Difference between revisions of "FP11-A Floating-Point Processor"

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[[Image:FP11-A.jpg|250px|right|thumb|FP11-A floating point card]]
 
[[Image:FP11-A.jpg|250px|right|thumb|FP11-A floating point card]]
  
The '''FP11-A Floating-Point Processor''' is the optional [[hardware]] [[floating point]] unit for the [[PDP-11/34A]] ([[KD11-EA CPU|KD11-EA]] [[Central Processing Unit|CPU]]). It supports the full [[PDP-11]] [[FP11 floating point]].
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The '''FP11-A Floating-Point Processor''' is the optional [[hardware]] [[floating point]] unit for the [[PDP-11/34A]] ([[KD11-EA CPU|KD11-EA]] [[Central Processing Unit|CPU]]). It consists of a single [[DEC card form factor|hex]] board, the '''M8267'''. It supports the full [[PDP-11]] [[FP11 floating point]].
  
It consists of a single [[DEC card form factor|hex]] board, the M8267. Its connections to the KD11-EA include two [[over the back]] connectors; a 20-pin connector to the M8265 card of the KD11-EA, and a 10 pin connector to the M8266 card. (This was because the [[PDP-11/34]] could be field-upgraded from a [[KD11-E CPU]], which did not support the floating point unit, to a KD11-EA, which did - but the original [[DD11-P backplane]] was retained.)
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The FP11-A uses a bank of 16 [[Am2901 Four-Bit Microprocessor Slice]] [[integrated circuit|chips]] to perform all its computations; the main CPU is also used, to load and store [[operand]]s in [[main memory]], etc. Both are [[microcode]]d; the microcode width is 48 bits in each. The microcode for the CPU is contained on the CPU's M8266 card; the portion used for the FP11-A is the high half.
  
The latter over-the-top connector uses the connectors on the M8266 card which normally hold the maintenance cables to the [[KY11-LB Programmer's Console]]; in systems with a KY11-LB, the cables to the console will now connect to the M8267 card. (This is all necessitated because the FP11-A needs access to signals carried over the maintenance cables.)
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The FP11-A's connections to the KD11-EA include two [[over the back]] connectors; a 20-pin connector to the M8265 card of the KD11-EA, and a 10 pin connector to the M8266 card. (This was likely because the [[PDP-11/34]] could be field-upgraded from a [[KD11-E CPU]], which did not support the floating point unit, to a KD11-EA, which did - but its original [[DD11-P backplane]] was retained.)
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==Installation==
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This is mostly covered [[KD11-EA CPU#FP11-A/KK11-A installation|here]]. The latter over-the-top connector uses the connectors on the M8266 card which normally hold the maintenance cables to the [[KY11-LB Programmer's Console]]; in systems with a KY11-LB, the cables to the console will now connect to the M8267 card. (This is all necessitated because the FP11-A needs access to signals carried over the maintenance cables.)
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For hardware debugging/repair, when the M8267 card is normally placed on a hex [[extender card]] to allow physical access to internal signals, a special W9042 Extender Board exists, to be used in place of the usual over the back connector, when so doing.
  
 
{{semi-stub}}
 
{{semi-stub}}
  
{{PDP-11}}
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==External links==
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* [http://www.bitsavers.org/pdf/dec/pdp11/1134/EK-FP11A-UG-001.pdf FP11-A floating-point processor user's guide] (EK-FP11A-UG-001)
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* [http://www.bitsavers.org/pdf/dec/pdp11/1134/EK-FP11A-TM-002.pdf FP11-A floating-point processor technical manual] (EK-FP11A-TM-002)
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* [http://wwcm.synology.me/pdf/MP00189%20FP11-A%20Field%20Maintenance%20Print%20Set.pdf FP11-A Field Maintenance Print Set] (MP00189) - contains the FP11-A microcode on pp. 42-89
  
 
[[Category: PDP-11 Processors]]
 
[[Category: PDP-11 Processors]]

Revision as of 17:01, 12 January 2022

FP11-A floating point card

The FP11-A Floating-Point Processor is the optional hardware floating point unit for the PDP-11/34A (KD11-EA CPU). It consists of a single hex board, the M8267. It supports the full PDP-11 FP11 floating point.

The FP11-A uses a bank of 16 Am2901 Four-Bit Microprocessor Slice chips to perform all its computations; the main CPU is also used, to load and store operands in main memory, etc. Both are microcoded; the microcode width is 48 bits in each. The microcode for the CPU is contained on the CPU's M8266 card; the portion used for the FP11-A is the high half.

The FP11-A's connections to the KD11-EA include two over the back connectors; a 20-pin connector to the M8265 card of the KD11-EA, and a 10 pin connector to the M8266 card. (This was likely because the PDP-11/34 could be field-upgraded from a KD11-E CPU, which did not support the floating point unit, to a KD11-EA, which did - but its original DD11-P backplane was retained.)

Installation

This is mostly covered here. The latter over-the-top connector uses the connectors on the M8266 card which normally hold the maintenance cables to the KY11-LB Programmer's Console; in systems with a KY11-LB, the cables to the console will now connect to the M8267 card. (This is all necessitated because the FP11-A needs access to signals carried over the maintenance cables.)

For hardware debugging/repair, when the M8267 card is normally placed on a hex extender card to allow physical access to internal signals, a special W9042 Extender Board exists, to be used in place of the usual over the back connector, when so doing.

External links