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From: tomlinson@elec.canterbury.ac.nz
Newsgroups: comp.sys.amiga.emulations
Subject: IBeM: The author responds
Message-ID: <1991May30.130410.1@elec.canterbury.ac.nz>
Date: 30 May 91 01:04:10 GMT
Organization: Electrical Engineering, University of Canterbury, New Zealand.
Lines: 77
Nntp-Posting-Host: elec.canterbury.ac.nz

Here are the answers to all (well - most) of the questions I have received
through e-mail in the past week (over 40 items!)

DOS 4.01 locks up.
This is caused by dos thinking that IBeM supports the enhanced keyboard
functions.  It doesn't.  Why dos thinks this I don't know, as the bios
is dated 1984, and the ID byte says its an XT (doing this fixed another
program with a similar problem).  To fix this I'll just emulate the other
function calls as well (ie fixed by the time you order).

PC-Tools crashes on exit.
I know, but I don't know why.  You might have to be patient on this one.

A3000 and speed.
As someone has already pointed out, the 68000 version can be faster than the
68020 version, as it can use less fast mem and doesn't go to chip for its
meg of memory.  Since most of the slowdown in the 68000 version is from
using segmented memory, this version is almost optimal for this set up.
On a GVP accelerator which won't run IBeM but does run IBeM000, it would
be possible to make a more optimal version - but I am trying to keep the
number of versions as small as possible.

Speed.
The speed of the 68000 version running on a standard machine is roughly the
same as transformer (what did you expect?)

Access.
For those who can't FTP, I have requested it to be posted in
comp.binaries.amiga.  All we have to do is wait...

Video modes.
I have no immediate plans to emulate EGA/VGA graphics.  Remember that the Amiga
stores data as bitplanes and IBMs store 1/2/4/8 pixels (depending on colours)
in the same byte.  The time taken to split these is considerable.  A mono
mode does make sense, as this would speed up scrolling, especially on chip-
only machines.

Existing Users.
If you want to know if you would benefit from the new version, try out the
new demo.  There is an update file explaining all the differences between
versions.  Version 1.04 is the same as 1.05 except 1.05 contains the 68000
version as well.

GVP accelerators.
If you get the message "illegal instruction" then your accelerator will need
the new PAL to run this version.  The 68000 version should run fine (it runs
at about 70% of the speed though).  It is difficult to show this using
a monitor or writing small programs because of the cache and the way the
030 works internally.

Mouse Support.
This will be coming soon - just like the mono display.  All I need is some
time to write it!

Hard Disks.
Something which has been bought to my attention is one of the disks in common
use on A3000's has 70 sectors per track.  MS-DOS won't handle more than 63.
If you want to use a drive like this, you can make a "fake" mountlist entry
with five times the number of cylinders, and only 14 sectors per track. 
(Remember that the start and end cyls change also!)

Payment.
For everyone who can't read the docs, my address is
M Tomlinson
30 Kirner St
Christchurch 9
New Zealand.

If you don't want to go to the bank to get a money order, send cash - that's
the way most orders have been sent.
If you like you can send NZ currency instead of US (US$30 = NZ$50, regardless
of exchange rate :-).

Mark Tomlinson
(tomlinson@elec.canterbury.ac.nz)

Disclaimer:  I only wrote the thing!