Star Castle Free Play / High Score Save ROM Hack

DogP

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Hey,

For years, my games haven't been saving scores, and I haven't really cared... I was mostly worried about getting them all working, and then getting them on free play. But finally I've gotten around to replacing dead batteries, installing NVRAM, buying high score save kits, making high score save hacks, etc. Now almost all my games should be saving high scores... but the one that was bugging me was Star Castle. It was coming down to either hacking it or selling it. :p

Star Castle is an oddball system... it's a CPU based system, but there's no actual CPU chip (the CPU is designed using a bunch of logic chips). It has its own instruction set, 12-bit wide memory, etc. Overall, it's weird. I had done a free play hack for it 5 or 6 years ago, but it was mostly just tweaking a few instructions. This hack actually required writing some code. It also required a hardware change, since the old RAM has no battery backup.

Anyway, attached is the hacked ROM set to preserve the high score, and a few pictures of the mod. There are details in the zip regarding the ROMs, chips, wiring, etc. But the TL;DR of it is:
1) Based on the older (easier) starcas1 ROM set
2) Score is saved when DIP SW 6 is ON, and can be cleared (or used as free play w/o score save) by switching DIP SW 6 OFF
3) Requires desoldering 3x 2101 RAM chips and installing 3x 5101 RAM chips (2101s would quickly drain the battery), plus a battery switchover circuit to keep it powered when the game is off (unfortunately, FRAM 5101 replacement modules won't work)
4) I created a battery switchover using a DS1210 and CR2032 battery on a piece of perfboard, and double-sided taped it to the top of my 5101s.

I'm providing this information and hack for free with no warranty... I'm not interested in providing this modification service, but feel free to ask if you have any questions.

DogP
 

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Finally a Cinematronics hack. :) Nice job (as always).
Too bad it involves some desoldering and not just plug-ins and soldering. But that's the price we pay for these boards being all TTL.
 
HiScoreSaves get in on this and get it online. Please. I have a Star Castle lead i'm working on! :D
 
Nice work! I didn't not realize there were other non discrete CPU based games. I remember reading that pong or breakout had no physical CPU did not think any others were like that. very cool work!
 
Thanks guys... I don't expect it to be very popular (not a very popular game to begin with, and it takes some work to make happen), but I'm glad to see it's appreciated. Hopefully it helps someone in the future.

BTW, I updated the readme in the first post. I power cycled the game a bunch of times to make sure everything worked... after 50 or so power cycles, the RAM got corrupted. So, I made a small modification to route the R/W pin through the DS1210. This prevents the chip from being written unless the power is good. So far, it seems to have fixed the problem. I'll post another update if I run across any other problems. The ROM hack itself hasn't changed.

Too bad it involves some desoldering and not just plug-ins and soldering. But that's the price we pay for these boards being all TTL.
Yeah, not much you can do when the board doesn't have many socketed parts. :-/

Nice work! I didn't not realize there were other non discrete CPU based games. I remember reading that pong or breakout had no physical CPU did not think any others were like that. very cool work!
Well... it's a bit different than games like Pong and Breakout (and even Monaco GP) which were designed completely with discrete logic circuits. Star Castle (and all Cinematronics CCPU games) has a CPU, runs code from ROMs, etc. But the CPU is implemented using discrete logic. Check out the attached diagram from the manual... it maps out which chips are the ALU, accumulators, address counter, registers, etc. Pretty cool to see, but IMO they should have just used a 6502 and had a single chip and a good instruction set. ;)

DogP
 

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BTW, there was a request for HSS without Free Play (since the castle animation only shows when there are no credits), so it's attached to this post. I haven't tested it on real hardware, but it should work. Please let me know if you try it and whether it does or doesn't work.

For an update on the status... the hack has been running solid in my cab for the past couple years... still has a ~14K score on it from my first party.

DogP
 

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BTW, there was a request for HSS without Free Play (since the castle animation only shows when there are no credits), so it's attached to this post. I haven't tested it on real hardware, but it should work. Please let me know if you try it and whether it does or doesn't work.

For an update on the status... the hack has been running solid in my cab for the past couple years... still has a ~14K score on it from my first party.

DogP

I tested this code today, on real SC hardware, with the new HSS/(FP) board kit ... and ... and ... and ... it works. :) Thanks for taking the time to update/change the ROMs.
 
I got a high score of 14640. And it's stored. Just thought you'd want to know. :D
Looks like you're gonna have to do a little bit better... 14770.


(though that's not actually my score... I think LogicalHighs set that) ;)

DogP
 

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Damn, so close. LOL

Oh, and mine doesn't say FREEPLAY anymore, but, for now, I'm OK with that. HSS for the win. ;)
 
Been playing a lot of Star Castle today.
Look what just happened ... I'm getting skillz ... :)

SC_HSS_FP_ATT_17K.md.jpg

NOTE: screen shows high score saved after game turned off, waited, and turned back on. (this is the new unreleased HSS/FP/AM ROM version too) :)
 
Wow... nice score!

Attached is the newest hack, which has the High Score Save, Free Play, AND castle animation attract mode. VC tested it and says it works, so it should be good to go!

DogP
 

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Wow... nice score!

Attached is the newest hack, which has the High Score Save, Free Play, AND castle animation attract mode. VC tested it and says it works, so it should be good to go!

DogP

And, I assume since I have not tried it yet, ... keeps the DIP Switch feature for the ALIGNMENT TEST SCREEN. ;)
 
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