View source for 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-wrap]]ped [[backplane]] which bolted into the front of a 19 inch rack, such as an [[H960]]; into it plugged about 40 small M-Series [[FLIP CHIP]]s.

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.

==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:

{| class="wikitable"
! Type	!! Count !! Function
|-
| G736 || || Jumper
|-
| G740 || || Disk selection
|-
| colspan="3" | 
|-
| 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):

{| class="wikitable"
! Slot	!! A !! B !! C !! D
|-
| 1 || colspan="2" style="text-align:center;" | UNIBUS in
|-
| 2 || colspan="2" style="text-align:center;" | UNIBUS out
|-
| 3
|-
| 4
|-
| 5 || M105 || M784
|-
| 6 || M782 || M79
|-
| 7 || colspan="2" style="text-align:center;" | M795
|-
| 8 || M784 || M784
|-
| 9 ||  ||  || M623 || M307
|-
| 10 || colspan="2" style="text-align:center;" | Disk bus 2* || M623 || M307
|-
| 11 ||  ||  || M623 || M307
|-
| 12 || colspan="2" style="text-align:center;" | 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 || colspan="2" style="text-align:center;" | W130* || M113 || M113
|-
| 31 || colspan="2" style="text-align:center;" | 6775* || M113 || M205
|-
| 32 || colspan="2" style="text-align:center;" | 6775* || M116 || M216
|}

W130 = Maintenance board
<br>
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):

{| class="wikitable"
! Type	!! Count !! Function
|-
| G736 || || Jumper
|-
| G740 || || Disk selection
|-
| colspan="3" | 
|-
| 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):

{| class="wikitable"
! Slot	!! A !! B !! C !! D
|-
| 1 || colspan="2" style="text-align:center;" | UNIBUS in || M606 || M113
|-
| 2 || colspan="2" style="text-align:center;" | 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 || colspan="2" style="text-align:center;" | M795 || M606 || M112
|-
| 8 || M784 || M784 || M112 || M111
|-
| 9 || M117 || M111 || M623 || M307
|-
| 10 || colspan="2" style="text-align:center;" | Disk bus 2* || M623 || M307
|-
| 11 ||  || M113 || M623 || M307
|-
| 12 || colspan="2" style="text-align:center;" | 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 || colspan="2" style="text-align:center;" | W130* || M113 || M113
|-
| 31 || colspan="2" style="text-align:center;" | 6775* || M113 || M205
|-
| 32 || colspan="2" style="text-align:center;" | 6775* || M116 || M216
|}

W130 = Maintenance board (optional)
<br>
6775 = Cable to indicator panel

==Documentation==

* [http://toresbe.dreamhosters.com/redirect.php?res=bitsavers&doc=dec/unibus/RK11-C_manual1971.pdf RK11-C manual, 1971]
* [http://toresbe.dreamhosters.com/redirect.php?res=bitsavers&doc=dec/unibus/RK11-C_schemFeb1971.pdf RK11-C schematics, February 1971]

[[Category:UNIBUS Storage Controllers]]