DEC-10-RWVA-D DC08 689G Data Line Scanner For PDP-10

This document describes the S6801 program, which transforms a PDP-8/1 into a data line scanner for a PDP-10, effectively replacing dedicated hardware scanners like the 630 DCS or DC10.

The system requires a minimum configuration PDP-8/1, the 680 Data Communication System hardware (DL8I, DC08A, 689AG), a DA10 PDP-10 to PDP-8 interface, and a PDP-10 running a time-sharing monitor.

The S6801 program, delivered on paper tape in BIN format, is loaded via the RIM loader. Operators must set the highest physical Teletype line number in location 377 and start the program at 200g. A key feature is its dynamic initialization, allowing it to adapt to changes in PDP-10 monitor configurations or 680 hardware line assignments without requiring a full reload, only a restart after updating location 377.

For PDP-10 programming, the document outlines procedures for initializing the DA10/S6801 system, including clearing interrupts and assigning a PI channel. It details how to process interrupts, specifically for 'To-10-Buffer Empty' and 'From-10-Buffer Empty' conditions, and describes the 36-bit data format used for transmitting and receiving characters, which includes both line number and character data.

Finally, instructions are provided for assembling S6801 for different DC08-A hardware clock speeds (Clock 1-4) by modifying a specific line in the source file.