Causing a bit of a stir.

[Hamsun]

33 minutes ago, edwardb said:

You are imagining it 

It's mainly Barcrest AWPs released in the late 80's/early nineties that I've noticed this when playing in the emulator. I suppose it's possible that they have routines that tell the machine not to offer certain features if they detect that the current player is taking a lot of value from them in a single session, even when slightly behind percentage?

I'm thinking mainly of low down skill features that a skillful player can take to JP every time (in theory, at least).

Also, 'late chip' JPMs from the £15/£25 JP era appear to have something similar. They can block all potentially high value features for a long period before dumping a JP on the win line. If you gamble it for the top streak  feature and lose, they spin in a JP for every single credit until you either take it or win the gamble.

It could just be that the way I've been playing these on the emulator, loading a lot of coins in one go, has led me to imagine this but maybe not...

Edited August 27, 2025 by Hamsun

[Boulderdash]

49 minutes ago, Hamsun said:

It's mainly Barcrest AWPs released in the late 80's/early nineties that I've noticed this when playing in the emulator. I suppose it's possible that they have routines that tell the machine not to offer certain features if they detect that the current player is taking a lot of value from them in a single session, even when slightly behind percentage?

I'm thinking mainly of low down skill features that a skillful player can take to JP every time (in theory, at least).

Also, 'late chip' JPMs from the £15/£25 JP era appear to have something similar. They can block all potentially high value features for a long period before dumping a JP on the win line. If you gamble it for the top streak  feature and lose, they spin in a JP for every single credit until you either take it or win the gamble.

It could just be that the way I've been playing these on the emulator, loading a lot of coins in one go, has led me to imagine this but maybe not...

That reminds me at my golf club many years ago playing Blackjack Club, which let me climb to the pot, which was £100, but it wouldn't let me climb past it to the £100 jackpot and leave the pot intact. It just gave 'snap' constantly, so after about two dozen attempts I assumed it was blocked and collected the pot. 

[johnparker007]

44 minutes ago, Boulderdash said:

That reminds me at my golf club many years ago playing Blackjack Club, which let me climb to the pot, which was £100, but it wouldn't let me climb past it to the £100 jackpot and leave the pot intact. It just gave 'snap' constantly, so after about two dozen attempts I assumed it was blocked and collected the pot. 

I've heard gamble blocks were a common thing among MPU3/4 club machines (folks asked me to hack them out) - I guess there was a slim chance the algorithm could be abused or something (gambling every win until one went up before %age had been correctly met).

Hopefully with those new rom hacking tutorials, some folks might get into it and start hacking those blocks out  

[johnparker007]

2 hours ago, edwardb said:

All Mazooma club machines were just clones of BFG machines; we got the code and just changed the audio, feature names and stuff. All the control/compensation was identical to the original machine. I think Pac Man Club took a few days to do.

Good historical info that  I noticed Bwb would do a bit more than just change the text - on MPU4 they had their own Chr routine that was reminiscent of Amiga games (unwritable disk sectors), where they'd work after a ROM hack, but, then use a return bit to affect the payout so slowly over time the machine would not adhere to the set program %.  I suspect that as code got more based on C routines (MPU5/SC5), those tight hardware tricks were less common.

Edited August 27, 2025 by johnparker007

[johnparker007]

1 hour ago, Hamsun said:

It's mainly Barcrest AWPs released in the late 80's/early nineties that I've noticed this when playing in the emulator. I suppose it's possible that they have routines that tell the machine not to offer certain features if they detect that the current player is taking a lot of value from them in a single session, even when slightly behind percentage?

I'm thinking mainly of low down skill features that a skillful player can take to JP every time (in theory, at least).

Also, 'late chip' JPMs from the £15/£25 JP era appear to have something similar. They can block all potentially high value features for a long period before dumping a JP on the win line. If you gamble it for the top streak  feature and lose, they spin in a JP for every single credit until you either take it or win the gamble.

It could just be that the way I've been playing these on the emulator, loading a lot of coins in one go, has led me to imagine this but maybe not...

I think with all this stuff - the best strategy is to find a machine that you can prove is reliably doing the behaviour by MFME coin in/out stats, and then once that's identified and reproducible, someone could look at hacking or at least analysing the ROM, to find where the 'naughty' code is  

[wearecity]

As I said on the re-release thread

As for this machine, I seem to remember when it was released years ago, people saying the machine will never give the jackpot if you try to hi lo gamble to it, even if the machine was running at 1% against a target 90% +

 

[wearecity]

2 minutes ago, wearecity said:

As I said on the re-release thread

As for this machine, I seem to remember when it was released years ago, people saying the machine will never give the jackpot if you try to hi lo gamble to it, even if the machine was running at 1% against a target 90% +

 

Ah it was Retrofruit

Unfortunately because it was too easy to just force a JP from several Maygay clubbers by hi-lo gamble on a reel win, they introduced a £25 block on the gamble that you couldn't ever get past regardless of happiness or number. Sad really. They could have gone the BFM route which was to allow hi-lo on the printed values and block the variable ones. By that I mean if you look at something like Cops and Robbers club, there are fixed (printed) values then the top of the trail has blacked out values that were only lit depending on the prize level. Typically the printed values went to £50 or £75 max. Eventually when BFM's are happy enough you can break through the printed ceiling, then it pretty much doesn't matter what number you gamble on.

[Mort]

11 hours ago, wearecity said:

Ah it was Retrofruit

Unfortunately because it was too easy to just force a JP from several Maygay clubbers by hi-lo gamble on a reel win, they introduced a £25 block on the gamble that you couldn't ever get past regardless of happiness or number. Sad really. They could have gone the BFM route which was to allow hi-lo on the printed values and block the variable ones. By that I mean if you look at something like Cops and Robbers club, there are fixed (printed) values then the top of the trail has blacked out values that were only lit depending on the prize level. Typically the printed values went to £50 or £75 max. Eventually when BFM's are happy enough you can break through the printed ceiling, then it pretty much doesn't matter what number you gamble on.

Yep remember speaking with @Retrofruit about the unfortunate £25 block which was imposed by Maygay on the Club Coronation Street M1A machine with the v1.1 ROM. Unfortunately we never got hold of v1.0 which didn't have this block. Whilst I loved many things about Maygay machines, especially the themes and samples, I didn't think too much of their programming skills on some machines. Classic examples are the likes of Italian Job and Great Escape, such wonderful themed machines, but when you understand what the code is doing, it's utterly lazy and boring, compare that to the gameplay variance of the likes of a JPM such as Fast Trak.

Edited August 28, 2025 by Mort

[Dougsta]

On 30/07/2025 at 15:28, Projectgilda said:

Hi everyone, my name's Andrew. First time on the forum. I'm the chap who leaked the Union Jackpot exploit on Facebook and that has made a couple of YouTube videos from a guy off the forum. I was a games designer in the industry for 15 years and worked for JPM, Perfect Coin Machines and Barcrest. I also worked in London for an online, now defunct, company called Kismet Studios. I'll have a look around and contribute where I can. Peace out ✌

Good to have you around. Would have been great to have more industry insiders on the forums down the years, it's always super interesting to hear you guys talk about this era of fruit machines. You've personally made some excellent games there in your time at JPM - well done. Always had a real soft spot for Sonic, even though many seem to have disliked it.

A few questions I have for you:

- You've talked about dodgy code coming from elsewhere in the industry. Apart from emptiers and obvious stuff like last-credit-incentives, what other stuff have you been aware of down the years?

- When JPM was its height, which manufacturers were top competitors you had respect for, and which did you not rate and why?

- It sounds like the game's developer and coder were two different people at JPM. Why this division of labour, and wasn't a lot of the developer's vision lost at the coding stage? 

- Last one. What were the main things you did/produced for your part of developing a game. You've talked about generating probability tables in Excel, but what else in terms of the final game?

[Manana]

On 25/08/2025 at 13:47, Hamsun said:

A shark basically. I hate sharking. You almost always found a few in busy arcades, often apparently friendly with the staff. Either the staff were stupid or corrupt or a bit of both. It's one of the reasons I stopped going to arcades, even when they contained emptiable machines [getting barred for winning was another reason...].

To my mind a'pro' is a player who has advanced skills and knowledge and targets specific machines, often travelling around the country to find them.

Sharks target other players, pros target certain machines.

There is a grey area in between, of course. To be honest, neither are particularly nice ways to make money.

He was a bit more than a shark. He 2ent around with a three others. They were always in the arcades. If ever you went on machines after them they were totally dead 99% of the time so they must have known what they were doing. Either way I found them annoying, especially him. 

[Manana]

On 25/08/2025 at 15:52, Cavey said:

Yeah, that's what I did, essentially. Got a (sole) joint account with the missus, she knew exactly what was going in and out each month, with nowhere to hide.

It worked.

Has your desire to gamble gone now? My desire has totally vanished, it's been well over ten years now. Even in pubs I can sit there and the machines don't even attract my attention whereas before I would have been on them the whole time.

[Cavey]

6 hours ago, Manana said:

Has your desire to gamble gone now? My desire has totally vanished, it's been well over ten years now. Even in pubs I can sit there and the machines don't even attract my attention whereas before I would have been on them the whole time.

Well, I never play any form of fruit machine or slot, don't do casinos or bookies. I do like a punt on the Lottery (without much success, but it's just a few quid), and love the horses - I have a terrace "medal" for Chester Racecourse and am taking the missus and daughter #2 to Ladies Day tomorrow, as it goes.

When I'm there, I do like to have a blast with the Totes etc., it's all part of the spice. I take £300 for gambling money and when it's gone it's gone, albeit I won £800 last visit and £1250 the one before that. I walked away cash in pockets both times (or more accurately, gave the lot to Mrs Caveman for a nice treat, it's the least she deserves for all the shit she went through with fruities).

EDIT to add - I genuinely never notice fruities in pubs or anywhere else anymore.

Edited August 29, 2025 by Cavey

[edwardb]

On 27/08/2025 at 18:43, Hamsun said:

I suppose it's possible that they have routines that tell the machine not to offer certain features if they detect that the current player is taking a lot of value from them in a single session, even when slightly behind percentage?

No. Machines really aren't that intelligent, nor were most of the developers (in the nicest possible way - they aren't PhD level anyway!). There really is no mystery to them - sorry to burst many bubbles - but the aura, myth and legend that surrounds machines is almost entirely false. If anyone doesn't believe me, come and sit next to me in my office for a week or two and I'll show you the code from all the machines I've done, and those I have code for (which is quite a few!).

[edwardb]

On 27/08/2025 at 20:34, johnparker007 said:

I noticed Bwb would do a bit more than just change the text

BWB had no Forth programmers, and everything on MPU4 from Barcrest was written in Forth. They were all ASM coders and got a hell of a lot more performance out of MPU4 than Barcrest did, on MPU4 Video in particular. - high speed ASM blitter routines that did what Barcrest couldn't.

[Chopaholic]

19 minutes ago, edwardb said:

BWB had no Forth programmers, and everything on MPU4 from Barcrest was written in Forth. They were all ASM coders and got a hell of a lot more performance out of MPU4 than Barcrest did, on MPU4 Video in particular. - high speed ASM blitter routines that did what Barcrest couldn't.

That's quite interesting because I mentioned more than once in videos on my channel covering BWB AWPs that they had a 'feel' all of their own. I described it as 'smoother and slicker' (something like that anyway), almost like they were running a whole tech ahead of Barcrest.

In light of the fact they were in assembly rather than Forth, that makes sense  

For example if you play something like BWB's Sinbad and compare it to Barcrest's MPU4 machines of the time, it's a noticeably better experience in terms of 'tech feel'.

[edwardb]

8 minutes ago, Chopaholic said:

That's quite interesting because I mentioned more than once in videos on my channel covering BWB AWPs that they had a 'feel' all of their own. I described it as 'smoother and slicker' (something like that anyway), almost like they were running a whole tech ahead of Barcrest.

In light of the fact they were in assembly rather than Forth, that makes sense  

For example if you play something like BWB's Sinbad and compare it to Barcrest's MPU4 machines of the time, it's a noticeably better experience in terms of 'tech feel'.

Spot on. They were so much more efficient than Barcrest - and when Miami Dice/Red Hot Poker came out apparently Barcrest were astounded that they could get so much performance out of the hardware. The developer of those games was an ex-ZX Spectrum coder with a few well known games released - he really knew how to squeeze every last drop of performance from MPU4.

[Hamsun]

3 hours ago, edwardb said:

Machines really aren't that intelligent

I'm sure you are right but take,say,  early 90s Barcrest AWPs with true skill climb features that can give JP if hit all the way (Cash Counter, Cash Zone &c). They obviously do have a routine that makes the skill stop progressively faster the more times it is hit accurately, to the point where it becomes insanely fast (but still possible if you can hit it). When players begin missing it more than hitting it, it gradually slows down again.

So at a simplistic level, the machine is reacting and adjusting to player input.

I've often wondered why Barcrest put these true skill feature so low down on the features table, Did they not realise that some players would work out how to hit them consistently and thus empty the tubes of all the money in them?

They must have realised with later revisions because the true skill was chipped out but that range of AWPs were effectively SWPs in disguise

Edited August 29, 2025 by Hamsun

[Manana]

9 hours ago, Cavey said:

Well, I never play any form of fruit machine or slot, don't do casinos or bookies. I do like a punt on the Lottery (without much success, but it's just a few quid), and love the horses - I have a terrace "medal" for Chester Racecourse and am taking the missus and daughter #2 to Ladies Day tomorrow, as it goes.

When I'm there, I do like to have a blast with the Totes etc., it's all part of the spice. I take £300 for gambling money and when it's gone it's gone, albeit I won £800 last visit and £1250 the one before that. I walked away cash in pockets both times (or more accurately, gave the lot to Mrs Caveman for a nice treat, it's the least she deserves for all the shit she went through with fruities).

EDIT to add - I genuinely never notice fruities in pubs or anywhere else anymore.

Having spent so much time in bookies playing roulette I also gambled on horses and dogs. I was so succesful that I had more more on virtual racing as I would just pick a number

I have no desire for any of it anymore but it's good you are able to enjoy a day out without getting the gambling bug again. 

[Cavey]

2 hours ago, Manana said:

Having spent so much time in bookies playing roulette I also gambled on horses and dogs. I was so succesful that I had more more on virtual racing as I would just pick a number

I have no desire for any of it anymore but it's good you are able to enjoy a day out without getting the gambling bug again. 

I base my choices on numbers and colours. I frequently don't even know the odds of the horses I'm betting on, never back the favourite, always bet on the nose, always ignore the "helpful" form guide left on all the terrace tables.

Needless to say, I'm more successful than most of the self-proclaimed "experts". With the horses it's best to know everything or nothing (I'm the latter). Anything in between is very dangerous.

"Golden Ferrari" was irresistible last meet; the favourite "Herschel" was 4/6 (hardly worth the risk, surely), whereas it was a 25/1 no hoper. It romped home, which made for a rather excellent late afternoon courtesy of Perrier-Jouet.

Edited August 29, 2025 by Cavey

[Hamsun]

I'm not sure if this is the best thread to ask but I wonder if anyone knows how many (if any) original ROMs we have for JPM and ACE from the late 1990s/early 2000s.

This period includes many of my favourite machines but the layouts I've tried (apart from maybe Fast Trak and one or two others) all seem to be on those crappy chips that spin in JPs while blocking JP features and setups for hidden bonus features &c.

Edited September 10, 2025 by Hamsun

[thealteredemu]

Sadly we don’t have a massive amount of first release chips as mostly roms came from the old bulletin boards which just delivered programme updates.

My most wanted list includes

JPM MONOPOLY V2

JPM MOMEY TALKS PRE V3

Sadly it’s unlikely these will ever turn up.

J

[Hamsun]

That's a pity. In many ways it gives a false impression of why certain machines were so popular with dedicated players. Playability plus profitability.

A lot of these late chip JPMs and ACEs give very little advantage to the player who knows all (or most) of the hiddens and can hit the skills when they arise.  A bit depressing but it is what it is, I guess.

The layouts I tend to go back to the most are for the few late 80s/early 90s Barcrests that still have true skill features. I quickly get bored of AWPs that present no real challenge. Even emptiers on those machines get boring after a while.

Saying that I have recently put quite a lot through the Big 50 DX trying to figure out why it seems to play very differently to ones I remember in the wild. I certainly don't remember them checking the JP in regularly as soon as they got a bit behind percentage, even when played casually. A lot of these chipped JPMs also appear to give fake or unreliable numbering. That was something I was aware of when played in the wild but it's good to see it confirmed on the emulator.

I'm not sure if it was a deliberate tactic from JPM to trap 'pro' players or just a consequence of flattened profiles.

[Chopaholic]

There are a couple of videos about Big 50 on my channel, in particular this table shown below turned up.

JPM really did butcher a lot of their machines as they moved through multiple rechips over the years, leaving many of them a shadow of their former selves.

The emulated ROM for Big 50 is Series 12.

Series 12 can do a £50 repeater but only if you deliberately play it 'wrong' for quite a while. When played even half competently it literally never will.

 

[Hamsun]

I watched (most of) your video a while ago and was a bit bemused by the whole concept of going all out for okey dokey on this machine and yet...having played the DX quite a bit, that seems as good a strategy as any.

This chip is not generous enough with bonus features to get a lot of player advantage. If you play it like a casual punter, messing up things like nudge steppa and nudges from the feature it simply starts landing JPs straight on the winline. It also loves to force the 'hidden' features, usually for a crappy £1 or £2 win feature.

I'm not sure how/why it would repeat big unless it's been played really badly for a long time and has held on to a lot of value.

I note that the series 11 rechip states 'tighten % control in arcade mode'. That might explain why it plays like it does.

I tried playing it badly but it kept forcing JPs on me and it was hard to get it far behind percentage. 

I'm guessing I've been playing the same version (DX by Tommy C)?

 

Edited September 11, 2025 by Hamsun

[Hamsun]

I've since had it on autoplay for several hundred credits but even that couldn't get it far over percentage. It still kept chucking in JPs. After that I played it quickly for a bit taking small wins and ignoring all opportunities for big wins.

It has now started playing very differently, a lot more like I would expect. I managed to steal several JPs from nudge steppa, hidden features and the odd okey dokey. Numbering on this Big 50 is not reliable so it's hard to know when to quit but I ended up well ahead on this session (£50+), even though none of the JPs repeated.

I guess the lesson here is that it is not always wise to make snap judgements about the playability of a machine that hasn't had a lot of credits or mixed styles of play.

Edited September 11, 2025 by Hamsun