Path: utzoo!attcan!uunet!mcvax!unido!tub!tmpmbx!netmbx!hase
From: hase@netmbx.UUCP (Hartmut Semken)
Newsgroups: comp.sys.atari.st
Subject: Re: slow in mono and 68020 boards...???
Message-ID: <2132@netmbx.UUCP>
Date: 21 Jul 88 02:50:04 GMT
References: <3960@watvlsi.waterloo.edu>
Reply-To: hase@netmbx.UUCP (Hartmut Semken)
Organization: netmbx Public Access Unix, Berlin
Lines: 55

In article <3960@watvlsi.waterloo.edu> jparker@watvlsi.waterloo.edu (James Parker) writes:
>I have been told that the ST runs as much as 30% slower than 'normal' when
>used with the Atari monochrome monitor.
>I assume this means compared to running the same software using the color
>monitor.
>Does anyone know if this is true, and if it is, why ?

Hmm, ja.  It's true: the VBLANK interrupt comes with 71 Hz instead of 60
HZ (or 50 Hz here in Germany..)
That could slow him down a bit (but not 30%!). I see no speedup with the
color monitor (subjective), but I do my work on mono and play on color
:-)

>
>Secondly, I have also heard reports of 68020/68881 boards available for
>the ST ( ie. a series of articles in the German magazine c't ) and at the
>same time, I have been told by several people that at present TOS does 
>not handle the 68020 instruction set ( TOS uses instructions for system 

Ja. Tos runs into trouble with the stack format, with Line-F (the
floating point instructions) and so on.

>calls that are now legal 68020 instructions, etc).
>So, does this mean that those people using 68020's are running different 
>operating systems...?

If you really want to *use* the 881 (and 020), You'll need RTOS/PEARL or
the like.
We use RTOS for realtime applications (train controlling, controlling a
[simulated] nuclear power plant) and I like the speed of the 020.

The c't also published a patch and a modified TOS to run with the PAK68.
The Line-F's are converted to (not used) Line-A's. 90% of all software
runs under this TOS; the 10% *You* like will probably never run (Murphy
:-)...
I had a PAK68 and the modified TOS installed in my home ST. The speed
was not soooo impressive ('cause the 020 can only run with 8 MHz in the
ST).
Another, cheaper modification will do almost the same: replace the 68000
with a socket. Put a board with a 12 MHz type, a new set of ROMs  (not
patched but faster; -OE used instead of -CE) and a little, fast adress
decoder (fast DTACK on ROM access) into the socket.
A very friend of mine is working on the little details about it. For
now, it works *sometimes*. The fallback to 8 MHz on VPA (I/O access)
seems to cause the trouble...

summary: the $500+ "patch" with a 020/881(or 882 :-) and new ROM set is
very useful with the german RTOS-UH (RealTime Operating System der
Universitaet Hannover); it is not worth the money+trouble (hacking the
hardware, new case, compatibility, still not impressive fast) for TOS.

hase
-- 
Hartmut Semken, Lupsteiner Weg 67, 1000 Berlin 37 hase@netmbx.UUCP
High on a rocky promontory sat an Electric Monk on a bored horse. (D. Adams)