unsigned char e100_wait_scb (struct e100_private * bdp);
This routine checks to see if the e100 has accepted a command. It does so by checking the command field in the SCB, which will be zeroed by the e100 upon accepting a command. The loop waits for up to 1 millisecond for command acceptance.
true if the SCB cleared within 1 millisecond. false if it didn't clear within 1 millisecond