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Running your own
program code automatically when power is applied
requires the creation of a Custom ROM.
The Custom ROM
replaces the System ROM (IC6) and so the lower half of
the Custom ROM resides in memory at FC0000-FFFFFF, the
upper half is unused and unaddressable.
The Custom ROM
must contain code to bring the system up as well as code
to reset/initialise any programmable I/O devices prior
to use.
Follow the instructions below to create a very simple
Custom ROM. The source code can be used as a template
for getting started with "Bare Metal Programming" on the Mega-68000 Computer System.
The example presented here simply boots-up and then displays "12340000"
shortly followed by "00005678" on the Hex Display Board.
You will require
the following:
Mega-68000 Hardware:
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1x |
Backplane or
Backplane-2 |
|
1x |
68000 CPU Board
(J2 pins 2-3 short) |
|
1x |
Memory-2 Board
(IC2 with gal8 firmware + J1 open & JB1 pins 5-6
short) |
|
1x |
Hex Display Board
(Base Address: ABxxxx) |
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1x |
Blank AMD
Am27C4096 256K x 16 UV EPROM |
PC Software:
EASy68K Assembler
and EASyBIN Utility.
You can find a
download link and more
information on the FREE PC software here:
Software/EASy68K
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