Re: Missile Command ROM hack?

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You should be able to join the images into one or two eproms, depends if
the files are contiguous for program and characters. Just start with the
schematic and memory map to figure out the locations of the eproms. The
easy way to link them is to load the buffer with the bottom-most image and
then just shift the buffer start address by the width of the file you are
using. You do want the highest file to be at the end of the eprom (F800
[2716 in a 27512]) as that is the boot file. Count back from there to the
first file. So if there are five contiguous eproms, the first would be
loaded at D800, the next at E000, E800, F000, F800 for the last. I use an
eprom that is the same size or just a bit larger than the total number of
images-just for ease of addressing. You will need to set up the chip select
and output enable to enable the output only during the group you want.

Clear?

John :-#)#

At 10:06 AM 10/10/00, tom mcclintock wrote:
>I want to test a couple of Missile Command boards that are currently
>ROMless. Instead of burning new ROMs, replacing the sockets and all that
>trouble, is there a way to burn all the ROM images into a single EPROM?
>
>I've got an EPROM reader/writer, but not sure if the code can be
>combined like that. help?
>
>
>tm
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Received on Tue Oct 10 11:23:41 2000