VINUM_CONFIG_OFFSET
error = write_drive(drive, config, MAXCONFIG, VINUM_CONFIG_OFFSET); /* first config copy */
error = write_drive(drive, config, MAXCONFIG, VINUM_CONFIG_OFFSET + MAXCONFIG); /* second copy */
error = read_drive(drive, config_text, MAXCONFIG * 2, VINUM_CONFIG_OFFSET);
DATASTART = (MAXCONFIG * 2 + VINUM_CONFIG_OFFSET) / DEV_BSIZE