Make a VT game work on nes

Discuss technical or other issues relating to programming the Nintendo Entertainment System, Famicom, or compatible systems.

Moderator: Moderators

User avatar
Ben Boldt
Posts: 756
Joined: Tue Mar 22, 2016 8:27 pm
Location: Minnesota, USA

Re: Make a VT game work on nes

Post by Ben Boldt » Tue Jan 19, 2021 9:52 am

It probably isn't so simple of an answer to change a few bits and expect VTx game to run on NES. The honest answer is, NEITHER of us know how to do it. You have to think about it from our perspective too, not just from your own. To us, you are asking us to do a lot of work for you, to figure out how to convert or rewrite a VTx game into a normal NES game. And the reason you are asking us to do this is because you don't want to have to figure it out yourself, or you gave up or got lazy. We can see your intentions clearly and it doesn't motivate us to volunteer to help you. Rest assured, if we gave you some starting point code, instead of using that to learn and make your own contribution, you would come directly back with a list of additional changes that you want added. And we don't want to sign up for that kind of support. We do that kind of thing at work and make big bucks for it. That obligation is not for free for you to have. I am not trying to be mean to you, this is the way the real world works and it is fair when you understand to see things from other people's perspective. Always ask yourself, what if someone did this to me. There's 2 test for most correct decisions in life:

What if someone did this to me?
What if this is on the front page of the newspaper?

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Tue Jan 19, 2021 10:02 am

Ben Boldt wrote:
Tue Jan 19, 2021 9:52 am
It probably isn't so simple of an answer to change a few bits and expect VTx game to run on NES. The honest answer is, NEITHER of us know how to do it. You have to think about it from our perspective too, not just from your own. To us, you are asking us to do a lot of work for you, to figure out how to convert or rewrite a VTx game into a normal NES game. And the reason you are asking us to do this is because you don't want to have to figure it out yourself, or you gave up or got lazy. We can see your intentions clearly and it doesn't motivate us to volunteer to help you. Rest assured, if we gave you some starting point code, instead of using that to learn and make your own contribution, you would come directly back with a list of additional changes that you want added. And we don't want to sign up for that kind of support. We do that kind of thing at work and make big bucks for it. That obligation is not for free for you to have. I am not trying to be mean to you, this is the way the real world works and it is fair when you understand to see things from other people's perspective. Always ask yourself, what if someone did this to me. There's 2 test for most correct decisions in life:

What if someone did this to me?
What if this is on the front page of the newspaper?
i know someone, who does know this: Newrisingsun
I don't have enough knowledge and because someone else has better knowledge, i have my rights for asking.

User avatar
Ben Boldt
Posts: 756
Joined: Tue Mar 22, 2016 8:27 pm
Location: Minnesota, USA

Re: Make a VT game work on nes

Post by Ben Boldt » Tue Jan 19, 2021 10:12 am

I am just trying to help you in the most useful way kelvin donna. I am not being mean or incorrect, it is only to help you. You reach out to us for help, and I provide the help you actually need. You should think about what I said carefully and not dismiss it. This is all that you get for now. I won't beat a dead horse.

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Tue Jan 19, 2021 10:23 am

Ben Boldt wrote:
Tue Jan 19, 2021 10:12 am
I am just trying to help you in the most useful way kelvin donna. I am not being mean or incorrect, it is only to help you. You reach out to us for help, and I provide the help you actually need. You should think about what I said carefully and not dismiss it. This is all that you get for now. I won't beat a dead horse.
This isn't helping me out but thank you for your understanding

User avatar
aquasnake
Posts: 208
Joined: Fri Sep 13, 2019 11:22 pm

Re: Make a VT game work on nes

Post by aquasnake » Fri Jan 22, 2021 3:52 am

The one bus enhanced Famiclone of VR tech, is not fully compatible with NES. It has additional hardware (such as enhanced color palette, enhanced audio, built-in mmc3 mapper), and fixed 2KB ciram, which is always selected.

This kind of hardware is no longer defined as a mapper of nes2.0. But if we ignore the special hardware and force to define it, it has also been assigned to maper256

Mapper256 at this time does not represent vt2 / VT3 / vt168, but only refers to some ROMs or carts released by waixing net platform that can be executed on a real NES/FC

Code: Select all

						15'h2016: r1[2:0] = 0;
						15'h2017: r1[2:0] = 1;
						15'h2012: r1[2:0] = 2;
						15'h2013: r1[2:0] = 3;
						15'h2014: r1[2:0] = 4;
						15'h2015: r1[2:0] = 5;
						15'h4107: r1[2:0] = 6;
						15'h4108: r1[2:0] = 7;
						//15'h4109: prg_bank_c = cpu_data_in;
`ifdef MAPPER_256_WXN
						if (scrambled_reg)
							case (r1[2:0])
								3'b000: chr_bank_h = cpu_data_in;
								3'b001: chr_bank_g = cpu_data_in;
								3'b010: chr_bank_f = cpu_data_in;
								3'b011: chr_bank_e = cpu_data_in;
								3'b100: chr_bank_c = cpu_data_in;
								3'b101: chr_bank_a = cpu_data_in;
								3'b110: prg_bank_a = cpu_data_in;
								3'b111: prg_bank_b = cpu_data_in;
							endcase
						else
`endif
							case (r1[2:0])
								3'b000: chr_bank_a = cpu_data_in;
								3'b001: chr_bank_c = cpu_data_in;
								3'b010: chr_bank_e = cpu_data_in;
								3'b011: chr_bank_f = cpu_data_in;
								3'b100: chr_bank_g = cpu_data_in;
								3'b101: chr_bank_h = cpu_data_in;
								3'b110: prg_bank_a = cpu_data_in;
								3'b111: prg_bank_b = cpu_data_in;
							endcase

The above variants based on mmc3 can be supported.
Last edited by aquasnake on Fri Jan 22, 2021 4:11 am, edited 1 time in total.

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Fri Jan 22, 2021 4:10 am

aquasnake wrote:
Fri Jan 22, 2021 3:52 am
The one bus enhanced Famiclone of VR tech, is not fully compatible with NES. It has additional hardware (such as enhanced color palette, enhanced audio, built-in mmc3 mapper), and fixed 2KB ciram, which is always selected.

This kind of hardware is no longer defined as a mapper of nes2.0. But if we ignore the special hardware and force to define it, it has also been assigned to maper256

Mapper256 at this time does not represent vt2 / VT3 / vt168, but only refers to some ROMs or carts released by waixing net platform that can be executed on a real NES/FC
thank you for the explanation.
Because of the external Pallete and PCM, i configured a plenty of games to VT02:
https://mega.nz/file/Fpd0XTRC#ZH2gsXIQx ... 4peobpa-Uw
those have weakenend graphics and the PCM is cut off entirely.
so it would be enough to configure those games to work on FCEUX, since i configured the games VT02

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Sat Jan 23, 2021 3:12 am

well, to get everything straight.
my mission for you is EITHER to inject the 256 NES 2.0 Mapper together with the Submappers (in the Attachments) to FCEUX, Pocketnes or HVCA ,

or...

configure the games' functions to work on lower mappers, especially since FCEUX only has a lower Mapper.


don't blame me for doing nothing. i Hacked the games to be VT02 Conform (link somewhere above). so it would be teamwork.
Attachments
mapper256.cpp
(4.37 KiB) Downloaded 45 times

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Wed Jan 27, 2021 12:01 pm

NewRisingSun wrote:
Wed Dec 23, 2020 7:15 am

http://www.ipyear.cn/copyright/detail_2007SR01138.html

Registration number: 2007SR01138
Name: 《WAVE TIGER--深海之虎》游戏软件 [Deep Sea Tiger - Game Software]
Copyright owner: 福州外星电脑科技有限公司 [Fuzhou Waixing Computer Technology Co. Ltd.]
Registration date: 2007-01-18
Publication date: 2006-09-25
too bad we have no idea, on what console that game version exists.

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Thu Jan 28, 2021 5:58 am

or how about hacking the submapper, to be an battery for the nes rom?

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Sat Jan 30, 2021 7:05 am

alright, now onto some info material:
i read a bit through this wiki entry about mapper 256:
https://wiki.nesdev.com/w/index.php/NES_2.0_Mapper_256
looking up the charts from "Bank register address and CPU opcode scrambling", i found out, that it is possible to change hex values of the mapper code, so it can work differently.

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Sat Feb 06, 2021 9:40 am

and btw, cube tech's hack of international cricket by mitashi is truly VT02 with mapper 4, despite being vt369 with mapper 256
Attachments
Cricket World Cup 2003.nes
(512.02 KiB) Downloaded 23 times

kelvin donna
Posts: 60
Joined: Sat Feb 01, 2020 5:49 am

Re: Make a VT game work on nes

Post by kelvin donna » Mon Feb 15, 2021 9:24 am

UPDATE: Here is a version of the backgammon game once again.
but this time, i cut out the pcm audio for real.
now, in order to make the game work as standard famicom, some bytes of this game need to be changed.
help me out please.
Attachments
Backgammon.nes
(256.02 KiB) Downloaded 21 times

Post Reply