PCW_21_MSK       2492 src/dps8/dps8_iom.c     p -> PCW_21_MSK         = getbits36_1  (p -> PCW0, 21);
PCW_21_MSK       3357 src/dps8/dps8_iom.c           sim_printf ("//   M                %o\r\n",  p->PCW_21_MSK);
PCW_21_MSK       3378 src/dps8/dps8_iom.c       q -> PCW_21_MSK         = p -> PCW_21_MSK;
PCW_21_MSK       3383 src/dps8/dps8_iom.c       q -> masked = p -> PCW_21_MSK;
PCW_21_MSK        149 src/dps8/dps8_iom.h     word1 PCW_21_MSK; // Sometimes called 'M' // see 3.2.2, pg 25