[COFF] Other OSes?

[Clem Cole]

On Mon, Jul 9, 2018 at 1:23 AM Theodore Y. Ts'o <tytso at mit.edu> wrote:

>
> There were multiple OS's for the PDP-8 and PDP-15.

Right.  You can find them on the PDP-8 web sites for instance.  Check out
sigh or better yet the PiDP-8 which I have running at with 4 OS loaded into
the ROMs.  The RIM loader can be loaded from the toggle switches for the
purist, but the Pi will do it for you on power up if you like and don’t
want the tedium.


I used on the
> PDP-8/i was the 4k disk monitoring system, so named becasue it only
> required 4k of 12-bit wide core memory.

Right I believe that was the first widely available OS and described in the
small computer handbook.  Remember mini (as in minicomputer) was term
Gordon coined to mean minimal computer.


The resident portion of the
> OS only required 128 12-bit words, loaded at octal 7600, at the top of
> the 4k memory.  It could be bootstrapped by toggling in 4 (12-bit
> wide) instructions into the front console which had about 24 binary
> switches[1].


>
> [1] https://www.youtube.com/watch?v=yUZrn7qTGcs
>
> The OS was distributed on paper tape, which was loaded by toggling in
> 18 instructions of the RIM loader, which was then to load the BIN
> loader from paper tape into core memory.  The RIM loader was designed
> to be simple and easy to toggle into the console.  (ROM?  EPROM?  We
> don't need no stink'in firmware in read-only memories!)  The BIN
> loader could read in a more effoiciently packed data stored in punched
> paper tape.  The BIN loader would then be used to load the disk
> builder program which would install the OS into the DF-32 (which
> stored 32k 12-bit words on a 12" platter).

rIght and the RIM loaded was printed on front panel of the console.  btw
the disk was 19” in diamete.  Danny Klein has the original disk platter
from the one of the original PDP-8 - before marriage it used to hang in his
living room. FYI that was the system at the computer museum from the EE
Dept after it died in approx ‘75  I was there the disk crashed.


>
> Later PDP-8's would run more a sophisticated OS, such as OS/8, which
> had a "Concise Command Language" (CCL) that was designed to be similar
> to the TOPS-10 system running on the PDP-10.  OS/8 was a single-user
> system, though; no time-sharing!


Be careful grasshopper.   TSS/8 is available on those web sites although I
admit it does not run on my PiDP-8 and I have not figured why (Something is
corrupt and I have not spent the time or energy to chase it).  Anyway,
TSS/8. Supported 4-8 ASR-33 terminals, each had 4K words as you described
before.  There was assembler, basic, focal, Fortran-IV and an Algol circa
1965 extensions.

>
>
>
> The PDP-15/30 that I used had a paper tape reader and four DECtape
> units.  It ran a background-foreground monitor.  The background system
> was what was used for normal program development.  The foreground job
> had unconditional priority over the background job and was used for
> jobs such as real-time data acquisition.  When the
> background/foreground OS was started, initially only the foreground
> teletype was active.  If you didn't have any foreground job to
> execute, you'd start the "idle" program, which once started, would
> then cause the background teletype to come alive and print a command
> prompt.  So it was a tad bit more sophisticated than the 4k disk
> monitor system.

RIght this is really the model for RT11 which would begat CP/M and last
DOS-86 (aka PC-DOS, later renamed MS-DOS).

-- 
Sent from a handheld expect more typos than usual
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