SegaSonic The Hedgehog suicide chip & battery

[petieken]

Hi all,

As some of you know I acquired a SegaSonic The Hedgehog pcb some time ago. The pcb I have is the final revision and has a protection module (suicide). The module looks like this:


As you can see, it will be a bitch to replace that battery. 1 fraction of a second without power and it's dead!

Since System 32 games are emulated in MAME the protection module is probably also built into the engine. So I guess it's possible to decrypt the roms to let the pcb operate without the protection module.

Is there anyone who knows someone who may be able to decrypt these roms, or what procedure I should follow to do this myself maybe?

The game is from 1992-93 so that battery could die any moment I think.... Of course I will try to replace the battery first with a helper battery, but this will be VERY hard to accomplish. So it would be great to know if it's possible to run this game without the worry of a battery that may be dying any minute.

[Muerto]

sorry, i don´t have any offers how to do this..
I´m just curious  why they did make it like this, damn expensive for the company if the battery somehow fails (in the early 80.)

[petieken]

They did this to avoid piracy (bootlegging). Sega first started using this suicide technique on the System 16 boards (which are developed around the mid 80's). They built in the security ram INSIDE the 68000 processor. They contined using the encrypted processor technique during System 18, System X (Turbo Outrun,..). Decrypted romsets are available for these 16-bit systems by now (www.segaresurrection.com), so you can play suicided games again with a regular 68000 processor and decrypted program roms.

The System 32 is a 32-bit system and uses a NEC V60 processor. The security chip is seperate from the cpu now. The 16-bit system changed a few program bits by a constantly changing table in the battery powered ram. From what I understand System 32 works completely different, by swapping address lines around.

A System 16, 18, X game doesn't power up when the battery is dead. I tried powering up SegaSonic with the security chip removed and it powers up, plays demo sequence, but crashes when inserting a coin. The prototype version of SegaSonic doesn't have the security module, so it should be possible to decrypt this game by an expert.

I ordered a decrypted romset for Moonwalker a few years ago and this is definitely the best option for these games, no more worries about dying games .

[DarthNuno]

Is there anyone who knows someone who may be able to decrypt these roms, or what procedure I should follow to do this myself maybe?

Maybe you can try to contact 'The Guru', somewhere here?

[petieken]

I will do that! Thanks for the tip

I just measured the voltage on the battery and it's only 2.71V anymore , that means it's almost dead. I studied how to exchange the battery with a new one but it seems very hard work, mostly because the small pcb can't be taken out of it's plastic cage. I've never tried this before, but if I piggyback a new battery and leave the old one in place, will the (by then) dead battery drain the new one?

[level42]

I will do that! Thanks for the tip

I just measured the voltage on the battery and it's only 2.71V anymore , that means it's almost dead. I studied how to exchange the battery with a new one but it seems very hard work, mostly because the small pcb can't be taken out of it's plastic cage. I've never tried this before, but if I piggyback a new battery and leave the old one in place, will the (by then) dead battery drain the new one?

Actually, 2.71V is still pretty good for a lithium battery that is about 18 years old ! Does it show any leaking ? Just wondering because I'm modding the Berzerks boards now with a lithium battery.

I'm pretty happy I don't have to handle those crap suicide stuff. I read about them but have no experience with them. However, piggy-backing is NOT a good idea. The old battery will fail eventually and the good one could very well be drained by the old one. From that picture, are those two big "lumps" above the battery carrying the battery voltage ? If so it should be possible to apply some power on these with some clamps or even solder some wires carefully. Then you should be able to carefully remove the old cell and replace it with a new one.

[petieken]

No it's not leaking at all. I've replaced a Moonwalker suicide battery in the past (also CR2032) and no leaking there either. That battery was also about 17-18 years old then.

The battery is a CR2032 with solder lugs attached to it. Most CR2032 batteries with tags I found are this type:


I think I will order this type and bend the tags, solder wires onto it and solder it together with the old cell's solder blob, then cut off the old battery. This way I will have wires to attach the battery to and will make changing the battery in the future easier (or at least until decrypted romsets are available )
There is just enough space under the cover to hold a pair of wires so it should be possible. I'll just apply some electrical tape to the battery to make sure it doesn't short anything.

....why isn't this more like Capcom CPS2 suicide batteries, with these systems you get a few hours to change the battery, no worries to leave the system without power for a fraction of a second....

[level42]

Sounds like a good plan.

Don't solder too long on batteries, they don't like it....better good hot and powerful and SHORT then too low temp and power and LONG.....

Anyway, I bet the SEGA figured that the battery would live long enough for the game to be commercially interesting, and seeing it's _still_ backing up after 17-18 years prove they were right.

Remember that arcade games only have a short life-span to earn money (although I think it's longer now then it was 20-30 years ago).

[petieken]

Yes, I've seen a diagram of the lifespan and capacity of lithium cells and they last the longest when kept between 0-10°C. The higher the temp the shorter the lifespan and capacity. So I'm going to turn up the heat and do a quick solder job. Fingers crossed I don't blow it and lose power for a second on that protection module.

I also had contact with TheGuru and he told me lithium cells keep their charge for years but when they die they die immediately, so it's not like regular batteries were the voltage declines over a certain timespan.

If I can keep it alive with changing the battery, good. But if someday there's a decrypted romset, great!

[level42]

Yes of course decryption would be best.
No need to keep them encrypted after so much time...

Well, the fresh CR2032's I got here give about 3.1 Volts. Seeing yours is 2.7 V now says that it has decreased in voltage a bit, still amazingly little for such a time period !.

I just checked a datasheet of just one of the many brands who make these CR2032's.You can find it here:
http://www.renata.com/pdf/3vlithium/DBCR2032.05.pdf

The specified self discharge (so if you would put it on a shelf for years without actually using it) is less than 1% per year. If we assume worst case (1% per year) than after 17 years the voltage should be 2,573 Volts. (Assuming a starting voltage of 3.1 Volts). Your battery is still better than this ! So, the current drain is apparently SO low that that the discharge is much less than 1% per year, even when loaded.

The key is the load. The static Ram (or whatever it keeps under voltage) uses SO little current that the battery will last this long. Also, whenever the game is on, the battery is actually under no load at all (at least on a game like Berzerk it isn't).
I have a CR2032 in my Apple remote control that came with my Mac Mini, and it's now a little low (bought it in 2006). However, this battery is the only source of power on that remote and it's sure being loaded a lot more than in a memory back-up situation.

The best thing is that it's not leaking (yet)....

Anyway, if you look at the tables in the doc I linked to you can see about where the battery is regarding it's lifetime.
Check out the upper-right graph and look at the 68.1kOhms line.(This is the closes to "our" load). The real sharp bend comes at 2.5 Volts....Anyway, best to replace it of course

[petieken]

FUCK!! 

I'm so mad at myself, I blew it!

All went well, attaching the new battery, disconnecting the negative terminal of old battery. But then it went wrong, when disconnecting the positive terminal.... I had to pull up the battery a little so I could reach the leg to cut it off and I pulled it too hard, the copper land came off the little pcb . The copper came off the board way too easy, It's almost like there wasn't any bonding material between the copper and the board...

[vib_ribbon]

so... it's now dead?

[level42]

You bet !


That SUCKS !!! 

I know that feeling, trust me....I f-ed up during this hobby a couple of times. It's not long ago that I did it and it still hurts me....

[petieken]

I can only hope that someone is prepared to decrypt the roms now....

The battery was on it's last legs anyway, the voltage was already dropped to 2,67V in a couple of days. I know I will feel bad for some time now, for how stupid I was!!!

What did you f*** up Level42 that it still hurts you? For me it's the first time I really f***** up bad since I started collecting arcade pcb's. I changed a Sega suicide battery in the past (System 18) successfully and I probably was a bit too confident now because of my previous success.

[level42]

Believe it or not but I f-ed up my Berzerk bezel.

And it was LIKE NEW ! 

Was dirty though so I wanted to clean it carefully. Used some soapy water, but it turned out the artwork _really_ didn't like that. I tried to keep the water from the artwork but not good enough.

Imagine the horror going through me when I saw some of the edge parts flaking off !!!
Thought I went nuts !!!

In the end the damage is "not that bad".  But for me it's screwed. I'll post pics later in the Bererk thread....
The _WORST_ thing is that it was totally undamaged. Here I go wreck up a classic original part that looks totally mint. It survived for 30 years and then I go and f it up..... I was SO mad at myself that I didn't post about it here until now....

Only Ully and Muerto knew right away, because I wanted to warn them to be EXTREMELY careful...

On the positive side: Luigi (Thorsten) from Germany had the bezel repro'd in the UK and that guy should still have the artwork so I'll order that. I first thought I could repair the damage as one part of the damage was only the black area in the lower part. But the robots "shoulder" (blue stripes) on the left are damaged too, and it took me a couple of days to see that the top-most part was screwed too.

So there you have it....glad it's off my shoulders....

Shit happens, and this is the risk of trying to get the cab back to it's full glory but I'm still mad at myself about it because I _KNEW_ the risks but still f-ed up....