Space Invaders/Eprom burning question :-)

orion3311

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Welcome me to the Eprom burning family :) I picked up a BP Micro EP-1140 over the weekend and so far its rockin great! Been playing with some old roms laying around and learning a lot.

Also made a home-made eprom eraser using a CVS germicide light and a Sears woodchip smoker box :)

Anyhow, I'm looking at these instructions:

http://www.brentradio.com/images/SpaceInvaders/midway_8080_tech.txt

and it mentions replacing all the roms on a Space Invaders with a single 27C128. I happen to have one of these, so as I wait for it to erase, how do I go about putting ALL the various roms into this one? Can I merge the files somehow, then burn one file, or do I burn each one seperately, turn off blank detection and offset the addresses somehow?

If it sounds like I know what I'm doing, I kinda don't (I'm an eprom NEWB) so plain Engrish prease :)
 
Also made a home-made eprom eraser using a CVS germicide light and a Sears woodchip smoker box :)

Man you are wasting no time, and is that the Space Invaders PCB I gave you? You know when I get a few Bucks I will buy some extra ROM's and you will have to help me burn a set for my Marble Madness PCB to see if we can get it working again.
 
Yeah, I was looking at that as well... but it wasn't really explained well (read at "dumbed down for me"), so I just skipped it and burned some 2732's instead and skipped the whole single ROM thing.

I don't even think I can have a multigame like that because I was under the impressing that SI boards can't run SIDlx while SIDlx CAN run regular SI... honestly, wasn't worth me risking anything over.
 
You're correct - if you have the SI "Deluxe" board it can run both, but a standard SI board can only run SI. You can still do the single rom mod though and you wouldn't need the 27128.

I dug through some junk and found some 2716's, so I may just burn a replacement romset and be done, but would still like to try the single rom mod if anyone can help me out.
 
how do I go about putting ALL the various roms into this one? Can I merge the files somehow, then burn one file, or do I burn each one seperately, turn off blank detection and offset the addresses somehow?

It can be done either way, but I usually burn one image, change the offset and burn the next, etc. But I'm using a Pocket Programmer and changing the offset is pretty simple - not sure how easy it is on yours. You could also use a hex editor to merge the files (or even 'cat' them together if you're on a Unix machine), and burn the one image. FWIW, if you're on a windows machine, the little calculator app that comes with the OS can do Hex arithmetic, but you have to set it to "scientific" mode first (view -> scientific). This can help when figuring offsets and is a big help in tweaking checksums.
 

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The easiest thing to do (IMHO) is to concatenate all the 2176 files into one larger file.

There is a simple DOS command you can use

copy /b file1.bin + file2.bin + file3.bin largefile.bin

You obviously add as many bin files as needed
( 8 in case of the 27128 eprom ), and the resulting file will be largefile.bin

If you have a Hex editor, you can do the same thing
by simply opening all the files and then copying/merging then into one large file.


You then only need to program that single file (largefile.bin).

No multiple burns or offsets or anything like that.

I find this to be easier, especially if you want to program more than 1 eprom.

Let me know if that makes any sense...


cheers,
Steph
 
to concatenate the ROMs just use the DOS binary copy command.

should be something like this:
copy /b ROM.1+ROM.2+ROM.3+ROM.4 single.rom

add in as many roms as you need, and 'single.rom' is the output.

depending on what size ROMs you're using there are some jumpers to mess with on a midway board, the chip select jumpers and the voltage/addr jumpers--if they aren't documented anywhere they're easy enough to figure out with the eprom pinout and the midway schematics.

here is a Boot Hill on a single 2764:

midwaytest7.jpg


midwaytest9.jpg
 
copy /b ROM.1+ROM.2+ROM.3+ROM.4 single.rom

Ya know, I'm a DOS veteran (IT person here) and I was going to ask about that but just never did. I'm used to asking about stuff like that and having people sit there and scratch their heads. I guess that explains why I'm always on here.

Sweet that really helps guys, also that pic showing the S6 jumper really helped too, as apparently midway didn't label that particular jumper! Its there though.

I'll give it a shot in the next couple days if I have time (extremely busy week scheduled) and see what happens.
 
PS - Steph I just wanted to say when I was on Johnny-5 input mode yesterday reading up on eprom stuff, I found a bunch of your posts and learned a lot! You're always very helpful and informative.

So, THANK YOU!
 
OLD POST QUESTION

Guys, If I want to put all SI roms on one eprom but only SI (not multigame)...
1. do I need to still jump traces
2. what socket would i put it in
Please let me know as i have a bunch of 27128's 27256's and 27512's laying around
 
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