                                                              Uster, 05/22/90
                                 TT-Tools 1

                         Some tools for the Atari TT

                                 Version 1.0



First some copyright stuff:

Copyright (c) 1990 by Marcel Waldvogel. All rights reserved. You may use
and copy these programs freely, as long as you

- don't modify the copyright messages
- don't charge ANYTHING for copying (no commercial PD dealers either)
- don't bundle these tools with any commercial product

unless you have written permission to do so. The author takes no
responsibility, neither implied nor explicit, for any damage resulting
from to use of these programs. You use them at your own risk!

Please let me know if you make any changes to the source code. You may also
let me know if you want to improve/correct the documentation (English is not
my mother tongue). BTW: The source code is partly in German...

You may reach me under the following addresses:

Snail mail:                     E-mail:
Marcel Waldvogel                Fidonet: Marcel Waldvogel on 2:302/802.26
Hgestalstr.  37                UUCP:    mwaldvog@inf.ethz.{ch,UUCP}
CH - 6810  Uster                         (possibly cannot answer from here!)


And now the documentation:




        TT-Tools 1 consists of the following three programs:

        * BLiTSIM       - A BLiTTER "simulator"
        * TT2TF         - 32- to 24-Bit address bus converter
        * TEMPPTCH      - Patches TEMPUS for use with the TT shifter


BLiTSIM - A BLiTTER "simulator"
*******************************
        
Some programs, e.g. the enhanced Desktop GEMINI by G. Steffens & S. Eissing
and others programs making use of the FlyDials by J. Reschke provide some
extra capabilites if a BLiTTER is installed. BLiTSIM gives you the
opportunity to see the dialogs moving around in real time on the Atari TT
and other Atari machines not equipped with a BLiTTER.

How to install BLiTSIM

You can either start it from the Desktop or put it in your AUTO folder on
the boot drive. As it is installing, it shows its copyright notice and 
terminates while staying resident. It uses less than 512 Bytes of memory when
installed.

How to uninstall BLiTSIM

If you have an application which gives you any problems if BLiTSIM is
installed, simply start any copy of BLiTSIM. This one tells the resident
part of BLiTSIM to deactivate itself. To reinstall BLiTSIM simply start it
again, which tells the resident part to reinstall. Whenever you (re)install
or deinstall BLiTSIM, you get the appropriate message.

How BLiTSIM works

Installed: Whenever the XBIOS function Blitmode() is called, BLitSIM returns
           a value of 3, indicating that a BLiTTER is installed and active.
Uninstalled: BLiTSIM behaves completely transparent, with no effect to the
           functionality of the operating system.
           
Compatibility problems

TEMPUS 2 does not work BLiTSIM, because it looks out for the BLiTTER using
Blitmode() but accessing the BLiTTER directly which results in a bus error
when you attempt to scroll. There may be other programs not working together
with BLiTSIM.

Some technical information

BLiTSIM uses the XBRA ID "BSIM". The byte at offset -14 to the entry point
is a flag indicating the activity (bit 7 set: active). You may change this
flag whenever you want, changes take place immediately.




TT2TF - Thirty-Two to Twenty-Four
*********************************

Some "old" Atari ST programs use the upper 8 Bits of the address bus for
their own purpose (e.g. TEMPUS 2 stores there the length of a text line).
TT2TF enables you to use these programs further on.

How to install TT2TF

Like BLiTSIM, you can either start it from the Desktop or put it in your
AUTO folder on the boot drive. As it is installing, it shows its copyright
notice, the message "24 bit address bus installed", and terminates while
staying resident. It uses about 1K bytes of memory when installed.

How to uninstall TT2TF

To be able to uninstall TT2TF, you must have a cookie jar installed with at
least one more free entry at the time you installed TT2TF. A cookie jar is
installed by default when booting up your TT. When using other machines,
you will have to put another program in your AUTO folder which installs a
cookie jar (e.g. COOKIEJR.PRG or any of the POOLFIX?.PRG) before TT2TF.
If TT2TF was able to install into the cookie jar, you can uninstall it by
starting it agagin. It then says "Old MMU settings restored" and terminates.
If an error occured while installing TT2TF (No MMU or 68030, or the MMU
suddenly disappeared [GRIN]), the messages says "ERROR: Resident TT2TF badly
installed!".

Compatibility problems

Any program that needs the full 32 bit address bus may have problems (e.g.
programs accessing the VME slot or perhaps the fast RAM). As I have not
gotten any technical information along with the TT, I cannot make them an
acceptable MMU translation tree.

Some technical information

The addresses $xx00'0000 through $xxFF'7FFF are mapped to $0000'0000 through
$00FF'7FFF, while $xxFF'8000 through $xxFF'FFFF are mapped to $FFFF'8000
through $FFFF'FFFF (the apostrophes are for readability only). The addresses
from $xx02'0000 through $xxDF'FFFF (between the RAM and the ROM space) may
change in mapping, if they are needed otherwise.
TT2TF uses the cookie jar ID "TTTF". An address of 0 means an installation
error (see "How to uninstall TT2TF"). Any other address is a valid pointer
to a subprogram changing the MMU status. The word at offset -2 to this sub-
program is a status variable. Its bit 15 (which is the same memory location
as bit 7 of the byte at offset -2) is the "disabled" bit. If it is set, the
TT2TF is inactive. After changing this status variable, you MUST call the
subprogram!
The flag TWOLEVEL in the source determines whether the translation tree will
be two levels deep (=1) or only one level deep (=0). With TWOLEVEL=1, it
uses much less memory when staying resident (1K instead of 3K).




TEMPPTCH - disables the screen saver in TEMPUS 2
************************************************

TEMPUS has a built-in screen saver which blanks the screen by setting the
shifter to "external sync". You may disable this screen saver, as soon as
one exits TEMPUS, it switches to "internal sync". Because the meaning of this
bit has changed in the TT shifter, THIS really turns the shifter to external
sync. Now this patch removes all accesses to the shifter sync register in
the german version 2.05 of TEMPUS. It should work with other versions as
well, but APPLY THIS PATCH TO A BACKUP COPY OF TEMPUS and test it carefully
afterwards!

How to install TEMPPTCH

You simply copy TEMPPTCH into the same folder as TEMPUS.PRG and start it.
It then reads it in and saves the result into TEMPUS.APP. Before saving,
it shows you how many locations were patched (in my version, there were
four of them). If all worked well, you can delete TEMPPTCH and TEMPUS.PRG,
and you may rename TEMPUS.APP into TEMPUS.PRG.



And now good luck with your TT and TTTOLLS1!
