is a z80 a z80? working on this right now, would like some facts

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is a z80 a z80? working on this right now, would like some facts

I ordered a couple of z80's from bob roberts. 1 to put in my tapper set, 1 for my tron set.
I told him this when I ordered them.

So I am going to change one out on the center board of the tapper set and I am noticing that the current one is (z80 b) bob sent me (z80 a) does it matter?

The sound board has (z80 a) on it.
 
You can go like for like or up but not back. A z80 can be replaced with a z80b. The difference is that as the letter increases so does the speed. Putting a faster (capable) chip in place of a slow is ok. It just runs slower.

On the taper, check he manual and see wharves supposed to be there. Someone may have swapped in a b because that is what they had close by.
 
You may want to check the schematics to be sure, but I believe Tapper clocks the Z80 at 5MHz, which is too fast to reliably run a Z80A (spec'd for 4MHz). Z80B is good to 6MHz.
 
You can go like for like or up but not back. A z80 can be replaced with a z80b. The difference is that as the letter increases so does the speed. Putting a faster (capable) chip in place of a slow is ok. It just runs slower.

On the taper, check he manual and see wharves supposed to be there. Someone may have swapped in a b because that is what they had close by.

You may want to check the schematics to be sure, but I believe Tapper clocks the Z80 at 5MHz, which is too fast to reliably run a Z80A (spec'd for 4MHz). Z80B is good to 6MHz.

Not sure if I was clear.
I am changing the z80Bon the main board,, with a z80A , is this ok? likely to cause damage?

or is it simply a waste of time, because I would not want to leave the game in that state?
 
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Not sure if I was clear.
I am changing the z80Bon the main board,, with a z80A , is this ok? likely to cause damage?

or is it simply a waste of time, because I would not want to leave the game in that state?

I thought my answer was pretty clear.... :(
If you check the schematics on page 25:

http://arcarc.xmission.com/PDF_Arcade_Bally_Midway/Tapper_Parts_and_Operating_Manual_(Dec_1983).pdf

you'll see that the main board clocks the CPU at 5MHz. So you need a Z80B.
 
yeah I guess that's pretty clear, lmao.

so these chips from bob have no value to me. ok then, thanks.

If you ordered B's, then do shoot an e-mail to Bob. If something went wrong at his end, he'll make it right (on the other hand, if you mis-ordered, well, that's on you).

But it wouldn't be the first time that someone sold Bob parts where the tube was labelled wrong - he can't check every part that goes out, so if the tube was wrong, he'll end up sending the wrong part. I got a couple of incorrect transistors once that way - I checked them before installing and found the problem, and it was no sweat to get it fixed.
 
for the record, I do not believe I indicated what I wanted.

I told him the games they were for (tapper and tron) and he sent them.

no big deal, I am just going to send the boards out for repair now. I wanted to mess with them myself for a bit, but it 's more than I am capable of.

thanks guys
 
note for future use: always buy faster z80's because they are backwards compatible and most chips run cooler when they are under-clocked.
 
note for future use: always buy faster z80's because they are backwards compatible and most chips run cooler when they are under-clocked.

thanks dokert.

Hey anyway, I FIXED THAT BITCH

pulled all the boards and metal plates apart, reseated everything, got the ribbons on deep, put it back in the cab, ram error.

ok, at least I had something.

self-diagnostic, no problems.
flipped it back to game play and it's perfect.


YES, and now it's an upright tapper, cocktail is long gone
 
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