FPF11 floating point processor - Revision history

Jnc: plugs into UNIBUS or QBUS

2022-10-12T00:31:12Z

plugs into UNIBUS or QBUS

Jnc: +manual, FMPS

2021-11-19T03:16:11Z

+manual, FMPS

Jnc: Go via redir so that if a separate page gets done...

2018-11-18T13:13:48Z

Go via redir so that if a separate page gets done...

Jnc: copyedit for clarification

2018-11-18T13:12:46Z

copyedit for clarification

Jnc: Very good coverage

2018-11-18T03:29:14Z

Very good coverage

New page

The '''FPF11 floating point processor''' is an optional [[co-processor]] module which provides high-performance [[floating point]] for [[KDF11 CPUs]] which use the [[F-11 chip set]]; it implements [[FP11 floating point|FP11]]-compatible [[floating point]].

It is a [[DEC card form factor|quad]] [[printed circuit board|board]] (the M8188) which plugs into the [[backplane]] slot next to the [[Central Processing Unit|CPU]] board. It only gets power from the backplane, though; a [[flat cable]] connects the FPF11 to the CPU board, and plugs into the [[chip socket]] which the [[KEF11-A floating point chip]] normally goes into.

That socket gives the FPF11 access to both the [[data bus]] and the [[microcode|microinstruction]] [[bus]] on the CPU card. The FPF11 contains [[microcode]] to control both the main CPU, and the floating point [[hardware]] on the FPF11. The main CPU is sent [[no-op]] microinstructions when there is nothing for it to do; e.g. when the FPF11 does not need it to [[fetch]] data from, or [[store]] it in, [[main memory]].

Control of the main CPU is transferred to the FPF11 in the same way as to the KEF11-A when a floating point instruction is seen, but while the latter uses the hardware on the CPU to perform all its calcuations, the FPF11 has extensive hardware to perform floating point calculations at higher performance on-board. The FPF11 has its own [[clock]], and its microcode can select cycles of different durations, as needed; the FPF11 can re-synchronize with the main CPU when control is to be transferred back to it at the end of the floating point instruction.

The floating point [[register]]s are actually on the FPF11 (probably for performance), unlike those for the KEF11-A, which are in the [[KTF11-A memory management chip]].

[[Category: PDP-11 Processors]]

@@ Line 1: / Line 1: @@
 The '''FPF11 floating point processor''' is an optional [[co-processor]] module which provides high-performance [[floating point]] for [[KDF11 CPUs]] (which use the [[F-11 chip set]]); it implements [[FP11 floating point|FP11]]-compatible [[floating point]].
-It is a [[DEC card form factor|quad]] [[printed circuit board|board]] (the M8188) which plugs into the [[backplane]] slot next to the [[Central Processing Unit|CPU]] board. It only gets power from the backplane, though; a [[flat cable]] connects the FPF11 to the CPU board; it plugs into the [[Dual Inline Package|DIP]] [[chip socket]] which the [[KEF11-A floating point chip]] normally goes into.
+It is a [[DEC card form factor|quad]] [[printed circuit board|board]] (the M8188) which plugs into the [[backplane]] slot next to the [[Central Processing Unit|CPU]] board.  It can be plugged into either a [[UNIBUS]] or [[QBUS]] backpane, since it does not use the [[bus]]; it only gets power from the backplane. All [[signal]]s are received over a [[flat cable]] which connects the FPF11 to the CPU board, where it plugs into the [[Dual Inline Package|DIP]] [[chip socket]] which the [[KEF11-A floating point chip]] normally goes into.
-That socket gives the FPF11 access to both the [[data bus]] and the [[microinstruction]] [[bus]] on the CPU card. The FPF11 contains [[microcode]] to control both the main CPU, and the  [[hardware]] on the FPF11. The main CPU is sent [[no-op]] microinstructions when there is nothing for it to do; e.g. when the FPF11 does not need it to [[fetch]] data from, or [[store]] it in, [[main memory]].
+That socket gives the FPF11 access to both the [[data bus]] and the [[microinstruction]] bus on the CPU card. The FPF11 contains [[microcode]] to control both the main CPU, and the  [[hardware]] on the FPF11. The main CPU is sent [[no-op]] microinstructions when there is nothing for it to do; e.g. when the FPF11 does not need it to [[fetch]] data from, or [[store]] it in, [[main memory]].
 Control of the main CPU is transferred to the FPF11 in the same way as to the KEF11-A when a floating point instruction is seen; but while the latter uses the hardware on the CPU to perform all its calcuations, the FPF11 has extensive hardware to perform floating point calculations at higher performance, on-board.

@@ Line 1: / Line 1: @@
 The '''FPF11 floating point processor''' is an optional [[co-processor]] module which provides high-performance [[floating point]] for [[KDF11 CPUs]] (which use the [[F-11 chip set]]); it implements [[FP11 floating point|FP11]]-compatible [[floating point]].
-It is a [[DEC card form factor|quad]] [[printed circuit board|board]] (the M8188) which plugs into the [[backplane]] slot next to the [[Central Processing Unit|CPU]] board. It only gets power from the backplane, though; a [[flat cable]] connects the FPF11 to the CPU board; it plugs into the [[chip socket]] which the [[KEF11-A floating point chip]] normally goes into.
+It is a [[DEC card form factor|quad]] [[printed circuit board|board]] (the M8188) which plugs into the [[backplane]] slot next to the [[Central Processing Unit|CPU]] board. It only gets power from the backplane, though; a [[flat cable]] connects the FPF11 to the CPU board; it plugs into the [[Dual Inline Package|DIP]] [[chip socket]] which the [[KEF11-A floating point chip]] normally goes into.
 That socket gives the FPF11 access to both the [[data bus]] and the [[microinstruction]] [[bus]] on the CPU card. The FPF11 contains [[microcode]] to control both the main CPU, and the  [[hardware]] on the FPF11. The main CPU is sent [[no-op]] microinstructions when there is nothing for it to do; e.g. when the FPF11 does not need it to [[fetch]] data from, or [[store]] it in, [[main memory]].
@@ Line 10: / Line 10: @@
 The floating point [[register]]s are actually on the FPF11 (probably for performance), unlike those for the KEF11-A, which are in the [[KTF11-A memory management chip]].
 [[Category: PDP-11 Processors]]

@@ Line 3: / Line 3: @@
 It is a [[DEC card form factor|quad]] [[printed circuit board|board]] (the M8188) which plugs into the [[backplane]] slot next to the [[Central Processing Unit|CPU]] board. It only gets power from the backplane, though; a [[flat cable]] connects the FPF11 to the CPU board; it plugs into the [[chip socket]] which the [[KEF11-A floating point chip]] normally goes into.
-That socket gives the FPF11 access to both the [[data bus]] and the [[microcode|microinstruction]] [[bus]] on the CPU card. The FPF11 contains [[microcode]] to control both the main CPU, and the  [[hardware]] on the FPF11. The main CPU is sent [[no-op]] microinstructions when there is nothing for it to do; e.g. when the FPF11 does not need it to [[fetch]] data from, or [[store]] it in, [[main memory]].
+That socket gives the FPF11 access to both the [[data bus]] and the [[microinstruction]] [[bus]] on the CPU card. The FPF11 contains [[microcode]] to control both the main CPU, and the  [[hardware]] on the FPF11. The main CPU is sent [[no-op]] microinstructions when there is nothing for it to do; e.g. when the FPF11 does not need it to [[fetch]] data from, or [[store]] it in, [[main memory]].
 Control of the main CPU is transferred to the FPF11 in the same way as to the KEF11-A when a floating point instruction is seen; but while the latter uses the hardware on the CPU to perform all its calcuations, the FPF11 has extensive hardware to perform floating point calculations at higher performance, on-board.