Major havoc boardset differences

DPtwiz

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So, i hear there's a dedicated MH boardset, and a conversion boardset. what's the difference?
 
From Mike's Arcade.

"To allow the X adjustment to take place on the adaptor pcb, Atari cut P19 M/N
from ground, and jumped M/N to the legs of two ICs in the vector generation
circuitry.
If these two jumpers are present on your board, you MUST REMOVE THEM
(desolder both ends, and pull the wire off the board) BEFORE CONTINUING.
If your board, does not have the jumpers, it was probably used in a
dedicated MH cabinet.

If you remove the jumpers, this board will no longer work with an official
Atari adaptor, unless you reconnect the jumpers."

http://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=conv&page=Gravitar2majorHavoc.txt
 
heh. i just got a dedicated boardset, so it will not have the jumpers. But i need it to have them so i can use it with the MH to Tempest adapter.
 
heh. i just got a dedicated boardset, so it will not have the jumpers. But i need it to have them so i can use it with the MH to Tempest adapter.

Does your board say "Tollian Web"? That would be a further indication that it is likely an original dedicated board. I thought somebody said the didicated boards all said this, but I am not certain on that.
 
heh. i just got a dedicated boardset, so it will not have the jumpers. But i need it to have them so i can use it with the MH to Tempest adapter.

I have a conversion board, but would rather have the dedicated (since it's going in to a 'dedicated' cab with Amplifone). Want to trade?
 
But what makes you think our cabinet maker extraodinaire who coincidentally is looking for a dedicated Havoc CP, isn't going the same route? ;)

Yeah, I saw that later but...

heh. i just got a dedicated boardset, so it will not have the jumpers. But i need it to have them so i can use it with the MH to Tempest adapter.

So hope springs eternal. I can de-convert mine (including changing the crystals) but it will still have the CK prefix on the serial number sticker. Oh well. First world problem.
 
Actually, i have someone well known on here willing to swap boards, i picked up the conversion board to tempest, i have a tempest to strip, and i may have a trade worked out for a dedicated CP. Even though i do not have an Amp, i did find an NOS 6100 tube, so i'd think the value would be comparable with an Amp.
 
Actually, i have someone well known on here willing to swap boards, i picked up the conversion board to tempest, i have a tempest to strip, and i may have a trade worked out for a dedicated CP. Even though i do not have an Amp, i did find an NOS 6100 tube, so i'd think the value would be comparable with an Amp.

Well Maybe, with the exception of a NOS Amp. :D
 
FYI, I just changed the crystals on my conversion board from the slower (conversion) frequencies to the higher (dedicated) ones. Y1 went from 10MHz to 12MHz, and Y2 went from 8.98675MHz to 10MHz. Also had to change the AVG chip as it had died while in storage. The board plays fine.

I haven't undone the X signal bypass since I'm still using the converter board (it's in a Space Duel cab). So the mods are confirmed to be completely independent (as expected).

Will get some video of the board running on both the Amplifone and WG6100 to see if there's a noticeable difference.
 
FYI, I just changed the crystals on my conversion board from the slower (conversion) frequencies to the higher (dedicated) ones. Y1 went from 10MHz to 12MHz, and Y2 went from 8.98675MHz to 10MHz. Also had to change the AVG chip as it had died while in storage. The board plays fine.

I haven't undone the X signal bypass since I'm still using the converter board (it's in a Space Duel cab). So the mods are confirmed to be completely independent (as expected).

Will get some video of the board running on both the Amplifone and WG6100 to see if there's a noticeable difference.

The Amp will be a much cleaner picture with sharper and thinner lines, my dedicated machine had a 6100, after the swap to an Amp the difference was night and day.
 
Conversion and dedicated are different crystals. I thought it was to compensate for the spinner vs roller trackball, but maybe it's just to make the game harder.

I just swapped crystals on 2 pcbs. I have 3 pcbs to test all are conversion pcbs and I have 2 tempest to mh adapter pcbs to test.
 
thread revive! Here's an update.. i am no longer going to use the tempest harness and adapter.. i'm going to use this instead:

http://www.biltronix.com/Space_Duel_to_Major_Havoc_Conversion_Board.html

this has the pincushion corrector, but i now have an amp monitor, so i wonder how that will affect it.

I assume i still have to swap crystals, but what about the jumpers? I really suck at anything electronic, i'd have to forget everything i know about woodworking to have room in my brain to learn the electronic side of things.
 
FYI, I just changed the crystals on my conversion board from the slower (conversion) frequencies to the higher (dedicated) ones. Y1 went from 10MHz to 12MHz, and Y2 went from 8.98675MHz to 10MHz. Also had to change the AVG chip as it had died while in storage. The board plays fine.

I haven't undone the X signal bypass since I'm still using the converter board (it's in a Space Duel cab). So the mods are confirmed to be completely independent (as expected).

Will get some video of the board running on both the Amplifone and WG6100 to see if there's a noticeable difference.

Man this is EXACTLY what I want to do when my MH/Tempest gets here. Maybe I can bug you for some help since you live so close... I can bribe with beer!
 
thread revive! Here's an update.. i am no longer going to use the tempest harness and adapter.. i'm going to use this instead:

http://www.biltronix.com/Space_Duel_to_Major_Havoc_Conversion_Board.html

this has the pincushion corrector, but i now have an amp monitor, so i wonder how that will affect it.

I assume i still have to swap crystals, but what about the jumpers? I really suck at anything electronic, i'd have to forget everything i know about woodworking to have room in my brain to learn the electronic side of things.

You will still need the jumpers with that board as its the same as the old atari one. Unless the display corrector can be turned down to 0 correction, its probably going to bend image reverse hourglass with an amp tube in the cab.

If you have an amp tube and you use a tempest harness, pretty sure you don't need any board. Just flip the lower connector, and plug it in. You probably have to undo the jumpers. If you cant do that, I would be shocked. Your talking cutting 2 wires. Under the wires you will see where they cut the traces on the board. 1 solder blob or maybe a cap leg to bridge the cut and it should be done.
 
my board is a dedicated board, not the conversion board meant for a tempest.. i do have the option to trade a klover for his conversion style MH board...
 
to clarify:

Conventional wisdom is that the slower crystals were used on conversion boards to slow down the drawing when hooked up to WG6100s. The Amplifone (in addition to the finer dot pitch/resolution) has a higher slew rate and can keep up with all the vectors being drawn especially in the maze sequence. Never thought about it but watching on a scope... it's busy! The rate of the roller controller vs. Tempest spinner is controlled by a resistor elsewhere on the board (or not).

I changed my crystals because my Space Duel cab does have an Amplifone. Until I change the harness to match the MH PCB pinout, I need to use the adapter board, which means I need to leave the jumpers in place. Eventually I will remove the adapter board in favor of wiring my own adapter harness to connect between the native pins on the edge connector into the correct wires of the Space Duel harness. That will return the correction and adjustments to the on-board circuitry (as appropriate for the Amplifone) instead of the WG version on the adapter board.

Note that the jumpers do not need to be removed to do this: the last two pins on the parts side of the smaller edge connector were ground pins on a dedicated board, but are cut to free them up for use as XY pre-outs on a conversion board. The factory signals still survive and go to the original pins.

However, this does not mean a conversion board can be exchanged with a dedicated board... if the dedicated harness is expecting a dedicated board and has the last two pins grounded, it will short out the signals being put out by the conversion PCB board. And the conversion PCB board is needed in a cab using the adapter board because otherwise it would have no video.
 
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