>> 644

84行目は
# Floppy drives　の一行です。

前後を書くと、以下のようになります。

# To support HyperThreading, HTT is needed in addition to SMP and APIC_IO
#options HTT # HyperThreading Technology

device isa
#device eisa
device pci

# Floppy drives
device fdc0 at isa? port IO_FD1 irq 6 drq 2
device fd0 at fdc0 drive 0
device fd1 at fdc0 drive 1