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Re: 8-bit OS sought

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The programmers always whine about the boiler explosions...
Back when we hired hardware engineers, we'd ask them
to hold up their hands.  Anyone missing a couple of
fingers was an experienced flipflop designer...




Re: 8-bit OS sought

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You had ones?!?

When I started out, we had nothing but zeros...

--
Grant Edwards                   grante             Yow!  Will this
                                  at               never-ending series of
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Re: 8-bit OS sought
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  I think your memory is probably hazy, ( understandable given your
great age...:) - Civilisations generally had ONE first, and discovered
Zero later...

See http://www.geocities.com/rmlyra/hindi.html

"The discovery of Zero was made only trice in history: by Babylonian
scholars, the Hindus and the Mayans."


Re: 8-bit OS sought

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This all makes light of things, of course.  But there was a lot of reality in
John Perry's comments.  We really *did* toggle in our bootstrap problems,
memorized from frequent use, to load from disk or paper tape.  We really *did*
use 7 switches and a push button to enter ASCII text.  We really *could* read a
paper tape directly by just looking at it.  We really *did* write sophisticated
and fast time-sharing systems with both BASIC *and* assembler support (I did,
anyway) using a system with only 16k word of core memory.

Sometimes, in the spate of Windows VxDs, DLLs, COM, ATL, .NET, and the constant
propaganda about how all the C++ compilers are just as good at generating code
as any assembler programmer is... well, one may very well think that old war
stories about commercial grade compilers and operating systems and so on running
in 8k or 16k machines are like old-timer stories of having to walk 10 miles to
school in the snow, uphill both ways.  ;)

But quite satisfying and sophisticated systems really did happen in limited
memory.  The system I worked on in the early 1970's, for example, ran in 16k of
memory, provided time-shared BASIC and assembler, used a 10k swap area for each
user that was logged in, managed a complete file system with user accounts and
directories, supported up to 32 timeshared users via serial communications over
modem, and provided extremely good execution times and at the same time quite
satisfying response times when a user entered a command or line (1/4 sec waits
were typical.)  Of course, it was written entirely in assembly, from scratch.

Jon

Re: 8-bit OS sought

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Bit of a Freudian slip, there.  I meant, "We really *did* toggle in our
bootstrap __programs__,"

hehe.

Jon

Re: 8-bit OS sought

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Put me in front of a PDP-8 and I bet I can still boot it from the
front panel switches.  I used a PDP=8 to test the original 30-30
Winchester drives and vacuum column tape drives for Mr. Wang.



Re: 8-bit OS sought

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My memory has since failed me, I suspect.  I still have my "8" manuals and I
used to program on 8's, as well.  Also, the IBM-1130; the PDP-11's of course,
PDP-10, IBM-360's, and eventually I was lucky enough to actually build my own
Altair 8800 -- which started with a wonderful 256 bytes of memory!  (Could not
afford to fill the other three sockets with the static ram chips that would have
brought this up to 1k.)  I often hand-entered bootstraps for the PDP-8, PDP-11,
and of course, my Altair.

Jon

Re: 8-bit OS sought
snipped-for-privacy@easystreet.com says...
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have
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I feel like such a weenie!   My first personal computer was a SWTPC 6800
that had a bootstrap ROM.  No toggle switches on the front panel for
address and data.  My greatest hardware accomplishment at that time
was to add solenoids and fishing line to an IBM Selectric---which
my girlfriend then used to type here MS thesis with a very primitive
word processor.  I also wrote a simple file system for a fast
digital cassette drive that I used for a few years until floppy
drives became affordable.

I started real-time programming on a DG Nova machine.  It had 5MB
14" disk packs and processor boards made out of TTL logic. The
CPU rack was quite heavy.   I pulled some muscles severely one
time when the unit slid out of the rack somewhat more easily
than expected.  You seldom had to key in startup sequences, since
it used core memory, and you could simply set up the address of
the boot loader and hoped it was still in core.

Mark Borgerson



Re: 8-bit OS sought

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No address and data lights, either?  Oh, the shame of it all.

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Interestingly, I modified an IBM model 85 (?) electronic typewriter by examining
all the reed relay signals as I typed keys and documenting them and then
designing and hooking up an 8051 CPU to sit in parallel over them so it could
replicate the timing required.  I then wrote the serial code, with buffering and
flow control, so that I could hook it up to my IBM PC and use it as a printer.
To my surprise, the whole thing worked the very first time after I carefully
wired it up.  Whew!

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Ah, like a DECTape file system?

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I used the 5Mb 14" removable packs on PDP-8s.

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Yup.  Core memory planes usually included a write-after-read step to restore the
value to the memory location after reading it.  If it doesn't include this extra
circuitry, reading the core destroys the contents -- "destructive read."  The
PDP-8's accumulator may have used core memory (my memory fails me about whether
or not I ever read if this is a fact or simply my conjecture), because the DCA
instruction (in effect) wiped the value in the accumulator when it wrote its
value to memory.

Jon

Re: 8-bit OS sought
On Friday, in article

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Remember doing that sort of thing often, as late 70's I was working for
Digital and one of my jobs was running the PDP-11/70 for the engineering
department. That division did all sorts of things from mimic displays[1]
using colour graphics, to bit mapped graphics and even for UK Teletext
inserters for the ITV network.

It was amazing how many terminals (even colour mimic display and graphic
ones) were controlled from one system. At one time the Norwegian railway
network ran off a dual system, not that I think the use of multiple
processor networks in use today are any more efficient in MOST cases.

[1] Mimic display the (at that time normally) character based graphics for
    plant diagrams, railway networks, power grids etc...

--
Paul Carpenter          | snipped-for-privacy@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/ PC Services
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Re: 8-bit OS sought
John Perry said ...

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Data Genera's RDOS ran on Nova's and the early model Eclipse's.  AOS
was introduced for the Eclipse, and AOS/VS followed for the MV line.

And yep, I used to boot using the front panel switches.  I think the
first removable disk packs that I used were 5 Mbyte ones.

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Me neither.  It was fun back then though.


Casey

Re: 8-bit OS sought

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I worked for many years with Varian/Sperry Univac Vortex, a real-time,
multi-tasking OS which used less than 24K.

--
Al Balmer
Balmer Consulting
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Re: 8-bit OS sought
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We did all that in well under 64k of memory 25 years ago.  It was
called CP/M.  One clone of that, with full source, is available at:

   <http://cbfalconer.home.att.net/download/cpm

--
Chuck F ( snipped-for-privacy@yahoo.com) ( snipped-for-privacy@worldnet.att.net)
   Available for consulting/temporary embedded and systems.
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Re: 8-bit OS sought

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CP/M itself didn't require anywhere near that much. I was the envy of
my friends when I got a Kaypro which had a full 64K. We really didn't
know what to do with so much memory.

--
Al Balmer
Balmer Consulting
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Re: 8-bit OS sought
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That's what I developed DOSPLUS/CCPLUS on.  I also replaced the
EPROM, which originally had anomalous connections to the bios -
something to do with the DEFDMA location, IIRC.  That gave me the
opportunity to correct some things, such as column 80 wraparound,
and provide the ability to return serial and parallel port status,
etc. that enabled routine remote operation.

That machine actually had over 64k available.  Another 2k lived in
the video memory, and still another 2k in the EPROM.  The video
decoding left 80 or so bytes available in the video memory, which I
could use for some ROM specific things and know they were protected
until banked in.  That was the last machine I had 100% under my
control.  If anything annoyed me, I fixed it.

The end result was a system that could run BIG programs, the
equivalent of 2 Meg of 8080 code (except actually more compact
PCode - also my own) in a position independent segmented system
that had intersegment calls and LRU automatic segment swapping.
However the data memory was still limited, due to the lack of
hardware support.  And the biggest code item actually run was the
compiler, which was about 65k of PCD and equivalent to about 200k
of 8080 object.

--
Chuck F ( snipped-for-privacy@yahoo.com) ( snipped-for-privacy@worldnet.att.net)
   Available for consulting/temporary embedded and systems.
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Re: 8-bit OS sought

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Some people might forget that AutoCAD (yes, AutoCAD) started life on a CP/M
system.  I was running version 1.2 on an S-100 based box.  It was sold with
an 8087 math co-processor card and a 512K "ramdisk" board.  I still have an
eight inch floppy somewhere with design files.


--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Martin Euredjian

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Re: 8-bit OS sought


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The hooked an 8087 to a Z80?



Re: 8-bit OS sought
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CP/M was available for the 8086.

--
Grant Edwards                   grante             Yow!  How's it going in
                                  at               those MODULAR LOVE UNITS??
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Re: 8-bit OS sought

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What graphics card(s) did it support?

Bob

Re: 8-bit OS sought
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CP/M didn't support any graphics cards.  

AutoCAD, however, did.  Graphics was strictly an application
thing under CP/M.  When you built a graphics card you didn't
write a CP/M driver for it (except to make it look like a dumb
ASCII terminal), you wrote an AutoCAD driver for it. That
said, I don't remember any specific S-100 graphics cards, but I
remember they were _expensive_ ($thousands).

Here's what google found:

http://www.cadalyst.com/cadalyst/article/articleDetail.jsp?id80%519
http://pluto.njcc.com/~hjohnson/s_zenith.html

Here's an interesting blurb from '85:

[excerpted from http://www.znode51.de/articles/newslets/z_news.205 ]

   More on Quadram S-100 Boards: Set consists of two IEEE /696
   boards, 1) single board computer and 2) graphics board--Valiant
   is name to be given board-pair!  Very appropriate, "courageous"
   and "valuable." SBC contains new AMD 9580 combined hard and
   floppy (auto-select between 5.25" and 8") disk controller chip
   along with AMD 9581 data separator, and of course, Hitachi
   HD64180 microprocessor.  From what we've seen, HD64180 makes
   Intel 80186 chip look weak.  Furthermore, we understand HD64180
   has built-in (hidden) circuits to on-chip manage RAM to one
   megabyte, same as 8088, 8086 and 80186!  Such circuits will
   likely be made operative if demand requires it.

   Get ready for real graphics quality from this Quadram duo.
   Initially, resolution offered is up to 2,048 horizontal
   (columns) by 1,024 vertical (rows, scan lines) pixels, with
   256-color palette out of possible 1,024 palettes: 262,144 total
   color possibilities! Graphics board uses Motorola 68020 as
   co-processor, Hitachi HD63484 CRT graphics controller, and up
   to 2 megabytes of RAM (using 8419 DRAM controller), all
   dedicated to graphics.  NEC 7220 GDC chip simply can't compare
   in performance to later-design HD63484. Time-of-day stamp is
   built into SBC hardware and BIOS.  OS runs near top- of-RAM
   using less than 20k-bytes, with applications allowed remainder
   of 512k- bytes. Z-News 204 has more about these S-100 boards.

--
Grant Edwards                   grante             Yow!  Oh my GOD -- the
                                  at               SUN just fell into YANKEE
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