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Rastan pcb conversion to Rastan Saga

Pythagoras said:
Too bad that we not have another bootleg to test. To verify if the behavior is same or if it's just your bootleg that behave strange.
Since the coin inputs work with the earlier revision on the bootleg it should be possible to fix it for this revision but more information is needed to be able do to so.

Another problem is that we can't trust Mame to 100%. The coin inputs does not work in service mode in Mame, but I asked someone to try this on their Rastan Saga and on his PCB did the coin input work. So I suspect something is wrong in Mame. That is very strange. But I have tested som other game and they had the same problems. For example "Armed Police Batrider" and some other Taito games. from the same period as Rastan.
Click to expand...
Coin worked in service menu on my Retail Rastan. It also works fine in the MiSTer core.

I believe the MiSTer core is actually based on the bootleg PCB. Jotego often fixes design flaws, so it may not be an exact clone. I'll try to look into it further.

I suspect most bootleg Rastan will perform the same. The repair logs I've seen have all looked just like mine. I'm guessing they behave similarly.

I understand that it's not really a fix, and is more of a work around, but I have put a lot of time, effort, and money into the PCB and it's nice to finally be able to enjoy it

Thanks again.
 
Good to know. Must be a bug with Mame. Strange that the coin switches works outside service mode.
So you think all bootlegs have problem entering the service menu? And with the coin input?

Yes, it's good att you could play it. But still strange that the coin inputs work with one revision and not the other.
I could do another hack to try to get some information that might help. But I understand that you might be tired of burning and swapping eproms ;)
 
I got an idea. So I made a little test. The files are for CPU3-6. I have moved the service mode to rom 5/6 and made the game start in service mode. I also open the coin locks. Try and see you can get the service mode work on your pcb and if something happens when you insert a coin...
 
Pythagoras said:
I got an idea. So I made a little test. The files are for CPU3-6. I have moved the service mode to rom 5/6 and made the game start in service mode. I also open the coin locks. Try and see you can get the service mode work on your pcb and if something happens when you insert a coin...
Click to expand...
Cool. I happen to have 4 extra EPROMs, so this works. I just ordered 20 more. I'm sure I'll misplace those too...

I'll give it a shot later today.
 
It booted into service mode, but only the ON/OFF indicators ere displayed. The descriptions were missing.

The color bars portion was skipped.

It was not hard to tell what the indicators represent, once you hit the buttons. Everything worked; including coin.

The board was in rolling reboot, which is also what happens when I enable service mode on the regular ROMs.

It stays up long enough to press some buttons and see the results.

EDIT: the board is not in rolling reboot. it reboots when start is pressed. I guess I was pressing start a lot...
 
The colorbars have I skipped. Strange that it doesn't work for you. Must be something that is different with the bootleg. If there was any problem with the ram, you should not be able to play the game for long. But you have proved that everything seems to work That is very strange.

...Anyway here is a another patch... Only 1 byte differs from the original. So you just need to replace rom 4 with this one. Use the original roms for other 5 CPU roms...
 
ok, but in the partly working service mode the coin inputs did work. So we getting closer... I think I will add a little thing to the 99 credits version and see what that can tell us...
 
OK,

Here is another test. If it works on your side it will show some information and hopefully a clue...
 
Pythagoras said:
OK,

Here is another test. If it works on your side it will show some information and hopefully a clue...
Click to expand...
I tried it out and I see this:

IMG_20221013_091824785~2.jpg

I'm not that surprised to see a RAM ERROR, if that is a legit failure, because it does exhibit some graphical anomalies. Nothing crazy but you can kinda see that sometimes things don't move as quickly or line up as they should.

For example, when jumping over the brown pools of water, you can see the background through a GAP that develops between the brown water and the ground when scrolling.

Also, sometimes, the green lizard men are split down the middle by about a pixel width.

The game is still fully playable. And it really doesn't detract that much.

I will probably invest in a logic probe and see if I can figure out which RAM is bad. I will also have to see if I can figure out how to figure out which RAM is bad 🤣

Edit: and maybe that's why service mode didn't work?
 
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Yes, that explains the problems with service mode. I think you can get help how troubleshooting the ram or perhaps the ic's that handle adress decoding.

Here is another test hack That tries to force the right bits to the coin registers.
 
Pythagoras said:
Yes, that explains the problems with service mode. I think you can get help how troubleshooting the ram or perhaps the ic's that handle adress decoding.

Here is another test hack That tries to force the right bits to the coin registers.
Click to expand...
Here are the results.

Started with 1 credit. I could not add more.

IMG_20221014_193616632.jpg
 
There is some problem with writing to the registers, as you can see $390008 all bits are set to high ($FF). There is a one thing I can try. If I let the code ignore the bits for the coin lock... Let's see what happens...
 
I don't think I can find a workaround for this. It's a mystery that noting happens with the register at $390004. I'm working on a Rastan Saga patch and hopefully will I be able to make a proper free play switch for that. But it will take some time. At the moment do I working on sound in attract mode and also trying to add the instruction scroller from the US version...
 
Pythagoras said:
I don't think I can find a workaround for this. It's a mystery that noting happens with the register at $390004. I'm working on a Rastan Saga patch and hopefully will I be able to make a proper free play switch for that. But it will take some time. At the moment do I working on sound in attract mode and also trying to add the instruction scroller from the US version...
Click to expand...
Thanks very much for all the effort.

I am good with the 99 credits but I do love attract modes.
 
I did a check in MAME to see if credits were registering in test mode. Turns out they don't.
Haze told me that you have to run MAME with the -nocoinlock option since TAITO turn on the coin lock in test mode.
 
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