RE: New Vector monitor project progress

Does anyone make 'standard' 19"-32" tubes with anything other than P22 for
color phosphor?

It might be pretty interesting to be able to pop in a long-persistance tube
into a vector monitor... (Star Wars/ESB flickers like a bastard, I'd be
curious to see what the display looks like with a longer persistance. Could
be pretty cool.)

James probably has the answer he needs, but in the case of Tempest and Star
Wars the refresh rate is variable. I think Star Wars runs around 40Hz most
of the time, with some segments hopping up above 60 and some below 30...

Asteroids runs at 60Hz. The VGGO signal always triggers at the sime time.
Maybe it's tripped from an ISR or something.

All the Space Duel/BlackWidow/Gravitar etc. are variable refresh also-- I
don't know the game code well enough say if it's constant during game play
or not (I suspect it is).

Vector Breakout runs around 40Hz during gameplay.

One thing worth mentioning is that games like Star Wars really over-draw the
boundary of the screen. Probably be wise to allow for 50% overshoot in
deflection when designing the drive section if you want to have the game
"flashing" supported.

Seems like as good of place as any to mention this (not that it's terribly
related, but I want to write it down so I don't forget) --

One of these days I'm going to an experiment with the vector generator for a
special-effect in a game. Basically make a chain of objects that sort-of
overlap but are slightly offset. (Kind-of the "comet trail" cursors you see
now.) Then, in the VRAM, structure the objects so that the "last" object in
the chain is the first in VRAM. The first VRAM instruction is a jump. So,
let's say there are 16 objects, on each "pass" I increment the jump to skip
over one more of the preceeding objects in the following pattern:

draw objects #
15, 14, 13, 12... 1,0
14, 13, 12, 11... 1,0
13, 12, 11, 10... 1,0
...
2,1,0
1,0
0

So, for whatever the refresh speed, object 15 gets drawn at 1/16 duty-cycle,
object 14 gets drawn at 2/16, on up to object 0 which gets drawn on every
frame. This should have a couple nice effects-- the "last" objects will
have a dim, flickery appearance; and the objects above the "flicker"
threshold will have the appearance of multiple color intensities (even on
hardware with limited brightness controls like Tempest). If the objects also
change colors on alternate frames a color "mix" would occur that would give
more colors than are normally possible...

Probably too time consuming for in-game use, but might be neat on a
title-screen or something...

-Clay

> ----------
> From: James Nelson[SMTP:nelsonjjjj@didactics.com]
> Reply To: vectorlist@lists.cc.utexas.edu
> Sent: Tuesday, October 19, 1999 5:07 AM
> To: vectorlist@lists.cc.utexas.edu
> Subject: Re: New Vector monitor project progress
>
> Excellent! After looking around, It looks like P22 is used in about all
> Wells Gardner monitors today (and on the Wells Gardner vector monitors),
> so
> there should be no problem using any standard tube on Tempest.
> Thanks,
> James
>
>
> ----- Original Message -----
> From: Rodger Boots <rlboots@cedar-rapids.net>
> To: <vectorlist@lists.cc.utexas.edu>
> Sent: Tuesday, October 19, 1999 6:47 AM
> Subject: Re: New Vector monitor project progress
>
>
> > 46a01bf196a$e38f2460$0c01010a@daytrader2>
> > Content-Type: text/plain; charset=us-ascii
> > Content-Transfer-Encoding: 7bit
> >
> > That "P22" you see at the end of the CRT part number is the
> > phosphor used in the tube. P22 is the standard home TV
> > phosphor. It is a "medium" decay rate type that works pretty good
> > at 60 Hz refresh (or higher), but flickers pretty bad on anything
> > slower.
> >
> >
> > James Nelson wrote:
> >
> > > I'm a little concerned about the refresh rate:
> > > If I use a non-vector CRT, the phosphors may not glow long enough to
> make
> > > the picture tolerable to look at. Does anyone know the refresh rate
> of
> > > Tempest or Star Wars (and don't tell me there is no such thing because
> there
> > > is.) It may vary from screen to screen. If nobody knows, I'll break
> out
> > > the scope and find out myself.
> > >
> > > My guess is that it's somewhere around 30 - 60 Hz, but I need to know.
> > >
> > > -James
> > >
> > > ----- Original Message -----
> > > From: Zonn <zonn@zonn.com>
> > > To: <vectorlist@lists.cc.utexas.edu>
> > > Sent: Thursday, October 14, 1999 6:32 PM
> > > Subject: Re: New Vector monitor project progress
> > >
> > > > On Thu, 14 Oct 1999 18:16:13 -0400, you wrote:
> > > >
> > > > >It's looking like a good choice is a new 19" WG monitor K7000
> series
> I
> > > think.
> > > > >The specs say standard horizontal resolution of 640 I think that's
> good
> > > enough.
> > > > >Do we need to mess with "medium resolution" monitors? I'm not
> familiar
> > > with them.
> > > >
> > > > Yes!! Medium resolution rules! And if you want the proper
> > > > replacement for your Star Wars, it'll have to be medium res.
> > > >
> > > > The only difference (as far as X/Y goes, since scan rate will be
> > > > meaningless at this point) is the pixel size of the CRT, whatever
> you
> > > > come up with for the low res, should work the same on med res.
> > > > monitors. You might want to start with low res for *experiments*
> > > > since I'm sure these are cheaper..
> > > >
> > > > -Zonn
> > > >
> > > >
> >
> >
>
Received on Wed Oct 20 12:22:32 1999