> I keep hoping that an IBM 650 programmer will stop by and explain how the= y > dealt with latency on a computer with drum memory... I believe they had a pretty cunning compiler that would order the instructi= ons on the drum so that as one instruction was completing the next was just= coming up to the read head. It certainly boggles my mind how they did this= .. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .