Hatsune Mike
Champion
I expect that ‘010 in the middle is a lookup table used in the boot hardware, so it might not correspond to anything on the real board.
- Thread starter xodaraP
- Start date
xodaraP
Legendary
I have a Wellon VP-280 which should be able to do that.
xodaraP
Legendary
I finally got my EPROMs so I've burnt the 2x 27C020 ROMs for the main CPU code
Survey says!
No dice.
Behind the wall of garbage I can see what appears to be some of the fix layer, or it could be nothing at all, it's just something flickering. Something else is definitely wrong here. That's frustrating.
At least now I know I have a known working set of main CPU code so I can start figuring out where else the fault might be.
Survey says!
No dice.
Behind the wall of garbage I can see what appears to be some of the fix layer, or it could be nothing at all, it's just something flickering. Something else is definitely wrong here. That's frustrating.
At least now I know I have a known working set of main CPU code so I can start figuring out where else the fault might be.
For the graphics fault i'd scan the 157's first, followed by the ram and 161's.
Tile rom does the title screen and overlay text and not the in game scroll layers so you want to check starting from the back. The scroll layers will be mask rom(s).
For the CPU problem, check clock lines and reset first, then traces to the roms and main ram, followed by any buffers / select lines connected with the cpu.
CPU may be toast if it's running overclocked, seen that all the time on bootlegs.
Tile rom does the title screen and overlay text and not the in game scroll layers so you want to check starting from the back. The scroll layers will be mask rom(s).
For the CPU problem, check clock lines and reset first, then traces to the roms and main ram, followed by any buffers / select lines connected with the cpu.
CPU may be toast if it's running overclocked, seen that all the time on bootlegs.
xodaraP
Legendary
It's repeating the same thing over and over again and I've got no sound, so I don't think it's booting. It looks like a RAM test screen.
I'll take a video of it and upload it to YouTube but it looks exactly like the kind of test screen you see on an MK, Irem M92 game etc where it scrolls through a bunch of stuff then gives the OK and boots
Clock has been checked and it's good, RESET and HALT are not asserted
I'll take a video of it and upload it to YouTube but it looks exactly like the kind of test screen you see on an MK, Irem M92 game etc where it scrolls through a bunch of stuff then gives the OK and boots
Clock has been checked and it's good, RESET and HALT are not asserted
xodaraP
Legendary
So I finally got around to removing, socketing and dumping the 2 16mbit mask ROMs on this board - as well as socketing the other work RAM I hadn't previously. I tested the second main CPU RAM off board and it tested fine, so that's not the fault.
Still can't figure out why it won't fire up (and need to repair a couple of traces I screwed up removing the mask ROM underneath the 2 PALs on the daughterboard and the main CPU RAMs)
One of the 2 16mbit mask ROMs (the one with the 2 PAls above it) identifies as from the GunNail set in MAME. The other mask ROM doesn't. Whether or not this is because the data is bad or because it is different, I'm not entirely surprised that at least one identified exactly the same as the original, my guess is the other is identical other than the bootleggers probably removed copyright text or something.
I have attached both 16mbit ROMs here. A9 identifies in MAME, K10 doesn't.
@sylphia hopefully this helps you with yours
Still can't figure out why it won't fire up (and need to repair a couple of traces I screwed up removing the mask ROM underneath the 2 PALs on the daughterboard and the main CPU RAMs)
One of the 2 16mbit mask ROMs (the one with the 2 PAls above it) identifies as from the GunNail set in MAME. The other mask ROM doesn't. Whether or not this is because the data is bad or because it is different, I'm not entirely surprised that at least one identified exactly the same as the original, my guess is the other is identical other than the bootleggers probably removed copyright text or something.
I have attached both 16mbit ROMs here. A9 identifies in MAME, K10 doesn't.
@sylphia hopefully this helps you with yours
Last edited:
xodaraP
Legendary
Spent a couple of hours on this to see if I could get anywhere:
Repaired 4 traces on the main CPU RAM that didn't beep, one of the 2 RAMs also didn't have ground. These pins were very corroded when I got it so I can't say I'm surprised.
It no longer gives me a full screen of garbage, instead it gives me a shrunk line of garbage in the middle of the screen, so I think it's actually giving me the correct output resolution now meaning it's getting further than it was in the boot process.
@sylphia - if/when you have time, would you be able to test for continuity between the main CPU RAMs and ROMs?
I'm currently mirroring both ROMs and RAM traces and I'm not sure if this is correct but without another board to compare it to it's difficult
Repaired 4 traces on the main CPU RAM that didn't beep, one of the 2 RAMs also didn't have ground. These pins were very corroded when I got it so I can't say I'm surprised.
It no longer gives me a full screen of garbage, instead it gives me a shrunk line of garbage in the middle of the screen, so I think it's actually giving me the correct output resolution now meaning it's getting further than it was in the boot process.
@sylphia - if/when you have time, would you be able to test for continuity between the main CPU RAMs and ROMs?
I'm currently mirroring both ROMs and RAM traces and I'm not sure if this is correct but without another board to compare it to it's difficult
xodaraP
Legendary
So I thought I would update this thread as I have spent quite a bit of time trying to get this board to boot but sadly it seems to be too far gone. I'm not going to be going any further with this, at the end of the day it's a bootleg, albeit an extraordinarily rare one. I have dumped the ROMs along with @sylphia for preservation.
I have done extensive trace repair after removing everything from the area to trace where it is all supposed to go and it now boots to a screen of garbage (it's reading main program code but crashing) instead of the rug patterns I was getting before where it was searching for the work RAM and couldn't see it.
And here is a shot of all the repaired traces. Yes it's a bit ugly because I haven't cleaned it up, I just needed it to have all the correct connections in place to see if it would boot. Also, ignore the flux I haven't yet cleaned off
I have done extensive trace repair after removing everything from the area to trace where it is all supposed to go and it now boots to a screen of garbage (it's reading main program code but crashing) instead of the rug patterns I was getting before where it was searching for the work RAM and couldn't see it.
And here is a shot of all the repaired traces. Yes it's a bit ugly because I haven't cleaned it up, I just needed it to have all the correct connections in place to see if it would boot. Also, ignore the flux I haven't yet cleaned off
