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- Newsgroups: alt.folklore.computers
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!darwin.sura.net!uvaarpa!concert!samba!usenet
- From: Tony.Duell@launchpad.unc.edu (Tony Duell)
- Subject: Re: RSX-11 console light-show / HOW?
- Message-ID: <1992Nov23.210358.10584@samba.oit.unc.edu>
- Keywords: rsx-11m, console lights, implementation
- Sender: usenet@samba.oit.unc.edu
- Nntp-Posting-Host: lambada.oit.unc.edu
- Organization: University of North Carolina Extended Bulletin Board Service
- References: <By0n1M.7MC@sci.kun.nl>
- Date: Mon, 23 Nov 1992 21:03:58 GMT
- Lines: 24
-
- On t PDP11/45, and I assume the 11/70 as well, the data lights could be
- switched to one of 4 sources by a rotary switch on the panel. They were:
- Data Path (basically, ALU data register)
- Bus register
- Microcode address (low 8 lights = CPU microcode program counter, top 8 for
- the Floating point microcode counter)
- Display register (Contents of 777570)
- To get the lights display under RT11, you selected display register here.
- On RSX, I think you have to select Data path, but I'm not sure. I don't
- know how RSX does its lights display, but it doesn't do continual
- resets(The RX02 does a head-load/unload on a reset, so think what that
- would do :-))
- On RT11, yuo can changer the SR variable in the config file and then
- sysgen the system, if for example, you want the idle light pattern
- somewhere else - like on a parallel port. I've heard of a system, ewhere
- Xmas lights were driven in that manner off the idle loop :-)
- -tony 'PDP11 Hacker' Duell
- ard@siva.bris.ac.uk
-
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