Date   : Wed, 10 Jun 1981002:09:00-MDT
From   : Keith B. Petersen <W8SDZ@MIT-MC>
Subject: Saving money on F80 and M80

I recently noticed the following message on a remote CP/M
system and thought it might be of interest here:

Date: 5/30/81
From: ANDY BENDER
To:   ALL
Re:   CHEAP FORTRAN AND MACRO 80 PROGRAMS

If you want a copy of the Microsoft F80 and M80 programs
as well as their support software and you want to get them
with free updates for a year and be a legal user read on.
While not free, Heathkit sells these programs, doctored up
so they only run on Heath systems, at a discount.  The
discount is quite steep and the free updates are attractive.
You will need to know about DDT and SAVE to fix them so you
can use them:

FOR FORTRAN: >DDT F80.COM
then alter the LXI d,barf at 2C38 to jmp 2C90.
Exit from DDT and do a SAVE 107 F80.COM

FOR MACRO80: >DDT M80.COM
then alter the LXI d,barf at 4392 to jmp 43EA.
Exit from DDT and do a SAVE 75 M80.COM

You now own legal copies of both programs suitable for use
on your CP/M 1.4 or 2.2 system.

This patch bypasses the vendor code check in the CP/M
serial number and also bypasses some I/O twitching that
must be important for Heath systems.  The other system
programs distibuted on the disk do not need patching
these programs (LIB, L80 XREF etc) assume if you got to
use them you must be ok.

The same patch is probably possible in other Heath
software such as BASIC Compiler or COBOL Compiler.  I
have not researched these programs however.

My advice to fix other software would be to look at the
area in which the vendor code check is being carried out
and follow the same bypass as I did in M80.

Lots of Luck - Happy Computing from us at NSI.