GTROM/Cheapocabra mapper for Everdrive N8

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Broke Studio
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GTROM/Cheapocabra mapper for Everdrive N8

Post by Broke Studio »

Hi everyone,

Inspired from NovaSquirrel's work here, I added GTROM support to the Everdrive N8.

It doesn't support self-flashing yet, I'll have to add it later.

Don't forget to update your MAPROUT.BIN file in your EDFC folder. (write 0x6F at offset 0x6F)
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111.zip
Mapper 111 RBF file
(14.12 KiB) Downloaded 888 times
My first game : Twin Dragons available at Broke Studio.
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NOOPr
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by NOOPr »

It's awesome!!

By the way, there's such a implementation of mapper 30 (UNROM 512) out there?
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Memblers
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by Memblers »

That's great, thanks for making that! One day people will be able to release a mapper #111 ROM without fear of people saying "uh, how I do run this?". I think NEScape might might be the first game to use the 8 nametables.
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by Banshaku »

@Memblers

8 nametables? I guess I'm late on the news about mappers? ^^;; How does it work and what it the usage for? I guess there must be a thread on nesdev talking about it? I must have missed it.
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by tepples »

GTROM has two 8K banks of CHR RAM for pattern tables and two 7.75K banks of RAM for nametables. Each nametable bank consists of 4K at $2000 for a four-screen layout plus 3.75K of scratch space at $3000 that can be accessed during vblank or forced blank.

One four-screen layout in nametable bank 0 plus a second in nametable bank 1 equals eight screens.
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by nesrocks »

Yes I think this had been done before, but maybe there are differences in the implementation.
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Memblers
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by Memblers »

Banshaku wrote:@Memblers

8 nametables? I guess I'm late on the news about mappers? ^^;; How does it work and what it the usage for? I guess there must be a thread on nesdev talking about it? I must have missed it.
The main thread is kinda hidden in the Membler Industries section, it's all very disorganized:
https://forums.nesdev.com/viewtopic.php?f=4&t=12716

My original thinking with bankswitched nametables, is that it combines the advantage of 4-screen (being the PPU's native screen size) with the advantage of 1-screen mode (easier to scroll vertically with the status bar being in another bank).
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by rainwarrior »

It's documented on the Wiki too:
https://wiki.nesdev.com/w/index.php/GTROM
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by Banshaku »

@Memblers

Ha, it the specification of your board, wasn't aware of all those details ^^;; I see.

@rainwarrior

I will check the wiki then. Thanks!
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by thanius »

Hi guys, just got NEScape in my mailbox and after adding the mapper to Everdrive, the screen turns yellow.
Anyone had any luck running NEScape with this mapper?
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Broke Studio
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by Broke Studio »

What ROM version did you use ?
Did you dump the game yourself ?
My first game : Twin Dragons available at Broke Studio.
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by Bananmos »

Broke Studio wrote: It doesn't support self-flashing yet, I'll have to add it later.
Feel free to re-purpose the code from my Powerpak mapper30 implementation if it makes things easier for you.

(if I understand the wiki correctly, the self-flashing sequence should be more or less the same on both)

Edit: Oops! You want the Everdrive version of course, and not the Powerpak one.

Though with the Everdrive N8, it might not be worth adding the flash ROM support - as you won't be able to get it to save the written ROM back to the memory card. That's where the easily downloadable and moddable source code of the Powerpak OS really shines.
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Re: GTROM/Cheapocabra mapper for Everdrive N8

Post by huuanhuynh »

NOOPr wrote: Mon May 13, 2019 2:54 pm It's awesome!!

By the way, there's such a implementation of mapper 30 (UNROM 512) out there?
Hi there!
Can you make and share file for mapper 157?
and some another unsupported mapper? (Everdrive show ERROR:A4 Mapper is not supported).
Thank you so much.
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