HelenOS sources
DP_RBCR1 123 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RBCR1, (esize >> 8) & 0xff);
DP_RBCR1 148 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RBCR1, (esize_ru >> 8) & 0xff);
DP_RBCR1 224 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RBCR1, 0);
DP_RBCR1 242 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RBCR1, 0);
DP_RBCR1 302 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RBCR1, 0);
DP_RBCR1 382 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RBCR1, 0);
DP_RBCR1 512 uspace/drv/nic/ne2k/dp8390.c pio_write_8(ne2k->port + DP_RBCR1, (size >> 8) & 0xff);
HelenOS homepage, sources at GitHub