Name/Title
1974- IBM 3850 Mass Storage Cartridges (1 ea)Tags
IBMDescription
1974- Beginning in the late-1960s, IBM engineers in Boulder, Colorado, began development of a low-cost mass storage system based on magnetic tape in cartridges. By 1970, the proposed device was code named "Comanche" and described as an online tape library to provide computer-controlled access to stored information. Numerous marketing studies and design changes were made during the early 1970s, and finally Comanche was announced as the IBM 3850 Mass Storage System (MSS) in October 1974.General Notes
Note
Cartridges:
The system used cylindrical plastic cartridges, each two inches wide and four inches (100 mm) long. Each cartridge held a spool of tape measuring 770 inches (20 m) long, storing 50 MB of data.
A virtual disk required a pair of these cartridges.
Storage Facility:
The cartridges were stored in a hexagonal array of bins within the IBM 3851 Mass Storage Facility. New cartridges were automatically stored in vacant bins.
Data Transfer:
Data were accessed via virtual IBM 3330 disk drives. The system cached data on a combination of 3330 and 3350 staging drives.
Cartridges were moved by motorized accessor arms for reading and writing.
Recording Method:
The drive pulled tape from the cartridge and wound it around a cylindrical mandrel in a helix. The drive’s head rotated to read or record a diagonal track. This method was ahead of its time and resembled digital helical scan recording.