Namco assault no tanks

[Retroman839]

Ok, mine gets 4 RAM Error 0480000
Ignore the 4 - I think that just means the RAM is the 4th thing tested.
The second number is the memory address. In the case of mine, that address corresponds to the communications RAM, which isn't used, so I just ignore it.

Are you REALLY sure yours says 0000002? That's not even a RAM memory address.

I still don't think that's why the sprites are like that though. Need to be a bit more scientific that shotgunning anything with a 4 on the label.

I guessed the amount of zeros we at work. 😉

 

[John Bennett]

OK. That's a bit confusing .
A bit of mame debugging needed.

 

[Retroman839]

I'll stare at the schematics a bit, there's a lot of customs, but a few other things around those. Might also find you could nick customs off a Final Lap if it's the sprites that are bad (that part is common I think...).
Probably easier to say 'give it here' than to diagnose the entire object section of the video hardware over the internet how to fix it.
When you play the game, are any sprites visible at all, or are they all shadows?
To lose everything makes it seem to be more likely something addressing the ROMs than the ROMs themselves.

I haven’t completed the first level .. but all sprites are shadows so far yea
Sorry dark pic but Lots little shadows here -

 

[Retroman839]

Pallet ram ? Tile ram ?
Sprite present just no tile ?

Seems to be only tanks and bullets that’s missing .
Tree sprites are ok
Bomb crater sprite are ok

I knocked a tree over ..
That changes to a fallen tree .
And sound effect. The sprite graphics for this was ok

 

[ExZX]

I would if I could ..
I’m stuck with my programmer

I get a message switch jumper to 3.6v.

? I don’t know how ?
I can’t see a jumper like that.

so I will program a 32 pin eprom 1004. With obj 4 from mame ..

In mean time … ( haven’t located a 1004 in my Stash yet.

I’m looking for a bad ram in this block of 4 @ 4
View attachment 35717

Here is the mask and EPROMs
And jumpers
View attachment 35718
What do you make of it ?
Is Roz 7 inactive then ?

The jumpers on the fucking Namco board not your programmer!
The jumpers labelled JP that determine how the row of sockets are read depending on whether you have a 28 pin mask or 32 pin eprom in there!
Going round in circles with this and off on tangents over a month later rather than sorting out something really simple which is you cannot mix a row of eproms and mask roms as they are not read in the same way because they have different pinouts! Fuck me I'm out

 

[Retroman839]

The jumpers on the fucking Namco board not your programmer!
The jumpers labelled JP that determine how the row of sockets are read depending on whether you have a 28 pin mask or 32 pin eprom in there!
Going round in circles with this and off on tangents over a month later rather than sorting out something really simple which is you cannot mix a row of eproms and mask roms as they are not read in the same way because they have different pinouts! Fuck me I'm out

I got your point first time dude .
Keep your hat on 😁👍
I need to burn that 28 dip to a 32 !
I’m waiting for johns direction
With the ram error 4 first to see what the ram error is about .

I’m not confusing jumpers with my programmer with the jumpers on the pcb ? Just trying to read the chip 😁🤣

Appreciate your help man
And as that’s the sprite bank
Make total sense …

I have a 4mb eprom 32 dip
Would that be ok ?
Or do I need to stick to 1mb type ?

No prob burning an eprom
Just can’t read that mask

 

[TheDaddy]

OK. That's a bit confusing .
A bit of mame debugging needed.

Mame debugging, Something I have never done and not sure if I could get my head around it ??

Dave.

 

[Retroman839]

Mame debugging, Something I have never done and not sure if I could get my head around it ??

Dave.

Remove part of code to recreate a fault ?

Bugging in reverse

I wanted to be a debugger when I we young…

Applied for the job

Didn’t get it
Over qualified. They said I was a Total Bugger

 

[Retroman839]

🤣

 

[John Bennett]

I’m waiting for johns direction
With the ram error 4 first to see what the ram error is about .

I was afraid you'd say that .

I certainly wouldn't pin your hopes on the memory error being the cause, but we should get to the bottom of it.
I'll do a 'show and tell' with MAME later (or try to), might be of use generally.
Basically you run it in debug mode and type random stuff into RAM to try and break the bootup in the same way.
Craters and trees will be the rotation layer, so they're ok.
I think it is just the object/sprite layer that's bad. Sprites are in the right place, they're just not scanning out properly to the screen. It's probably video hardware unfortunately, rather than RAM/ROM.

 

[Retroman839]

Ok sounds good.
I need to burn an eprom 32 pin dip to replace this radon 28 dip mask type ..

If jumpers only read 32 or 28

Then I’m not using this sprite bank ? Sound like a possible cause to me ..
But I know nothing

 

[John Bennett]

I'll be honest, I've not looked at what you're doing with ROMs, maybe I'll catch up later. Just be careful, don't go breaking anything more.

 

[Retroman839]

I'll be honest, I've not looked at what you're doing with ROMs, maybe I'll catch up later. Just be careful, don't go breaking anything more.

Not touched anything 🙌
All it is is
I have one mask rom 28 dip
And all the rest are 32 dip
As xfm said
That don’t work -
Either all need to be 32 or 28.
Not mixed ..

 

[John Bennett]

Ah, ok. Well 4RAM is the memory for the C139 communications chip, which often fails and isn't used. The fact yours says 00000002 doesn't mean a lot - it's a totally duff RAM chip, but it isn't used by Assault so that's not the problem.

As a brief show-and-tell.
mame -debug.
Load Rolling Thunder 2 as that actually shows you the memory tests, whereas Assault does them silently. Both have the same memory locations though.
Hit F8 repeatedly to advance the game one frame at a time until it says 4RAM Test.
Now hold F11 to slowly go through instructions and you'll see it's changing Register A1 and it's got a number in the 0x480000's


If you look at namcos2.cpp, you'll see that's the 'sci' RAM

Which, if you read around that file, you'll see that's the serial communications.

Now if you go to debug and open a memory window and type in 0x480000, and keep pressing F11, you'll see it's changing all the 00's to FF's in that area as part of a memory test.
Type some crap into the FFs.

Press F5 to run the game

And it's not happy:


Now you could go and do the same to break Assault by putting a watchpoint in the SCI memory region ('wpset 0x480000,0x1000,rw' in the console), running until it pauses, then mashing the address, but I'll leave that unless someone needs a further tutorial. I did do it though:


So that's not your sprite problem.

 

[Retroman839]

Ah, ok. Well 4RAM is the memory for the C139 communications chip, which often fails and isn't used. The fact yours says 00000002 doesn't mean a lot - it's a totally duff RAM chip, but it isn't used by Assault so that's not the problem.

As a brief show-and-tell.
mame -debug.
Load Rolling Thunder 2 as that actually shows you the memory tests, whereas Assault does them silently. Both have the same memory locations though.
Hit F8 repeatedly to advance the game one frame at a time until it says 4RAM Test.
Now hold F11 to slowly go through instructions and you'll see it's changing Register A1 and it's got a number in the 0x480000's
View attachment 35811

If you look at namcos2.cpp, you'll see that's the 'sci' RAM
View attachment 35810
Which, if you read around that file, you'll see that's the serial communications.

Now if you go to debug and open a memory window and type in 0x480000, and keep pressing F11, you'll see it's changing all the 00's to FF's in that area as part of a memory test.
Type some crap into the FFs.
View attachment 35812
Press F5 to run the game

And it's not happy:
View attachment 35813

Now you could go and do the same to break Assault by putting a watchpoint in the SCI memory region ('wpset 0x480000,0x1000,rw' in the console), running until it pauses, then mashing the address, but I'll leave that unless someone needs a further tutorial. I did do it though:
View attachment 35814

So that's not your sprite problem.

Thank you for that tutorial .
Taking time to do that really
Appreciate it 🙏

so as you say it’s just the c139
That Has failed and mem test is picking it up 👍

Although that chip is redundant on this game it is used by others .



So now likely it’s this mask rom


Roz 7 ?
Needs to be a 32 dip like all the others

 

[John Bennett]

Somehwere around 0%. That's the background/rotation layer.

There's no way every single OBJ ROM is dead either.
I reckon it's a custom or glue logic that's packed in and someone harvested the CUS106 from it to use in something else. In terms of repair difficulty, I'd say it's non-trivial now.

 

[Retroman839]

little logic chip failed somewhere then
or another bad custom ..
🤔

 

[John Bennett]

I'm busy now, but I'll try to decipher the obj layer later.

 

[Retroman839]

I will just change the title of thr game to shadow tanks

I’m happy that I have the shadow sprites as I can now
Aim and fire 👍 and see my tank location .. so the game makes sense and at least .. I can play it .. I love the play mechanics .. want to make a control pannel for it ..

guess I need to keep an eye out
For a non worker and try swapping some customs around

 

[Retroman839]

If I could only read them object mask roms ! Just to at least know of they are good or not!

Need to find out how I set my programmer to 3.6v