I did a log but I think that there is nothing interesting to put the full log. I put the same end of the log boot from a floppy image and floppy disk.
 
Succesful qemu boot from BOOT-PROM3 floppy image:
=================================================
Booting from Floppy...
Floppy_drive_recal 0
Floppy_enable_controller
i8042_command cmd=ae
i8042_wait_write
Floppy_media_sense on drive 0 found rate 0
Booting from 0000:7c00
Floppy_disable_controller
Floppy_enable_controller
Floppy_drive_recal 0
Floppy_media_sense on drive 0 found rate 0
i8042_command cmd=ae
i8042_wait_write
i8042_command cmd=ae
i8042_wait_write
Floppy_disable_controller
Floppy_enable_controller
Floppy_drive_recal 0
Floppy_media_sense on drive 0 found rate 0
=================================================
 
Unsuccesful boot Abit BF6 from BOOT-PROM3 floppy disk:
=========================================================================
Booting from Floppy...
Floppy_drive_recal 0
Floppy_enable_controller
Floppy_media_sense on drive 0 found rate 0
Booting from 0000:7c00
Floppy_disable_controller
Floppy_enable_controller
Floppy_drive_recal 0
Floppy_media_sense on drive 0 found rate 0
i8042_command cmd=ae
i8042_wait_write
i8042_command cmd=ae
i8042_wait_write
floppy error: 44 20 20 1c 01 0a 02
invalid basic_access:96:
   a=00000200  b=00000000  c=00001c0a  d=00000100 ds=5000 es=6360 ss=df80
  si=00000000 di=000057c0 bp=0000001e sp=0000fd20 cs=5000 ip=0188  f=0246
=========================================================================
 
Recently i make full access for flashrom and now possible flash bios coreboot or vendor bios from linux. After flash vendor BIOS or coreboot bios I noticed problems with timeout while load file pxelinux.0 over gPXE from TFTP server. To reslove this problem after flash vendor bios I need go to CMOS Setup (Del) and load defaults settings.
To resolve problem after flash coreboot I need clear CMOS with jumper on board. After clear CMOS have not set RTC date and time and Debian-live over PXE not boot and have error Authentication error, '...respawning too fast: disable for 5 minutes'. This is only from Debian-live over PXE. The same Debian-live from CD boot ok. Also Debian installed on HDD boot OK. After set date and time in debian HDD like this:
 
date -s 2013-12-28
date -s 19:00
 
and reboot to debian-live from PXE the problem was gone and Debian boot OK.
 
I think the problem floppy error is related to the network adapter and timeout. This is not SeaBIOS fault.