>On Thu, Feb 10, 2000 at 08:45:57AM -0500, John B (dylanb(a)sympatico.ca) wrote:
>> I can't believe some list members here dive into dumpsters for computers.
>> That's dangerous. There could be dangerous,sharp items inside some. Toxic
>> residues (not all companies respect the environment), Legal reasons (maybe?)
>> not to enter one.
So... were you someone's mother in another lifetime? ;-) There are already
enough laws that try to protect stupid people from themselves, while putting
a real damper on those of us who have brains enough to safely engage in
"hazardous" activities. Relax!
A number of years ago, they filmed part of the movie "Amerika" (which was
apparently about the USA being taken over by Soviets or something; I've
never seen it). They had a big sale at the end of the movie, held inside
the former location of a big K-mart store. People went nuts buying all the
clothes and props from the movie. That night, we drove by and noticed that
there was a *bunch* of stuff in the dumpsters out back. Upon further
investigation, the alley was found to be blocked off with a semi trailer
parked across each end. As we were in a Fiat X-1/9 at the time, that wasn't
a problem; we just drove under the truck. Found a bunch of electronic odds
and ends (props from the "communication van" driven by the "resistance
fighters", so I'm told). Popped the removable hard top off the Fiat and
started lobbing stuff in. Also found a couple of cool little Northern
Telecom telephone terminals; 9" mono screens with membrane telephone keypads
in front and a handset on the side, and a miniature QWERTY chicklet keyboard
in a little draw that pulls out from underneath, and serial ports on the
back. About the time the car was getting full, the police arrived at the
near end of the alley, probably summoned by the night watchman. Since they
hadn't told us to stop or anything, we just hopped in the car, drove down
the alley, under the semi trailer at the far end, and off down the street.
Bet they're still scratching their heads over that one. :-)
(Home of the COSMAC Elf
To drag this in a different direction since the LISP discussion brought
a few memory frags to the surface...
Forth, LISP, PostScript and a few others I'll leave others to name
were all similar in that they were stack oriented languages. I never
worked with them much save for Postscript (it's core is Forth to me).
Now, I vaguely remember a series of articles in Kilobaud, Dr Dobbs or
maybe Byte on constructing your own forth like language in the early 80s.
Anyone remember these? Are there copies?
> From: Tony Duell <ard(a)p850ug1.demon.co.uk>
<> >Any other AM29xx chips on it, like a 2909 or 2910 sequencer? Or is this
<> >just a demo board for a 4-bit ALU chip?
<> >It sounds like a really interesting find, though. The 29xx series chips
<> >were interesting devices that have been used in all sorts of machines.
<> Yep, there is a 2909 on board too....
<Ah, so there's a sequencer. And presumably, therefore, there's some kind
<of control store (ROM or RAM) on the output of that. So it sounds like
<it's a complete processor, albeit a small one.
How small depends on the microcode. It could easily be PDP8 or Nova
emulation with one 2901 though it would be slow. I've seen at one commercal
design that use it as a fast version of TMS1000 4bitter.
It's an interesting chip. I have a bunch of the raw 2901C and 2911 parts.
One day when I have time I'd like to try an extended wordlength PDP-8 like
machine using them. Say something obcenely long like 20 or 32bits. After
all working with that chip 8bits or 80 is as easy from the microcode
perspective. Besides it's the microcontroller that is the complex part.
I'm sure some of you have seen this already...
Ramtron is a producer of "ferroelectric ram" devices. Two weeks
ago they announced a 256k bit part.
To keep on topic: this is exactly what I need for my single-board
Scenix-based PDP-8 emulator! No damn battery backup needed and
you don't have to reload RIM every time you boot.
<To add insult to injury, here in Pac*Hell land both PB and Covad consider
<DSL to be a "best effort" service; if they can't get it to work they can
<just walk away from the deal.
Or here 25mi west of Boston where I can nearly see the CO and BellAtlantic
says "soon" which translates to, your small fry, we can't bother.
In the meantime I have RCN ringing the doorbell every week for cable,
broadband and phone... I hold little interest in cable modem as I can
see that loading up and getting bogged down.
>Now, I vaguely remember a series of articles in Kilobaud, Dr Dobbs or
>maybe Byte on constructing your own forth like language in the early 80s.
>Anyone remember these? Are there copies?
There was an issue of BYTE dedicated to threaded languages; it's been a
while since I read it, but IIRC it was pretty much devoted to FORTH.
There was also a book which somehow was related to the articles that
went through the process of building your own FORTH. Unfortuantely, I
don't have a copy of that.
>This is almost 20 year old memory cells trying to activate here, but I
>thought Forth was generally implemented by "compilation" into a non-standard
>pCode which was then run interpretively by a stack oriented run time engine.
That's one way of doing it, but the most traditional (and still most
popular, at least from what I see) way of doing it is to compile
straight to threaded machine code.
Note that even though threaded code is usually most commonly associated
with Forth and other "non-traditional" languages, the technique
is applicable to old-line languages as well. For example, Fortran IV
compilers on the PDP-11 could optionally compile to threaded machine code,
usually producing smaller object code as a result.
>Thus, I would have said it was a stack oriented language. But I guess it
>depends on if you're looking at the language itself or how it is normally
To me, at least, threaded means "you call a subroutine for everything".
For instance, if you want to add two numbers, you push them onto a
(or the) stack and call the add routine. It's the extreme opositte
of "inline" code, to the point where you can think that you're working
on a "virtual" machine that doesn't have the limitations of your
"real" machine (probably why you've confused Forth with p-Code type
intermediate representations - after all, conceptually they aren't that
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
I'm in need of some printed documentation with regards to the HP2100 or
HP21MX diagnostics. While each of the diagnostics are available separately,
a large chunk of diagnostics are put on a single set of 3 paper tapes. I do
have the tapes, but not the manual that goes with it. The manual is
24396-14001. That's the one I need as this "manual" actually is a manual on
each diagnostic included in the three tapes above. Can any of the 2100 or
21MX folks check and see if they have this manual laying around?
In the event no one has 24396-14001, I would also be able to just get along
with the manuals on a few of the diagnostics. Those critical ones would be:
02100-90219 Core memory (2100/16/15/14)
24395-90001 Semiconductor memory (21MX)
02100-90221 Memory Parity Check
02100-90216 Power fail auto restart
24391-90001 General purpose register
24322-90002 Direct Memory Access (2100/21MX)
Thanks for checking!
I've long been intrigued by Symbolics LISP machines and I finally had the
opportunity to get one to poke at. (English grammar now requires me to
point out that I took advantage of that opportunity. (: )
I've been thumbing through some of the docs to get a better idea of how
things work, which effort has lead me to two questions:
1) Where am I likely to find a mouse for this beast? I haven't one and it
appears as though the environment expects to use one.
2) Can the FEP software be loaded onto a virgin disk by someone other than
Symbolics? The disk in my system may have problems, and as near as I can
tell the machines arrived new with at least a bare modicum of software on
Inquiring minds want to know.
I have a MPI (CDC) 5.25 full height 2sided drive and some questions.
Part number is 77711800
is this 35, 40 or "other" cylinders?
is it 48tpi, 96 or maybe 100 tpi?
It gets cranky from tracks 9-14 inward (even a Format) and it makes me
wonder what it is or is it just flakey? Appearances suggest flakey but I'm
making sure it's not an oddball MPI 100tpi.
FYI: it's a NS* Advantage and it runs fine off a generic HH5.25/48tpi
Anyone have a NS* CP/M OS manual for it. It has CP/M and it's apparently
a NS* version for the Advantage and slightly strange compared to others I've