<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body><div>There is the Commodore64 OS. Didn't it leave the file system stuff to the disk drive?</div><div><br></div><div>Is XXDP source available? that would represent a very simple OS.</div><div><br></div><div>Cp// was available for several machines, but I wouldn't want to based a new OS on it.</div><div><br></div><div><br></div><div><br></div><div><br></div><div id="composer_signature"><div style="font-size:85%;color:#575757" dir="auto">Sent from my Galaxy Tab® A</div></div><div><br></div><div style="font-size:100%;color:#000000"><!-- originalMessage --><div>-------- Original message --------</div><div>From: Rich Alderson <simh@alderson.users.panix.com> </div><div>Date: 10/26/16 1:06 PM (GMT-07:00) </div><div>To: simh@trailing-edge.com </div><div>Subject: Re: [Simh] RT-11 source </div><div><br></div></div>> From: Johnny Billquist <bqt@softjar.se><br>> Date: Sun, 23 Oct 2016 03:11:05 +0200<br><br>> In fact, I would probably suggest Ray start with just writing some code <br>> to do some simple things without looking at existing code. The first <br>> thing needed would be to just have something that can load programs from <br>> a device, and run them. This will require some simple device driver, <br>> some simple file system, and a simple command line interpreter.<br> ^^^^^^^^^^^^^^^^^^<br><br>That's not even needed. Beyond a 44 character file id in the VTOC on a disk,<br>none of the IBM batch operating systems for the System/360 has what we would<br>call a file system. OS/360 requires the programmer to know how much space a<br>file might occupy in its lifetime and allocate that (including overflow areas);<br>DOS/360 requires the programmer to do all of that, *AND IN ADDITION* to define<br>the exact location of the file on disk. I don't think anyone would argue that<br>those operating systems were unsuccessful in the marketplace.<br><br>Just sayin'.<br><br> Rich<br>_______________________________________________<br>Simh mailing list<br>Simh@trailing-edge.com<br>http://mailman.trailing-edge.com/mailman/listinfo/simh</body></html>