RK11-C disk controller
The RK11-C is the earliest version of the RK11 disk controller. (Nothing is known of the -A and -B, if they ever existed as products.)
Like many of the earlier large peripheral controllers for the PDP-11, it was a large custom wire-wrapped backplane which bolted into the front of a 19 inch rack, such as an H960; into it plugged about 40 small M-Series FLIP CHIPs.
The backplane is wired for connection to a standard DEC indicator panel, but no inlay for such has even been sighted, although the RK11-C Engineering Drawings allow one to work out exactly what such an inlay would have looked like.
Contents
Double Buffered RK11-C
There is also a rare variant of the RK11-C, the 'Double Buffer' RK11-C.
Engineering drawings
The engineering drawings for the Double Buffer RK11-C are very similar to those of the standard RK11-C. The differences are listed below.
Note: The engineering drawings available online for the original RK11-C are missing pages 18 and 19:
- 18 - Disk Cable and Termination
- 19 - Bus "D" Drvrs and Rcvrs
The Double Buffer set inludes those pages, numbered 21 and 18 there, respectively. (The re-numbering of that first drawing from 18 to 21 caused the prints numbered from 19 to 21 in the original RK11-C set to be numbered one lower in the Double Buffer set; e.g. RKDB Data Paths was 21 in the original RK11-C set, and is 20 in the Double Buffer set.)
New prints:
- 24 - DSB/Bus -> ABuf Controls
- 25 - ABuf/BBug Reg
- 26 - Interbuffer Transfer Control
- 27 - Buffer Control
Major changes:
- 10 - RKDB and Control
- 11B - Reg Sel, NPR & Int Control
Minor changes:
- 13 - Adder Control (Adder Control #2 flop set input logic)
- 15 - RKBA - RKWC - RKMR (logic lower left corner)
- 16 - Errors (logic center driving DLT flop)
- 17 - Cable Drivers (hand-written gate lower left)
- 20 - RKDB Data Paths (replace 'BUS D' with 'BBUF' on all data bits)
RK11-C module count/location tables
The following tables give a listing of the Flip Chips used in the RK11-C, and their location in the backplane.
Module counts
(Drawn from module utilization drawing, confirmed in module count chart):
Single height boards:
| Type | Count | Function |
|---|---|---|
| G736 | Jumper | |
| G740 | Disk selection | |
| M002 | 15 Loads | |
| M105 | Address selector | |
| M111 | 2 | Inverter |
| M112 | 5 | NOR gate |
| M113 | 7 | 10 x 2-Input NAND gates |
| M115 | 3 | 8 x 3-Input NAND gates |
| M116 | 3 | 6 x 4-Input NOR gates |
| M117 | 3 | 6 x 4-Input NAND gates |
| M119 | 2 | 3 x 8-Input NAND gates |
| M121 | 3 | AND/NOR gates |
| M141 | 2 | NAND/NOR gates |
| M149 | 10 | 9 x 2-NAND wired OR matrix |
| M161 | Binary to octal/decimal decoder | |
| M163 | Dual binary to decimal decoder | |
| M203 | 4 | 8 x SR flip-flops |
| M205 | 3 | 5 x 'D' flip-flops |
| M207 | J-K Flip-flops (3-3 configuration) | |
| M208 | 2 | 8-bit buffer shift register |
| M214 | 3 | 6-bit register |
| M216 | 5 | 6 x flip-flops |
| M236 | 12-bit binary up/down counter | |
| M238 | Synchronous 4-bit up/down counter | |
| M239 | 2 | 3 x 4-bit up/down counter/register |
| M304 | 3 | One shot delay |
| M307 | 3 | Integrating one shot |
| M405 | Crystal clock | |
| M611 | High speed power inverter | |
| M617 | 6 x 4-input NAND buffers | |
| M623 | 3 | Bus driver |
| M782 | Interrupt control | |
| M784 | 3 | UNIBUS receivers |
| M796 | UNIBUS master control | |
| M797 | Register select | |
| M798 | UNIBUS drivers | |
Double height boards:
- M795 - Word Count and Current Memory Address
Module Utilization Chart
The Flip Chip module utilization chart for the RK11-C backplane is as follows (* = Connector):
| Slot | A | B | C | D |
|---|---|---|---|---|
| 1 | UNIBUS in | |||
| 2 | UNIBUS out | |||
| 3 | ||||
| 4 | ||||
| 5 | M105 | M784 | ||
| 6 | M782 | M79 | ||
| 7 | M795 | |||
| 8 | M784 | M784 | ||
| 9 | M623 | M307 | ||
| 10 | Disk bus 2* | M623 | M307 | |
| 11 | M623 | M307 | ||
| 12 | Disk bus 1* | M207 | M163 | |
| 13 | M798 | G736 | G740 | M405 |
| 14 | M149 | M149 | M116 | M161 |
| 15 | M149 | M149 | M304 | M119 |
| 16 | M149 | M149 | M113 | M113 |
| 17 | M239 | M238 | M216 | M141 |
| 18 | M239 | M214 | M115 | M115 |
| 19 | M214 | M214 | M121 | M112 |
| 20 | M208 | M208 | M111 | M111 |
| 21 | M203 | M203 | M112 | M112 |
| 22 | M149 | M149 | M205 | M117 |
| 23 | M149 | M149 | M203 | M203 |
| 24 | M121 | M002 | M116 | M115 |
| 25 | M216 | M797 | M611 | M617 |
| 26 | M141 | M119 | M113 | M304 |
| 27 | M304 | M112 | M112 | M113 |
| 28 | M236 | M121 | M216 | M216 |
| 29 | M205 | M117 | M117 | |
| 30 | W130* | M113 | M113 | |
| 31 | 6775* | M113 | M205 | |
| 32 | 6775* | M116 | M216 | |
W130 = Maintenance board
6775 = Cable to indicator panel
Double Buffered RK11-C module count/location tables
The following tables give a listing of the Flip Chips used in the Double Buffered variant of the RK11-C, and their location in the backplane.
Module counts
(Drawn from module count chart):
| Type | Count | Function |
|---|---|---|
| G736 | Jumper | |
| G740 | Disk selection | |
| M002 | 3 | 15 Loads |
| M105 | Address selector | |
| M111 | 5 | Inverter |
| M112 | 7 | NOR gate |
| M113 | 10 | 10 x 2-Input NAND gates |
| M115 | 4 | 8 x 3-Input NAND gates |
| M116 | 3 | 6 x 4-Input NOR gates |
| M117 | 4 | 6 x 4-Input NAND gates |
| M119 | 2 | 3 x 8-Input NAND gates |
| M121 | 3 | AND/NOR gates |
| M141 | 2 | NAND/NOR gates |
| M149 | 12 | 9 x 2-NAND wired OR matrix |
| M161 | Binary to octal/decimal decoder | |
| M163 | Dual binary to decimal decoder | |
| M203 | 4 | 8 x SR flip-flops |
| M205 | 4 | 5 x 'D' flip-flops |
| M207 | J-K Flip-flops (3-3 configuration) | |
| M208 | 6 | 8-bit buffer shift register |
| M214 | 3 | 6-bit register |
| M216 | 5 | 6 x flip-flops |
| M236 | 12-bit binary up/down counter | |
| M238 | Synchronous 4-bit up/down counter | |
| M239 | 2 | 3 x 4-bit up/down counter/register |
| M304 | 5 | One shot delay |
| M307 | 3 | Integrating one shot |
| M405 | Crystal clock | |
| M606 | 2 | Pulse generator |
| M611 | High speed power inverter | |
| M617 | 6 x 4-input NAND buffers | |
| M623 | 3 | Bus driver |
| M782 | Interrupt control | |
| M784 | 3 | UNIBUS receivers |
| M796 | UNIBUS master control | |
| M797 | Register select | |
| M798 | UNIBUS drivers | |
Double height boards:
- M795 - Word Count and Current Memory Address
Module Utilization Chart
The Flip Chip module utilization chart for the RK11-C backplane is as follows (* = Connector):
| Slot | A | B | C | D |
|---|---|---|---|---|
| 1 | UNIBUS in | M606 | M113 | |
| 2 | UNIBUS out | M115 | M002 | |
| 3 | M149 | M149 | M208 | M208 |
| 4 | M111 | M002 | M205 | M113 |
| 5 | M105 | M784 | M208 | M208 |
| 6 | M782 | M796 | M304 | M304 |
| 7 | M795 | M606 | M112 | |
| 8 | M784 | M784 | M112 | M111 |
| 9 | M117 | M111 | M623 | M307 |
| 10 | Disk bus 2* | M623 | M307 | |
| 11 | M113 | M623 | M307 | |
| 12 | Disk bus 1* | M207 | M163 | |
| 13 | M798 | G736 | G740 | M405 |
| 14 | M149 | M149 | M116 | M161 |
| 15 | M149 | M149 | M304 | M119 |
| 16 | M149 | M149 | M113 | M113 |
| 17 | M239 | M238 | M216 | M141 |
| 18 | M239 | M214 | M115 | M115 |
| 19 | M214 | M214 | M121 | M112 |
| 20 | M208 | M208 | M111 | M111 |
| 21 | M203 | M203 | M112 | M112 |
| 22 | M149 | M149 | M205 | M117 |
| 23 | M149 | M149 | M203 | M203 |
| 24 | M121 | M002 | M116 | M115 |
| 25 | M216 | M797 | M611 | M617 |
| 26 | M141 | M119 | M113 | M304 |
| 27 | M304 | M112 | M112 | M113 |
| 28 | M236 | M121 | M216 | M216 |
| 29 | M205 | M117 | M117 | |
| 30 | W130* | M113 | M113 | |
| 31 | 6775* | M113 | M205 | |
| 32 | 6775* | M116 | M216 | |
W130 = Maintenance board (optional)
6775 = Cable to indicator panel
