TI-83 Plus EmulatorStatic-Compilation and ROM Files

[blacksun07]

This is my first post, though I am a very experienced programmer for many platforms and in many languages (that includes assembly language). I'm starting work on an emulation project, and I realize that for a TI emulator to work it must read from a ROM file. For most users, obtaining the ROM file will be an ordeal, and will likely deter them from using the emulator.

Most emulators either interpret or dynamically compile the ROM file. But, if I were to statically compile a TI 83 Plus ROM of my own (legally dumped from my own calculator) into non-Z80 code, and then bundle the compiled file into the release of my emulator, would that be legal? I'm really looking for a way to release an emulator that will not require the user to mess around with ROM files.

[brandonw]

I doubt that it's any less legal that way. However, even though it's kind of a roundabout method, you could come up with something to extract the 83+ ROM from the TI83Plus.clc file from the TI-83 Plus Flash Debugger, freely downloadable from education.ti.com. So all they'd have to do is download and install that application, run yours which would extract the ROM, and everyone would be happy.

This of course means you'd be downloading an emulator to run a different one. I think we already have enough emulators in the TI community, but that's just me.

[blacksun07]

If the ROM in the Flash Debugger is legal, can I just bundle that with my emulator? If I do what brandonw says and extract the ROM from the debugger, would I be free to legally distribute that ROM as part of my emulator?

Part of what I'm trying to do is make an emulator that somebody who isn't a TI expert could actually find useful, which is why its important not to make users have to dump their own ROM files. I'm trying to make an emulator that's polished, convenient, and easy to control with keyboard strokes, so that people can use it for more than just testing applications. They could, say, actually do math with it :biggrin: .

[benryves]

[WikiGuru]

Or, matlab, or mathematica, or maple...

[calc84maniac]

But... how will you run dynamic code? O_o

[blacksun07]

I'd write a set of code to turn native Z80 hex code into code readable on a computer. I was thinking that I would compile the TI 83+ ROM statically, then include it in the package with the emulator. I could then use the same routines to dynamically compile any new programs or apps loaded into the emulator.

The static compilation of the ROM really isn't essential, I just thought it might be a good workaround for packaging a ROM into an emulator without hitting legal issues. I'm also curious if including the ti83plus.clc file and using its ROM would be legal, as that file is freely available as part of the 83+ SDK.

And for you guys who are saying that a user-focused emulator would be useless, tell me you've never found yourself programming and really needed to do some math but didn't have a calculator around. MATLAB is 5GB and expensive. An 83+ is lightweight and good for doing just about anything mathwise.

[elfprince13]

[brandonw]

[tr1p1ea]

Emulators are always good, you may want to check out PindurTI and WabbitEmu. Those are pretty far along emulation wise however wabbit is the only one with a gui.

[blacksun07]

TI does have 8XU operating systems on their site, free for download. I could have a feature of my emulator "Get Rom" which could just download that. I think that would be allowed.

I have one question to clear up about the memory architecture on the TI 83+. ROM is a term that has come to be abused (thanks to video game emulators), but does a TI 83+ dumped ROM actually refer to the Read-Only Memory in the calc? If so, what exactly is contained on the ROM? Would an OS, free to download from TI's website, serve the same purpose as a ROM? Would it be enough to operate an emulator?

Sorry for the questions. I really am an excellent programmer who has studied the Z80, I'm just not a megaexpert on the TI's architecture. Thanks in advance for any help.

[benryves]

A ROM dump is what it says on the tin: a direct dump of the calculator's ROM, which includes the boot code, operating system and any installed applications or archived variables.

An 8xu only covers the operating system part of the ROM, not the boot code.

[blacksun07]

Thanks for the help, guys, but I took a good look at the license for the OS and the SDK. They're both pretty clear that no copying and distribution is allowed at all. Maybe I'll just release the ROM dumping software with my app so that it's easier for users to get ROM's from their calcs.

[WikiGuru]