fixes a buffering bug in the first production run of the Buster chips
Buster is based on the PAL equations of the original German A2000 bus controller logic
the German PALs contained a bug which did not let the buffers between the 68000 bus and the Zorro bus point away from Zorro when a Zorro bus master talked to a Zorro bus target
in Germany it was fixed by a replacement PAL, but with the Buster it had to be corrected with the tower