8 6 ▁and ▁the ▁even ▁less ▁known ▁ 3 8 6 ▁variant . ▁Microsoft ' s ▁H IME M . SY S ▁version ▁ 2 . 0 6 ▁also ▁used ▁LO AD ALL ▁to ▁quickly ▁copy ▁to ▁and ▁from ▁extended ▁memory ▁on ▁ 2 8 6 ▁systems . ▁ ▁Another ▁interesting ▁usage ▁of ▁LO AD ALL , ▁laid ▁out ▁in ▁the ▁book ▁The ▁Design ▁of ▁OS / 2 , ▁would ▁have ▁been ▁to ▁allow ▁running ▁former ▁real - mode ▁programs ▁in ▁ 1 6 - bit ▁protected ▁mode , ▁as ▁util ized ▁by ▁Digital ▁Research ' s ▁Con current ▁D OS ▁ 2 8 6 ▁since ▁ 1 9 8 5 , ▁as ▁well ▁as ▁F lex OS ▁ 2 8 6 ▁and ▁IBM ▁ 4 6 8 0 ▁OS ▁since ▁ 1 9 8 6 . ▁Mark ing ▁all ▁the ▁des criptor ▁c aches ▁in ▁the ▁G DT ▁and ▁L DT s ▁" not ▁present " ▁would ▁allow ▁the ▁operating ▁system ▁to ▁trap ▁segment - register ▁re loads , ▁as ▁well ▁as ▁attempts ▁at ▁performing ▁real - mode – specific ▁" segment ▁arithmetic " ▁and ▁em ulate ▁the ▁desired ▁behavior ▁by ▁updating ▁the ▁segment ▁descript ors ▁( LOAD ALL ▁again ). ▁This ▁" virtual ▁ 8 0 8 6 ▁mode " ▁for ▁the ▁ 8 0 2 8 6 ▁was , ▁however , ▁too ▁slow ▁to ▁be ▁practical . ▁The ▁idea ▁had ▁to ▁be ▁mostly ▁disc arded , ▁further more , ▁due ▁to ▁err ata ▁in ▁some ▁early ▁Intel ▁ 8 0