h. Carefully remove the electrostatic shield from the A500.
i.
Locate the 68000 chip in the front left-hand corner of the A500.
j.
Using a small, flat-bladed screwdriver, carefully remove the MC68000 MPU from
its Amiga socket noting the location of the polarity semi-circle on the MC68000 (a
small, circular indentation near one of the top comers identifies pin 1. Position the
MC68000 in the 64-pin socket on the
Mega-Midget Racer
accelerator so that the
polarity semi-circle of the MC68000 is aligned with the polarity semi-circle of the
64-pin socket. This assures that pin 1 of the MC68000 is next to the symbol
R23
on the
Mega-Midget Racer
. The
Mega-Midget Racer
will replace the MC68000 which
was located on the A500 motherboard.
k. Very carefully plug the
Mega-Midget Racer
board into the motherboard MC68000
socket. Be very careful to make sure that all board pins are inserted in the A500
MC68000 socket before applying final seating pressure to the
Mega-Midget Racer
board. Moderate pressure must be applied to properly seat the board.
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