- 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
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.
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.
|v • d • e PDP-11 Computers and Peripherals|
| Unibus PDP-11s - PDP-11/20 • PDP-11/15 • PDP-11/35 • PDP-11/40 • PDP-11/45 • PDP-11/50 • PDP-11/55 • PDP-11/70 • PDP-11/05 • PDP-11/10 • PDP-11/34 • PDP-11/04 • PDP-11/44 • PDP-11/60 • PDP-11/24 • PDP-11/84 • PDP-11/94
Clones: CM 1420