Sunday 28 August 2016

Sega System 24 - Super Master Golf - swapping CPU battery



Sega System 24 boards were included in Sega's copy protection measures, this included a custom 68000 CPU that included a battery and some RAM which I believe stores code which is needed for the game to run. If the battery goes flat, (they're generally over 20 years old now) the game will not run. Certain games have had the game code 'cracked' to enable the use of a regular 68000 CPU by having to use re-programmed CPU ROMs. This is not possible with System 24 games so I needed to take some action to maximise the chance of my Golf Masters game working for the longest period of time possible.

Below, the Custom Sega IC


Old battery removed, with a new replacement in place... NOTE: You need to keep a battery connected at all time by wiring the new battery in parallel and then cutting the old battery out of circuit. This will ensure you don't end up with a IC that's only use will be disposing of in the bin!


The Original battery was date stamped 1989 and had started to corrode so I think my timing was right with this one. The battery still measured 3 volts dc with a multi meter, the nww battery was sitting at 3.25 volts.

One the CPU was put back into the game PCB it was still working which for now is a good sign :)


Bookkeeping info from the game, closing in on 7000 credits since the info was last reset with the game being played for 305 hours.


 Attract mode screen shot of the game playing below.


The next part of this story will cover how I used a floppy disk drive replacement device to replace the old Floppy drive and disk that were not working when I picked the cab up.


Monday 15 August 2016

Taito Field Goal - PCB Repair

I recently picked up a Taito Field Goal cocktail cabinet, upon powering up the game was showing a graphical fault. The game played correctly when coined up, but every graphical item or text were just blocks of colour. The image below shows how it looked.


After using my logic probe running over the video section of the PCB I found what I though could be an issue. The MB14241 custom IC had data being fed into it and the clocking/enable signals all seemed to be pulsing away, but all of the Data Output pins were not showing as having any signals on them.

Reading online about the Custom IC I found mention of it having tri-state outputs which could have been the reason my IC didn't show any activity. The IC in question is a video shifter which was used to assist with drawing of sprites in early Taito and Midway games.

Part of the schematic diagram shown below which includes the Custom IC which i suspected was faulty, The scan of the original schematic is difficult to read, the IC pin numbers are very blurry which makes working out issues more time consuming.


Whilst probing around i put my logic probe on pin24 which is the supply voltage pin, the pin snapped off from the IC! Clearly it was weak and corroded, I filed the IC down to expose the contact so I could solder my own 'IC leg' back on. I was hoping this would have been the issue, no supply voltage to the IC would match up with all the output pins being 'dead'.

Well this didn't fix the problem but the image of the display slightly changed. A couple of the output pins were now stuck high or low but most were still showing as being 'dead'.


My next option was to swap the IC with a known worker to see if this was the issue, luckily the custom was already socketed so I just needed to find a replacement and plug it in. Cue me asking a collector friend for a loan if he had one, luckily a Zenitone Invader Revenge PCB was found that had the same IC needed.

Once popped into my PCB the game fired and and played perfectly! I now need to procure a replacement IC and return the loaned IC.



Another 35 year old game lives on to be played!

Sunday 14 August 2016

Sega system 24 - Super Masters Golf

A cab I picked up recently. Looks like it has a faulty floppy disk as the game fails to load with error 'cannot read track #0'











 

Tuesday 9 August 2016

Super Breakout Cocktail restoration

I picked up three Super Breakout cocktails in part of the UKVAC Pete 'Invader' Davies machine collection which I'm sure you all know about know. Tony Temple has written a great article over at arcadeblogger.com if you would like more info on the back story of these cabs.

As it turned out there were three Super Breakout Cocktail's that ended up coming back in the van along with my other cabs. I've got a soft spot for B&W arcade games and these cab definitely sparked interest that I could do something with them.

After getting the cabs home and looking them over it looks like two of the three cabs can be saved and restored. I plan to restore one cab, with the other two being offered for someone else to restore. The first picture shows cabs that I'll call number two & three. These two are available if you fancy a project, the only requisite is that one of them does get restored and they are not left to rot away. More on these two cabs later.

This first post is just a selection of photos from the cabs in their 'stored' condition. As the restoration moves on I will update this thread with my progress.


Onto the cab that I will be restoring, they appear to be bootleg/licensed cabinets made by Bonanza Enterprises. Ever heard of them?


Monitor mounted to the tabletop lid, supported by a metal by which is mounted in the main cab.



Small amount of mould to be cleaned up.


Player 1 controls


Slightly cleaned up.


 

Player 2 controls


Top glass player instructions



More to come as I make any progress.

Cheers, Mart.