From: Peter Flass on
Brian Inglis wrote:

> On Wed, 1 Nov 2006 10:23:32 +0000 in alt.folklore.computers, Steve
> O'Hara-Smith <steveo(a)eircom.net> wrote:
>
>
>>On Tue, 31 Oct 2006 10:12:38 -0800
>>glen herrmannsfeldt <gah(a)ugcs.caltech.edu> wrote:
>>
>>
>>>Steve O'Hara-Smith wrote:
>>>
>>>(snip)
>>>
>>>
>>>> Cue many people to tell us where relocation is still in active
>>>>use and why it's better than PIC or memory mapping :)
>>>
>>>PIC tends to be slower on most processors, such that it isn't
>>
>> Hmm that's a surprise. ISTR using relative addressing as an
>>optimisation back in the days I wrote Z80 assembler a lot and surely PIC is
>>mostly using relative addressing exclusively. I had occasionally wondered
>>why it was not the default.
>>
>>
>>>the default when it isn't needed. Memory mapping is usually on
>>>to coarse of boundaries, maybe 4K. (At least for link time relocation.)
>
>
> It's not the default because it's slower, and it's slower because the
> current PC/IP address has to be added to the relative address to get a
> virtual address before being translated thru the segment and/or page
> directory and/or page tables to get a physical address. Maybe need to
> add a relative branch buffer to the microarchitecture to keep the
> pipes full?
>

That's what I like best about S/360 base-displacement addressing. The
major problem is that a 4k displacement has proved far too small.

From: Steve O'Hara-Smith on
On Wed, 1 Nov 2006 09:24:53 -0500
krw <krw(a)att.bizzzz> wrote:

> [*]Even saw "magnetic paint" at the BORG a few days ago.

That stuff is amazingly heavy for paint - less amazing when you
think if it as iron filings with just enough paint to bind it.

--
C:>WIN | Directable Mirror Arrays
The computer obeys and wins. | A better way to focus the sun
You lose and Bill collects. | licences available see
| http://www.sohara.org/
From: Charles Richmond on
Brian Inglis wrote:
>
> On Mon, 30 Oct 2006 15:34:39 -0600 in alt.folklore.computers, Charles
> Richmond <richchas(a)comcast.net> wrote:
>
> >Brian Inglis wrote:
> >>
> >> [snip...] [snip...] [snip...]
> >>
> >> ...and ISTR their standard drivers went haywire if you didn't clip or
> >> scale the vectors to the paper width: drew right down the edge of the
> >> paper, then started drawing from wherever they ended up, a few feet
> >> away from where they should be plotting.
> >>
> >> I'm a big fan of previewing, to avoid including insignificant outlying
> >> data, and autoscaling, to be able to show all of the data, regardless
> >> of output media size.
> >> Nice to be able to view project plans a few feet high and umpty feet
> >> long on the wall.
> >>
> >"Back in the day", at a PPoE, we taped strips of "butcher paper"
> >to the wall and used Magic Markers to draw our project plans and
> >flows. These were umpty-ump feet wide and tall.
>
> But so lo-tech! ;^>
>
It's like Richie Rich spelling the word "GIRLS" on the
beach with $100 bills...crude but effective.

--
+----------------------------------------------------------------+
| Charles and Francis Richmond richmond at plano dot net |
+----------------------------------------------------------------+
From: Charles Richmond on
jmfbahciv(a)aol.com wrote:
>
> In article <k5cdk2t78n3vv3dpav0v5nlqus9j4rrgpg(a)4ax.com>,
> Brian Inglis <Brian.Inglis(a)SystematicSW.Invalid> wrote:
> >On Mon, 30 Oct 2006 15:34:39 -0600 in alt.folklore.computers, Charles
> >Richmond <richchas(a)comcast.net> wrote:
> >
> >>Brian Inglis wrote:
> >>>
> >>> [snip...] [snip...] [snip...]
> >>>
> >>> ...and ISTR their standard drivers went haywire if you didn't clip or
> >>> scale the vectors to the paper width: drew right down the edge of the
> >>> paper, then started drawing from wherever they ended up, a few feet
> >>> away from where they should be plotting.
> >>>
> >>> I'm a big fan of previewing, to avoid including insignificant outlying
> >>> data, and autoscaling, to be able to show all of the data, regardless
> >>> of output media size.
> >>> Nice to be able to view project plans a few feet high and umpty feet
> >>> long on the wall.
> >>>
> >>"Back in the day", at a PPoE, we taped strips of "butcher paper"
> >>to the wall and used Magic Markers to draw our project plans and
> >>flows. These were umpty-ump feet wide and tall.
> >
> >But so lo-tech! ;^>
>
> ARe you kidding? That's hi-tech. I never used magic markers
> (they were too expensive).
>
> I used blackboards and chalk and erasers. hmmm...I could put
> a blackboard up if I'm willing to give up the wall space in
> leiu of bookshelves. That would be wonderful.
>
In the first place, our project was too *poor* to have a
black board. In the second place, it is too easy to get your
diagram erased on a blackboard, and this was a long term plan
on the butcher paper. If two guys on the project wanted to
discuss some aspects of the project, they went in the office
with the wall diagram and had a diagram to refer to while
discussing things. This was only good for the high level
aspects of course, but it showed where things fit into the
design.


--
+----------------------------------------------------------------+
| Charles and Francis Richmond richmond at plano dot net |
+----------------------------------------------------------------+
From: Charles Richmond on
Joe Morris wrote:
>
> Charles Richmond <richchas(a)comcast.net> writes:
>
> >I knew several engineering graduate students in the late 70's,
> >and understand that programming work for their theses *had* to
> >be done in FORTRAN. The thesis would be rejected if the software
> >was done in another language.
>
> Ouch. What was the justification for that policy? And at what university?
>
> Assuming that FORTRAN was not the *subject* of the thesis, I can't
> see any reason why "the most appropriate tool available" would not
> have been the test. Or *was* that the issue -- discouraging the
> use of cute alternatives which at that particular university were
> inferior *for the specific thesis topics*? (e.g., using COBOL
> to do scientific calculations)
>
The alternatives might have been PL/I, Pascal, or APL. ISTM
that the reason was the thesis committee would only know
FORTRAN, which was about the extent that most engineering
professors knew at that time. This was circa 1977.

--
+----------------------------------------------------------------+
| Charles and Francis Richmond richmond at plano dot net |
+----------------------------------------------------------------+