[Milsurplus] IBM PC

[Peter Gottlieb]

I had an old PDP-11/05 with 12 K words (16 bits) of CORE memory.  I ran 
RT-11 on it, which had to be assembled after you answered this long series 
of questions relating to what peripherals you had and their bus and 
interrupt numbers.  This process was called a "sysgen."  RT-11 was, for all 
practical purposes, DOS.  I got the box cheap, it was being scrapped by a 
DEC office and had lots of bad boards in it.  I ran into a very nice DEC 
office and they helped me get the thing up and running, gave me replacement 
boards, and RT-11.  I had a RX-01 dual 8 inch floppy and a VT-52 terminal. 
I wrote programs in ASM and Basic and even got a copy of the Adventure game 
("You are in a maze of twisty passages, all alike").  I eventually acquired 
a hard drive (Xerox Diablo, 5 MB fixed platter, 5 MB removable cartridge), 
28 KW RAM memory, and then moved to an 11/23 (switching from Unibus to 
Qbus), with AMD math coprocessor, a couple of quad serial cards, and one I 
designed, an ADAC data acquisition card (analog in/out parallel in/out).

Man, that was one heavy, big, and finicky system.  If I had to go back in 
time to it, I would change fields instead.



----- Original Message ----- 
From: "J. Forster" <jfor at quik.com>
To: "Ray Fantini" <RAFANTINI at salisbury.edu>
Cc: <milsurplus at mailman.qth.net>
Sent: Thursday, September 16, 2004 5:43 PM
Subject: Re: [Milsurplus] IBM PC


> Ray Fantini wrote:
>
> . The IBM had DOS, ok so it's a Microsoft reverse engineered version of 
> CPM, but
> once again everyone else used it, well except for Mac people.
>
> DOS was around YEARS before. There was certainly a stripped down version 
> of DOS,
> loaded from paper tape onto a head per track hard disk with a capacity of 
> 64K 16
> bit words and up in about 1969. It was the DG 4019A and used an Alpha Data
> drive. They were available in sizes up to at least 512 KW. Small, but 
> fast. No
> head seek time, just the latency. That DOS would run in something like 8 
> KW.
>
> There were two versions, RTOS (Real Time Operating System) and RDOS (Real 
> Time
> Disk Operating System). I first came across RDOS with the Diablo 31s which 
> were
> pizza oven like 2,5 M hard drives (IBM 2315s).
>
> IMO, S-100 and CPM were significantly later.
>
> -John
>
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