Sort of based on Magrom

Everything about Martin Allcorn's Games ROM
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Martin A
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Sort of based on Magrom

Post by Martin A » 27 Feb 2014 21:18

Well Dave's still wanting MORE happening on the forum, so....

Having got Magrom more or less "done", here's another idea for an external rom board with even less chips.

This one just mimics the Memotech internal Rom2 board. Initial results are encouraging.

The demo version has a single 128k flash chip on-board, seen here running Newword.

It will run the Pascal roms as well, but unfortunately putting both in the same image doesn't seem to work.

Any idea's for improvements ?
Attachments
Pascal rom board v0.1.pdf
The point to point wiring picture.
(136.9 KiB) Downloaded 134 times
Newword2.jpg
Running Newword
Newword2.jpg (54.58 KiB) Viewed 2686 times
5 Chip Board.jpg
Top view
5 Chip Board.jpg (39.01 KiB) Viewed 2686 times

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AndyKey
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Re: Sort of based on Magrom

Post by AndyKey » 02 Mar 2014 20:27

I wonder if the MAGROM software could be tweaked to run in a regular 16 subpage x 8KB ROM 2 card.

If so, would run in MEMU and REMEMOrizer without modification.

I'm thinking a ROM 2 card with 16 subpages probably could be a 128KB ROM, GAL and latch.
{{{ Andy

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AndyKey
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Re: Sort of based on Magrom

Post by AndyKey » 02 Mar 2014 20:36

By the way, I wrote REZROM2.COM today.
Its the software for loading the "ROM" content, and configuring it.
The hardware supports non-subpaged (single fixed 8KB) ROM 2, or 16 subpages (in a manner that is compatible with the original 16 subpage ROM 2 card.


Note, most ROMs weren't subpaged.
The vast majority of ROM 2 cards had 4 subpages only.
It was only really the ROM cards used in videowall MTXs that had 4x32KB chips and thus 16 subpages.
There was one yellow-wired version of this board with 4x32KB RAMs, primarily for testing videowall ROM images before burning real EPROMs.
{{{ Andy

Martin A
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Re: Sort of based on Magrom

Post by Martin A » 02 Mar 2014 21:25

AndyKey wrote:I wonder if the MAGROM software could be tweaked to run in a regular 16 subpage x 8KB ROM 2 card.

If so, would run in MEMU and REMEMOrizer without modification.

I'm thinking a ROM 2 card with 16 subpages probably could be a 128KB ROM, GAL and latch.
It probably could. Most of the 8k rom space is taken up with the backdrop image The actual code is pretty small. Less than 1/2 a K If the loader code and the "directory" were written to be moved into high ram. and run from there, it ought to be possible.

Use the rom to start up, generate the image, and move the keyboard/loader/directory to ram before running it.

That would allow 120k game space so anywhere between 2 and 15 games, and since its not then restricted to using the half page ram. The whole 64k is available on a 512. Highway encounter anyone ?

Martin A
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Re: Sort of based on Magrom

Post by Martin A » 02 Mar 2014 23:13

Yes it's doable.

Here's MAG2ROM the quick and dirty hack I've put together.

There are 15 short games in the image, and a loading screen I had pre-written for a 128k MAGROM.

It uses 300 odd bytes of high ram (at 0F900h if anyone's interested) and so could cause issues on larger games.

Only lightly tested, but Nemo, Blobbo and Toado seemed to be OK.
Attachments
mag2rom022.zip
128k ROM2 image with 16 subpages
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thewiz
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Re: Sort of based on Magrom

Post by thewiz » 03 Mar 2014 14:27

Always impressed with these hardware add ons and mods you guys do. Its all greek to me so I'll stick to software and look on with envy.
THIS is what Memotech is doing now.

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Crazyboss
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Re: Sort of based on Magrom

Post by Crazyboss » 10 Apr 2014 12:46

Martin A wrote:Yes it's doable.

Here's MAG2ROM the quick and dirty hack I've put together.

There are 15 short games in the image, and a loading screen I had pre-written for a 128k MAGROM.

It uses 300 odd bytes of high ram (at 0F900h if anyone's interested) and so could cause issues on larger games.

Only lightly tested, but Nemo, Blobbo and Toado seemed to be OK.
Most Memotech MTX games I have been looking at uses variables inside the code. So F900 is a pretty sure location. There are a few games using out of its own. Superminefield does that but never go to F900 :)
//CLAUS - Webmaster at www.mtxworld.dk

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