Rockbox Technical Forums

Rockbox Development => Starting Development and Compiling => Topic started by: gmanol on December 08, 2011, 05:34:21 PM

Title: zx spectrum .tap codec implemented
Post by: gmanol on December 08, 2011, 05:34:21 PM

I am new to rockbox, this is actually my first message, so hi everyone :p

Recently I purchased an old zx spectrum 48k to have some retro-fan time. I was looking for ways to load some games using my sansa clip+ as a cassette player. The obvious way was to convert first the .tap files into mp3s using offline tools, then load the files to the mp3 player, replay them and wait for the spectrum to load the data. This works but it is quite inefficient, it takes some time to convert and copy the tapes and a lot of storage in the sd card.

So, to keep it short, after doing some web research I discovered rockbox and decided to give it a go and try to create a .tap codec for it. It proved much easier than I was expecting thanks to the well written rockbox source code. I finished it and tested it for a while. It works really great, and now I would like to share it so others can benefit from it.

Since I'm new here are there any guidelines that I should follow before submitting a patch?

thank you,

George Manolaros
aka emc/d.
Title: Re: zx spectrum .tap codec implemented
Post by: saratoga on December 08, 2011, 05:40:09 PM
Submit your patch against current SVN, make sure all your code is under GPL suitable license, and avoid making changes to other parts of rockbox in your patch.  Otherwise that should be sufficient.

You can take a look at other people's patches if you're really unsure, but people well let you know if theres things that need fixing.
Title: Re: zx spectrum .tap codec implemented
Post by: gmanol on December 09, 2011, 10:00:41 AM
Ok, done. I created a patch against the trunk revision (31187) and upload it to FlySpray.
Btw, something is broken since revision 31086 in the simulator of Sansa Clip+, it causes a segmentation fault when it starts (without my patch applied).

thank you for your help,
George
Title: Re: zx spectrum .tap codec implemented
Post by: torne on December 09, 2011, 10:11:13 AM
You've made heavy use of floating point in the codec implementation...
Title: Re: zx spectrum .tap codec implemented
Post by: gmanol on December 09, 2011, 10:23:32 AM
The floating point calculations are called once during the codec initialization. During playback there are no calculations at all, only memory copying.