Digital Storage Systems Interconnect - Revision history

Flx: typo? DDSSI -> DSSI in 1 place

2025-11-28T02:29:23Z

typo? DDSSI -> DSSI in 1 place

Jnc: Better cat

2023-12-02T19:30:39Z

Better cat

Jnc: +New cat

2023-12-02T15:21:32Z

+New cat

Jnc: DSSI is also an alternative mass storage interface bus to earlier DSI

2023-12-02T12:25:26Z

DSSI is also an alternative mass storage interface bus to earlier DSI

Jnc: /* DSSI Solid State Disk Drives */ Add DSSI solid state disks

2023-12-02T12:16:46Z

‎DSSI Solid State Disk Drives: Add DSSI solid state disks

Vaxorcist: /* DSSI Controllers/Interfaces */ Internal link corrected

2023-09-11T18:09:40Z

‎DSSI Controllers/Interfaces: Internal link corrected

Vaxorcist: /* DSSI Controllers/Interfaces */ Two more DSSI adapters added

2023-09-11T18:08:44Z

‎DSSI Controllers/Interfaces: Two more DSSI adapters added

Jnc: Add cable names, more images; re-order contents a bit by importance

2023-09-08T11:25:53Z

Add cable names, more images; re-order contents a bit by importance

Vaxorcist: New section "Advance in DSSI Interface Usage"

2023-09-07T07:11:03Z

New section "Advance in DSSI Interface Usage"

Vaxorcist: /* DSSI Hierarchical Storage Controllers (HSDs) */ "HSD-10" link corrected

2023-09-06T16:34:47Z

‎DSSI Hierarchical Storage Controllers (HSDs): "HSD-10" link corrected

← Older revision		Revision as of 02:29, 28 November 2025
Line 1:		Line 1:
−	[[File:BC22Q-09 DSSI Cable.jpg\|thumb\|right\|250px\|~~DDSSI~~ cable]]	+	[[File:BC22Q-09 DSSI Cable.jpg\|thumb\|right\|250px\|DSSI cable]]

	The '''Digital Storage Systems Interconnect''' (usually given as '''DSSI''') is a [[mass storage]] [[bus]] from [[Digital Equipment Corporation\|DEC]]. The DSSI specification lists the main attributes of DSSI as: 8-bit wide [[parallel]]; multi-drop linear bus electrical topology; low-cost, [[single-ended signalling]] interface circuitry; [[direct current\|DC]] coupling. The DSSI's [[analog]] characteristics mean that DSSI installations require [[terminator]]s.		The '''Digital Storage Systems Interconnect''' (usually given as '''DSSI''') is a [[mass storage]] [[bus]] from [[Digital Equipment Corporation\|DEC]]. The DSSI specification lists the main attributes of DSSI as: 8-bit wide [[parallel]]; multi-drop linear bus electrical topology; low-cost, [[single-ended signalling]] interface circuitry; [[direct current\|DC]] coupling. The DSSI's [[analog]] characteristics mean that DSSI installations require [[terminator]]s.

@@ Line 189: / Line 189: @@
 [[Category: DEC Mass Storage]]
 [[Category: DSSI]]
-[[Category: Interface Standards]]
+[[Category: DEC Interface Standards]]

← Older revision		Revision as of 15:21, 2 December 2023
Line 189:		Line 189:
	[[Category: DEC Mass Storage]]		[[Category: DEC Mass Storage]]
	[[Category: DSSI]]		[[Category: DSSI]]
		+	[[Category: Interface Standards]]

@@ Line 3: / Line 3: @@
 The '''Digital Storage Systems Interconnect''' (usually given as '''DSSI''') is a [[mass storage]] [[bus]] from [[Digital Equipment Corporation|DEC]]. The DSSI specification lists the main attributes of DSSI as: 8-bit wide [[parallel]]; multi-drop linear bus electrical topology; low-cost, [[single-ended signalling]] interface circuitry; [[direct current|DC]] coupling. The DSSI's [[analog]] characteristics mean that DSSI installations require [[terminator]]s.
-The DSSI is an alternate physical layer in the [[Computer Interconnect]] system; the CI system had a 'native' physical layer before the creation of DSSI. The relationship between the DSSI and the CI's physical layer is shown in the following diagram:
+The DSSI is an alternate physical layer in the [[Computer Interconnect]] system; the CI system had a 'native' physical layer before the creation of DSSI. (DSSI is also an alternative mass storage [[drive]] to [[device controller|controller]] interface bus, from the earlier [[Standard Disk Interconnect]].) The relationship between the DSSI and the CI's physical layer is shown in the following diagram:
 <pre>
                                                            <-----+

@@ Line 126: / Line 126: @@
 == DSSI Disk Drives ==
 * [[RF30]]
@@ Line 141: / Line 143: @@
 * [[RF74]]
 * [[RF75]]
 == DSSI Tape Drives ==

@@ Line 102: / Line 102: @@
 * [[EDA640]] [[MicroVAX 3300/3400]] [[KA640]] embedded DSSI Adapter (EDA)
 * [[KFA40]] [[DEC 4000]] I/O Module
-* [[SHAC]] [[VAX 4000]] embedded DSSI Adapter
+* [[SHAC]] [[VAX 4000 series]] embedded DSSI Adapter
 * [[SWIFT]] [[VAXft series]] embedded DSSI Adapter

@@ Line 1: / Line 1: @@
 The '''Digital Storage Systems Interconnect''' (usually given as '''DSSI''') is a [[mass storage]] [[bus]] from [[Digital Equipment Corporation|DEC]]. The DSSI specification lists the main attributes of DSSI as: 8-bit wide [[parallel]]; multi-drop linear bus electrical topology; low-cost, [[single-ended signalling]] interface circuitry; [[direct current|DC]] coupling. The DSSI's [[analog]] characteristics mean that DSSI installations require [[terminator]]s.
@@ Line 49: / Line 51: @@
   "The DSSI, supporting the needs of low-end and mid-range systems, is one in a family of high-performance computer-to-computer interconnects .. that combine a common host interface and port layer with an implementation-specific datalink and physical interconnect.
   CI-class interconnects provide the transmission services required by Digital's [[System Communication Architecture]] (SCA) - a four-tiered set of protocols and interfaces.."
 == DSSI Cabling ==
@@ Line 65: / Line 73: @@
 * '''PS''' (Pin Socket or pedestal style), with round [[pin]]s = "50 Way High Density Honda"
-[[File:DSSI_PS_Connector_female_(Cable).jpg|thumb|right|200px|PS Connector female (Cable)]]
+[[File:DSSI MR Connector female (Cable).jpg|thumb|right|80px|MR female connector]]
-With these two different types of connectors, ''three'' different types of long DSSI cables are needed:
+When found on cables, these exist in both 'straight' and 'right-angle' forms (to allow cables to be neatly dressed, in part so they are less likely to get damaged).
-* MR-MR
+With these two different types of connectors, ''three'' different basic types of long DSSI cables are needed (cable names for types available from DEC included):
 * PS-PS
-* MR-PS (can be reversed to provide PS-MR)
+* MR-MR - BC21Q-xx (2x straight); BC29S-xx (right-angle to straight)
 Two types of DSSI connectors are found on devices:
@@ Line 137: / Line 149: @@
 * [[TF88]]
 * [[TF89]]
 == Images ==
-[[File:DSSI_PS_Connector_male_(CPU).jpg|thumb|left|300px|PS Connector male (CPU)]]
+[[File:DSSI_PS_Connector_female_(Cable).jpg|thumb|left|300px|PS female  connector]]
-[[File:DSSI_PS_Terminator_female.jpg|thumb|left|300px|PS Terminator female]]
+[[File:DSSI PS Connector female (Cable)-2.jpg|thumb|left|80px|PS female connector]]
 [[File:DSSI_Interface_Card_Assembly.png|thumb|left|350px|Interface Card Assembly (5.25" FH disk)]]
 [[File:DSSI_Interface_Card_Assembly_Dual_RF35_Connector.jpg|thumb|left|300px|Interface Card Assembly Dual RF35]]

@@ Line 96: / Line 96: @@
 * [[HSD05]]
-* [[HSD10]]
+* [[HSD10 DSSI-to-SCSI Bus Adapter|HSD10]]
 * [[HSD30]]
 * [[HSD50]]