vrijdag, april 07, 2006

DosBox on Nokia 770

As I am experimenting with videoplayback on the Nokia 770, I had a look at both GTK+ and SDL for this purpose. After a quick hello-world style SDL application, I decided to get something cute running on the device.

I had a quick look at the Maemo Application Wishlist, and saw DosBox. This looked interesting to me, so I had a quick go at getting it up and running on the device. It compiled just fine in Scratchbox.

Several issues showed up. The first being related to SDL screen initialisation: you should always init SDL in 800x480 16 bits per pixel mode, fullscreen, with hardware accelerated SDL surfaces. Second issue was exactly the same as with Google LibJingle: it quickly ran out of memory and got killed by the kernel. Skimming through the sourcecode, followed by a quick hack fixed the first issue, while a swapfile fixed the second (16M swap appears to be enough).

Then as it seemed to work perfectly, I noticed that the virtual keyboard on the N770 was not accessible from within SDL, so I couldn't really do anything in my cute little DosBox :o) Anyways, likely it is possible to let DosBox start an app right from the commandline of an xterminal, and if the DOS application only requires a mouse, it could still be useful :)

Furthermore, DosBox seems to use the Alsa sequencer for MIDI support, that doesn't seem to work either, as there appears to be no sequencer. I haven't looked into this.

The binary is available here. The patch , horrible as it is -remember, it was a quick 2 min hack with grep and sed- is available here: Dosbox ugly N770 patch. It is truly a stupid patch, but as I'm distributing the binary, the GPL requires the availability of the code.