Difference between revisions of "DJ11 asynchronous serial line interface"

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The '''DJ11 asynchronous serial line interface''' is a [[UNIBUS]] [[peripheral]] which provides up to 16 [[asynchronous serial line]]s. Both input and output used [[programmed I/O]]; on input a 64-character [[First-In First-Out buffer|FIFO buffer]] made over-runs unlikely. [[Modem]]s were not supported.
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The '''DJ11 asynchronous serial line interface''' is a [[UNIBUS]] [[peripheral]] which provides up to 16 [[asynchronous serial line]]s. Both input and output used [[programmed I/O]] (with separate receive and transmit [[interrupt]]s). On input, a 64-character [[First-In First-Out buffer|FIFO buffer]] made over-runs unlikely. [[Modem]]s were not supported.
  
 
It was less flexible than, and not as efficient as, the roughly contemporaneous [[DH11 asynchronous serial line interface|DH11]].
 
It was less flexible than, and not as efficient as, the roughly contemporaneous [[DH11 asynchronous serial line interface|DH11]].
 
It was effectively replaced by the [[DZ11 asynchronous serial line interface|DZ11]], which was cheaper (it was a single [[DEC card form factor|hex]] [[Printed circuit board|board]]), and more flexible.
 
It was effectively replaced by the [[DZ11 asynchronous serial line interface|DZ11]], which was cheaper (it was a single [[DEC card form factor|hex]] [[Printed circuit board|board]]), and more flexible.
  
The DJ11 allowed support of either all [[20mA current loop serial line interface|20mA]] or all [[EIA RS-232 serial line interface|EIA RS-232]] serial lines, by means of a dual-width level converter board. The parameters for each line:
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The DJ11 allowed support of either all [[20mA current loop serial line interface|20mA]] or all [[EIA RS-232 serial line interface|EIA RS-232]] serial lines, by means of a dual-width level converter board. The versions of the DJ11 were:
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* DJ11-AA - EIA level conversion
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* DJ11-AB - No level conversion ([[transistor-transistor logic|TTL]] levels)
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* DJ11-AC - EIA level conversion
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The parameters for each line:
  
 
* separate input and output baud rates (75 to 9600)
 
* separate input and output baud rates (75 to 9600)
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could only be set with [[jumper]]s, in groups of four lines. A 'break' condition on the line (i.e. continuous assertion) could also be generated and detected.
 
could only be set with [[jumper]]s, in groups of four lines. A 'break' condition on the line (i.e. continuous assertion) could also be generated and detected.
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Another group of jumpers allowed configuration of the input FIFO level at which an input interrupt occurred; choices were: 1, 5, 9, 17, or the sum of all selections (up to 32).
  
 
==Implementation==
 
==Implementation==
  
The implementation took a single custom [[system unit]] [[backplane]], containing multiple cards (see list below).
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The implementation took a single custom [[system unit]] [[backplane]], containing multiple cards:
 
 
===Versions===
 
 
 
The versions of the DJ11 were:
 
 
 
* DJ11-AA - EIA level conversion
 
* DJ11-AB - No level conversion ([[TTL]] levels)
 
* DJ11-AC - EIA level conversion
 
 
 
===Boards===
 
 
 
The DJ11 included the following boards:
 
  
 
* M7285 - Mux control (hex)
 
* M7285 - Mux control (hex)
 
* M7279 - Receive silo (dual)
 
* M7279 - Receive silo (dual)
* M7280 (2) - Multiple UARTs (quad)
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* M7280 (2) - Octal [[Asynchronous serial line#UART|UARTs]] (quad)
* [[M7821]] - Interrupt control
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* [[M782 Interrupt Control‎|M7821]] - Interrupt control
* [[M105]] - Address selection
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* [[M105 Address Selector|M105]] - Address selection
  
 
The -AA, -AB and -AC versions of the DJ11 also included one:
 
The -AA, -AB and -AC versions of the DJ11 also included one:
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respectively, which occupied a dual slot.
 
respectively, which occupied a dual slot.
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Board locations (as seen from the board insertion side of the backplane, not the [[wire-wrap]] pin side, as is common in [[DEC]] documentation) are:
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{| class="wikitable"
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! !! colspan="6" | Connector
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|-
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! Slot !! A !! B !! C !! D !! E !! F
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|-
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| 1 || colspan="2" style="text-align:center;" | UNIBUS In || M105 || M7821 || colspan="2" style="text-align:center;" | M7279 Receive Silo
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|-
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| 2 || colspan="6" style="text-align:center;" | M7285 Mux Control
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|-
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| 3 ||   ||   || colspan="4" style="text-align:center;" | M7280 Octal UART
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|-
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| 4 || colspan="2" style="text-align:center;" | UNIBUS Out || colspan="4" style="text-align:center;" | M7280 Octal UART
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|}
  
 
===Distribution panels===
 
===Distribution panels===
  
The rack-mounted passive distribution panel used in the -AA EIA version was the H317-B distribution panel, which mounted directly into a standard 19" rack, and contained 16 DB-25P connectors. It was connected to the DJ11 with a pair of BC08S cables, which carried the 'main' signals (data, etc - i.e. non-modem control).  
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The rack-mounted passive distribution panel used in the -AA EIA version was the H317-B distribution panel (the same as used by the DH11), which mounted directly into a standard 19" rack, and contained 16 DB-25P connectors. It was connected to the DJ11 with a pair of BC08S cables, which carried the 'main' signals (data, etc - i.e. non-modem control).  
  
 
The -AC used an H317-A distribution panel, which had screw connectors.
 
The -AC used an H317-A distribution panel, which had screw connectors.
  
 
[[Category: UNIBUS Serial Interfaces]]
 
[[Category: UNIBUS Serial Interfaces]]

Revision as of 13:43, 23 September 2019

The DJ11 asynchronous serial line interface is a UNIBUS peripheral which provides up to 16 asynchronous serial lines. Both input and output used programmed I/O (with separate receive and transmit interrupts). On input, a 64-character FIFO buffer made over-runs unlikely. Modems were not supported.

It was less flexible than, and not as efficient as, the roughly contemporaneous DH11. It was effectively replaced by the DZ11, which was cheaper (it was a single hex board), and more flexible.

The DJ11 allowed support of either all 20mA or all EIA RS-232 serial lines, by means of a dual-width level converter board. The versions of the DJ11 were:

  • DJ11-AA - EIA level conversion
  • DJ11-AB - No level conversion (TTL levels)
  • DJ11-AC - EIA level conversion

The parameters for each line:

  • separate input and output baud rates (75 to 9600)
  • character length (5-8 bits)
  • stop bits (1, 1-1/2 and 2)
  • parity (odd, even, none)

could only be set with jumpers, in groups of four lines. A 'break' condition on the line (i.e. continuous assertion) could also be generated and detected.

Another group of jumpers allowed configuration of the input FIFO level at which an input interrupt occurred; choices were: 1, 5, 9, 17, or the sum of all selections (up to 32).

Implementation

The implementation took a single custom system unit backplane, containing multiple cards:

  • M7285 - Mux control (hex)
  • M7279 - Receive silo (dual)
  • M7280 (2) - Octal UARTs (quad)
  • M7821 - Interrupt control
  • M105 - Address selection

The -AA, -AB and -AC versions of the DJ11 also included one:

  • M5901 EIA conversion module
  • M5900 TTL 'conversion' module
  • M5902 20mA conversion module

respectively, which occupied a dual slot.

Board locations (as seen from the board insertion side of the backplane, not the wire-wrap pin side, as is common in DEC documentation) are:

Connector
Slot A B C D E F
1 UNIBUS In M105 M7821 M7279 Receive Silo
2 M7285 Mux Control
3     M7280 Octal UART
4 UNIBUS Out M7280 Octal UART

Distribution panels

The rack-mounted passive distribution panel used in the -AA EIA version was the H317-B distribution panel (the same as used by the DH11), which mounted directly into a standard 19" rack, and contained 16 DB-25P connectors. It was connected to the DJ11 with a pair of BC08S cables, which carried the 'main' signals (data, etc - i.e. non-modem control).

The -AC used an H317-A distribution panel, which had screw connectors.