The Microbits Peripheral Products
MPP-1000C modem is unique to the
Atari computer as it is designed
to operate from the second joystick
port rather than from a standard
RS-232 interface like that found
on the Atari 850. The benefit
of this is obvious, the expensive
850 interface is not required
for operation. However, because
of the need for a special software
driver to make the joystick port
function as an asynchronous communica
tions port, it will only work
with the Smart Terminal software
provided on ROM cartridge with
the modem.

The MPP terminal software provides
for two types of up or download
protocols. The first method is
simply to save a downloaded file
to a memory buffer by using the
OPTION key to manually open and
close the BUFFER. The second option
is to select the X-MODEM protocol.
X-MODEM automatically corrects
any transmission errors that might
occur because of a bad connection,
random phone noise, etc. This
is similar in function to the
TSCOPE protocol used on this SIG
but it is NOT compatible. Because
of this incompatibility, the only
way an MPP user can download from
the Atari SIG is to manually download
 to a buffer or a disk drive with
no error checking. Although this
is not as convenient as X-MODEM,
most files on this board can still
be downloaded in the following
ways.

A standard basic file can be download
ed by selecting the BROWSE function
in one of the XA databases (please
see other help files on using
the ACCESS portion of the SIG
for more help on these functions
or obtain the Compuserve guide
to Special Interest Group/Forum
by ordering through Feedback).
After presenting a description
of the file three options are
presented; Read the file, Download
the file or return to menu. Pressing
<RETURN> will force a description
of the next file in the database.
To download the file press <D>.
Three messages will appear on
the screen. The last message will
end with three periods. When you
see the three periods press the
<OPTION> key to open your buffer.
The file will begin to download
into your memory buffer and list
to the screen at the same time.
At the conclusion of the download
a FILE BUFFER CLOSED message will
be displayed. You should press
your <OPTION> key again to close
the buffer. You have now downloaded
the file into memory. The next
step is to save the file to disk
or cassette by invoking the C
option from the terminal main
menu. A sub-menu will appear on
your screen allowing you to select
the device to copy to as well
as a file name. Remember, the
file will be saved in the LIST
format as a non-tokenized file
and must be loaded using the ENTER"D:
FILENAME.EXT" command. Once it
has loaded, ignore any error messages
 and save the file back to disk
using the SAVE"D:FILENAME.EXT"
command. This will create a standard
tokenized basic file.

If a file is designated as a binary
file (usually with the extension
.BIN) it can be downloaded using
the same procedures just explained.
After the file has been downloaded
and saves, however, it is not
in an executable format and must
be converted by using a binary
file conversion utility. There
is an excellent one on XA2 called
CONBIN.ATR that can be downloaded
as a standard basic file. After
you have saved a downloaded binary
file to disk, run the CONBIN.ATR
program. It will prompt you for
the source filename - this is
the name you gave the binary file
just downloaded (be sure to proceed
the filename with D: and do not
use quotation marks). It will
then prompt for the destination
filename - this is the name of
the file written to disk after
the conversion process. Be sure
the name is different form the
source filename or you will destroy
the downloaded binary version.
When the conversion is complete
you will have an executable version
of the binary file on your disk.
This will either be a machine
language file which can be run
using the Atari DOS L command
or a standard Basic file that
was downloaded in a binary format.
I have found this procedure to
work with all binary files, even
those marked for download with
TSCOPE only. I have, however,
downloaded a couple files that
would not execute after conversion.
This indicates that an error occurred
 during the actual download process
(remember, no error checking without
X-MODEM or TSCOPE!). The only
remedy for this problem is to
try a new download of the file
from the database. I've only experien
ced this on a one or two downloads
in the past couple months. If
you do experience alot of errors
on a download try disconnecting
your phone connection and dial
back on. Chances are you'll get
a different line with a cleaner
signal path. By the way, it is
not unusual to receive an error
message when the conversion process
is complete. It is usually caused
by extraneous characters downloaded
before the buffer was closed.
Just ignore it, it won't hurt
a thing. However, if your a perfectio
nist like me. almost any text
editor can be used to clean-up
the binary file before converting.
Look at the beginning and the
end of the file for extraneous
information.

You will undoubtedly notice files
in the databases that use an extensio
n of .CRE. These are file that
create another file when executed.
Many times these are multiple
files that create a single file
when run. Any of this type of
file I've run across will download
like a standard basic file. Remember,
 the file will be saved to your
disk as a LIST file and must be
loaded by using ENTER and then
RUN.

The MPP manual states that a file
download can be made direct to
disk by selecting the B option
from the terminal main menu. A
sub-menu will appear allowing
you to establish a filename for
the download. All of the procedures
discussed above still apply. The
only difference is that the downloade
d file is written direct to disk
instead of to a memory buffer
and then being saved to disk.
Selecting this option will save
you time in downloading and, therefor
e, money. It also eliminates the
worry of running out of memory
in your buffer on extremely large
files. The choice, however, is
yours.

If you would like to experiment
with using X-MODEM, most private
Atari bulletin boards support
this protocol. Once you've tried
it you'll realize how much you're
missing by not being able to use
it (or something similar) on this
SIG. However, with a little effort,
every file in the SIG databases
can be successfully downloaded]
Be sure to read your MPP manual
carefully and follow these instructio
ns exactly as given. If you have
specific question, or are still
experiencing problems, leave a
message on the message board and
we'll try to help. And, most of
all, have a good time as a member
of the Atari Special Interest
Group!

            Larry Sullens (71625,1711
)

The Microbits