Plan 9 from Bell Labs’s /usr/web/sources/patch/maybe/dmaon/dmaon.orig
#!/bin/rc # dmaon - turn on ide dma, if possible rfork e for (ctl in /dev/sd[C-H]?/ctl) if (test -e $ctl && grep -s '^config .* dma ' $ctl && ! grep -s '^config (848A|.* dma 00000000 )' $ctl) echo 'dma on' >$ctl