Difference between revisions of "KDF11 CPUs"
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The '''KDF11 CPUs''' are single-[[printed circuit board|board]] [[PDP-11]] [[Central Processing Unit|CPUs]] which all use the 'Fonz' [[F-11 chip set]]: | The '''KDF11 CPUs''' are single-[[printed circuit board|board]] [[PDP-11]] [[Central Processing Unit|CPUs]] which all use the 'Fonz' [[F-11 chip set]]: | ||
| − | *[[KDF11-A CPU]] - M8186 - [[QBUS]] [[DEC card form factor|dual]]-width CPU used in the [[PDP-11/23]] | + | * [[KDF11-A CPU]] - M8186 - [[QBUS]] [[DEC card form factor|dual]]-width CPU used in the [[PDP-11/23]] |
| − | *[[KDF11-B CPU]] - M8189 - QBUS quad-width CPU used in the [[PDP-11/23_PLUS|PDP-11/23+]] | + | * [[KDF11-B CPU]] - M8189 - QBUS quad-width CPU used in the [[PDP-11/23_PLUS|PDP-11/23+]] |
| − | *[[KDF11-U CPU]] - M7133 - [[UNIBUS]] hex-width CPU used in the [[PDP-11/24]] | + | * [[KDF11-U CPU]] - M7133 - [[UNIBUS]] hex-width CPU used in the [[PDP-11/24]] |
| − | The basic [[clock]] µcycle is 300 nsec; simple [[register]]-register [[instruction]]s (e.g. MOV, ADD,etc) took 1.7 µseconds Depending on the [[operand]] [[PDP-11 architecture#Operands|modes]] used in a particular instruction, and the [[main memory]] speed (with the [[asynchronous]] QBUS), that could add roughly 8.5 µseconds to that | + | The basic [[clock]] µcycle is 300 nsec; simple [[register]]-register [[instruction]]s (e.g. MOV, ADD, etc) took 1.7 µseconds (1.2 µseconds on the KDF11-U). Depending on the [[operand]] [[PDP-11 architecture#Operands|modes]] used in a particular instruction, and the [[main memory]] speed (with the [[asynchronous]] QBUS), that could add up to roughly 8.5 µseconds (4.2 µseconds on the KDF11-U) to that basic time. (The extra time is roughly linear in the number of [[memory cycle]]s, at roughly 1.2 µseconds (0.8 µseconds on the KDF11-U) per cycle - PDP-11 instructions could add up to 6 additional memory cycles per instruction, above the 1 needed to [[fetch]] the basic instruction.) |
Like the [[LSI-11 CPUs|LSI-11]] models, as a cost-reduction measure they do not have a [[front panel]] to control them; instead, when the CPU is halted, specialized [[microcode]] used the main [[asynchronous serial line]] as a operating console. The command set is named Octal Debugging Technique ([[QBUS CPU ODT|ODT]]); there are commands to read and write [[main memory]], start the CPU, etc. | Like the [[LSI-11 CPUs|LSI-11]] models, as a cost-reduction measure they do not have a [[front panel]] to control them; instead, when the CPU is halted, specialized [[microcode]] used the main [[asynchronous serial line]] as a operating console. The command set is named Octal Debugging Technique ([[QBUS CPU ODT|ODT]]); there are commands to read and write [[main memory]], start the CPU, etc. | ||
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* [[LSI-11 CPUs]] | * [[LSI-11 CPUs]] | ||
| + | * [[KDJ11 CPUs]] | ||
| − | + | [[Category: PDP-11 UNIBUS Processors]] | |
| − | + | [[Category: PDP-11 QBUS Processors]] | |
| − | [[Category: PDP-11 Processors]] | ||
Latest revision as of 13:49, 29 March 2022
The KDF11 CPUs are single-board PDP-11 CPUs which all use the 'Fonz' F-11 chip set:
- KDF11-A CPU - M8186 - QBUS dual-width CPU used in the PDP-11/23
- KDF11-B CPU - M8189 - QBUS quad-width CPU used in the PDP-11/23+
- KDF11-U CPU - M7133 - UNIBUS hex-width CPU used in the PDP-11/24
The basic clock µcycle is 300 nsec; simple register-register instructions (e.g. MOV, ADD, etc) took 1.7 µseconds (1.2 µseconds on the KDF11-U). Depending on the operand modes used in a particular instruction, and the main memory speed (with the asynchronous QBUS), that could add up to roughly 8.5 µseconds (4.2 µseconds on the KDF11-U) to that basic time. (The extra time is roughly linear in the number of memory cycles, at roughly 1.2 µseconds (0.8 µseconds on the KDF11-U) per cycle - PDP-11 instructions could add up to 6 additional memory cycles per instruction, above the 1 needed to fetch the basic instruction.)
Like the LSI-11 models, as a cost-reduction measure they do not have a front panel to control them; instead, when the CPU is halted, specialized microcode used the main asynchronous serial line as a operating console. The command set is named Octal Debugging Technique (ODT); there are commands to read and write main memory, start the CPU, etc.
The main asynchronous serial interface is normally configured so that when the CPU is running, sending a break on the console serial line halts the CPU.
Floating point
All the KDF11 CPUs have two choices for floating point support (full PDP-11 FP11 floating point): a on-board single chip, the KEF11-A floating point chip, which implements floating point using microcode; and a higher-performance co-processor on a separate quad board, the FPF11 (M8188).
The FPF11 communicates with the KDF11 via a flat cable that plugs into the chip socket on the KDF11 where the KEF11-A is installed; is unusual that it can plug into either a QBUS or UNIBUS backplane, since it draws only power from the backplane - all signals come over the cable to the KDF11.
