WFL/DCP SPO

4718 Story

The original meaning of the acronym (SFAIK) is given below and to the right and I believe Unisys had a backronym "Single Point Operations" which was discontinued in 2005.

		The SPO would be associated with a particular Operator Display Terminal (ODT), by assignment in the NDL (Network Definition Language) sources for the machine controlled. The TD series (classic TD830 shown) were typically used in the seventies and early eighties. The "dumb" terminal is actually in the keyboard. I also used an "SR" station type with a more programmable microprocessor introduced after the TD.
This image shows a lot of reverse video, they were normally white text on black. I believe they also could be configured like a contemporary IBM 3270 for "greenscreen" green on black or amber. There also was an ET series (shown below), a more modern version of the TD monitor (shown above).

In my reimagined context, the domain GUI (DGUI) or SPO is just the smalltalk code which is developed to run in SqueakJS or a Squeak 5 desktop.

• FileList adapted for MCP file system model
• CommandShell adapted for mcpcms.
• The metaphor of the AC client, just the buttons, input box, and transcript in MVC or morphic.

"DGUI" could be somewhat misleading, since here "domain" refers only to the MCP/DCP aspect of domain space GUI, which is strictly smalltalk. More broadly anything that could run on a node could produce a native or web UI. It is a matter of aesthetics that the MCP GUI is limited to smalltalk.

The Squeak 5 version can launch native platform GUI programs on linux, mac, or windows and will naturally be a superset of what works in SqueakJS.

CANDE

Command and Edit MCS was the MCP version of the better known CMS of IBM VM/CMS, with both session control and source editing capabilities. A reference card is in the MoCA page in my wikipedia user space.

Spec

DCMS shall support an API for use by the SPO and AC interfaces with a transformed set of the CANDE control commands in the same and common style of the MCP and WFL as these are implemented in the revival. The source editing commands are mooted but line number orientation of sources is not. When a WFL controlled program event is displayed it must report the source line number of the associated event (LINEINFO).

"Supervisory Print Out"

In the original MCP based systems one or more consoles could function as the "SPO", the system operator interface. Originally it stood for "Supervisory Print Out" in the early MCP (presumably B5000 or possibly earlier). I don't have a source for this and don't intend to supply one myself, but it should be doable and I'll provide the ref if I run into it. Less than certain on this.

Did find a reference in the DCALGOL manual, the ATTACHSPOQ and WRITESPO functions, which confirms the usage but not the origin of the acronym, the manual just refers to "supervisory console" (which suggest the origin I have) and ODT as SPO.

In my homage it has become simply "SPO" ('spoh') for DCP/MCP, the a set of squeak sources as described above as a UI for the dominion control program in the style of the Burroughs MCP. BTW, this is a good place to point out the diff between "Burroughs MCP", "Unisys MCP", and just "MCP". The second is the product marketed by Unisys which until recently I never had hands on. The last is my invention which is no more than inspired by Burroughs MCP 4, the version of the Algol OS with which I had paid experience.

Links

• Burroughs Large Systems (external)
• Burroughs MCP Architecture (internal)
• CANDE
• Squeak
• WFL