Review of T-BACKUP for the Model 100

   I recently bought T-BACKUP from Traveling Software, Inc. and thought
you might be interested in a review of it.  Even if you already have a
Chipmunk disk drive or other non-cassette mass storage capability, this
program can be very useful -- always a good idea to have multiple
backups, and cassette is last resort in any case.

   The program is written in BASIC but uses some machine code
temporarily poked from DATA statements into the LCD RAM buffer
(65024-65343) to do the dirty work.  This M/L code will not interfere at
all with any other .CO files or M/L you may have on the machine.  It
allows the program to make an exact cassette copy of the RAM image from
the start of RAM up to address 64992.  The backup copy then includes ALL
files and directory information including CA, CO, DO, BA, invisible,
etc., BASIC, TEXT & Lucid buffers, code between HIMEM & MAXRAM, and the
RST-7 vector areas.

   Of course I've disassembled, analyzed, printed, and totally revealed
the program's secrets for myself -- that's the only benefit I usually
derive from programs I buy or download -- but in this case I plan to
actually USE the program and keep it loaded on my M100 almost all the
time.

   It takes about 4 minutes to create a cassette backup file for a 32K
M100, plus another 4 mins to verify the save.  The program works well
and is fairly well written and compact (2.2K as .BA).

   For example, my machine may be loaded with some files I plan to
upload, plus some SIG messages, Xmodem, and a few other files.  I'll
save everything using T-BACKUP, then if CIS phone is busy (or I get too
drunk to operate) I can KILL everything, do other work, and restore the
stuff later very easily without having to do it file by file which
consumes much more time.

   Another use for me will be to make a backup with machine loaded with
all my game programs.  Then when my niece comes over, I can quickly load
up the machine for her to play with.

   Seems like this concept is similiar to the 'folders' in Chipmunk. 
But even when I get the darned Chipy, I'll still use this program for
failsafe security in backups.  It's unusual for me to find a program
useful, even the ones I write myself, but this one is exceptional; too
bad I didn't figure out how to do it myself, but it's only approx $20,
so it's worth it.

   I only have four minor complaints about T-BACKUP:

1) The verification function operates by reading through the cassette
backup file and computing an 8-bit checksum which it then compares with
the checksum read from end of backup file.  My complaint is that an
8-bit checksum does not give great assurance that the backup is correct
-- using more bits or even a CRC would have been better.

2) The program allows a comment field of only up to 28 characters to be
written in the header to the backup file.  I find the 28 char limit
restrictive sometimes and would have preferred a longer comment field. 
However the creative user could modify that part of the program if
desired (since it's in BASIC).

3) There are not enough bells and whistles, i.e. SOUND!  I would have
liked the program to BEEP at me after verifying or loading a backup (so I
could hear it from the next room and know when it's done) and emit nasty
buzzing sounds if a verify failed.  Instead it just prints a dull message.

4) Multiple cautions in the manual remind the user not to press BREAK
during a backup save or load; instead you must press the Reset button. 
This is necessary because the machine stack pointer is temporarily set
inside the LCD image area by the M/L part of the program, and if it
stopped in this state, scrolling of screen lines would blow away the
stack and lead to certain cold-start.  At least on the M100, the stack
could have been positioned in a safer area (like the COM: buffer).

   On the plus side, I found the manual clear, easy to read and understand;
but the Traveling Professor's spiel, on reverse side of tape, is rather dull,
essentially read from the manual, with no humor.

...Rick Perry [75665,1045]