Smash TV to MK board swap (copy protection?)

[DogP]

Yeah, it's been a long time since I've looked at a MK board. When you gave those resistor readings, I assume those were in Ohms? If so, there's almost certainly no difference between them, and swapping resistors would be a waste of effort. They're probably just for strapping the board for the ROM size or type, and their value probably doesn't matter much.

DogP

 

[kane086]

I have both these boards out in my garage, I'll give them a thorough look over tomorrow and see if I can spot any differences between my boards.

 

[mecha]

Yeah, it's been a long time since I've looked at a MK board. When you gave those resistor readings, I assume those were in Ohms? If so, there's almost certainly no difference between them, and swapping resistors would be a waste of effort. They're probably just for strapping the board for the ROM size or type, and their value probably doesn't matter much.

DogP

probably, I don't have any time to tinker with it today anyway.

the MK 3.0 roms (masked) worked fine in that 2.0 board that had EPROMs. the 2.0 roms won't work with the Smash TV board, and the Smash TV won't even do anything on the MK 3.0 board.

one thing I accomplished was I got a better MK board out of it. lol, my 3.0 had many damaged or missing headers. but I could've fixed those if the Smash TV would work with it.

mind you, the Smash TV worked with the 2.0 board, but gave me a CPU error -- the 3.0 works perfectly fine on it, just like the 2.0's, so that's definitely some kind of protection error, or a rom thing... my MK2 board would give me CPU errors periodically, until I cleaned the damn chip legs on the game roms.

 

[kane086]

OK, I checked over my boards today and it mostly looks OK but there are some small differences I noticed.

You can see from the above pics that the bottom row of 5 resistors has one resistor in the different holes. Don't know what difference this will make but worth looking into.

The other difference is the RAM speed. The MK board has faster RAM than the STV, 35ns versus 55ns and 100ns/120ns versus 150ns. This may or may not be problematic, but they obviouoly put faster RAM on for a reason.

Maybe check out these things on your boards to see if yours is the same.

 

[mecha]

I stared at those resistors for awhile, I swear they were all in the same positions lol

I would think MK would require the faster ram for the larger digitized graphics. I know Smash TV had very similar graphics (they were most likely drawn, but of a pretty high depth) but they were very small.

at this rate with the amount of surgery at stake, I'd probably be better off fixing whatever's wrong with the Smash TV board.

do you know what each IC component on the board does?

 

[kane086]

I stared at those resistors for awhile, I swear they were all in the same positions lol

That was the only resistor I could find that was different, will be interesting to see if your board is the same or not. Also, all the resistor values I tested were the same.

do you know what each IC component on the board does?

I have a basic understanding of how an arcade board works which comes with learning to fix them, but i'm far from an electrical engineer, and these later 90's boards can get alot more complicated.

 

[kane086]

I've been digging a bit deeper into this and found some interesting things. I've been looking over the MAME source code as they often have a lot of detailed information in there regarding PCB operation. Here is some excerpts ->

This game runs on (typical) Midway Y-Unit hardware. The PCB is a base
board 'system' that can run other Y-Unit games by swapping ROMs and
the protection chip.

Looks like it can be done, great, read on...

* - Intel P5C090-50 protection chip labelled 'A-5346-40025-8'

So the large 40 pin DIP chip in the corner of the board next to the largest square black chip is a protection chip, and most likely has to be swapped over aswell (not sure if you did this).
The 7 PALs may also need to be swapped over aswell (not sure about this, they might be the same, can't hurt to try if you havn't done so)

/* master clocks vary based on game */
#define SLOW_MASTER_CLOCK XTAL_40MHz /* "slow" == smashtv, trog, hiimpact */
#define FAST_MASTER_CLOCK XTAL_48MHz /* "fast" == narc, mk, totcarn, strkforc */
#define FASTER_MASTER_CLOCK XTAL_50MHz /* "faster" == term2 */

This is an interesting one, it appears that the Smash TV and MK CPUs (the TMS34010) run at different speeds!
According to MAME, Smash TV uses a 40 MHz crystal oscillator and MK a 48 MHz, but I can tell you that my boards are BOTH 48 MHz?? Check what value your oscillators are, they are the 2 silver rectangular boxes close to the TMS34010 near the corner. One is 24.000 MHz and the other 40.000 or 48.000 MHz.

That should keep you busy for a while

 

[mecha]

this is probably why the CPU came up bad in Smash TV then. it should be worth noting the CPU looks like it's socketed on my Smash TV board, soldered on the MKs.

the game still worked, albeit with even worse graphical errors. you would think the speed wouldn't make a huge difference you know. lol

I'll have to fix the RAMs I guess. but what exactly are the RAMs... that's what nobody can friggin tell me

 

[TRICKDRAGON]

Trouble

Man that sounds like a bunch of TROUBLE. I hope you got a good deal! You have made it way further down the road then I ever would have. I hope you get that thing working!! Good luck man!

 

[kane086]

this is probably why the CPU came up bad in Smash TV then. it should be worth noting the CPU looks like it's socketed on my Smash TV board, soldered on the MKs.

If you mean U99 (the L1A3787), then yes mine is the same and has been since the factory.

the game still worked, albeit with even worse graphical errors. you would think the speed wouldn't make a huge difference you know. lol

The clock speed more a timing thing that runs many chips not just the cpu (including the protection chip), no idea what the effects could be from running a different clock speed.

I'll have to fix the RAMs I guess. but what exactly are the RAMs... that's what nobody can friggin tell me

What do you want to know about the RAM? I'm getting a bit confused as to what the goal is here. Ask and ye shall receive!

 

[mecha]

If you mean U99 (the L1A3787), then yes mine is the same and has been since the factory.



The clock speed more a timing thing that runs many chips not just the cpu (including the protection chip), no idea what the effects could be from running a different clock speed.



What do you want to know about the RAM? I'm getting a bit confused as to what the goal is here. Ask and ye shall receive!

well the issue I have I imagine is caused by bad ram, yeah?

I can tell you now the PLCC chip swap didn't make any difference.. that was the kinda chip that wasn't making the best of contact on my MK2 board when it had the messed up text. not like the two monsters are related anyway, but was worth a try.

as it stands now, I'm probably better off tracking down a High Impact Football board somewhere and swapping into that.

 

[kane086]

well the issue I have I imagine is caused by bad ram, yeah?

Impossible to say without looking at the board unfortunately, otherwise it's just guessing.

 

[mecha]

interesting tidbit...

my board came with the Smash TV manual and I looked at the Y-unit parts diagram and those "resistors" (labeled B) next to the rom sockets (and the ones with the "jumper" arrangements) are actually listed as Capacitors.

food for thought.

looks like our only difference here is the CPU speeds then.

 

[DogP]

interesting tidbit...

my board came with the Smash TV manual and I looked at the Y-unit parts diagram and those "resistors" (labeled B) next to the rom sockets (and the ones with the "jumper" arrangements) are actually listed as Capacitors.

food for thought.

looks like our only difference here is the CPU speeds then.

The "B" ones are capacitors... but the ones that are different are "W", which are jumper wires (I'm getting this info from looking that the closeup pic). It shows W24-W33, etc. And if you're getting a reading of 0.1 ohms across it, it's definitely not a (good) capacitor .

DogP

 

[mecha]

they all read that. even on my MK boards I was getting readings. strange huh?

must be because they're in circuit or something. at any rate, I have a plan for this. lol

 

[DogP]

they all read that. even on my MK boards I was getting readings. strange huh?

must be because they're in circuit or something. at any rate, I have a plan for this. lol

That's normal... that's what I'm saying... the W's are just jumper wires (should be near 0 ohms). The B's are capacitors, but there's no differences between them on the boards. Those W's probably strap the board for different configurations.

DogP

 

[mecha]

latest developments...

tried moving the resistors the same way they are on the Smash TV board. one I even added resistors near the PAL #7 (the one all the way on the left) and even swapped over a 24 MHz crystal (from the Smash TV board), that board no longer even boots lol.

I moved the Smash TV roms to the board that gave me the CPU error before with the resistor mod, it still does the scrambled rolling hula.

what's the likelihood the roms got trashed? lol

 

[mecha]

ok, I put all the resistors and crystals and shit back where they came from. lol

the two MK boards both have RAM errors now. one has it at U10, the other at U28.

when I changed the jumper resistors over to the other pads, I didn't realize that the half (opposite to all the others) had the solder pads adjoined, and thinking I wasn't supposed to connect the two, I scraped a gap between them. (doh)

the one with the U28 error, I added a jumper wire between the resistor and the pad it's supposed to connect to, and the graphic glitches are less pronounced, but I still have a RAM error nonetheless.

did my booboo wind up ruining the RAM chips and it has nothing else to do with my solder work?