How to Load Tarbell BASIC

If you have TARBELL BASIC on a CP/M disk, simply put the disk
into the drive, and type TBASIC.  You can ignore the rest
of this page.


If you have TARBELL BASIC on cassette (Tarbell, of course),
first examine the listing of the I/O section that came with
the TARBELL BASIC.

Compare the console and cassette I/O routines to the ones you 
normally use in your system, to determine if there are any 
differences.  If there are, mark the necessary changes on
the listing.

Using either the bootstrap program or input program in the
Tarbell cassette interface manual, or the Read-Only-Memory
Program, or other monitor, read the TARBELL BASIC interpreter
from the cassette into your main memory, using the starting
address and length which is specified on the cassette.

NOTE:  TARBELL BASIC is stored on tape at a rate of 1500
bits per second, or 800 bits per inch.  A several-second
leader of clock cycles is followed by the start-byte (3C),
then the sync-byte (E6), then the number of bytes of program
indicated on the cassette label under "length", then the
checksum, all in one big block.  The start-byte and sync-
byte are detected by the hardware, and it is up to the
software to read the proper number of bytes after that,
and to check the checksum for errors, if desired.

If you need to make changes in the I/O section, now is the
time to do it, using either your front panel DEPOSIT button
or suitable monitor in ROM.  Note that the top of memory
address which is put into location SSSS is done automatically
in CP/M systems, but may need changing for other systems.
The default in cassette versions is to search for end of memory.

Start your computer running at the starting address specified
on the cassette, by doing an examine and run at that location,
or by using your ROM monitor to jump to it.

You should now get the opening message.















				J