[Simh] PDP10: KS10 console lights?

[Timothe Litt]

On 06-Sep-18 06:59, Lars Brinkhoff wrote:
> Hello,
>
> There is a USB device called the Panda Display.  Its purpose is to allow
> PDP-10 simulators to display internal state using LEDs, much like a
> front panel.  I have patched Richard Cornwell's KA10 simulator to make
> the DATA PI, instruction display on the LEDs.
>
> I have checked the KS10 instruction set.  It doesn't have a DATAO PI,
> instruction.  However that particular opcode isn't in used, so it's just
> a UUO.  This is also the case for ITS microcode.  Before I start working
> on anything, I'd like to ask if it would be OK to repurpose this opcode
> for its traditional use?
>
> https://gitlab.com/DavidGriffith/panda-display
>
Neither the KL nor the KS use DATAO PI,.  I don't have a problem with
implementing it for the KS.  It would need to act like any IO
instruction - MUUO in user mode, functional in Exec and with
User-In-Out.  It's also useless unless there is a place to display the
lights - so unless the display hardware is present, you might as well
let it MUUO.

The LIGHTS UUO (calli -1) was disabled in TOPS-10 when support for the
KI was dropped.  Early KS monitors compiled it as a NOP.  So to be
useful, you need a (trivial) monitor patch.  EDDT might need a tweak to
properly decode it.

Note that the corresponding DATAO PTR, (set switches, KI only) overlaps
TIOE on the KS, and thus could not be implemented.


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