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eForth is a simple Forth model which can be easily ported to a wide
range of CPU's. It is best put into ROM and communicate to the
outside through a serial RS232 line. Files can be downloaded through
the serial line also. This eForth Model includes an implementation
on IBM-PC. The assembly source code is designed so that one can use
MASM to assemble object code for any target CPU. Only 29 words are
coded in machine instructions, which can be easily modified to run
on a target CPU other than 8086. The eForth Model and the IBM-PC
implementation is in the public domain to encourage interested
programmers to port this model to different CPU's.

C. H. Ting
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July 29, 1990

Dear eForth Beta Tester:

This is the eForth Model which I promised to give you for evaluation
and implementation. Bill Muench and I labored quite intensively
over the last four weeks chasing bugs, discussing many implementation
and stylistic issues and experimenting various approaches and
solutions. We barely made the releasing date, July 28, at the FORML
session of the Silicon Valley FIG chapter meeting. As thing usually
go, after I printed the documentation, Bill found it was necessary to
overhaul the system for good reasons. When we arrived at the SVFIG
meeting, the documentation showed a phase delay from the code to be
formally released. Sounds very familiar. Did I tell the same story
somewhere else?

The solution is that we are including two versions of EFORTH.ASM on
this diskette. EFORTH.ASM is the new version that you should use
to implement eForth on the CPU of your choice. EFORTH.OLD contains
the source code which generates the assembly listing as printed
in the 'eForth Implementation Guide'. EFORTH.ASM has much improved
style and a set of new macros to assemble the headers. It also
fixed a bug in $," to aligned a compiled string to cell boundary.
The order of words is also changed slightly to highlight the machine
dependent I/O words.

The files on this diskette are:

EFORTH.ASM The source code of eForth for IBM-PC 8086.
EFORTH.SRC The Forth source of eForth Model.
EFORTH.GLO The glossary of words in eForth.
EFORTH.COM The executable object of IBM-PC eForth.
READ.ME This file.

The assembly commands are:

>MASM EFORTH;
>LINK EFORTH;
>EXE2BIN EFORTH EFORTH.COM
>EFORTH

The manual undoubtly needs much improvement. As we start porting
eForth to other CPU's, we will discover more problems which need
explanation, especially to the first time Forth users, who are the
intended audience of the eForth Model. Your feedback will be
greatly appreciated.

As machine dependency is consolidated into 29 code words, moving
eForth to other CPU's will be much less of a chore comparing to other
Forth models. I am expecting that an implementation could be
completed within 4 weeks, assuming that you are familiar with the
instruction set of the target CPU and its enviornment. I am especially
interested in how long a student, upper level college or graduate,
needs to implement it. If you are teaching microprocessor in a
school, please consider this model as a class assignment and
monitor the reactions from the students.

Please send me your implementation as soon as possible. Please
let me know of any deficiency in this model also. This project
could significantly broaden the user base of Forth. We really
hope that it will help Forth reclaim its glory as the language
of choice for embedded systems.

Thank you for your interests and encouragements in this project.
I hope to hear from you soon.

C. H. Ting
156 14th Avenue
San Mateo, CA 94402
(415) 571-7639

P.S. If you get this file from BBS, send me $15 for the manual
'eForth Implementation Guide' if you need it.