is it possible to load a .gb file?

[cyberic99]

I'd like to load a .gb file, simulate keypresses, and log the register writes.

is it possible or doable with the help of plugins?

Thx

[mmitch]

No, because gbsplay only supports the sound hardware of a Gameboy. Nothing related to screen or buttons is included (well, I think we have vsync/hsync, but that is timing only).
Also, gbsplay does a file format check and will only accept GBS files (they include a special header). I don't know if a full .gb dump and a .gbs are the same file format or not.

You should look for a "real" Gameboy emulator that emulates the whole Gameboy like VisualboyAdvance-M or Gnuboy.

[cyberic99]

Thx

I thought it was possible, because ot his commit:
a8aec38

I have been able to accomplish that with Sameboy.

[mmitch]

Ok, I don't know anything about that in detail. @ranma?

[ranma]

There is rudimentary support for .gb roms, but I only really tested it with one of the Pokemon roms, YMMV.
As mmitch said, there is no emulation for input or the graphics hardware, but if you're lucky the title screen music should work.

[cyberic99]

Thank you for your replies

there is no emulation for input

Would it be possible to press a button, using a custom plugin?

it seems that the gameboy only reads a register at FF00 to know if somme buttons are depressed

[aaaaaa123456789]

I don't know if a full .gb dump and a .gbs are the same file format or not.

They aren't. A .gb file is raw ROM data; the header is part of the ROM itself, not some separate header. It has a fixed entry point ($0100) and it starts executing from there.

it seems that the gameboy only reads a register at FF00 to know if somme buttons are depressed

It's a bit more complicated than that:

1. Set $FF00 to either $20 or $10 to respectively indicate that you want to read the D-Pad or the buttons
2. Wait 3us
3. Read the data for the selected inputs in the lower four bits of $FF00
4. Now set $FF00 to the value you didn't use in step 1
5. Wait another 3us
6. Read the data for the remaining inputs in the lower four bits of $FF00
7. Combine the values obtained in steps 3 and 6 for a full input read-out

Not to mention that it's not just input that you'd need to emulate. You'd have to emulate the whole state of the device up to the point when the first track plays. GBS files have their own special cut-down routines for playing a selected song after being given an ID externally. An actual ROM would attempt to initialize most of the GB's hardware, and most likely fail at it.

[ranma]

Some examples of GB roms that work:
http://www.pouet.net/prod.php?which=56367
http://www.pouet.net/prod.php?which=82460
and probably others from http://www.pouet.net/prodlist.php?platform%5B%5D=Gameboy

VGM files converted from VGM into a GB rom with https://vgmrips.net/wiki/Dmvgm

(For some you need to override the default silence timeout)

[cyberic99]

great, thanks for your answers and the progress on this issue