Small fee... The Eproms will be about $2 each, more with shipping. 27C256 eproms are what you need for U26 and U27. I would offer up what you are willing to pay for this. It shouldn't take more than 10 mins and cost any more than $15, including shipping. I can do it but don't have any 27C256 EPROMS. If you send me FOUR (two for each game), I will burn them and send them back to you for $20.

Oh wow that seems pretty good. Except I would like the jackpot to not stop at 2.5 if you keep completing the billboard because it is kind of easy to increase it.

U26 is a 27C128 EPROM but you can use a 27C256 in a pinch if needed. Taxi only requires 1 EPROM to be changed, Earthshaker requires 2.

Depends on how nice their equipment is. My rom burner is an el cheapo that gets recommended on here. Often times I can spend an hour or two burning a full set of roms for a new machine. Blasted thing is unreliable as all get out, but not very often needing to burn roms so hard to justify the replacement.

The Earthshaker manual indicates that both EPROMS for U26 and U27 are 27C256 in size. Didn't check Taxi.

I do not get many failures when actually burning that are the fault of the device or adapter itself. I would say 2 or 3 out of 1000.

Sometimes a leg on the EPROM is just bent a little...

However, I DO OFTEN often get failures when burning on to old erased EPROMS. Sometimes you just can't reuse them because they have internally failed.

Would this be an equivalent ROM to the 27C256 that's required?

http://www.mouser.com/ProductDetail/Atmel/AT27C256R-70PU/?qs=sGAEpiMZZMvKaIdSMCzQp7MEooDLcIyg1qHf3C4GXrQ%3d

I'm thinking of testing the waters and trying this out myself.

That Atmel "EPROM" is not erasable. It's a one time write device. Not a true EPROM, it's a one time PROM.

I know that my burner is limited to programming these types of IC's. I would recommend an EPROM or an EEPROM (electronically erasable programable read only memory) if you are not looking to erase and reuse your existing EPROMS.

I'm not an expert, but that looks like a one-time-write chip. Which is to say it might work, but you won't be able to re-use it for something else later, or if there's a problem, it has to go in the trash.

Dang. What a pain. That's a bit misleading, but you're right (I should've read the datasheet first), one time programmable.

Just buy some of these if you have a UV eraser:

ebay.com link: Advanced Micro Devices AMD AM 27C256 205DC UV EPROM 28 pin Ceramic Package

Mine is most definitely the device. The drivers were not written for anything past Vista. Haven't used it on 10, but for 7 and 8 it causes fun times. Favorite is that the device will not actually read or write to the chip. No, instead it will go through all the motions and tell you that the chip is blank if doing a blank check. It will say the chip has the checksum of what you want to write to it after burning.

Restart the system and *if* it decides to work you will find the chip might be blank, might have things written to it, etc. Blasted thing is such a headache. I need to try it with 10 as I have two games that need updating.

ebay.com link: STMicroelectronics M27256FI 28 Pin EPROM 15 Chips

$1.50 each used pulls shipped from USA

Odd since the U26 file is only 16 kilobytes in size.

Looks like that leaves quite a bit of room for additional rules in the file, if someone had the experience and/or time to do so. That might be a fun project to add a wizard mode or deeper ruleset.

Earthshaker manual shows a 27128 @ U26, same as Taxi...

ES (resized).png

Just double up 27128 images and you can use 27256. It is often done on WMS sys 11 era games.

copy /b image.128 + image.128 image.256

https://en.wikipedia.org/wiki/EPROM#EPROM_sizes_and_types

It doesn't on page 2! Odd.

Screen Shot 2016-09-28 at 3.38.36 PM (resized).png

Correct, hence my "you can use a 27C256 in a pinch if needed" comment. Thanks for elaborating on what I was alluding to though.

Those inconsistent bastards! Thanks for pointing out the manual inconsistency. I wonder if it was a typo or if they had really planned to use a larger EPROM from the beginning?

sometimes later software revisions needs more ROM space.

For those playing at home the "C" eprom types (cmos tech right??) isnt required. Plain Jane 27256 is fine too. The 27C256 versions probably program different voltages and consume less power during operation.