Jul 172015
 

Im currently working on a Time Pilot PCB and tested out Shoestrings diagnostic ROM.
This board is the Atari version which wasnt supported at the time but has now been updated.
I also ran into a problem where nothing appeared on the screen. Working together we eventually found the issue.
The original game code makes a write of 01 to address $c308. Using the Fluke 9010 I found that this write actually initialises the screen output.
MAME doesnt have any support for this so when testing the ROM in MAME it works fine. The test ROM has been updated with this now too and should work fine.

This highlights the need to test things on REAL hardware.
Thanks to Shoestring for making the diagnostic ROM and for putting up with all my questions.

 Posted by at 5:04 pm
Jul 112015
 

JAMMArcade.net is 5 years old!

I never would have thought 5 years ago that this blog would still be going today let alone be the project that it turned into.
Here is a brief history of the how this whole thing started.

It originally started out as a way for me to document my journey into building a home arcade and maybe provide other new starters with some basic information.
The arcade collecting part never lasted too long as the repair bug hit me and I ended up preferring repairing boards over actually playing them. This is where my obsession with PAL’s also started.

I found it really annoying that an otherwise good PCB had to be scrapped because one little 20 pin IC was dead and the code contained within it was lost. On my search for elusive JED files I found a small ZIP file with a few dumps in it and I also found a few more on Macro’s website. The later is where I read about a device called the Boardmaster 4000 which was apparently able to dump PAL chips.

I eventually found a Boardmaster on eBay (back when a bargain could be found) and that’s when I started dumping PAL’s. I dumped pretty much everything I had and around the same time started the Archive on this website. Pretty soon I started to think “what if the Boardmaster breaks down?”
The Boardmaster program was heavily based on the work of Charles MacDonald who had built a standalone device.
I had soon built his PAL dumper hardware and was ready to stop using the BM4K for dumping.

Shortly after I started adding PAL dumps I started getting people send their own private collection of JED files and the list started growing. Caius was one such donator and was sending them on a regular basis. It made sense to me to ask him to join my crusade so he did and now we have an excellent repository for PAL dumps, something which we are both very proud of.

 

I cant recall the exact date but it seems quite a while ago now that Runik joined the site.
After trying unsuccessfully to get the decrypted code for his Golden Axe game via the usual channels, he took it upon himself to learn how to decrypt the games. Not long after that he managed it and I guess there is little else to tell of that story.

More recently a few more people expressed an interest in contributing to the website and I’m very happy with it. There is a ton of information on it and having multiple people posting repair logs really does show how different people approach problems and faults. While its rare that a repair log will be the exact same fault a different person may have, it can at least give others ideas on how to start doing repairs of their own.

I’d like to make a special mention about Shoestring’s excellent self test ROM’s for Konami games and also his Konami-1 assembler.

That’s about all there is to say. I hope we are still going in another 5 years.
Thanks to all the people who contribute to the site and everyone that visits.

Special thanks goes to Charles MacDonald who without I would have never been able to start dumping PAL’s and is often the source of help when I’m trying to make sense of things.

Also a massive thanks to Muddymusic who has hosted this site for the last 12 months when my old provider, Servage.net, decided they couldn’t be bothered to deal with issues on their own servers.

So what’s in store for the future?
No idea really. Hopefully most things will carry on the way it has been.
I do a lot less repairing these days and focus more on the electronics side of things (arcade/retro related).
I recently made a homebrew cartridge for the GameKing handheld system in order to test the dumps myself and Team Europe have made.
I also teamed up with cmonkey not too long ago to make a mod for Outrun which saw the two new tracks found in the newly released 3DS version make their way into the original arcade version. cmonkey did the software side of things and I handled the new bankswitching that was required and also made the ROM adapter for it.

Other ongoing projects I have are a completely over the top supergun and I am also working on a couple of cabs too.

Hopefully the rest of the team continue to contribute and expand the site further.

 Posted by at 8:00 am

Gyruss test/diagnostic rom update

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Jun 302015
 

16/03/2018

Minor fix.

Text references 8C instead of 19E when sub-cpu EPROM fails checksum.

Fixed output to reference 19E.

04/07/2015
Minor changes.
1.Holding down player 2 start during powerup will enter the diagnostic mode.
2.Some changes made to the presentation of the sprite viewer

0007

30/6/2015
This update includes character and sprite test menu additions to the diagnostic mode.  Useful for verifying bad tiles and sprites.
See roms section / downloads for update.

0003 0005 0004

May 242015
 

I use OSH Park quite a lot for various projects.
Recently I received the second version of my JAMMA Supergun back but thats not all.
Inside the packet was a little note

gameon

A nice little touch I thought so here is a shameless plug for OSH Park.

Gameking multi cartridges

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May 162015
 

Im still working on Gameking things when time permits.
Team Europe has also started to dump new Gameking games and up until recently we have had no way to test our dumps.
I have now made a multi game cartridge for the Gameking which can hold 4 128KB size games and are selectable via two dipswitches.

So far all the games we have dumped seem to work just fine although Team Europe has recently dumped an actual multi game which will NOT work on this board.
GameKing Cart

I realise that there wont be many people in the world that would want one of these but if you do I currently have 4 spare for sale at £10gbp + postage fully assembled with blank flashROM.