Replacing a PE+ CRT with an LCD Monitor by Modifying the ROMs

[ersk3]

I know that many people would like to replace the original CRT monitor in a PE+ machine with a modern LCD display. There is already a forum thread discussing various approaches and solutions: /nlg/index.php?topic=336.0

I'd like to share a different approach that I have been experimenting with.

Background
The PE+ uses a CRT monitor, and there are two major challenges when replacing it with an LCD:

1. The video output is standard CGA at 15 kHz (not VGA)
2. The video colors are inverted.

Converting the 15 kHz CGA signal to a 31 kHz VGA signal is relatively straightforward. There are several inexpensive arcade video converters available, such as the GBS8200, that can handle this task.

The more difficult problem is the inverted video colors.

Existing Solution
The easiest solution is to purchase one of the LCD conversion kits from Ceronix:
https://www.ceronix.com/product-category/lcd-monitors/igt/igt-2/players-edge-pe/15-players-edge-upright/

At the time of writing, these kits cost $567. They are essentially a bolt-on replacement and handle both the CGA-to-VGA conversion and the inverted video colors automatically.

I have personally purchased and installed three of these displays, and they work extremely well. Installation is simple, and the results are excellent.

The downside, of course, is the price. Because of that, many people have been looking for a more affordable alternative.

My Approach
One day it occurred to me that the game graphics are colorized by the CAP/CAPX prom, so perhaps it would be possible to modify the color data itself and eliminate the need to invert the inverted video.

After some experimentation, I discovered that simply flipping every bit in the CAP/CAPX prom effectively reverses the colors to non-invertet state.

That solved half of the problem.

The remaining issue was the background color, which is generated directly by the program EPROM rather than the CAP/CAPX prom. Finding the correct location to modify was a bit more challenging, but after some reverse engineering I was able to identify the relevant code and modify it so the background color is generated correctly without inversion.

As a result, both the graphics colors and the background colors can be corrected at ROM level.

Sharing the Solution Without Sharing Software
Since NewLifeGames policy does not allow sharing copyrighted game software, I wanted to find a legal and responsible way to share this information.

Instead of distributing modified ROM images, I created two small utilities that perform the modifications on ROM dumps that you already own:

Invert Bit Map Graphic Color Tool V1.00.exe
* Reads a CAP/CAPX prom dump
* Flips all bits
* Creates a corrected output file

PE+ Background Color Invert Tool V1.00.exe
* Modifies the PE+ program EPROM dump
* Corrects the inverted background color generation
* Creates a corrected output file

Because you must read your own EPROMs, apply the modifications yourself, and program replacement devices for your own machine, no copyrighted software is being distributed.

Important Requirements
This solution is definitely not for everyone.

You will need to:

* Remove and read your own program EPROM.
* Remove and read your own CAP/CAPX prom.
* Run the ROM dumps through the utilities.
* Program replacement devices.
* Install the modified ROMs in your machine.

Reading and programming CAP/CAPX PROMs can be particularly challenging because many modern EPROM programmers do not support these devices. In many cases, an older programmer capable of handling these PROMs is required. To the best of my knowledge, the EEtools TopMax, TopMax II, Elnec LabProg48LV, LabProg+, JetProg, BeeProg, and BeeProg+ should be able to read and program the CAP/CAPX PROMs. Of these, only the BeeProg, BeeProg+, and TopMax II use a USB interface; the others require a parallel port connection. There are likely other programmers that are compatible as well, but these are the ones I am familiar with.

Additional Hardware Still Required
This solution only addresses the inverted color problem. You will still need a CGA-to-VGA converter (such as a GBS8200 or similar device) to convert the 15 kHz RGB signal into a VGA format accepted by most LCD monitors.

Current Status
So far, I have only tested these modifications in MAME, but the results look very promising.

Unfortunately, I do not expect to have time to test this on real hardware in the near future, so I decided to release the tools and information now in case others would like to experiment with it.

At some point in the future I may create a YouTube video demonstrating the complete conversion process step-by-step. If someone else wants to test it and document the process first, that would be great too.

I have attached the utilities below for anyone interested in trying this approach.

I'd love to hear your thoughts and feedback.

[jay]

This sounds like a great solution. Very Elegant.
Did you use any AI tools to help with decoding what needs to be edited ?
I also want to thank you for being so kind to the community by making this editing tool available.

Lucky Dog created a board to do this but it still relies on the GBS8200, I have had various success(es) with different versions of this board and older arcade cabinets.
He also put together a kit that includes a GBS8200 so it all works together.

Somewhere on our forum another member put together a schematic for a Caprom conversion kit.
CapRom / CapXRom blanks are hard to come by.
The small circuit board uses a Caprom sized socket that pierces through a small circuit board so the pins mate with the socket on the MPU and then uses a 27C256 on the other side that is burnt with the CapRom binary.
This avoids the need to invest in the older reader and if your burning new PE+ Game/Data Chips then you already have the 27C256 chips around.

Finally there was another person that posted a tool to edit the card backs - I have always wanted to try but have yet to find time.

Do you have a suggestion of what LCD monitors work best for these or a reliable source ..... the 4:3 or square format is hard to come by these days. I have a small 15" bench monitor that I keep around but don't want to sacrifice it for this.
I have found a few used on ebay.

[LuckyDog]

Thanks for sharing that with us.  Sounds awesome, a very Unique approach!!

Those conversion kits Jay mentioned on the Cap/Capx Roms worked very well.  I got one from a member here a couple years ago & it was great.

[FoRrHouse]

@ersk3  Just wanted to say, nice work and thanks forsharing.

[ersk3]

Thank you everyone for the kind words and feedback!

To answer Jay's question, I did not use AI during the reverse engineering work itself. I reverse engineered the color generation from the schematics and started with the CAP/CAPX PROM because that seemed like the most logical place to begin. Once I understood how the palette data worked, I wrote the code to perform the color inversion.

The program EPROM modification was a different story. A friend helped me with that part because it was honestly beyond my skills. Finding and modifying the background color generation inside the program ROM was much more challenging than working with the CAP/CAPX PROM.

Where I used AI was with creating the utilities themselves. The tools are Visual Basic projects, and Visual Basic is definitely not one of my strengths. AI was incredibly helpful for generating and refining the code for the utilities.

I want to give credit to LuckyDog's solution. I think his approach is probably the better solution for most people because it is essentially plug-and-play. Mine is aimed more at the people who enjoy thinkering, reading ROMs, modifying files, burning chips, and experimenting. His solution is much more approachable for the average user.

The CAP/CAPX adapter boards that use a 27C256 are also a very clever solution. One of the biggest challenges with CAP/CAPX PROMs is that both the Color PROMs and compatible programmers can be difficult to find. Using a 27C256 adapter avoids the need to program a CAP/CAPX PROM entirely. Of course, you still need to read the original CAP/CAPX PROM at least once in order to modify the data, but after that the process becomes much easier.

The card-back editing tool is also very interesting. Besides changing the card graphics, it gives you a nice way to view all of the palettes stored in the CAP/CAPX PROM. That's generally useful whenever you're trying to understand or modify the graphics.

One thing I should probably mention is that Jim (LuckyDog) asked me privately whether my solution also inverts the sync signals. I honestly wasn't aware that the sync signals might need to be inverted. As far as I know, my utilities only modify the color information and background color generation. I do not believe they affect the sync signals at all. Since I have only tested this in MAME and not on real hardware, there may still be hardware-related issues that I have not discovered yet.

As for LCD monitors, I honestly have no idea what works best because I haven't tested any of this on real hardware. My assumption is that if someone wants to save money compared to buying a new Ceronix monitor, they will probably need to find a suitable used LCD monitor. Otherwise there is little economics benefit.

The Ceronix displays are expensive, but they are also an excellent bolt-on solution. They handle both the CGA-to-VGA conversion and the inverted video colors automatically, and the three units I purchased worked flawlessly. If someone wants the easiest and most reliable path, I would still recommend the Ceronix solution. My approach is mainly intended for people who enjoy tinkering and want a lower-cost alternative using hardware they may already have available.

Thanks again for all the feedback. It is great to see interest in the project.

[LuckyDog]

Do you have a suggestion of what LCD monitors work best for these or a reliable source ..... the 4:3 or square format is hard to come by these days. I have a small 15" bench monitor that I keep around but don't want to sacrifice it for this.
I have found a few used on ebay.

I just ordered 2 different LCD monitors from Amazon to experiment with.  One 12" and one 14" Both are 4:3 and had physical sizes that will hopefully fit in the door without major mods.  They were both in the $100 range.  I'll post later how they worked out.
There is also a  4:3 15" monitor listed at $59, but was maybe 1/2" too wide??

[ersk3]

That is exciting to hear!

I'm looking forward to hearing how your experiments turn out and which monitor ends up being the best fit. Finding a suitable 4:3 LCD at a reasonable price seems to be one of the biggest challenges these days.

The fact that you found a couple of candidates in the $100 range sounds very promising. If one of them works well and fits without major cabinet modifications, that could be useful information for a lot of people here.

Please keep us updated on your progress and results. I'm very interested to see what works.

Good luck with the testing!

[jay]

Perhaps we start a new thread with LCD models (ie NEC 1523 Multisync) and then detail what mounting people did.
The most common that I have seen is that people mount the screen on the door. The Ceronix LCD drop ins typically have a metal frame around them like their CRT cousins.

[ersk3]

Perhaps we start a new thread with LCD models (ie NEC 1523 Multisync) and then detail what mounting people did.
The most common that I have seen is that people mount the screen on the door. The Ceronix LCD drop ins typically have a metal frame around them like their CRT cousins.

I think that's a great idea.

Let's leave that to LuckyDog (Jim) once he receives the monitors he ordered. It will be exciting to see how they fit and what mounting modifications are required.

[Chris-socal]

Man this is a lot of work! I probably have 4 complete 1492s sitting on a shelf! LOL
K-Lar has so many they are sitting on shelves outside!
They only use 65 watts and they will last….longer than some of us!

The last one I sold on Ebay only cost $40 to ship. Sometimes UPS rates are extremely competitive for heavy boxes, just don’t wait until December when rates are highest! Unfortunately this won’t help anyone in EU or AU.

One other thought, I appreciate that ersk3 is being sensitive to copyright and such, but aren’t we all basically doing the same thing when we change eproms on our BV’s? Im just sayin, is there really an issue “sharing” an updated eprom? Just charge shipping plus a “handling fee”. We aren’t taking any business away from IGT nor are we selling their software.

Chris

[ersk3]

One other thought, I appreciate that ersk3 is being sensitive to copyright and such, but aren’t we all basically doing the same thing when we change eproms on our BV’s? Im just sayin, is there really an issue “sharing” an updated eprom? Just charge shipping plus a “handling fee”. We aren’t taking any business away from IGT nor are we selling their software.

Chris, that's a fair point, and I've thought about it quite a bit.

In my opinion, there is a difference between a bill validator firmware and game software. A bill validator is a peripheral device that plugs into the machine. The firmware belongs to JCM, not IGT. For older validators, JCM declare the note sets obsolete, and firmware files tend to be shared much more freely between vendors and technicians. That being said, bill validator firmware is not shared on NewLifeGames either.

So in principle it is a similar issue, but I think there is a lower threshold for sharing bill validator firmware than there is for sharing game software. IGT has always been very clear that their game software is copyrighted.

Realistically, I doubt anyone would care about modified ROMs for older platforms like S+ or PE+, especially since these machines are no longer found in casinos. However, I don't think it's worth taking the chance. I'd rather respect both the forum rules and the copyright.

As I understand it, when you own a machine, you are generally free to read your own EPROMs and make modifications for your own use. The part I want to avoid is distributing copyrighted ROM images.

That's why I chose to release utilities instead of modified ROMs. People can dump the ROMs from their own machines, apply the modifications themselves, and burn new EPROMs. I think that's a good compromise that allows us to share knowledge and tools without sharing copyrighted software.

It's a bit like MAME. MAME itself is perfectly legal and doesn't include the ROM images. Users are expected to obtain those separately by reading their own ROM images. Even though ROMs can be found on various websites, the emulator itself doesn't distribute them. I see my utilities in much the same way.