Date   : Tue, 20 Aug 1985 18:45:46 PDT (Tuesday)
From   : TReed.ES@XEROX.ARPA
Subject: DBase II Questions, CALL Command

Quoteing verbatum from the DBase manual I have,

"SET CALL TO <address>

Sets the decimal address that will be called by dBASE CALL command.

CALL [<memvar>]

Performs a machine language call to the address set by a SET CALL TO or
the default address if no SET CALL has been done. There are about 254
bytes of stack available, the HL register pair points to the first byte
if the <memvar> was a character string.  It is most important that no
attempts be made to lengthen or shorten a character string.  Control can
be passed back to dBASE with a RET instruction."

The above is the sum total about the CALL instruction, that I have in my
manual.

I have used the combination SET CALL TO <address> and then CALL (with no
<memvar>) with a RET in the machine language code, and that functions as
expected, however, my questions are:

1. What is the DEFAULT address, to which the documentation alludes?
2. "There are about 254 bytes of stack available", where?  Starting at
the default address?
3. What is the function of <memvar>?  Is it to pass a parameter to the
machine language routine?  Give an example.
4. "the HL register pair points to the first byte if the <memvar> was a
character string"  the first byte of what, the <memvar> address? 

Any answers would be apperciated.

Thanks

--Terry