Re: ancient animation

[dempson@atlantis.actrix.gen.nz (David Empson)]

In article <4np1v1$2vn@crcnis3.unl.edu>,
Greg Berigan <gberigan@cse.unl.edu> wrote:
> 
> Has anyone found a way to run Integer BASIC programs under ProDOS?  I
> understand there was a conflict in that ProDOS stores itself where
> Integer BASIC would normally go.

That is correct.  To do this properly, you would need to implement an
"INTBASIC.SYSTEM" program, which would have to do some jiggery-pokery
to rearrange memory so that INTBASIC was available in the language
card (pushing ProDOS into the auxiliary memory language card, for
example).  This would require a 128K IIe.

Simple Integer BASIC programs could be supported by an INTBASIC.SYSTEM
which provided the language code (relocated) in the place where
BASIC.SYSTEM currently lives.  This wouldn't be compatible with any
INTBASIC program which uses CALLs into the $D000-$D7FF (Programmer's
Aid #1) or $E000-$F7FF (INTBASIC, Mini-Assembler, Sweet-16) areas.

In either case, you would run into problems with programs that make
direct access to DOS 3.3 internal locations, or depend too much on
features of DOS (such as long filenames).

> How about an INT to SYS compiler?

That wouldn't be too hard (it would certainly be easier than
Applesoft), but would be limited in the same way as method (b) above.

In fact, there IS an INTBASIC compiler: ORCA/Integer BASIC, from Byte
Works.  It turns simple enough Integer BASIC programs into IIgs
applications.  The main purpose of the compiler is as an example of
how to write a compiler - complete source code to the compiler
(written in ORCA/Pascal, I think) is included.

IIgs System 6.0.1 includes a native IIgs version of Apple Bowl, which
was compiled using this program, I believe.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand