- The drive is the part of the mass storage unit that reads the disk. A hard drive contains a hard disk; you insert an optical disc into a CD or DVD drive; a media card is placed into a media drive or media card reader or is connected directly to a USB port. The PC's hard drive cannot be removed.
- Well, the hard disk drive is a place where all of your computer's data is stored. Not just your pictures, songs, or games, but all of the information regarding operating systems, internet connectivity, drivers, and other pieces of information that are beyond the user's reach.
- Hard drive manufacturers advertise their products in the decimal system. But our operating systems, such as Windows are based on binary math, which means storage is counted using base 2, not base 10, which storage is advertised as. This means that for the computer system, a KB is 1024 bytes while for a hard disk manufacturer, one KB is 1000 bytes.
- When Atari first introduced its Atari ST computer line, it also shortly there after released a hard drive for your computers. It was called the SH204. SH standing for ST Line Hard disk and 204 for a 20MB storage unit. As for the '4' designation, it is unknown. Perhaps it was version 4 of the design.
Overview This unit is a hard disk storage unit specifically designed for P2 cards. The data recorded on P2 cards can be copied at high speed from the unit's P2 drive onto HDDs.
IBM 350
Hard Disk Drive Storage
- Model 1 announced September 14, 1956
- Model 2 announced May 5, 1958
- Models 3 & 4 announced September 15, 1958
- Models 11, 12, 13 & 14 announced January 12, 1959
- All models withdrawn August 18, 1969
The IBM 350 Disk Storage was a major component of the IBM 305 RAMAC (Random Access Memory Accounting) system, introduced in September 1956.
Hard Disk Storage Units For Sale
IBM 305 RAMAC
The 305 was a flexible, electronic, general purpose data processing machine that enabled businesses to record transactions as they occurred and concurrently reflect each entry in affected accounts. It maintained records on a real-time basis, provided random access to any record, eliminated peak loads, and could simultaneously produce output by either print or punched cards.
The 305 system consisted of the IBM 305 Processing Unit (containing the magnetic process drum, magnetic core register and electronic logical and arithmetic circuits), the IBM 370 Printer (an 80-position serial-output printer with tape control carriage), the IBM 323 Card Punch (similar to the IBM 523 Gang Summary Punch, providing for 80 columns of output punching), the IBM 380 Console (containing the card feed, typewriter, keyboard and indicator lights and control keys), the IBM 340 Power Supply (supplying power for all components except the motors in the 350 disk storage unit), a utility table adjacent to the console, and the IBM 350 Disk Storage Unit.
The 350 Disk Storage Unit consisted of the magnetic disk memory unit with its access mechanism, the electronic and pneumatic controls for the access mechanism, and a small air compressor. Assembled with covers, the 350 was 60 inches long, 68 inches high and 29 inches deep. It was configured with 50 magnetic disks containing 50,000 sectors, each of which held 100 alphanumeric characters, for a capacity of 5 million characters. Bluebeam loading slow.
Disks rotated at 1,200 rpm, tracks (20 to the inch) were recorded at up to 100 bits per inch, and typical head-to-disk spacing was 800 microinches. The execution of a 'seek' instruction positioned a read-write head to the track that contained the desired sector and selected the sector for a later read or write operation. Seek time averaged about 600 milliseconds.
In 1958, the 305 system was enhanced to permit an optional additional 350 Disk Storage Unit, thereby doubling storage capacity; and an additional access arm for each 350.
The dual arms used to record or read data from the 350 disk storage unit.With storage capacities of 5 million and 10 million digits, and the capability to be installed either singly or in pairs, the 350 provided the 305 system with storage capacities of 5, 10, 15 or 20 million characters.
More than 1,000 305s were built before production ended in 1961. The 305 RAMAC was one of the last vacuum tube systems designed in IBM.