Raiden pcb

[sukhbir]

Working on a raiden pcb for a member ,this revision boardset does not boot.
here it is on my bench. I did a romident on all the eproms and 5 dont match any romsets?
these are rom 3/4(cpu) rom 5/6(sub) rom 8(audio)

the other eproms checked out ok and i presume they are the parent roms.
Can anyone help to identify which romset this board should have.
The clue to the correct romset is to read the roms 3/4 and do a romident.

 

[cliff_poole]

I have a non-running PCB the same as that, but won't be able to get it out and read the ROMs until the weekend.

 

[sukhbir]

That will be very helpful if you can read the roms 3 and 4.
Strange revision PCB with 2 x 40 pin dil plds fitted.

 

[cliff_poole]

Here is a picture of the board.


ROM 3 identifies as multiple sets, but ROM 4 is unique. 4.u023 raidena (set 2).

Mine is also a not running. I only got as far as checking the four main ROMs and testing the main system RAM out of circuit. I'll be interested to read what you find out about yours, how it starts, if there are any special requirements such as proper initialisation of sub processor etc.

 

[cliff_poole]

I have also just noticed ROM 4 on mine is an EPROM with a handwritten label, so although it identifies OK, I guess it is not conclusive that it goes with this board. The label does look old though.

 

[sukhbir]

hi, thanks for the info ,but that Rom4 looks like its been reprogrammed as the original roms are OTP type,can you please romident roms 5 and 6 (sub) Please.
Another weird thing about the pcb I have is that roms 3 and 4 pins 27/28 are shorted to vcc on the solder side?
im pretty sure pins 27 are a address pin,can you check yours please and let me know.

cheers

 

[cliff_poole]

ROMS 5 and 6 are not unique either. Raiden, RaidenA, RaidenK, RaidenT, RaidenU.

Do you mean pins 31 and 32 ?. They are both connected to VCC on mine. Pins 27 and 28 are not.

 

[sukhbir]

Hi,
That’s interesting that many rom sets use the same code for roms 5 and 6.

Oops sorry but I was supposed to say that roms 1 and 2 pins 27/28 are shorted to vcc,please check for me.
Thank you

 

[cliff_poole]

Counting the pins on the chips (27512), Pin 28 goes to VCC and pin 27 is an address line. Pin 27 is connected to the same address bus as ROMs 1-4.

I was comparing the different ROM sets and it seems ROMs 4 and 8 are often different between the sets. My ROM 8 reads OK but cannot be identified. Either my ROM 8 is corrupt, or we could have boards with an un-dumped ROM set. If you sent me the image for your ROM 4, I could try it in my board, see if it boots.

 

[sukhbir]

Thanks for checking the pins on the 27512 and now I know something is very bizarre with this PCB.
I've removed the shorts between pin 27 and 28 and weirdly pin 28 on both 27512 roms are floating,they are not connected to vcc ?
The link must of been soldered to get vcc from socket pin 29.
Possibly the vcc trace must of vaporised due to a short circuit.
I will send you the ROM 4 data, like I mentioned previously this is not recognised on romident?

 

[sukhbir]

hi, heres the rom:-

 

[cliff_poole]

I just loaded mine and yours into a hex editor. The only difference is at 00001E3D, mine reads 19 and yours 18 (hex). I'm inclined to think yours might be an un-dumped variant, I doubt a fault would be that minor.

I've seen fused VCC tracks underneath chips so many times, and having caused it myself in the past, know how it is done. One slip of the scope probe, shorting a pin that is tied high with a ground pin, little wisp of smoke from under the chip !. It is good practice to use pull up resistors, but that would add to the costs.

 

[sukhbir]

But surely there has to be a rom dump on this revision pcb,seibu must of made millions of this raiden pcb.
these pcbs are very ROM specific,I reckon the pcb I have all 5 roms are corrupted.