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bytestorm

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Hey!

I have a Twin Cobra pcb that has a faulty TMS320C10 MCU, and when checking the mame source I can see that the original probably has some internal ROM split in 2 parts since there are 2 DSP rom files in the driver.
There are indeed a eprom version of this mcu availible but I am unsure how to program it, but when looking at other games using this MCU (like wardner) the bootleggers seem to have solved it by using external BPROMs.

Could anyone that owns a Twin Cobra bootleg please help me have a look if it indeed has one of these daughtercards instead?

This is the one from Wardner, and it has indeed all DSP data in external bproms..

20200820_114845.jpg
 

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I have a few of these bootlegs :/

see what you need? fingers are to delimit the daughter board

IMG_3546r.jpg

IMG_3547r.jpg

IMG_3548r.jpg



full boards for reference

IMG_3550.jpg

IMG_3552.jpg



IMG_3551.jpg



and this other, closer to the real thing
IMG_3549.jpg
 
WOW thanks! Thats awesome of you! :D. Hmm.. I wonder if they baked in another custom onto the same daughterboard or why they replaced 2 ICs with it..
Does the lowest one (closer to the real pcb) have the same daughterboard for the MCU? Replacing 2 ics?

Thanks so much for checking!!
 
I wonder if the mame source is wrong about thins beeing a 320C10.. Since they only carries 1.5k internal program rom (but can adress 4k external).
Since the DSP roms are 4k in total it would make more sense if it were a 320C15.. that actually has 4k internal.

320C15 is also availible in eprom type, using 4k eprom area instead of ROM.. that would be the simplest option...
Or just use a regular 32010/320C10 and set memory bit accordingly to use external 4k (microcomputer or microprocessor modes)

Someone also implemented this DSP on a fpga (TMS32010 DSP Processor on Altera FPGA)
https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.567.1157&rep=rep1&type=pdf
 
Ok so I've opened it up for you :

IMG_3554r.jpg



there are no "daughterboard" but the implementation appears to be the same and it's even socketed :
IMG_3555.jpg





and while I had it opened, I wanted to see what was underneath this other daughter board:

IMG_3556r.jpg





IMG_3557r.jpg


Now I know!

Let me know if you anything else!
 
Thank you so much for taking your time and showing all this to me! I need to have a look around locally to se if I can get a hold of a twin cobra bootleg with the small daughter boards so I can copy it and make a new pcb for my broken custom. I have newer seen the 3 first twin cobra bootlegs actually before.. all the ones i have come across looks like this last one :). Awesome find!

Its imressive how much work the bootleggers have done actually.. they much have been able to chage a premium for arcade pcbs back in the day??

Hopefully I can borrow/buy a twin cobra boot from a friend, if he finds time to look throu his storage :thumbsup: . Ill post my progress here!

Thank you once again!!!
 
Thank you so much for taking your time and showing all this to me! I need to have a look around locally to se if I can get a hold of a twin cobra bootleg with the small daughter boards so I can copy it and make a new pcb for my broken custom. I have newer seen the 3 first twin cobra bootlegs actually before.. all the ones i have come across looks like this last one :). Awesome find!

Its imressive how much work the bootleggers have done actually.. they much have been able to chage a premium for arcade pcbs back in the day??

Hopefully I can borrow/buy a twin cobra boot from a friend, if he finds time to look throu his storage :thumbsup: . Ill post my progress here!

Thank you once again!!!
Would you like me to send you one of the small daughter boards?! msg me your address and I'll mail it !
 
its getting there.. need to do some meassuring and check placements of stuff. Its tight between the boards and might be needed to have a little bit longer spacers.
 

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Hello Mrhide,

I'm a new member who just joined.

I own the same twin cobra bootleg pcb as you. The pcb form and the ic chip configuration are the same as yours.

20220206_103929.jpg


so it seems to have been made by the same manufacturer. However, various unknown errors have occurred, making it difficult to play.

1. During play It is frozen or switched to a garbage screen, making it no longer possible to play. The sound keeps coming out.

2. Messages such as 'TILT ERROR' and 'COIN ERROR' are displayed on the black screen and freeze.

3. There are cases where the enemy moves abnormally.

4. In almost the final round, there is a bug that does not die even when hit by an enemy bullet.

There is an abnormally disconnected trace on the solder side. I'm not sure if it was from the time of production or if the repair engineer was repairing it.
So when I connect this part (red circle in the picture), a typical RAM / ROM / SOUND CHECK OK message is displayed and a non-bootable TMS32010 mcu error appears.

20220206_103533a.jpg


20220206_103605a.jpg


Currently, it can only be booted from a disconnected state.

The white jumper wire next to it was temporarily connected by referring to another pcb, so you can ignore it.

Another interesting thing is that the second pin of 74ls299 on the top side of the lower board is all cut off like yours. Considering that it was cut equally, it is thought that it was intentionally cut later because of an error that was not found in the design.

20220206_102853a.jpg


Can you send me a picture of your board solder side? Also, I would appreciate it if you could any advise how to repair the above error.

Thank you.
 
long ago, i think there was a set of hacked roms for some of the toaplan games that did away with the mcu
i'll see if i can find them.

otherwise, maybe dissasemble the code in mame and re-write it to work in something modern - like an atmega.
 
@galaga1982 : interresting!!

mine appears to be connected:
1F0A4705-B811-4A0D-A707-648F12233452.jpeg


Weird that yours boot without it?

but your "a typical RAM / ROM / SOUND CHECK OK message is displayed and a non-bootable TMS32010 mcu error appears." might be a good place to start to explain your issues?

I wish I could disconnect mine and show you the results but that boards does not boot *at all* right now ! :(
 
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Hi Mrhide,

I'm sorry for the delay in answering. Since last time, there has been a problem that the tms32010 mcu cannot be booted after removing and reinstalling it from the pcb.
Even though the cut trace was restored to its original state, it does not boot.
The cause has not been found yet, and I will post it as soon as it is resolved.
 
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