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

Raiden DX repair log

 PCB Repair Logs, Repair Logs  Comments Off on Raiden DX repair log
Jul 102015
 

Another board from my friend ‘mastercello’ and another quick fix.

We have on the bench a Raiden DX (Seibu Kaihatsu) PCB in  good shape:

Raiden DX_PCB

Board booted but colors were wrong and sprites colored blocks:

issue

This Seibu hardware doesn’t use many components since most of logic has been condensed in some custom ASICs which have mostly graphics functions so I focused on them.Like I usually did I probed the tightness of each pin with a small needle and found some lifted pins of the one stamped  ‘SEI252 SB05-106’ (QFP208 package).

SEI252

A simple reflow did the trick and fixed graphics completely.

fixed

 

 Posted by at 10:47 pm

SEGA and Taito PAL dumps update

 PAL Updates  Comments Off on SEGA and Taito PAL dumps update
Jul 102015
 

Some PAL dumps update today.Porchy succesfully reversed into GAL16V8 format a dump (made by be some time ago) from a PLS153 device labeled ‘315-5244’ which, as far as we know, is present on Sega System16A hardware (Shinobi and Passing Shot for sure) and should be identical to the ‘315-5150″ one from Fantasy Zone (always on System16A).’Spectroman’ succesfully tested this dump on his Fantasy Zone PCB.

Andreas sent in an archive containing all the PLDs from a Taito Midnight Landing PCB (a flight simulator).All PLDs were unprotected PAL16L8 and PAL20L8 (except one PAL16L8 @IC54 which secured so was not dumped) and came from a not working board.So, we will mark them as untested.Drop us a line if you have any chance to test them.

Thanks to all for their precious contributions.

 Posted by at 3:14 pm

Out Zone repair log #1

 PCB Repair Logs, Repair Logs  Comments Off on Out Zone repair log #1
Jul 102015
 

This repair log is proof that we must always start from the simpliest things!

Another faulty board from my friend ‘mastercello’, this time an original Toaplan Out Zone :

Out Zone_PCB

He told me that it worked once and then nothing.Actually when I first powered it up I got this :

The screen with the wavy lines is common on all the Toaplan PCBs which run on similar hardware.It means that the system is being intialized but it should last until the CPU starts to properly execute code.In my case this screen was permanent so there had to be a problem in the main code execution.First thing I did was to check CLOCK, /RESET and /HALT lines of 68000 main CPU, they were fine.Then I dumped the two 27C010 programs ROMs and got from my programmer a warning about a poor contact on pin 17 (which is a DATA output) of the one labeled ‘TP018_08’:

poor_contact_PIN17

A closer inspection of the device revealed many oxidixed pins.A bit of fine sandpapering is what the EPROM device needed and enough to fix the board completely.

fixed

 Posted by at 1:48 pm

Donpachi repair log #1

 PCB Repair Logs, Repair Logs  Comments Off on Donpachi repair log #1
Jul 102015
 

My friend ‘mastercello’ sent me this Donpachi PCB for a repair:

Donpachi_PCB

The board was in good shape but had a GFX issue where background layer was partially missing with lines across it:

layer_issue_

Studying the hardware and with help of MAME I could identify the devices containing the data of the two background layers, they are two 42PIN 8 Mbit MASK ROM @U54 and U57.Probing them with a logic probe I found that the one @U54 has all its data lines stuck LOW or HIGH, also the two control lines /CE and /OE were stuck LOW though they were properly connected to a near ASIC which generates these signals.Obviously this was totally abnormal.As confirmation of my theory I was able to reproduce ths issue in MAME using a dummy ROM file of the background layer data instead of a good one:

MAME_reproduced_issue_

This was enough to convince me to desolder the MASK ROM and read it in my programmer resulting in an empty dump.Direct replacement for this 8 Mbit 42PIN MASK ROM is a 27C800 EPROM though the silkscreening under the chip sais ’23C16000′:Fitted a freshly programmed device restored graphics completely.

U54_replacement

fixed

 

 Posted by at 8:35 am