HSC70 Mass Storage Server - Revision history

Jnc: rm blank space

2025-04-12T11:57:24Z

rm blank space

Vaxorcist: RX33 Boot device added

2025-04-12T07:17:10Z

RX33 Boot device added

Jnc: Part of the Hierarchical Storage Controller series

2024-04-19T18:40:22Z

Part of the Hierarchical Storage Controller series

Jnc: +HSC70 Subsystem Block Diagram

2024-04-19T02:19:28Z

+HSC70 Subsystem Block Diagram

Jnc: Top of the 'wanted' list

2024-04-19T02:05:14Z

Top of the 'wanted' list

New page

The '''HSC70 Mass Storage Server''' (alternatively called the '''HSC70 Hierarchical Storage Controller''') is an intelligent [[mass storage]] sub-system [[server]] from [[Digital Equipment Corporation|DEC]], part of the [[Digital Storage Architecture]] (DSA). It was the first commercial [[RAID]] [[device controller|controller]]; a capability termed 'shadowing' in the documentation.

The HSC70 connects with one or more [[host]] computer systems; it communicates over the [[Computer Interconnect]] (CI), via the [[SC008 Star Coupler]] (a passive, [[RF]]-[[transformer]] coupling network). The HSC was the first DEC mass storage server to connect to multiple hosts. The [[Mass Storage Control Protocol]] (MSCP) is a communication [[protocol]] used over the CI between host system(s) and the HSC70. This protocol enables a single class [[driver]] to replace multiple device-specific drivers. Separate but similar protocols exist for disk and tape communication:

* Disk MSCP frees the host from responsibility for disk I/O functions and error recovery.
* Tape MSCP includes those protocol variations necessary for tape functionality in the subsystem.

The HSC70 also connects to a set of mass storage devices. If the devices that the HSC70 controls are [[disk]] [[drive]]s, the HSC70 communicates with them over the [[Standard Disk Interconnect]] (SDI) [[bus]]; if they are [[magnetic tape]] formatters, the [[Standard Tape Interconnect]] (STI) bus is used. The HSC70 can support a maximum total of eight disk and/or tape data channels (usually a minimum of two; the others are optional). Each one of the disk data channels accommodates up to four drives.  Each of the tape data channels accommodates up to four formatters, each of which can handle up to four [[magnetic tape drive]]s.

An HSC70 can perform up to 1,150 I/O operations per second. It contains a [[microprocessor]]; in the case of the HSSC70, this is a [[J-11 chip set]]. The HSC70 is housed in a single cabinet.

The successor model to the HSC70 was the [[HSC90]], to which an HSC70 can be field upgraded. (An [[HSC50 Hierarchical Storage Controller|HSC50]] cannot be upgraded into an HSC70.)

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==Further reading==

* ''HSC User Guide'' (AA-GMEAA-TK)
* ''HSC70 Illustrated Breakdown'' (EK-HSC70-IP)
* ''HSC70 Field Print Set'' (MP-01426)

==External links==

* [https://bitsavers.org/pdf/dec/dsa/hsc HSC] - documentation at [[Bitsavers]]
** [http://bitsavers.org/pdf/dec/dsa/hsc/EK-HS571-TM-001_HSC_hwTech.pdf HSC50/70 Hardware Technical Manual] (EK-HS571-TM-OO1)
** [http://bitsavers.org/pdf/dec/dsa/hsc/EK-HSC70-SV-002_Sep86.pdf HSC70 Service Manual] (EK-HSC70-SV-002) - replaced by the below
** [http://bitsavers.org/pdf/dec/dsa/hsc/EK-HSCMA-SV-001_HSCsv_Aug88.pdf HSC Service Manual] (EK-HSCMA-SV-001)
** [http://bitsavers.org/pdf/dec/dsa/hsc/EK-HSCMA-SV-002_HSC_Service_Manual_Dec89.pdf HSC Service Manual] (EK-HSCMA-SV-002)
* [https://support.hpe.com/hpesc/public/docDisplay?docId=c00480484&docLocale=en_US HSC70 (CI Based Hierarchical Storage Controller) - Overview]

[[Category: DEC Mass Storage]]
[[Category: CI Hierarchical Storage Controllers]]
[[Category: SDI Controllers]]
[[Category: STI Controllers]]

@@ Line 12: / Line 12: @@
 The HSC70 also connects to a set of mass storage devices. If the devices that the HSC70 controls are [[disk]] [[drive]]s, the HSC70 communicates with them over the [[Standard Disk Interconnect]] (SDI) [[bus]]; if they are [[magnetic tape]] formatters, the [[Standard Tape Interconnect]] (STI) bus is used. The HSC70 can support a maximum total of eight disk and/or tape data channels (usually a minimum of two; the others are optional). Each one of the disk data channels accommodates up to four drives. <!-- Maximum disk configuration for a single HSC50 is 24 drives. --> Each of the tape data channels accommodates up to four formatters, each of which can handle up to four [[magnetic tape drive]]s.
-An HSC70 can perform up to 1,150 I/O operations per second. It contains a [[microprocessor]]; in the case of the HSSC70, this is a [[J-11 chip set]]. The HSC70 is housed in a single cabinet. It uses the [[RX33 Flexible Disk Drive]] as boot device, reducing the [[Bootstrap|boot]] time from about 6 minutes (HSC50 with [[TU58 DECtape II]] boot device) to approximately 1 minute.
+An HSC70 can perform up to 1,150 I/O operations per second. It contains a [[microprocessor]]; in the case of the HSSC70, this is a [[J-11 chip set]]. The HSC70 is housed in a single cabinet. It uses the [[RX33 Flexible Disk Drive]] as boot device, reducing the [[bootstrap|boot]] time from about 6 minutes (HSC50 with [[TU58 DECtape II]] boot device) to approximately 1 minute.
 The successor model to the HSC70 was the [[HSC90]], to which an HSC70 can be field upgraded. (An HSC50 cannot be upgraded into an HSC70.)

@@ Line 12: / Line 12: @@
 The HSC70 also connects to a set of mass storage devices. If the devices that the HSC70 controls are [[disk]] [[drive]]s, the HSC70 communicates with them over the [[Standard Disk Interconnect]] (SDI) [[bus]]; if they are [[magnetic tape]] formatters, the [[Standard Tape Interconnect]] (STI) bus is used. The HSC70 can support a maximum total of eight disk and/or tape data channels (usually a minimum of two; the others are optional). Each one of the disk data channels accommodates up to four drives. <!-- Maximum disk configuration for a single HSC50 is 24 drives. --> Each of the tape data channels accommodates up to four formatters, each of which can handle up to four [[magnetic tape drive]]s.
-An HSC70 can perform up to 1,150 I/O operations per second. It contains a [[microprocessor]]; in the case of the HSSC70, this is a [[J-11 chip set]]. The HSC70 is housed in a single cabinet.
+An HSC70 can perform up to 1,150 I/O operations per second. It contains a [[microprocessor]]; in the case of the HSSC70, this is a [[J-11 chip set]]. The HSC70 is housed in a single cabinet. It uses the [[RX33 Flexible Disk Drive]] as boot device, reducing the [[Bootstrap|boot]] time from about 6 minutes (HSC50 with [[TU58 DECtape II]] boot device) to approximately 1 minute.
 The successor model to the HSC70 was the [[HSC90]], to which an HSC70 can be field upgraded. (An HSC50 cannot be upgraded into an HSC70.)

← Older revision		Revision as of 02:19, 19 April 2024
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		+	[[File:HSC70SubsystemBlockDiagram.jpg\|400px\|thumb\|right\|HSC70 Subsystem Block Diagram]]
		+
	The '''HSC70 Mass Storage Server''' (alternatively called the '''HSC70 Hierarchical Storage Controller''') is an intelligent [[mass storage]] sub-system [[server]] from [[Digital Equipment Corporation\|DEC]], part of the [[Digital Storage Architecture]] (DSA). It was the first commercial [[RAID]] [[device controller\|controller]]; a capability termed 'shadowing' in the documentation.		The '''HSC70 Mass Storage Server''' (alternatively called the '''HSC70 Hierarchical Storage Controller''') is an intelligent [[mass storage]] sub-system [[server]] from [[Digital Equipment Corporation\|DEC]], part of the [[Digital Storage Architecture]] (DSA). It was the first commercial [[RAID]] [[device controller\|controller]]; a capability termed 'shadowing' in the documentation.

@@ Line 1: / Line 1: @@
 [[File:HSC70SubsystemBlockDiagram.jpg|400px|thumb|right|HSC70 Subsystem Block Diagram]]
-The '''HSC70 Mass Storage Server''' (alternatively called the '''HSC70 Hierarchical Storage Controller''') is an intelligent [[mass storage]] sub-system [[server]] from [[Digital Equipment Corporation|DEC]], part of the [[Digital Storage Architecture]] (DSA). It was the first commercial [[RAID]] [[device controller|controller]]; a capability termed 'shadowing' in the documentation.
+The '''HSC70 Mass Storage Server''' (alternatively called the '''HSC70 Hierarchical Storage Controller''') is an intelligent [[mass storage]] sub-system [[server]] from [[Digital Equipment Corporation|DEC]], the second in their [[Hierarchical Storage Controller]] series (after the [[HSC50 Hierarchical Storage Controller|HSC50]]), and part of the [[Digital Storage Architecture]] (DSA).
 The HSC70 connects with one or more [[host]] computer systems; it communicates over the [[Computer Interconnect]] (CI), via the [[SC008 Star Coupler]] (a passive, [[RF]]-[[transformer]] coupling network). The HSC was the first DEC mass storage server to connect to multiple hosts. The [[Mass Storage Control Protocol]] (MSCP) is a communication [[protocol]] used over the CI between host system(s) and the HSC70. This protocol enables a single class [[driver]] to replace multiple device-specific drivers. Separate but similar protocols exist for disk and tape communication:
@@ Line 12: / Line 14: @@
 An HSC70 can perform up to 1,150 I/O operations per second. It contains a [[microprocessor]]; in the case of the HSSC70, this is a [[J-11 chip set]]. The HSC70 is housed in a single cabinet.
-The successor model to the HSC70 was the [[HSC90]], to which an HSC70 can be field upgraded. (An [[HSC50 Hierarchical Storage Controller|HSC50]] cannot be upgraded into an HSC70.)
+The successor model to the HSC70 was the [[HSC90]], to which an HSC70 can be field upgraded. (An HSC50 cannot be upgraded into an HSC70.)
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