Date   : Sun, 24 Jul 2011 13:53:00
From   : robert@... (Rob)
Subject: [BeebSoc] Re: Risc PC (Was 'Minitel in France')

On 24 July 2011 19:11, Rick Murray <heyrick.beebsoc@...> wrote:
> On 24/07/2011 11:42, Rob wrote:
>
>> Back in the day, I got part way through writing a full
>> multi-user multi-tasking OS for B&2P.
>
> How far did you get?

Terminal ROMS were done, and I found the code for that.  The rest I
think got to a point where I could run very very simple apps, but I
can't find the code any more, just an initial backup that is only the
raw skeleton of the code.

>
> I've thought of a simple multitasking OS for a 6502 board (not Beeb
> related), but run into a fair few issues, such as the limited fixed-position
> stack. I thought of "up to x processes" with timeslice task control using
> VIA timer to switch, with the stack being split into an OS chunk and private
> chunks for the tasks, but how far can you really hope to split up 256 bytes?

That was pretty much how I did it; but actually swapping the stack in
and out!  The time slices were fairly large so that the swapping
wasn't too bad an overhead, although response time was fairly slow!
And of course with needing I/O buffers for each user, actual memory
for the users was limited too.. This was all about 1986/7 so my memory
is a little rusty.  I know I gave up in the end with it unfinished.


> Yup. Doesn't surprise me at all. This is why we have a nation of doofusses
> who can *use*, but not *understand* computers.

And sometimes barely even that!

>
> I might have greying hair, saggy eyebrows, and memory flakier than a worn
> out flash chip - but I'm glad I was around in the days of the Beeb. When it
> was feasible to open up the computer, and understand it in its entirety -
> from every instruction in the MOS ROM to every logic gate.
> Can't do that these days.

You can't even open up a PC and point and say This Bit does That
easily any more!

>
>
> ROTFL! Sod harddisc size (it lies anyway). Stuff processor speed. Who cares
> what processor is inside, it runs Windows right? But look, you can have a
> RED lid. Oooooh, shiny!

Quite ... :-(


>> And : ?"But I read it on the Internet" ... ? (I think some people have
>> finally learned not to trust newspapers 100%...)
>
> <giggle> Especially Murdoch ones. But, then, is it better or worse to switch
> print for the internet? After all, there is *supposed* to be some sort of
> integrity with print, even if it has devolved into a case of "we'll publish
> and see who sues".

I like saying to people ... ever read an article about a topic or
event that you actually know about?  Found lots of mistakes in it?
(generally, yes!) So why believe what's written in the other articles?


>
> On the internet, any half-assed numpty can write incoherent drivel; look at
> my blog if you're ever in need of examples. ;-)

lol.  But you write copious and entertaining drivel..

Rob