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witchspace

Member Since 10 Jan 2017
OFFLINE Last Active Feb 4 2017 4:40 AM

Posts I've Made

In Topic: Game Disk Images as a Datasource

Tue Jan 31, 2017 12:12 AM

Have you heard of/looked into the Sundog Resurrection Project?

 

http://www.sundogres...ionproject.com/

Yes :) I think it's great that they're working on that. After all, the game was supposed to be a trilogy. 33 years late is better than not.

 

But indeed, my project's goal is different, it is about nostalgia and history and making the original game more accessible. I very likely won't be adding any new missions :)


In Topic: Red Screen On Sundog emulation in Steem

Sun Jan 29, 2017 3:50 AM

Just found the code responsible. It is exactly as you say. Track 3, sector 7 is read then the data is discarded, that read is just to (mis)direct the drive. Then Track 3, sector 4,5,6 are read. Sector 4 is check-summed and compared, and if it fails a state word is set which eventually leads to the Red screen of Death.

 

This is in addition to the per-track integrity check I posted about above. FTL was certainly paranoid :)

 

In my port I just pull down the state word involved in these checks. Too lazy to implement a more accurate implementation of the floppy controller just to make this weird code happy.


In Topic: MAME going to start using the GPU.

Sat Jan 28, 2017 1:12 AM

Seems MAME is caving in and going against what they once said they'd never do. And that is to use the GPU.

 

My opinion, they have to. Given that processor development and increases in speed is all but at a standstill these last couple of years.

 

 

The way you word it, it sounds almost like they had a deep philosophical issue with using GPUs? (for anything but rendering/scaling the final image?)

 

I guess because in the early days of GPU computing it all was proprietary and unstable and limited to a few vendors. Today, OpenCL and OpenGL compute shaders are mature open standards and supported by any GPU vendor worth it's salt, even embedded ones. Integer arithmetic is now available, which relieves the precision concerns with floating point handling on some GPUs.

 

Depending on the algorithm it is usually more work to write certain code for GPU, though, that still limits their use in open source projects. Having to implement things twice, once for CPU and once for parallelized GPU doesn't really help either.


In Topic: TI-99/8 emulation

Sat Jan 28, 2017 12:44 AM

 

Keep in mind: We are talking here an unreleased computer (TI-99/8) depending on using unreleased hardware (Armadillo Bus interface for the 99/8 to the PEB or the Hex-Bus Disk Drive Controller) running unreleased software (P-System for the 99/8). You can hardly except Out-of-the-Box Functionality like for End-User Products,

I fully realize that. My interest is historical. I don't intend to use it for safety critical production use.

That's what I use DosBox for icon_angry.gif

Simulating a computer that never really existed, from just prototypes, is fantastic. Keep up the great work!


In Topic: Best 68K disassembler for Windows

Sat Jan 28, 2017 12:38 AM

The open source reverse engineering framework Radare ( https://radare.org/r/). It is interactive and you can define labels and other metadata. It can also handle huge files. I personally like it lot, though I'm not sure about the state of its windows support because I use Ubuntu. There are however windows binaries available.

 

Alternatively, the non-free version of IDA Pro can handle 68000 just fine.