V9958 on an MTX

Modern, Memotech inspired, hardware projects
Martin A
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Joined: 09 Nov 2013 21:03

V9958 on an MTX

Post by Martin A »

Output from the V9958
Output from the V9958
after tweaking.jpg (93.99 KiB) Viewed 5682 times
MTX512 driving a V9958 video processor
MTX512 driving a V9958 video processor
Testing on the EB512.jpg (161.76 KiB) Viewed 5682 times
Minor success today, first output from the V9958 supplied by Lez, being driven by the much abused MTX500 I upgraded to 64k.

That's half the amount that's on the video board, and there are 2 sockets obscured by the daughterboard that could bump the video ram to 192k.

The visible empty socket is designed to take a sound chip, but that has yet to be tested.
lezanderson
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Re: V9958 on an MTX

Post by lezanderson »

AWESOME !!
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Dave
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Re: V9958 on an MTX

Post by Dave »

Well done !

That looks like a really good design, wherever did you find it?

:-)
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1024MAK
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Re: V9958 on an MTX

Post by 1024MAK »

I think the answer to Dave's question is: down the back of a sofa?

Well done Martin.

Now does this mean we get a colour version of textinvaders?

Mark
Martin A
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Re: V9958 on an MTX

Post by Martin A »

1024MAK wrote: Now does this mean we get a colour version of textinvaders?

Mark
Hm I guess that depends on the market, what's your estimate of the number MTX's there are out there running with a V9958 expansion? :D


I was cheating a little to get the display set up, the 9958 was set to respond to ports 1 and 2, effectively shadowing the on-board VDP (which is driving the mono screen). However it does also demonstrate the backward compatibility Yamaha built in.

It does work using it's "normal" ports, but takes a lot of OUT 152 and 153's just to print "Ready" in text mode, getting a display complex enough to "tune" in the picture would have taken quite a while.
Martin A
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Re: V9958 on an MTX

Post by Martin A »

Graphics mode 7
Graphics mode 7
G7 Test-sm.jpg (88.24 KiB) Viewed 5648 times
Graphics mode 7 tested

It's a bitmapped 256 x 192 mode in 256 colours

I'm still running composite video output.

The very basic BASIC used to set up the display can be seen on the other screen.
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1024MAK
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Re: V9958 on an MTX

Post by 1024MAK »

Nice :D

Keep them updates coming :P

Mark
Martin A
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Re: V9958 on an MTX

Post by Martin A »

Nothing new from the weekend, I got side-tracked putting together some 6309 based hardware.

I WILL get the 80 column text mode tested, I promise!
Martin A
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Re: V9958 on an MTX

Post by Martin A »

Just for Claus:

Have a look at E
Magrom gets a new option
Magrom gets a new option
menu option.jpg (136.94 KiB) Viewed 5602 times
I was experimenting with Graphic mode 7: I wanted to show something a litle more interesting that a colour chart.

As I'm using Magrom to load the image, I've had to keep within the 28k or so file size that the board limits me too.

The original image is 192 x 139 8 at 8 bits per pixel its just over 26k in size leaving enough room for the code.

It's scaled up to 192 x 208 to restore the aspect ratio.

A better "delivery system" would have allowed a full screen image, with a little more detail.

Still, it's not a bad indicator of the possibilities

It may be possible to rival the HRX?
Surprise!
Surprise!
output.jpg (84.96 KiB) Viewed 5602 times
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Dave
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Re: V9958 on an MTX

Post by Dave »

So, what would you little maniacs like to do first?

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