Difference between revisions of "RH750 Massbus Adapter"

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(CMI config info is not RH750-specific - move to general /750 page)
m (See also: +VAX Hardware Handbook)
 
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The '''RH750 Massbus Adapter''' was a [[MASSBUS]] [[device controller]] for the [[VAX-11/750]]'s [[CPU/Memory Interconnect]] (CMI).
 
The '''RH750 Massbus Adapter''' was a [[MASSBUS]] [[device controller]] for the [[VAX-11/750]]'s [[CPU/Memory Interconnect]] (CMI).
  
It was implemented on one [[DEC card form factor|extended hex]] card, which mounts in the VAX-11/750 [[backplane]] in one of the three [[VAX-11/750#CMI_backplane_configuration|CMI option slots]].
+
It was implemented on one [[DEC card form factor|extended hex]] card, which mounts in the VAX-11/750 [[backplane]] in one of the three [[VAX-11/750#CMI_backplane_configuration|CMI option slots]]. A VAX-11/750 could have up to three RH750 Adapters; the first one goes into CMI slot 9, the second into slot 8, and the third in slot 7.
 
 
A VAX-11/750 could have up to three RH750 Adapters, the first one goes into CMI slot 9, the second into slot 8, and the third in slot 7.
 
  
 
It was common practice to have two separate RH750s, one for [[magnetic tape|tape]] and another for [[disk]] devices. Combining both on one RH750 was possible, but tape usage had a negative impact on disk performance.
 
It was common practice to have two separate RH750s, one for [[magnetic tape|tape]] and another for [[disk]] devices. Combining both on one RH750 was possible, but tape usage had a negative impact on disk performance.
  
== See also ==
+
==See also==
  
 
* ''RH750 Massbus Adapter Technical Description'' (EK-RH750-TD) - not available online
 
* ''RH750 Massbus Adapter Technical Description'' (EK-RH750-TD) - not available online
 +
* ''VAX Hardware Handbook (1980-81)'' (EB-17281-20) - the RH750 is covered in some detail in Chapter 10, pp. 175-190
  
== External links ==
+
==External links==
  
 
* [http://www.bitsavers.org/pdf/dec/vax/750/MP01045_RH750_Engineering_Drawings_198102.pdf RH750 Field Maintenance Print Set] (MP-01045)
 
* [http://www.bitsavers.org/pdf/dec/vax/750/MP01045_RH750_Engineering_Drawings_198102.pdf RH750 Field Maintenance Print Set] (MP-01045)

Latest revision as of 01:03, 6 June 2022

The RH750 Massbus Adapter was a MASSBUS device controller for the VAX-11/750's CPU/Memory Interconnect (CMI).

It was implemented on one extended hex card, which mounts in the VAX-11/750 backplane in one of the three CMI option slots. A VAX-11/750 could have up to three RH750 Adapters; the first one goes into CMI slot 9, the second into slot 8, and the third in slot 7.

It was common practice to have two separate RH750s, one for tape and another for disk devices. Combining both on one RH750 was possible, but tape usage had a negative impact on disk performance.

See also

  • RH750 Massbus Adapter Technical Description (EK-RH750-TD) - not available online
  • VAX Hardware Handbook (1980-81) (EB-17281-20) - the RH750 is covered in some detail in Chapter 10, pp. 175-190

External links