The 6,000 RPM 2305 appeared in 1970, with capacities of 5 MB (2305–1) or 11 MB (2305–2) per module. Although these devices did not have large capacity, their speed and transfer rates made them attractive for high-performance needs. A typical use was overlay linkage (e.g. for OS and application subroutines) for program sections written to alternate in the same memory regions. Fixed-head disks and drums were particularly effective as paging devices on the early virtual memory systems. The 2305, although often called a "drum" was actually a head-per-track disk device, with 12 recording surfaces and a data transfer rate up to 3 MB/s.
The 6,000 RPM 2305 appeared in 1970, with capacities of 5 MB (2305–1) or 11 MB (2305–2) per module. Although these devices did not have large capacity, their speed and transfer rates made them attractive for high-performance needs. A typical use was overlay linkage (e.g. for OS and application subroutines) for program sections written to alternate in the same memory regions Fixed-head disks and drums were particularly effective as paging devices on the early virtual memory systems. The 2305, although often called a "drum" was actually a head-per-track disk device, with 12 re.cording surfaces and a data transfer rate up to 3 MB/s.