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Re: QBUS Prototyping

From Johnny Billquist <bqt@softjar.se>
Newsgroups alt.sys.pdp11, comp.sys.dec, comp.os.vms
Subject Re: QBUS Prototyping
Date 2011-04-18 20:35 -0700
Organization Update Computer Club
Message-ID <ioivtk$4ss$1@Iltempo.Update.UU.SE> (permalink)
References (1 earlier) <hps7i9$htt$1@naig.caltech.edu> <hr19ad$m2m$1@Iltempo.Update.UU.SE> <WgK6B$GCJWnT@eisner.encompasserve.org> <iohk2q$kmg$2@Iltempo.Update.UU.SE> <iohs8j$ha6$1@pcls6.std.com>

Cross-posted to 3 groups.

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On 2011-04-18 10:26, Michael Moroney wrote:
> Johnny Billquist<bqt@softjar.se>  writes:
>
>> On 2011-04-18 05:56, Bob Koehler wrote:
>>> In article<hr19ad$m2m$1@Iltempo.Update.UU.SE>, Johnny Billquist<bqt@softjar.se>   writes:
>>>>
>>>> (Oh, and a VAX is not a PDP... :-)
>>>
>>>      That's right.  No VAX ever implemented the MARK instruction.  Now
>>>      can you find a PDP-11 programmer who actually used it?
>
>> I used it.
>> But only to test how to, and then decided "never more". :-)
>
> I'm guessing that instruction was developed for some compiler(s) which had
> some bizarre linkages for subroutines, and very few, if any, assembly
> language programmers ever used it, beyond trying to figure out what to do
> with it.

One rumour has it that it was developed in order to extend some patent 
or something.

Another would be that they were just crazy.

I've not seen a single compiler use the subroutine linkage that 
explicitly makes the MARK instruction meaningful, and besides. It is not 
usable if you have split I/D space.

> (next question, which compiler(s) used it?)

I have no idea.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt@softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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Thread

Re: QBUS Prototyping koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-04-18 07:56 -0500
  Re: QBUS Prototyping Johnny Billquist <bqt@softjar.se> - 2011-04-18 08:07 -0700
    Re: QBUS Prototyping moroney@world.std.spaamtrap.com (Michael Moroney) - 2011-04-18 17:26 +0000
      Re: QBUS Prototyping koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-04-18 12:53 -0500
      Re: QBUS Prototyping Johnny Billquist <bqt@softjar.se> - 2011-04-18 20:35 -0700
        Re: QBUS Prototyping moroney@world.std.spaamtrap.com (Michael Moroney) - 2011-04-19 15:34 +0000
          Re: QBUS Prototyping Johnny Billquist <bqt@softjar.se> - 2011-04-19 09:47 -0700
    Re: QBUS Prototyping koehler@eisner.nospam.encompasserve.org (Bob Koehler) - 2011-04-18 12:49 -0500
      Re: QBUS Prototyping Johnny Billquist <bqt@softjar.se> - 2011-04-18 20:36 -0700

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