Difference between revisions of "RH750 Massbus Adapter"

From Computer History Wiki
Jump to: navigation, search
m (+MASSBUS Adapter image)
m (External links: +VAX-11/750 Installation Manual)
 
(One intermediate revision by the same user not shown)
Line 1: Line 1:
 
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, the ,which mounts in the VAX-11/750 [[backplane]] in one of the three [[VAX-11/750#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.
+
It was implemented on one [[DEC card form factor|extended hex]] card, the L0007 MASSBUS Adapter (MBA), which mounts in the VAX-11/750 [[backplane]] in one of the three [[VAX-11/750#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.
  
 
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==
+
==Further reading==
  
 
* ''RH750 Massbus Adapter Technical Description'' (EK-RH750-TD) - not available online
 
* ''RH750 Massbus Adapter Technical Description'' (EK-RH750-TD) - not available online
Line 12: Line 12:
 
==External links==
 
==External links==
  
 +
* [https://vt100.net/mirror/hcps/si75fin1.pdf VAX-11/750 Installation Manual] (EK-SI75F-IN-001) - the RH750 is covered in Chapter 10 (pp. 133-143 of the PDF)
 
* [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)
 
* [https://web.archive.org/web/20071004184551/http://computer-refuge.org/compcollect/dec/vax/11750/L0007-big.jpg L0007 (MBA)] - MASSBUS Adapter image
 
* [https://web.archive.org/web/20071004184551/http://computer-refuge.org/compcollect/dec/vax/11750/L0007-big.jpg L0007 (MBA)] - MASSBUS Adapter image

Latest revision as of 20:13, 17 May 2024

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, the L0007 MASSBUS Adapter (MBA), 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.

Further reading

  • 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