HelenOS sources

CR_PS_P1          313 uspace/drv/nic/ne2k/dp8390.c 	pio_write_8(ne2k->port + DP_CR, CR_PS_P1 | CR_DM_ABORT | CR_STP);
CR_PS_P1          489 uspace/drv/nic/ne2k/dp8390.c 		pio_write_8(ne2k->port + DP_CR, CR_PS_P1 | CR_STA);
CR_PS_P1          658 uspace/drv/nic/ne2k/dp8390.c 	pio_write_8(ne2k->port + DP_CR, CR_PS_P1 | CR_DM_ABORT | CR_STP);
HelenOS homepage, sources at GitHub