> From: Steve Johnson
> references that were checked using the pointer type of the structure
> pointer. My code was a nightmare, and some of the old Unix code was at
> least a bad dream.
I had a 'fun' experience with this when I went to do the pipe splice() system
call (after the discussion here). I elected to do it in V6, which I i) had
running, and ii) know like the back of my hand.
Alas! V6 uses 'int *' everywhere for pointers to structures. It also, in the
pipe code, uses constructs like '(p+1)' to provide wait channels. When I wrote
the new code, I naturally declared my pointers as 'struct inode *ip', or
whatever. However, when I went to do 'sleep(ip+1)', the wrong thing happened!
And since V6 C didn't have coercions, I couldn't win that way. IIRC, I finally
resorted to declaring an 'int *xip', and doing an 'xip = ip' before finally
doing my 'sleep(xip+1)'. Gack!
Noel
> From: Dave Horsfall
> We lost ... on this day
An email from someone on a related topic has reminded me of someone else you
should make sure is only your list (not sure if you already have him):
J. C. R. Licklider; we lost him on June 26, 1990.
He didn't write much code himself, but the work of people he funded (e.g.
Doug Engelbart, the ARPANet guys, Multics, etc, etc, etc) to work on his
vision has led to today's computerized, information-rich world. For people who
only know today's networked world, the change from what came before, and thus
his impact on the world (since his ideas and the work of people he sponsored
led, directly and indirectly, to much of it), is probably hard to truly
fathom.
He is, in my estimation, one of the most important and influential computer
scientists of all. I wonder how many computer science people had more of an
impact; the list is surely pretty short. Babbage; Turing; who else?
Noel
> From: Dave Horsfall
> We lost Jon Postel, regarded as the Father of the Internet
Vint and Bob Kahn might disagree with that that... :-)
> (due to his many RFCs)
You need to distinguish between the many for which he was an editor (e.g. IP,
TCP, etc), and the (relatively few, compared to the others) which he actually
wrote himself, e.g. RFC-925, "Multi-LAN address resolution".
Not that he didn't make absolutely huge contributions, but we should be
accurate.
Noel
> Now it could be that v7 troff is perfectly capable of generating the
> manual just like older troff would have.
On taking over editorship for v7, I added some macros to the -man
package. I don't specifically recall making any incompatible
changes. If there were any, they'd most likely show up in
the title and synopsis and should be fixable by a minor tweak
to -man. I'm quite confident that there would be no problems
with troff proper.
Doug
Angelo Papenhoff <aap(a)papnet.eu> writes about the conversion of
printer points to other units:
>> >From my experience in the world of prepress 723pts == 10in.
>>
>> Then Adobe unleashed PostScript on us and redefined the point
>> so that 72pt == 1in.
>>
>> Ibunaware of any other definitions of a point.
The most important other one is that used by the TeX typesetting
system: 72.27pt is one inch. TeX calls the Adobe PostScript one a big
point: 72bp == 1in. Here is what Don Knuth, TeX's author, wrote on
page 58 of The TeXbook (Addison-Wesley, 1986, ISBN 0-201-13447-0):
>> ...
>> The units have been defined here so that precise conversion to sp
>> is efficient on a wide variety of machines. In order to achieve
>> this, TeX's ``pt'' has been made slightly larger than the official
>> printer's point, which was defined to equal exactly .013837in by
>> the American Typefounders Association in 1886 [cf. National Bureau
>> of Standards Circular 570 (1956)]. In fact, one classical point is
>> exactly .99999999pt, so the ``error'' is essentially one part in
>> 10^8. This is more than two orders of magnitude less than the
>> amount by which the inch itself changed during 1959, when it
>> shrank to 2.54cm from its former value of (1/0.3937)cm; so there
>> is no point in worrying about the difference. The new definition
>> 72.27pt=1in is not only better for calculation, it is also easier
>> to remember.
>> ...
Here sp is a scaled point: 65536sp = 1pt. The distance 1sp is smaller
than the wavelength of visible light, and is thus not visible to
humans.
TeX represents physical dimensions as integer numbers of scaled
points, or equivalently, fixed-point numbers in points, with a 16-bit
fraction. With a 32-bit word size, that leaves 16 bits for the
integer part, of which the high-order bit is a sign, and the adjacent
bit is an overflow indicator. That makes TeX's maximum dimension on
such machines 1sp below 2^14 (= 16,384) points, or about 5.75 meters
or 18.89 feet.
-------------------------------------------------------------------------------
- Nelson H. F. Beebe Tel: +1 801 581 5254 -
- University of Utah FAX: +1 801 581 4148 -
- Department of Mathematics, 110 LCB Internet e-mail: beebe(a)math.utah.edu -
- 155 S 1400 E RM 233 beebe(a)acm.org beebe(a)computer.org -
- Salt Lake City, UT 84112-0090, USA URL: http://www.math.utah.edu/~beebe/ -
-------------------------------------------------------------------------------
> From: Jacob Ritorto
> If this is true, I wonder why the install only offers rl01?
Where does it say this? (I didn't search for that.)
> I'm totally in the market for an Able Enable board too! Out of
> zcuriosity, is it totally out of the question to just find the prints
> and do a production run?
Rotsa ruck! They're down the same mine as Jimmy Hoffa!! :-)
But seriously, if you could find them, that would be fantastic. I've managed
to collect (thanks Clem!) a tiny bit of info about them:
http://gunkies.org/wiki/Able_ENABLE
and I _think_ I've worked out how they worked, but more is better. We had a
set of the prints at MIT BITD, but we didn't have the PROM/PLA/PAL/etc
programming info, and one would need that too to reproduce them.
> I sure hope there's a pdp11 sdcard / usb disk solution someday like they
> did for the Commodore 64
So Dave Bridgham and I have been working on a QBUS card with an FPGA that uses
an SD card to hold the bits, and emulates an RK11/RP11/etc controller. We have
a wire-wrap prototype working (the RK11's done, the RP11 should be a short
edit of that), and UNIX boots and runs. Now to turn it into PCB's...
We've planned that the next step will be to do a UNIBUS version, which will
also include ENABLE functionality (although it won't be plug compatible with
an ENABLE, the memory will be on-board).
Now to find the time/energy to make it happen... :-(
Noel
> From: Noel Hunt
> In addition to SINE, does anyone know what happened to EINE?
Was replaced by ZWEI fairly early on.
Zwei
Was
Eine
Initially
Dunno if it still exists on an MIT dump-tape somewhere.
Noel
Hi All.
I am starting to collect, if possible, different versions of the QED
editor; with a hope to put up a git repo.
If you have a tarball of code, please send it to me with as much info
about it as you have. I would like to track down the qedbuf(1) man page
also.
I have contacted Rob Pike and got one tarball from him. I have another
tarball that I got sometime in 1987 and have a promise of code coming
Donald Mitchell.
Much thanks!
Arnold