Editing UNIVAC FASTRAND (section)

==Storage allocation==
Despite the name, FASTRAND was slow.  The head positioning time was significant, so software allocated storage by tracks (1,792 words, 10,752 characters or 8,064 eight-bit bytes) or "positions", a group of 64 tracks (114,688 words, 688,128 characters or 510,096 eight-bit bytes) which were under the heads at a single time.  This storage allocation method remained on the 1100 series machines long after drums had been replaced by disks.

The track storage units were checkboarded so that, with precise computation of the program's processing time, one could create software with processing time per unit of Fastrand blocks that resulted in a program running in synchronism with the data transfer rate of the drum.  Further, the track-to-track head movement time afforded an additional processing speed coordination possibility that permitted the computational rate to match the data transfer rate for large (for the time) data sets without being delayed by losing synchronism with the mass storage transfers.