Ports of Open Source Games and Programs I'd Like to See on Dreamcast

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leilei
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#31 » Tue Aug 20, 2019 6:39 pm

I don't believe looking in the earliest version is the best way to go nor be representative of the software, especially as the games evolve and develop. Old versions popping up again would fragment players, and likely embarrass and frustrate the developers. It's why FreeCNC is no alternative to OpenRA.

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Ian Micheal
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#32 » Tue Aug 20, 2019 8:12 pm

It might be the only way it can be ported to dreamcast. it's from 1999 if it's opensrc and older version could be best to start with and upport features it's the way i port games to dreamcast. It's far harder to downport from a a more complete powerfull version targeted at huge memory and speed.

I dont think developer that made an opensrc game minds someone trying to make a console version if they did i ask.. This is for dreamcast not worried about it lacking the features a new version has on pc..

I ported Ultmia 4 to dreamcast version 0.5 the author was very happy about seeing it on dreamcast. .. I started with the lowest version and moved up..

Were talking freeware games for dreamcast more the better.

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leilei
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#33 » Tue Aug 20, 2019 9:03 pm

No. The best way is to communicate with developers and inquire about the practicality and possibility of a DC port with their game. Allow them to explain where the problems lie, and if they would be comfortable with a DC port or if they want to do it themselves. Think from their perspective, and also respect their rights.

I know the DC's from 1999, but know that even some 1997-98 PCs can run some of these newer 201X open source games, and that's usually allowed with the luxury of a swapfile for memory usage and a hard drive to save data, and even some weaker GPUs with good driver support. The 16MB of system RAM and disc loading are the biggest achilles' heel for DC ports.

EDIT: Noticed the post was edited with more than just the first sentence.

Open source games are NOT "freeware games". They are not public domain either, and neither are freeware games.

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Ian Micheal
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#34 » Tue Aug 20, 2019 9:24 pm

I have asked and have allways been told go a head :) Kos and gcc does not support advanced C++ functions thats what the limting factor is.

im talking about opensrc GPL games

If you wish to use kos in mmu mode and write the mods to malloc 16 meg is no longer a problem.. Only one person i know of that used mmu mode and made it work that was chui and aes4all..


Code: Select all

]The SH4 CPU has a 29-bit physical memory space, so the range of addresses are 0x00000000 - 0x1FFFFFFF; thus it is capable of addressing 512 Mb of physical memory. This 512 Mb is split up into eight 64 Mb areas. Table 1 shows how the SH4 sees the physical memory.

Table 1: SH4 memory areas
Start End Area
0x00000000 0x03FFFFFF 0
0x04000000 0x07FFFFFF 1
0x08000000 0x0BFFFFFF 2
0x0C000000 0x0FFFFFFF 3
0x10000000 0x13FFFFFF 4
0x14000000 0x17FFFFFF 5
0x18000000 0x1BFFFFFF 6
0x1C000000 0x1FFFFFFF 7 (Reserved)
The Dreamcast splits this memory up thus:

Table 2: Dreamcast memory map
Start End Description Area
0x00000000
0x00200000
0x00240000 0x001FFFFF
0x0023FFFF
0x03FFFFFF Boot ROM (2 Mb)
Flash ROM (256 Kb)
System devices/Hardware registers 0
0x04000000
0x04800000 0x047FFFFF
0x07FFFFFF Video/Texture memory (8 Mb)
Unused 1
0x08000000 0x0BFFFFFF Unused 2
0x0C000000



0x0D000000 0x0CFFFFFF



0x0FFFFFFF System memory (16 Mb)
Repeated at:
0x8C000000 - 0x8CFFFFFF (MMU is enabled)
0xAC000000 - 0xAFFFFFFF (Cache is enabled)
Unused 3
0x10000000
0x10800000
0x12000000 0x107FFFFF
0x11FFFFFF
0x13FFFFFF Tile Accelerator (write only)
Texture memory (write only) I'm not sure about this one
Unused 4
0x14000000 0x17FFFFFF G2 devices 5
0x18000000 0x1BFFFFFF Unused 6
0x1C000000 0x1FFFFFFF SH4 control registers 7 (Reserved)
When looking at source code from other projects you may see registers starting at address 0xA05F8000, this may cause some confusion. As the SH4 has a 29-bit address space, the top 3 bits have specific meanings.

So, if we clear the top 3 bits we get, 0x005F8000 and as we can see from tables 1 & 2, this address is in area 0.

On the Dreamcast the MMU is not activated by default, this means that all programs executed are done so in priviledged mode rather than user mode. The only exception here would be games written using WinCE, as this is a real (yeah, right!) operating system.

When running in priviledged mode, the application has access to all of the memory areas. If an application is running in user mode, then it is limatited in what it can access.

If an applicion is running in user mode, then the MMU must be enabled. So, if the MMU is enabled, then some sort of memory mapping must be provided.

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Anthony817
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#35 » Tue Aug 20, 2019 9:45 pm

leilei wrote:Open source games are NOT "freeware games". They are not public domain either, and neither are freeware games.


That doesn't mean you can't do a source port and require somebody create their own disc from their legit PC version of the game.
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deluxux
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#36 » Tue Aug 20, 2019 10:29 pm

this is what you get for posting on reddit @Anthony817 :roll: another open source warrior

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Anthony817
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#37 » Tue Aug 20, 2019 10:31 pm

You should check his post in the Dreamcast Ultimate Archive lol. Pretty snarky.
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Nz17
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#38 » Tue Sep 10, 2019 1:16 pm

I'm an open source software developer. At times I defend commercial and non-commercial software alike against license infractions, but at the same time I also realize the futility of trying to convince someone to stop his ways if he won't change his mind. After all, I can tell him that his acts are breaking the terms of the license, but nonetheless many infractions are not resolved with respect to the terms of the chosen license (GPL, MPL, BSD, MIT, all rights reserved, etc.), yet no legal action is usually taken due to the expense of such a lawsuit and the unlikely result of it being worth the time, money, or effort.

All that said, most open source developers know the risks when they choose to use an open source license.

Furthermore, I want to take this opportunity to thank all of the people that port software to the Dreamcast or Linux. "Our console" and computers and our experiences are all the richer for it. Thank you!

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Nz17
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#39 » Mon Sep 30, 2019 4:14 am

How about these two?
1) JFBuild / KenBuild (3D first-person shooter engine / game)

Operating System:
Linux with kernel 2.2 or newer

Processor:
Pentium-class x86 or better (minimum Pentium 233MMX recommended)
PowerPC G3 or better
UltraSPARC IIi (may work on other models of SPARC, but have not been tested)

Graphics
OpenGL-capable card highly recommended
(Software rendering is also available.)

Compiler and libraries:
GCC 2.95.3 or better
SDL 1.2

Web site:
http://www.jonof.id.au/jfbuild.tech

2) Ken's Labyrinth LAB3D/SDL
OpenGL, SDL 1.2, C language (C++?)

Web site:
https://icculus.org/LAB3D/

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Ian Micheal
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Re: Ports of Open Source Games and Programs I'd Like to See on Dreamcast

Post#40 » Mon Sep 30, 2019 4:35 am

I dont see why both could not be ported Looked them over :) now who's going to do them

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