EBASDDJ.WS4
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- "Notes on CP/M's BASIC-E"
   Gordon E. Eubanks, Jr.
   DDJ, #19, Vol.2, No.9, October 1977, p.35

(Retyped by Emmanuel ROCHE, posted in comp.os.cpm 27 Oct 2007.)


Dear Mr. Warren,

        I  would  like  to  give  you  and  your  readers   some
background  on the current status of a public domain disk  BASIC
known as BASIC-E. BASIC-E was developed at the Navy Postgraduate
School,   Monterey,  California  for  my  Masters  thesis.   The
implementation is comprised of two subsystems, a compiler  which
generates code for a hypothetical stack machine, and a  run-time
monitor  which interprets this code. The systems was written  in
PL/M, and runs with Digital Research's CP/M.

        BASIC-E  provides  standard  Floating-Point   arithmetic
processing  features  following  the  proposed  ANSI   standard.
Additional  extensions  include  multi-dimensional  numeric  and
string arrays, logical operators (AND, OR, XOR, NOT), and string
processing.  Also, disk support methods include  sequential  and
random  access  to files. Strings are dynamically  allocated  as
required,  and may contain up to 255  characters.  Concatenation
and  all standard functions are implemented. Logical  operations
use 32-bit two's complement binary representation of the integer
portion  of  the  variables. Files may be  organized  as  either
sequential or direct. Sequential files are a linear sequence  of
data  items. Each reference to a sequential file  retrieves  the
next data item, or writes another data item. A file may also  be
declared  with  a user-selected blocksize. These  files  may  be
accessed either sequentially or randomly.

        The  original version (version 1) was distributed  by  a
number of companies, including IMSAI and Digital Systems.  There
were  several bugs in version 1 of BASIC-E. They  involved  file
operations,  string  processing,  and  some  of  the  predefined
functions!  Also,  because of the nature of  the  Floating-Point
package, integer numbers were often printed out with an error in
the  seventh digit. I have subsequently fixed the known bugs  in
version 1, and released version 2 of BASIC-E. Both versions  are
completely  in  the public domain. Version 2 fixes  the  integer
problem mentioned above by printing only six digits of the seven
which are maintained internally. Unfortunately, there are  still
copies  of  version  2 in use which have  not  had  the  integer
problem  corrected.  Structured  Systems  Group  has  a  patched
version  of BASIC-E which retains 7 digits without  the  integer
problem (version K2.0 of the run-time package).

        I strongly recommend that anyone using BASIC-E obtain  a
copy of version 2. It is available through several  distributors
and at many retail outlets. I would be glad to provide a copy to
dealers  who  need one for $30 copy charge. The source  is  also
available in machine readable form for a $50 copy charge.

        I would like to thank the many people who have shown  an
interest  in BASIC-E and, by using it, helped debug it.  Special
thanks go to Gary Kildall of Digital Research for converting  it
to  the resident PL/M, and to Alan Cooper and Keith  Parsons  of
Structured  Systems Group who managed to find that last  elusive
bug.


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