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Article #585 (635 is last):
From: aa700@cleveland.Freenet.Edu (Michael Current)
Newsgroups: freenet.sci.comp.atari.news
Subject: MYDOS 4.5 On Cart
Reply-To: aa700@cleveland.Freenet.Edu (Michael Current)
Posted-By: xx004 (Atari SIG)
Date: Thu Mar 26 14:08:22 1998


From: tikk@alt.anonymous.messages (tikk)
Date: Thu, 19 Mar 1998 02:29:37 GMT

MYDOS 4.5 ON CART

Since this cartridge based MYDOS is different than the
standard MYDOS a few words on the main differences is
in order.  The differences include a reverse OPTION key
function at power up.  Now if you want BASIC you must
hold down OPTION at power up.  Another difference is the
Ramdisk configuration tables. The available bank bytes
are ordered from highest to lowest value which is more
compatible with the XE standard banks.  The default 
configuration is also in this highest to lowest order 
such that a novice is less likely to blow his Ramdisk
away without wanting too!!  To configure your Ramdisk
to not use the BASIC/XE banks choose page sequence 1
as per the MYDOS technical manual.

Another difference is a working MEM.SAV feature.  I 
don't know why MYDOS was released with a defective 
MEN.SAY in the first place but it is now working.  If
you are sharp you will notice that DOS.SYS has grown 
by one sector and DUP.SYS has shrunk by one sector.  The
code for the MEM.SAV feature was moved back to DOS.SYS
which is the only place it could work from and thus the
different sector counts.  The purpose of the MEM.SAV 
feature is to allow the user to preserve the portion of 
Ram that DUP.SYS loads into.  It is used for producing 
modified files that would normally be stomped on by 
DUP.SYS. When the MEM.SAV feature is active and DUP.SYS 
is called to be loaded into memory again, a copy of the 
area in question is saved in the file named MEM.SAV.  
When a (K)SAVE is used for that area and the MEN.SAV 
feature is active then MEM.SAV is loaded into the area 
prior to the (K)SAVE.  MYDOS's MEM.SAV feature is actually 
quite a step above other DOS s MEM.SAU in that the feature
can be deactivated by simply choosing the (L)LOAD memory 
option and then pressing return.  You don t have to put up 
with constantly loading and reloading MEM.SAV or deleting 
a MEM.SAV you would really like to keep, it can sit on your 
disk unchanged until you need it.  To activate MEM.SAV you 
use the (N)LOAD memory w/MEM.SAV option.  These two functions
are identical in every way except (L) turns off the MEM.SAV 
flag and (N) turns it on.  In either case no file actually
needs to be loaded, just a return will toggle the flag. 

The last difference is probably the most noticeable and that
is some of the menu prompts have been changed to reveal their
purpose more clearly. (N)LOAD memory w/MEM.SAV is one.  Set 
D:#/Subdirectory lets you know that here is where you can set
your default drive number or use a Subdirectory as your default
drive (D:).  A Subdirectory CAN be used as a drive, but first
one must be created by (Q)MAKE Subdirectory and then your files
are copied into that Subdirectory by using (C)COPY files. 

To use the cart, just plug it in and turn on your computer.
You don't even need any drives to have this DOS but that 
really doesn't make much sense to do.  The fastest boot time 
will result when you have two drives (1 and 2) turned on.
A disk does not have to be in either drive, hut to take 
advantage of the built in Ramdisk loader it is necessary to
have on a disk that has been formatted by this version of 
MYDOS, a Subdirectory entitled RARDISK:.  The files you want
loaded at boot up are then copied from the Subdirectory 
RAMDISK  into whatever Ramdisk # you set when you formatted
the disk.  If the Subdirectory RAMDISK: is not found on Dl:
or is empty, then you will get a ramdisk format and DUP.SYS
copied to the ramdisk only if the ramdisk # was set when you 
formatted the disk in the drive.  If there is no disk in the
drive then you do not get a ramdisk format or DUP.SYS copied
to the ramdisk, you have to do all that from MYDOS proper. 

To get BASIC you just hold down OPTION at power up. A second
is almost a second too long.  Your ramdisk can be loaded or 
at depending on what you have in Dl .  When the DOS menu 
appears stable, press RESET to enter BASIC with the Miami Valley 
ACES s WEDGE program already installed!!  It is a DOS like shell 
that operates from ASIC.  The commands are listed every 
time you press RESET and the wedge is still there.  It can be 
removed by typing KILL.  From then on you have only the BASIC 
Atari gave you.  Entering DIR will give you a directory of your 
default drive, and that drive can be changed by POKEing 1803 
with what ever drive number you have.  SCRATCH is the same as 
delete filespec. SPRINT will send to your printer a screen dump.
SD and DD stand for single and double density for those with 
drives that can switch densities. You can now read and write
as you please from BASIC. 

>From this DOS you can kill BASIC by (M) running at address 
$1ECO.  And you can also go to BASIC by (M)running at address 
$1EE5. These routines may not always be there as they are not 
protected, so some luck and judgement on your part is required.
Don't forget to kill your Basic with a run at $1ECO prior to 
loading a program with DOS that "lives" in high Ram as BASIC is 
a ROM that lives from $AOOO to $BFFF and you will lock up if there
is a conflict. 

Whether you choose DOS or BASIC, just to make sure your display 
list is where it should be you should press RESET when the DOS 
menu appears stable.  This is IMPORTANT!  It allows MYDOS to be 
entered correctly via DOSVEC instead of the patched entry required 
to give you the option of having BASIC. 

At the moment the cart is pulled this MYDOS looks for AUTORUN.SYS 
on Dl: and if not there then the other features are looked for.  
This was done to more closely mimic a disk based DOS. Your 
AUTORUN.Sys file should NOT be a Ramdisk loader for the pending 
self contained Ramdisk loader will do what it can to ruin 
the previous format.

Enjoy!
POOR BOY
Video 61 BBS
612-462-3680

To load the cartridge, make sure that the power is tuned off and 
that all cartridges have been removed.  This version of MyDOS will 
work on XL/XE COMPUTERS ONLY WITH AT LEAST 64K. Now plug in the 
mydos cartridge and turn on your computer. If you want to access
basic, wait for the "pull cartridge and hit reset" command to 
appear, then put one hand on your computer and firmly grasp the 
mydos cartridge. Now pull it out of your computer (this will 
not hurt it), then hit reset and you will be in basic. To lock 
out basic follow the same commands except at boot up hold down
the option button to lock out basic. 
-- 
Michael Current, mailto:mcurrent@carleton.edu
8-bit Atari FAQ and Vendor Lists, http://www.faqs.org/faqs/atari-8-bit/
Cleveland Free-Net Atari SIG, telnet://freenet-in-c.cwru.edu (go atari)
St. Paul Atari Computer Enthusiasts, http://www.library.carleton.edu/space/





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