Drum - Revision history

Jnc: /* External links */ +Storage of Numbers on Magnetic Tape

2025-06-02T14:07:43Z

External links: +Storage of Numbers on Magnetic Tape

← Older revision		Revision as of 14:07, 2 June 2025
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	==External links==		==External links==

			* [https://vipclubmn.org/Articles/DrumPrototypeDesign.pdf Storage of Numbers on Magnetic Tape] - the title notwithstanding, this about early work on drums
	* [https://www.fourmilab.ch/documents/univac/fastrand.html The FASTRAND™ II] - amusing detailed description of the very large drum used on the [[UNIVAC 1100]] series		* [https://www.fourmilab.ch/documents/univac/fastrand.html The FASTRAND™ II] - amusing detailed description of the very large drum used on the [[UNIVAC 1100]] series

	[[Category: Device Basics]]		[[Category: Device Basics]]

Jnc: Problem with very large drums

2025-06-02T13:15:18Z

Problem with very large drums

← Older revision		Revision as of 13:15, 2 June 2025
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	Drums fell out of use in large part because they took more physical room than a disk with the equivalent surface area. A number of [[disk platter]]s, giving in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.		Drums fell out of use in large part because they took more physical room than a disk with the equivalent surface area. A number of [[disk platter]]s, giving in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.

			The very large (physically) FASTRAND I drum from [[Remington Rand Univac‎]] displayed another, previously unthought-of, issue. It had only a single, massive, drum; a massive drum rotating at high speed acts as a powerful gyroscope, which tries to stay in a fixed attitude with respect to an inertial frame of reference. As the Earth rotated, this led to the FASTRAND I tending to move around the computer room! The successor, the FASTRAND II, therefore had ''two'' physical drums, rotating in opposite directions!

			==External links==

			* [https://www.fourmilab.ch/documents/univac/fastrand.html The FASTRAND™ II] - amusing detailed description of the very large drum used on the [[UNIVAC 1100]] series

	[[Category: Device Basics]]		[[Category: Device Basics]]

Jnc: Tweak order, add LGP-30

2024-03-18T18:45:20Z

Tweak order, add LGP-30

← Older revision		Revision as of 18:45, 18 March 2024
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	'''Drums''' were the predecessor [[magnetic storage]] technology to [[disk]]s; they were (as the name suggests) in physical form a drum~~, and generally had a [[head]] per [[track]] (like [[fixed-head disk]]s)~~.		'''Drums''' were the predecessor [[magnetic storage]] technology to [[disk]]s; they were (as the name suggests) in physical form a drum.

	~~Like~~ fixed-head ~~disks~~, this avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components; drums also needed more volume for their installation.		They generally had a [[head]] per [[track]], like [[fixed-head disk]]s. Like them, on drums this avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components. Because of their fundamental geometry, drums also needed more volume for their installation than disks did.

	The very first drums were actually used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (~~e.g.~~ the [[IBM 650]] ~~and~~ [[Bendix G-15]]). Such use often required the use of [[optimum programming]], to control the execution delays (due to rotational latency) which resulted if [[instruction]]s were not placed in the optimum positions on the drum. Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.		The very first drums were actually used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (notably the [[IBM 650]], [[Bendix G-15]], and [[LGP-30]]). Such use often required the use of [[optimum programming]], to control the execution delays (due to rotational latency) which resulted if [[instruction]]s were not placed in the optimum positions on the drum. Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.

	Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.		Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.

	Drums fell out of use because they took more physical room than a disk with the equivalent surface area. A number of [[disk platter]]s, giving in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.		Drums fell out of use in large part because they took more physical room than a disk with the equivalent surface area. A number of [[disk platter]]s, giving in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.

	[[Category: Device Basics]]		[[Category: Device Basics]]

Jnc: Need optimum programming if used for main memory

2024-03-17T15:53:21Z

Need optimum programming if used for main memory

← Older revision		Revision as of 15:53, 17 March 2024
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	Like fixed-head disks, this avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components; drums also needed more volume for their installation.		Like fixed-head disks, this avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components; drums also needed more volume for their installation.

	The very first drums were ~~actuallly~~ used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (e.g. the [[IBM 650]]). Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.		The very first drums were actually used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (e.g. the [[IBM 650]] and [[Bendix G-15]]). Such use often required the use of [[optimum programming]], to control the execution delays (due to rotational latency) which resulted if [[instruction]]s were not placed in the optimum positions on the drum. Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.

	Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.		Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.

Jnc: minor tweaks

2020-09-01T21:18:25Z

minor tweaks

← Older revision		Revision as of 21:18, 1 September 2020
Line 1:		Line 1:
	'''Drums''' were the predecessor [[magnetic storage]] technology to [[disk]]s; they were (as the name suggests) in physical form a drum, and generally had a [[head]] per [[track]] (like [[fixed-head disk]]s).		'''Drums''' were the predecessor [[magnetic storage]] technology to [[disk]]s; they were (as the name suggests) in physical form a drum, and generally had a [[head]] per [[track]] (like [[fixed-head disk]]s).

	~~This~~ avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components.		Like fixed-head disks, this avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components; drums also needed more volume for their installation.

	The very first drums were actuallly used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (e.g. the [[IBM 650]]). Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.		The very first drums were actuallly used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (e.g. the [[IBM 650]]). Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.
Line 7:		Line 7:
	Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.		Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.

	Drums fell out of use because they took more physical ~~space~~ than a disk with the equivalent surface area. A number of [[disk platter]]s, ~~given~~ in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.		Drums fell out of use because they took more physical room than a disk with the equivalent surface area. A number of [[disk platter]]s, giving in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.

	[[Category: Device Basics]]		[[Category: Device Basics]]

Jnc: typo

2018-12-13T14:39:20Z

typo

← Older revision		Revision as of 14:39, 13 December 2018
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	This avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components.		This avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components.

	The very first drums were actuallly used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (e.g. the [[IBM 650]]. Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.		The very first drums were actuallly used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (e.g. the [[IBM 650]]). Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.

	Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.		Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.

Jnc: +cat

2018-12-13T14:38:34Z

+cat

← Older revision		Revision as of 14:38, 13 December 2018
Line 3:		Line 3:
	This avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components.		This avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components.

	The very first drums were actuallly used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones. Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.		The very first drums were actuallly used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones (e.g. the [[IBM 650]]. Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.

	Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[paging]] purposes.		Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[virtual memory\|paging]] purposes.

	Drums fell out of use because they took more physical ~~room~~ than a disk with the equivalent surface area. A number of [[disk platter]]s, given in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.		Drums fell out of use because they took more physical space than a disk with the equivalent surface area. A number of [[disk platter]]s, given in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.

			[[Category: Device Basics]]

Jnc: Yes, that was why

2018-04-14T19:06:55Z

Yes, that was why

← Older revision		Revision as of 19:06, 14 April 2018
Line 7:		Line 7:
	Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[paging]] purposes.		Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[paging]] purposes.

	Drums ~~likely~~ fell out of use because they took more physical room than a disk with the equivalent surface area. A number of [[disk platter]]s, given in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.		Drums fell out of use because they took more physical room than a disk with the equivalent surface area. A number of [[disk platter]]s, given in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.

Jnc: +link

2017-09-30T12:57:22Z

+link

← Older revision		Revision as of 12:57, 30 September 2017
Line 1:		Line 1:
	'''Drums''' were the predecessor magnetic storage technology to [[disk]]s; they were (as the name suggests) in physical form a drum, and generally had a [[head]] per [[track]] (like [[fixed-head disk]]s).		'''Drums''' were the predecessor [[magnetic storage]] technology to [[disk]]s; they were (as the name suggests) in physical form a drum, and generally had a [[head]] per [[track]] (like [[fixed-head disk]]s).

	This avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components.		This avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components.

Jnc: Add a bit more detail

2017-09-24T14:40:41Z

Add a bit more detail

← Older revision		Revision as of 14:40, 24 September 2017
Line 1:		Line 1:
	'''Drums''' were the predecessor magnetic storage technology to [[disk]]s; they were (as the name suggests) in physical form a drum, and generally had a head per track (like [[fixed-head disk]]s.		'''Drums''' were the predecessor magnetic storage technology to [[disk]]s; they were (as the name suggests) in physical form a drum, and generally had a [[head]] per [[track]] (like [[fixed-head disk]]s).

	~~The very first drums were actuallly used for~~ [[~~main memory~~]] ~~on some very early computers;~~ and also ~~on slightly later~~, but ~~low-end, ones. Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[paging]] purposes~~.		This avoided the delays involved in having the head(s) [[seek]] to the correct track, and was also mechanically simpler (an important point at this early stage of development), but did require more components.

	Drums likely fell out of use because they took more physical ~~space~~ than a disk with the equivalent surface area. A number of [[disk platter]]s, given in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.		The very first drums were actuallly used for [[main memory]] on some very early computers; and also on slightly later, but low-end, ones. Some drums were actually used to store [[register]]s, storing several registers in each track, and using multiple heads on that track to give faster access to the contents of the registers.

			Once [[core memory]] appeared, drums were only seen in the role of high-speed [[secondary storage]]; often being used for [[swapping]] or [[paging]] purposes.

			Drums likely fell out of use because they took more physical room than a disk with the equivalent surface area. A number of [[disk platter]]s, given in total a significantly greater amount of storage, could be stacked in the volume occupied by a single drum.