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

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(Formal board names)
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* Floating Point ALU (FALU - M7881)
 
* Floating Point ALU (FALU - M7881)
  
which mounted in slots 8-11 of the CPU [[backplane]]. The main CPU can detect the presence of the FP11-E, and, if present, uses it to perform any floating point [[instruction]]s found in the [[program]].
+
which mounted in slots 8-11 of the [[Central Processing Unit|CPU]]'s [[backplane]]. The main CPU can detect the presence of the FP11-E, and, if present, uses it to perform any floating point [[instruction]]s found in the [[program]].
  
Electrically, it connected directly to the CPU and is controlled bu it; unidirectional data buses are provided to move information (including instructions) from the CPU to the FPP, and vice versa.
+
Electrically, it connected directly to the CPU and is controlled by it; unidirectional data buses are provided to move information (including instructions) from the CPU to the FPP, and vice versa.
  
 
The FP11-E has its own microcode, 88 bits wide, to control its operation, and interaction with the main CPU.
 
The FP11-E has its own microcode, 88 bits wide, to control its operation, and interaction with the main CPU.

Revision as of 02:41, 18 June 2020

The FP11-E Floating Point Processor is the optional hardware floating point unit for the KD11-K CPU of the PDP-11/60. The KD11-K provided the full FP11 floating point using microcode; the FP11-E was an option which provided considerably improved floating point performance.

It was a 4 hex board co-processor:

  • Floating Point Next Micro-Address (FNUA - M7878)
  • Floating Point Exponent (FLTEXP - M7879)
  • Multiplying Network (MULNET - M7880)
  • Floating Point ALU (FALU - M7881)

which mounted in slots 8-11 of the CPU's backplane. The main CPU can detect the presence of the FP11-E, and, if present, uses it to perform any floating point instructions found in the program.

Electrically, it connected directly to the CPU and is controlled by it; unidirectional data buses are provided to move information (including instructions) from the CPU to the FPP, and vice versa.

The FP11-E has its own microcode, 88 bits wide, to control its operation, and interaction with the main CPU.