Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!sunic!tut!tukki!eloranta
From: eloranta@tukki.jyu.fi (Jussi Eloranta)
Newsgroups: comp.sys.apple2
Subject: Re: apple // and multitasking, perfect together! (??????????)
Message-ID: <3664@tukki.jyu.fi>
Date: 7 Mar 90 05:48:08 GMT
References: <14298@phoenix.Princeton.EDU>
Reply-To: eloranta@tukki.jyu.fi (Jussi Eloranta)
Organization: University of Jyvaskyla, Finland
Lines: 39

In article <14298@phoenix.Princeton.EDU> tbrakitz@phoenix.Princeton.EDU (Byron Rakitzis) writes:
>I was (am) thinking long and hard about implementing a multitasking
>operating system on the apple //. Let me state right away that I don't
>ever expect to accomplish anything useful with such an operating
>system; it would be way too slow.

Too slow, 6502 stack (256 bytes), no MMU, small amount of mem., ... ,
forget it..

>A multitasking operating system implies the existence of a multi-user/
>permission structure in the hardware itself.
....
>has just two. The 6502 obviously has just one "mode"!!!
>

Well not all multi-tasking systems need this... 

>I was wondering how much fun it would be to at least get a program
>started on the 6502 which could *emulate* a more serious processor and
>then to build an operating system on top of that. I was not sure what
>to call this processor, and I was not even sure what kind of processor
>architecture I needed, so I ended up calling it "BISC" (Byron's
>Instruction Set Computer) since that is certainly what it is going to
>be.
>

Huh?! Even slower! ... I would suggest to forget the whole thing...
May be 68xxx series would be a more reasonable processor to start with.

Jussi




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Jussi Eloranta               Internet(/Bitnet):
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