[Àû¿ë´ë»ó: 0.74_SVN_new, DOSBox-x]

ISA BCLK frequency.

WARNING: In future revisions, PCI/motherboard chipset emulation will allow the guest OS/program to alter this value at runtime.

std8.3 : 8.333MHz (typical 386-class or higher)
std8 : 8MHz
std6 : 6MHz
std4.77 : 4.77MHz (precisely 1/3 x 14.31818MHz).              Bus frequency of older PC/XT systems.

oc10 : 10MHz
oc12 : 12MHz
oc15 : 15MHz
oc16 : 16MHz
<integer or float>: Any integer or floating point 
                          value will be used as the clock
                          frequency in Hz
<integer/integer ratio>: If a ratio is given                           (num/den), the ratio will be
                          used as the clock frequency