Re: Major Havoc -> Tempest Adapter Schematic

From: Clay Cowgill <clay_at_supra.com>
Date: Tue Sep 02 1997 - 15:04:29 EDT

>Could someone scan in the schematic for the adapter board
>to put a Major Havoc into a Tempest? I've noticed there are
>subtle tweeks to the multiplier values for the different
>game implementations, and was wondering if this circuit was
>identical to that on a Tempest.

I've got a few variations on this if Jess doesn't get around to it.

It's very close to Tempest. I think it's almost identical-- it's been a
while since I tinkered with it. I actually have it breadboarded up and
running, but with other projects always getting in the queue...

>Also, does anyone have any opinions why the Quantum PCB
>HAS the XY correction circuit, when it shipped with an
>Ampliphone monitor?

Beats me. Did Atari actually populate it? (Haven't seen a real Quantum board.)

On another note... Have any of you tried removing the VDR's from the
output section of the AVG and seen the effect it has on the display? I did
this on a Space Duel and couldn't notice the difference-- however, I was
only running it on a scope, which masks a LOT of little details compared to
the big monitors.

Does the VDR prevent some blooming as the deflection gets larger? (I'm
trying to remember Al's IE curve from last week.) Anyone know where to get
VDR's like those that Atari used? My quick search through Newark came up
empty. Maybe EE Master has a source...

Related topic-- anyone have the tube characteristics for the CRT used in
the WG vector monitor (I think it's the same as the GO-7?). Stuff like
heater voltage, gun voltages, screen and grid, etc.? I wonder if it might
be possible to swap tubes with a modern 19-27" tube and keep the deflection
yoke, but get the benefit the no curvature... Worst case I suppose it
would require a new (or modified?) neck board and HV unit. Probably want
to stay away from Sony tubes since the aperature grille would mess with
vertical vectors, but some standard shadow mask type thing like a flat
Panasonic or Toshiba would be neat. (Nice dark phosphor coat too...)

-Clay

Clayton N. Cowgill Engineering Manager
_______________________________________________________________________
/\ Diamond Multimedia Systems, Inc. clay@supra.com
\/ Communications Division http://www.supra.com/
Received on Tue Sep 2 11:03:48 1997

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