Difference between revisions of "Chaosnet interface"

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(A start; will add register defs later)
(External links: Converted SUDS drawings.)
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** [https://github.com/PDP-10/its-vault/blob/master/files/chaos/quad.eco QUAD ECO] - "ECO to .. Change cable speed to 4 MHz"
 
** [https://github.com/PDP-10/its-vault/blob/master/files/chaos/quad.eco QUAD ECO] - "ECO to .. Change cable speed to 4 MHz"
 
** [https://github.com/PDP-10/its-vault/blob/master/files/chaos/qadchs.note QADCHS NOTE] - random jottings
 
** [https://github.com/PDP-10/its-vault/blob/master/files/chaos/qadchs.note QADCHS NOTE] - random jottings
 +
* [https://github.com/larsbrinkhoff/chaos-schematics/tree/master/converted SUDS drawings converted to PNG pictures]
  
 
[[Category: UNIBUS Network Interfaces]]
 
[[Category: UNIBUS Network Interfaces]]
 
[[Category: QBUS Network Interfaces]]
 
[[Category: QBUS Network Interfaces]]

Revision as of 19:42, 15 September 2023

CH11 Unibus board

The Chaosnet UNIBUS interface (also called the CHAOS-11, CH11, QUAD and QAD; there was no generally-used name) and QBCHNI are Chaosnet network interfaces, for the UNIBUS and QBUS respectively. (The two device controllers are identical in programming terms, so they are both covered in this single article.)

They use programmed I/O to transfer data to and from buffers in main memory. They have on-board buffers (one each for inbound and outbound) which can hold one packet of data.

They are both a single quad wire-wrapped card.

Their bus address can be set via DIP switches; the default is 0764140. The network address is also set via a DIP switch.

Device registers

They have 7 registers:

Register Abbreviation Address
Command and Status Register CAICSR 764140
My address (read only) CAIMYN 764142
Write buffer (write only) CAIWBF 764142
Read buffer CAIRBF 764144
Read bit counter CAIRBC 764146
Unused   764150
Initiate transmission CAIXMT 764152
Unused   764154
Unused   764156
Load interval timer (write only) CAITIM 764160


In the register contents (below), bits which are read/write or unused are shown in normal font, those which are read-only are in italics, and those which are write-only are shown in bold.

External links