(Topic ID: 109732)

New gecko ability...ROM burning...:)


By NJGecko

4 years ago



Topic Stats

  • 67 posts
  • 28 Pinsiders participating
  • Latest reply 4 years ago by jalpert
  • Topic is favorited by 9 Pinsiders

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There are 67 posts in this topic. You are on page 2 of 2.
#51 4 years ago

Got my programmer weeks ago after I ordered, only got the eraser today from China. Going to try this today. I found a site that explains a lot of little bits of info I'm sure others are interested in as well, and includes a chart for the types, sizes and manufacturers of them, which I'm guessing is useful.

I'll report back later, and hopefully I figure this out as easy as well.

What time are you guys using for the eraser? I'm sure this is likely consistent for all of us.

#52 4 years ago

Erase the chips til they pass a blank test with the programmer. There's no definitive time for a chip, will depend on the bulbs in the eraser, etc.

One tidbit - be careful with eproms with 'A' in their P/N - they often program at a different voltage than standard. A lower voltage. If you program them at the higher voltage, they *may* program - but they may not program - but odds are really good that they will erase again, but will never program again.

#53 4 years ago

it appears to be 30-40 minutes? does that sound right? These are 2-4M eproms I'm working with right now.

Anyway to get the labels off more easily? Ironic I have had game where they fall off, and I have to put tape over them to protect. All the ones I have, old new, whatever, seem to be a nightmare to get all the sticker and residue off.

#54 4 years ago

Drop of window cleaner and a razor blade.

#55 4 years ago

acetone + a rag is what we used back in the day to clean the chips... and simple avery label types cut to appropriate sizes.

#56 4 years ago

BTW, this the link I thought I posted in a previous post with interesting eprom history and info:

http://wiki.xtronics.com/index.php/How_EPROMS_Work#Programming_an_EPROM

#57 4 years ago

If you want the history of the EPROM get it from the guy who invented it:

http://archive.computerhistory.org/resources/access/text/Oral_History/102702214.05.01.acc.pdf

Interesting fact - the EPROM was originally designed to be erased with X-Rays and the idea of using UV light and a window was not something the designer thought would be possible.

viperrwk

#58 4 years ago

How the heck do I confirm what size eproms I need, other than pulling the prior ones and removing the label and checking for that game? I'm trying to update Maverick as my first udpate, found the cpu 404, displays 402, and the sound roms, but can't seem to find anything on the size of rom needed for each...

#59 4 years ago
Quoted from Atomicboy:

How the heck do I confirm what size eproms I need, other than pulling the prior ones and removing the label and checking for that game? I'm trying to update Maverick as my first udpate, found the cpu 404, displays 402, and the sound roms, but can't seem to find anything on the size of rom needed for each...

Size of the file - EPROMs arre sold in bits, so a 8k ROM would take a 1M file. A 512k file would go for a 4k ROM.

#60 4 years ago

Don't bother with the sound ROMs, they never change.

You need a 27c512 for the CPU ROM and 27c040 or 27c4001 for the display ROMs. They MUST be 120 NS or faster, 150 NS will NOT work. The 120 NS or faster only matters for the DE/Sega games with the big DMDs.

The speed will be displayed on the chips, typically -12 = 120 NS, -10 = 100 NS, -15 = 150 NS. You may also find some 80 ns in some makes of chips.

#61 4 years ago

I think you mean an 8Mb ROM for a 1MB file, and a 4Mb ROM for a 512 KB file.

#62 4 years ago
Quoted from johninc:

I think you mean an 8Mb ROM for a 1MB file, and a 4Mb ROM for a 512 KB file.

You're right. Got my decimals messed up.

#63 4 years ago

For the game rom, given it's so small, can I use a larger 4m if that's all I have?

for the display roms, can I mix and match different speed roms? I have a 120, 100, and one that says -90, I assume 90?? But it has an "A", so not a good one right?

#64 4 years ago

No, a 27512 has 28 pins. A 27c040 has 32. Won't physically fit

#65 4 years ago

And as long as they are all faster than 150ns, mixing is ok.

#66 4 years ago

Gotcha, didn't realize the last few numbers were indicative of the kbytes.

#67 4 years ago

I use goo gone not he windows of the chips before I erase. It saves a lot of time, they erase a lot better, more often, quicker.

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