HelenOS sources
DP_RCR 208 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RCR, RCR_MON);
DP_RCR 295 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RCR, ne2k->receive_configuration);
DP_RCR 632 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RCR, ne2k->receive_configuration);
DP_RCR 642 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RCR, ne2k->receive_configuration);
DP_RCR 652 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RCR, ne2k->receive_configuration);
HelenOS homepage, sources at GitHub