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Bochs have a small problem with mem size detection. int15 C7 doesn't work, CMOS always return 32MB eaven if in config file I gave him 16MB.

Do you know how to make the proper call to get the size of ram??

Oh, and the time in CMOS goes a little fast for me, 1 min, takes 20 seconds on my PC with bochs.

Read some others threads in this board (eg. direct memory probing).
I think, you may use the CLOCK field in the .bochsrc configuration file:
Maybe:
clock: sync=realtime, time0=local

I think Bochs has a minimum RAM size of 32MB

p.s. enabling the PIT in your .bochsrc should help with the time problem