RSR_BFULL
if (ISSET(rsr, RSR_BFULL|RSR_BREAK)) {
for (; ISSET(rsr, RSR_BFULL|RSR_BREAK) && cc > 0; cc--) {
while (ISSET(rsr, RSR_BFULL|RSR_BREAK)) {
while (!ISSET(stat = MFP->mf_rsr, RSR_BFULL)) {
while (ISSET(MFP->mf_rsr, RSR_CIP|RSR_BFULL))