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I think we need good linking to Zoned Bit Recording, otherwise any understanding about sectors is really confusing. I was trying to work out how the data transfer rate "depends on the track location, so it will be higher for data on the outer tracks (where there are more data sectors) and lower on the inner tracks". This article, and the diagram in particular, indicate there are the same number from inside to outside. It now appears that this hasn't been the case for 20 years.
See also the following, particularly the diagram: http://www.pcguide.com/ref/hdd/geom/tracks_ZBR.htm. Amniarix ( talk) 20:00, 9 April 2010 (UTC)
It should be noted that there have been sector sizes that were not a power of two. Disk drives produced for the IBM System/38 and it's follow-on products used 520-byte sectors. drh ( talk) 22:20, 17 November 2012 (UTC)
It should be noted that a sector size of 256 bytes was quite common. The HP 3000 operating system (MPE), and others, had that number well enshrined in their code and documentation. — Preceding unsigned comment added by 50.76.52.65 ( talk) 18:47, 20 February 2013 (UTC)
I agree that the claim
The standard sector size of 512 bytes for magnetic disks was established with the inception of the hard disk drive in 1956.
is dubious. See Talk:Advanced Format#512-byte ... since the inception of the hard-disk drive in 1956. DHR ( talk) 17:43, 9 April 2013 (UTC)
If you look at the citation to that claim, it is for a disk with 100 character sectors. On top of all that 128 byte sectors were reasonably common on single density disks and later CP/M formats used sectors up to 2048 bytes (that I know of) all with block sizes of 128 bytes. — Preceding unsigned comment added by 173.163.243.81 ( talk) 19:54, 15 September 2015 (UTC)
The standard sector size of 512 bytes seems to date from the introduction of the IBM 3370 drive in 1979.
Were there any FBA devices prior to the 3370?
Please refer to the articles :-
Fixed Block Architecture
History of IBM magnetic disk drives — Preceding
unsigned comment added by
Phil from fitzroy (
talk •
contribs) 3 April 2014 (UTC)
<ref>
tag is missing the closing </ref>
(see the
help page). and the 12960A for the 2100 minicomputers
[2] also had 256-byte sectors. The HP 9153/9154's hard drives, used in the HP-UX 68k-based 9000/300, also had 256-byte sectors,
[3] so it appears that not all drives intended for UN*X systems had 512-byte sectors.Early disk drives did not have standardized sector sizes. Each drive was simply a physical device and the drive control logic existed outside the hard disk drive, in the host. The number of bytes per sector was dependent on the HDD manufacturer, the operating system or application accessing the drive on the host, and what sort of error detection/correction mechanism the host used to ensure data integrity. In the 1980s, Western Digital invented the Integrated Drive Electronics (IDE) interface, which moved the drive controller into the physical drive. This created and standardized a command set for host- drive interaction, part of which defined a logical sector as 512 bytes long, with each byte consisting of 8 bits of data.
<ref>
tag is missing the closing </ref>
(see the
help page). as did the ST-412.
[11] The ST-412 wa, apparently the 10MB drive for the PC and PC XT; perhaps IBM said "OK, you know who we are and what product we want this for, and we want a version with 512-byte sectors" and Seagate said "OK, 512-byte sectors it is, heck, for the PC we'll give you 377-byte sectors if you want". Again, maybe the 512-byte sectors was to match the floppy drive.
Guy Harris (
talk) 06:41, 13 October 2023 (UTC)So, for whatever reason, IBM went with 512-byte sectors on the floppy drives for the PC and, when they added a hard drive, again went with 512-byte sectors, perhaps for compatibility with the floppy drives. Then WD came out with IDE, and Conner built the first(?) IDE drive, and it had 512-byte sectors for compatibility with the existing PC hard drive(s), and, as a result of the success of the Conner drive, ANSI standardized on 512-byte sectors in an IDE standard at some point? Guy Harris ( talk) 01:08, 16 October 2023 (UTC)
For an unknown reason, IBM went with 512-byte sectors on the floppy drives for the PC and, when they added a hard disk drive, again went with 512-byte sectors, most likely to minimize impact on device driver and BIOS development. WD invented the IDE interface but they did not promulgate detail publicly; it featured full compatibility with the IBM PC/AT HDD BIOS and device driver, including but not limited to 512-byte sectors. Conner's highly successful commercialization of IDE drives beginning 1987 led to a multitude of competitive offerings, which in turn led an ANSI committee to standardize the interface beginning about 1989. It appears that the 512-byte sector size was adopted without discussion. IDE went on to become the dominant interface in the HDD industry thereby establishing the 512-byte sector as a Defacto standard.
References
The definition offered in this unsourced article makes it sound as though storage block and disk sector are synonymous Ringbang ( talk) 21:12, 5 August 2014 (UTC)
Dsimic and Ringbang, did it really make sense to redirect storage block here rather than Block_(data_storage)? These two articles are intertwined and perhaps should be actually be merged into one so that the subtle differences are more cohesively presented. There are differences between the two, but they always coexist. Disk Sector and Block Allocation For File seems like a pretty good discussion, and one of the answers notes that on Linux you can get Sector Size with "fdisk -l | grep -E "Sector size" and block size with "blockdev --getbsz /dev/sda". There are around a dozen related questions with various takes on the question. For example, What does chunk, block, offset, buffer and sector means? says that "typically sectors contain blocks", which seems wrong (but this book has the same statement. Also, this answer parrots this article's uncited statement "Early in the computing industry, the term "block" was loosely used to refer to a small chunk of data. Later the term referring to the data area was replaced by sector", which is misleading because block is a modern storage term. II | ( t - c) 18:22, 13 December 2015 (UTC)
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Tom, I did not get a reply from you after March 15th so I am putting this response at the top. This work represent the first mention of disk sectors with blocks and tracks as a method of greatly speeding up data transfer. The disc layout described in graphics in 1963 was completely novel at that time. The patent you did not find is below:
https://www.google.com/patents/US3439340 for Sequential access memory systems. The patent provides a new and improved method and arrangement for increasing the information transfer rate of sequential access memory systems. He had several other patents in this area as well. -- Gallahed ( talk) 21:20, 29 March 2018 (UTC)gallahed
I was hoping to add some relevant information to the history of disk sectors and their development. I recently discovered files regarding the original designs for disk sectors from 1963 and all the related internal correspondence from Bell Labs (Homdel). These files can be reviewed at https://archive.org/details/DiskDrivePatent. I am aware of the rules regarding original works but given the internal documents from Bell Labs, I thought they might suffice. Please advise on how to proceed. Gallahed ( talk) 15:09, 14 March 2018 (UTC)gallahed Gallahed ( talk) 15:09, 14 March 2018 (UTC)
This work represent the first mention of disk sectors with blocks and tracks as a method of greatly speeding up data transfer. The disc layout described in graphics in 1963 was completely novel at that time. The patent you did not find is below:
https://www.google.com/patents/US3439340 for Sequential access memory systems.
The patent provides a new and improved method and arrangement for increasing the information transfer rate of sequential access memory systems.
He had several other patents in this area as well.~~gallahed~~ — Preceding unsigned comment added by Gallahed ( talk • contribs) 16:01, 15 March 2018 (UTC)
The result of the move request was: not moved to the proposed title at this time, per the discussion below. Dekimasu よ! 01:45, 24 December 2019 (UTC)
Disk sector → Sector (computing)? – Disks are not the only storage devices to have sector organization. Shmuel (Seymour J.) Metz Username:Chatul ( talk) 17:20, 16 December 2019 (UTC)
It may be desirable to identify a possible ambiguity in usage, in which the term is not always used as per the definition "The sector is the minimum storage unit of a hard drive." but instead "A sector is the minimum addressable storage unit of a hard drive."
Under the definition, modern 'advanced' hard drives have a sector size of 4096 byte (or more), but can address 512-byte sub-sector blocks. These smaller blocks very often inherit the term 'sector' from current (or possibly older) ATA standards. This may be made clearer if explained that ATA terminology is limited to host-device interface, and the above definition applied to HDD-platter (or equivalent) transfers.
It may be also desirable to explain why [1] is *the* authoritative source for the definition of the term, or if it isn't, why it has been used here. Athulin ( talk) 09:27, 27 August 2020 (UTC)
Data storage devices with variable block sizes fit neither the definition of sector in the lead nor the usage of the term in the literature. The term sector is totally inappropriate for the IBM 1301, IBM 1302 and the count key data [a] (CKD) DASD of the IBM System/360 and successors. -- Shmuel (Seymour J.) Metz Username:Chatul ( talk) 09:03, 22 May 2023 (UTC)
The 1961 IBM 1301 disk storage introduced variable length blocks, termed records or physical records by IBM,,
The disk drives and other DASDs announced with the IBM System/360 in 1964 used self-formatting variable length blocks, termed records or physical records by IBM.and
Ultimately all fields of disk blockss had ECCs., possibly using physical record in the last two.
The 1961 IBM 1301 disk storage introduced variable length sectorswhich you changed in 2018. IBM said in 1961 that:
...self-formatting variable length blocks, termed records or physical records by IBM.[Emphasis added]
the data (the logical volumes) are mapped over fixed-size blocks or sectors.[Emphasis added]
To repeat myself:
We are not quoting historical literature, just using English in ordinary meanings to explain what is a "disk sector" and how its meaning evolved from the introduction of HDDs. As such the lack of usage of the phase "sector" in IBM DASD many descriptions of "record" is pretty much irrelevant. The only question is it reasonably accurate to describe a "record" as a variable length sector in an article about disc sectors?
Specifically, "variable" and "length" are being used in their ordinary English language meanings to modify the term of art "sector." It is used this way in other media (About 2,550 results on Google) and at least one place within Wikipedia. The fact IBM publications do not specifically use the phrase "variable length sector" to describe what it variously calls a record, physical record or block is irrelevant to this article and the note adds nothing of value to the article and should be removed. Since no one else has commented on this dialog I think it is time to go to the Village Pump. Tom94022 ( talk) 20:15, 9 March 2024 (UTC)
Notes
This is the
talk page for discussing improvements to the
Disk sector article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
This article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||
|
I think we need good linking to Zoned Bit Recording, otherwise any understanding about sectors is really confusing. I was trying to work out how the data transfer rate "depends on the track location, so it will be higher for data on the outer tracks (where there are more data sectors) and lower on the inner tracks". This article, and the diagram in particular, indicate there are the same number from inside to outside. It now appears that this hasn't been the case for 20 years.
See also the following, particularly the diagram: http://www.pcguide.com/ref/hdd/geom/tracks_ZBR.htm. Amniarix ( talk) 20:00, 9 April 2010 (UTC)
It should be noted that there have been sector sizes that were not a power of two. Disk drives produced for the IBM System/38 and it's follow-on products used 520-byte sectors. drh ( talk) 22:20, 17 November 2012 (UTC)
It should be noted that a sector size of 256 bytes was quite common. The HP 3000 operating system (MPE), and others, had that number well enshrined in their code and documentation. — Preceding unsigned comment added by 50.76.52.65 ( talk) 18:47, 20 February 2013 (UTC)
I agree that the claim
The standard sector size of 512 bytes for magnetic disks was established with the inception of the hard disk drive in 1956.
is dubious. See Talk:Advanced Format#512-byte ... since the inception of the hard-disk drive in 1956. DHR ( talk) 17:43, 9 April 2013 (UTC)
If you look at the citation to that claim, it is for a disk with 100 character sectors. On top of all that 128 byte sectors were reasonably common on single density disks and later CP/M formats used sectors up to 2048 bytes (that I know of) all with block sizes of 128 bytes. — Preceding unsigned comment added by 173.163.243.81 ( talk) 19:54, 15 September 2015 (UTC)
The standard sector size of 512 bytes seems to date from the introduction of the IBM 3370 drive in 1979.
Were there any FBA devices prior to the 3370?
Please refer to the articles :-
Fixed Block Architecture
History of IBM magnetic disk drives — Preceding
unsigned comment added by
Phil from fitzroy (
talk •
contribs) 3 April 2014 (UTC)
<ref>
tag is missing the closing </ref>
(see the
help page). and the 12960A for the 2100 minicomputers
[2] also had 256-byte sectors. The HP 9153/9154's hard drives, used in the HP-UX 68k-based 9000/300, also had 256-byte sectors,
[3] so it appears that not all drives intended for UN*X systems had 512-byte sectors.Early disk drives did not have standardized sector sizes. Each drive was simply a physical device and the drive control logic existed outside the hard disk drive, in the host. The number of bytes per sector was dependent on the HDD manufacturer, the operating system or application accessing the drive on the host, and what sort of error detection/correction mechanism the host used to ensure data integrity. In the 1980s, Western Digital invented the Integrated Drive Electronics (IDE) interface, which moved the drive controller into the physical drive. This created and standardized a command set for host- drive interaction, part of which defined a logical sector as 512 bytes long, with each byte consisting of 8 bits of data.
<ref>
tag is missing the closing </ref>
(see the
help page). as did the ST-412.
[11] The ST-412 wa, apparently the 10MB drive for the PC and PC XT; perhaps IBM said "OK, you know who we are and what product we want this for, and we want a version with 512-byte sectors" and Seagate said "OK, 512-byte sectors it is, heck, for the PC we'll give you 377-byte sectors if you want". Again, maybe the 512-byte sectors was to match the floppy drive.
Guy Harris (
talk) 06:41, 13 October 2023 (UTC)So, for whatever reason, IBM went with 512-byte sectors on the floppy drives for the PC and, when they added a hard drive, again went with 512-byte sectors, perhaps for compatibility with the floppy drives. Then WD came out with IDE, and Conner built the first(?) IDE drive, and it had 512-byte sectors for compatibility with the existing PC hard drive(s), and, as a result of the success of the Conner drive, ANSI standardized on 512-byte sectors in an IDE standard at some point? Guy Harris ( talk) 01:08, 16 October 2023 (UTC)
For an unknown reason, IBM went with 512-byte sectors on the floppy drives for the PC and, when they added a hard disk drive, again went with 512-byte sectors, most likely to minimize impact on device driver and BIOS development. WD invented the IDE interface but they did not promulgate detail publicly; it featured full compatibility with the IBM PC/AT HDD BIOS and device driver, including but not limited to 512-byte sectors. Conner's highly successful commercialization of IDE drives beginning 1987 led to a multitude of competitive offerings, which in turn led an ANSI committee to standardize the interface beginning about 1989. It appears that the 512-byte sector size was adopted without discussion. IDE went on to become the dominant interface in the HDD industry thereby establishing the 512-byte sector as a Defacto standard.
References
The definition offered in this unsourced article makes it sound as though storage block and disk sector are synonymous Ringbang ( talk) 21:12, 5 August 2014 (UTC)
Dsimic and Ringbang, did it really make sense to redirect storage block here rather than Block_(data_storage)? These two articles are intertwined and perhaps should be actually be merged into one so that the subtle differences are more cohesively presented. There are differences between the two, but they always coexist. Disk Sector and Block Allocation For File seems like a pretty good discussion, and one of the answers notes that on Linux you can get Sector Size with "fdisk -l | grep -E "Sector size" and block size with "blockdev --getbsz /dev/sda". There are around a dozen related questions with various takes on the question. For example, What does chunk, block, offset, buffer and sector means? says that "typically sectors contain blocks", which seems wrong (but this book has the same statement. Also, this answer parrots this article's uncited statement "Early in the computing industry, the term "block" was loosely used to refer to a small chunk of data. Later the term referring to the data area was replaced by sector", which is misleading because block is a modern storage term. II | ( t - c) 18:22, 13 December 2015 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Disk sector. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
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(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 09:55, 11 September 2017 (UTC)
Tom, I did not get a reply from you after March 15th so I am putting this response at the top. This work represent the first mention of disk sectors with blocks and tracks as a method of greatly speeding up data transfer. The disc layout described in graphics in 1963 was completely novel at that time. The patent you did not find is below:
https://www.google.com/patents/US3439340 for Sequential access memory systems. The patent provides a new and improved method and arrangement for increasing the information transfer rate of sequential access memory systems. He had several other patents in this area as well. -- Gallahed ( talk) 21:20, 29 March 2018 (UTC)gallahed
I was hoping to add some relevant information to the history of disk sectors and their development. I recently discovered files regarding the original designs for disk sectors from 1963 and all the related internal correspondence from Bell Labs (Homdel). These files can be reviewed at https://archive.org/details/DiskDrivePatent. I am aware of the rules regarding original works but given the internal documents from Bell Labs, I thought they might suffice. Please advise on how to proceed. Gallahed ( talk) 15:09, 14 March 2018 (UTC)gallahed Gallahed ( talk) 15:09, 14 March 2018 (UTC)
This work represent the first mention of disk sectors with blocks and tracks as a method of greatly speeding up data transfer. The disc layout described in graphics in 1963 was completely novel at that time. The patent you did not find is below:
https://www.google.com/patents/US3439340 for Sequential access memory systems.
The patent provides a new and improved method and arrangement for increasing the information transfer rate of sequential access memory systems.
He had several other patents in this area as well.~~gallahed~~ — Preceding unsigned comment added by Gallahed ( talk • contribs) 16:01, 15 March 2018 (UTC)
The result of the move request was: not moved to the proposed title at this time, per the discussion below. Dekimasu よ! 01:45, 24 December 2019 (UTC)
Disk sector → Sector (computing)? – Disks are not the only storage devices to have sector organization. Shmuel (Seymour J.) Metz Username:Chatul ( talk) 17:20, 16 December 2019 (UTC)
It may be desirable to identify a possible ambiguity in usage, in which the term is not always used as per the definition "The sector is the minimum storage unit of a hard drive." but instead "A sector is the minimum addressable storage unit of a hard drive."
Under the definition, modern 'advanced' hard drives have a sector size of 4096 byte (or more), but can address 512-byte sub-sector blocks. These smaller blocks very often inherit the term 'sector' from current (or possibly older) ATA standards. This may be made clearer if explained that ATA terminology is limited to host-device interface, and the above definition applied to HDD-platter (or equivalent) transfers.
It may be also desirable to explain why [1] is *the* authoritative source for the definition of the term, or if it isn't, why it has been used here. Athulin ( talk) 09:27, 27 August 2020 (UTC)
Data storage devices with variable block sizes fit neither the definition of sector in the lead nor the usage of the term in the literature. The term sector is totally inappropriate for the IBM 1301, IBM 1302 and the count key data [a] (CKD) DASD of the IBM System/360 and successors. -- Shmuel (Seymour J.) Metz Username:Chatul ( talk) 09:03, 22 May 2023 (UTC)
The 1961 IBM 1301 disk storage introduced variable length blocks, termed records or physical records by IBM,,
The disk drives and other DASDs announced with the IBM System/360 in 1964 used self-formatting variable length blocks, termed records or physical records by IBM.and
Ultimately all fields of disk blockss had ECCs., possibly using physical record in the last two.
The 1961 IBM 1301 disk storage introduced variable length sectorswhich you changed in 2018. IBM said in 1961 that:
...self-formatting variable length blocks, termed records or physical records by IBM.[Emphasis added]
the data (the logical volumes) are mapped over fixed-size blocks or sectors.[Emphasis added]
To repeat myself:
We are not quoting historical literature, just using English in ordinary meanings to explain what is a "disk sector" and how its meaning evolved from the introduction of HDDs. As such the lack of usage of the phase "sector" in IBM DASD many descriptions of "record" is pretty much irrelevant. The only question is it reasonably accurate to describe a "record" as a variable length sector in an article about disc sectors?
Specifically, "variable" and "length" are being used in their ordinary English language meanings to modify the term of art "sector." It is used this way in other media (About 2,550 results on Google) and at least one place within Wikipedia. The fact IBM publications do not specifically use the phrase "variable length sector" to describe what it variously calls a record, physical record or block is irrelevant to this article and the note adds nothing of value to the article and should be removed. Since no one else has commented on this dialog I think it is time to go to the Village Pump. Tom94022 ( talk) 20:15, 9 March 2024 (UTC)
Notes