[Project] Williams Robotron Cocktail!

KeRbDoG

I picked up the Williams Defender Cocktail cab from FixitFelix. Seems Mitch had it in the past and did some work with it, but unsure what. Looks like someone tried to convert it back from whatever got hacked into it post its first life as Defender.

The cab was still wired for 110V/US, complete with dodge US plug and cable nut connections inside :D followed instructions which can be found online to convert the main PSU to 220V with some replacement parts and to my surprise no smoke when I powered it back on. The transformer steps down the 220V to 110V for the monitor. Connected up the monitor and it seems to be working. So I went for broke after testing the power supply board outputs which seemed in spec and plugged in the game boards...nothing but wasn't really expecting it to work.

The ROM/Program board (top right in the below photo) has a single digit display on the board which gives basic error messages which showed an error so I looked it up online. Turns out, the ROM/Program board is actually a Robotron ROM board! Looks like the Defender CPU/video board (right in photo) is correct along with the interface board (small board on right).

Will see if I can pickup a replacement that's working so I can see if the CPU/video board works. I can see this quickly turning into a money pit. Cab has no control/coindoor wiring no any original control buttons. The control panels themselves have been hacked up real good. This thread might go dead unless I can find a ROM board for a low low working price 😁

KeRbDoG

Found a nice lad in Australia who sells replacement custom/new ROM PCBs so that will be a known working board so I can start to test the CPU/video board.

Also, had a brain fart and ordered a replacement PSU as I thought the voltage conversion wasn't gonna work. Tbh, I didn't think the payment went though but it showed up in my Shipito US locker so payment must have happened :D woops. This might still turn into an expensive free pickup...but I'm learning quite a bit.

dav09

I really wanted this but wasn't feasible with about 5 projects too many as is. Looking forward to seeing how it turns out, I definitely wish you luck with anything Williams related always a headache for me, hopefully you get lucky! If not JRok could be the way maybe, looking forward to seeing it finished!

CathalDublin

Nice, I've a Defender upright machine, unfortunately it was gutted back in the day. I'm running a cheap Chinese 19-1 Williams multigame but I am looking to get an original boardset at some stage, so following this closely

BGOllie

nice . looks like a fun project for sure. Defender/Robotron cabs aren't exactly common and cheap so it's well worth taking the time to restore it :)

KeRbDoG

Old project which I'm tackling again and with a fresh look, it seems that the board setup might actually be Robotron and not defender which I first thought. From the note from the advert from FixitFlex, suggests it was a Defender, convered to a pokie and Mitch had replaced the boards within. Maybe he installed the Robotron boards instead of Defender?

Work so far - RAM voltages are good. The ROM board has a single character error/diag code display and it shows RAM errors, which semi follows certain RAM chips when moved. Ordered up a tested set of chips for it from the Americans, so the cab is packed away until those show up.

KeRbDoG

Got the 4116 RAM and started to swap them in as the diag digit display noted an issue…after the 3rd one, I suddenly heard the Robotron boot sound!

I didn't have the monitor plugged in at this stage, so powered off and connected up the monitor again and…

WTF! Its working, even the monitor is working! Monitor looked liked it has the drive a little high, a twiggle later

Sound stopped working quite fast, but there are no control wiring that survived the pokie conversion back in the day so that will prob be the next focus - some basic controls to test further.

dav09

https://www.boards.ie/discussion/comment/122059759#Comment_122059759

I commend anyone brave enough to still be battling Williams hardware of the 1980s, especially in 2024! Fair play!

KeRbDoG

https://www.boards.ie/discussion/comment/122059983#Comment_122059983

Cheers - tbh I expected the monitor to be kaput. Some bits to do.

• Wiring - Ordered up some Molex type connector bits to look to make a temp controller and hopefully in the longer run return the controls back to as they would have been, part of that will also to get some sort of service buttons back in there
• Audio - I think it might be down to dodge RAM also, not to pushed to get that working just yet though.
• 'CapKits for everyone!' - will look to get some capkits for the monitor chassis and audio board. I've bypassed the orignial PSU for now as its -5v was towards -12v. That could have been what killed the RAM on the CPU (& audio?) board as I think thats the only thing on the boards that uses the -5v rail
• Cosmetic - things like the actual control panel, top glass, locks etc. are far far down the road at this point. Control panel(s?) might need some woodworking skills I'll have to learn.

Thanks for editing the thread name admin peoples :D

geotrig

great work , what monitor is in it ,I like wg models as they are well document and somewhat ok to work on , also for the same reason I like those williams ,atari era boards although it they are time traps and eat up all your time chasing that one dodgy component.It also always feels like you be changing old dodgy ram more than your underwear !

o1s1n

How long has that monitor sat unused? That's some fantastic picture quality, looks like it's recently been recapped!

dav09

https://www.boards.ie/discussion/comment/122060477#Comment_122060477

There's a nice Williams wiring to easily convert to a modern power supply without chopping looms. I've used them before they're great.

https://www.arcadeshop.com/i/892/williams-power-supply-conversion-kit.htm

Sound could be anything, I've found on a lot of older PCBs sound chips tend to go bad, could be caps, ram, etc also.

Fair play anyway, looks like a great project.

KeRbDoG

https://www.boards.ie/discussion/comment/122060726#Comment_122060726

Yup, thats the one I had bought a year or so ago and just installed in a temp way, will look to make more 'secure'

https://www.boards.ie/discussion/comment/122060703#Comment_122060703

It might turn out to have been recapped :) I've yet to pull it out to have a good look as I thought it wouldn't be working

A note for any/all - for the love of bejasus, if you ever modify a cab for a new control panel, different game, monitor etc. - please leave the old wiring/'bits' in place as much as possible for someone in the far far future to revert if they so want :D

KeRbDoG

More research over the weekend on these cabs, found out a few things

• This can was originally a Defender cab for sure, the old remains of the control panels and the remains of the controls harness at the game boards seems to back that up. Also it's a 13inch monitor which Defender game with, Robotron only came in a 19inch.
• It was modified into a trivia quiz machine (game was copyright 1985 from text on the control panel overlay which was hidden away under tape). Looks like it was then a poker machine
• Someone did re-add the boards, but a Robotron set
• Defender control panel space is less deep than a Robotron seemingly, gonna get some leaf joysticks to see if there is a chance of it maybe working…I'm not much of a carpenter to modify if not 😀
• I'll have to replace all of the RAM sockets, the old ones are 'single wipe' meaning they only hold a chip leg on one side

Some bits arriving during the week like the chip sockets and molex connectors to make up some cabling for joysticks.

KeRbDoG

OK, long time haven't touch this project. Since the last post I've replaced all RAM sockets and no more issues so far. Just dug some bits out this evening which I had picked up over the past while…two leaf joysticks, now semi wired up to do some testing

…and connectors to wire them and the service/coin switches up to the PCBs

Joysticks look like they will fit

The PCB set is from an upright, so for now there will just be joysticks on the cab for now so should be able to rig up something.