Has anyone had experience or have ideas about compressing / decompressing
English text with a PIC?

I have an application that would benefit from having the PC that is sending
data to the PIC compress text and then having the PIC expand it. The text is
just standard English words, phrases, sentences etc...

To make things more complex, the compressed text cannot use non-printable
characters, i.e. we get only 96 possible values per byte or only one of the
following patterns in each byte. 3 x 2^5 = 96

001x xxxx
010x xxxx
011x xxxx

BCD numbers pack into this fairly nicely, 9 x 9 = 81 < 96 so each byte still
holds two BCD digits. But 26 letters plus shift plus space don't seem to map
well. <GRIN> (this is, of course, because they map perfectly) I was thinking
that some Huffman compression system may exist that works well here? Easy to
de-compress on a PIC is important as well.

If you have good text compression / expansion code that produces binary, I
can translate that into printable only but thought I would mention it on the
chance that someone else has hit this before.

If this sounds like a really weird application, think about this: if you
wanted to make a device that could be updated via an email.... without
running an application on the remote email users machine... just send the
email and tell the user to connect the device and copy the email out...
Anyone who has struggled with update files that get munched in transit or
when the user on the other end can't figure out how to run your app or
winzip (or doesn't want to or can't etc...) will see the utility here. And,
of course, the smaller the email the better...

James Newton mailto:jamesnewton@geocities.com phone:1-619-652-0593
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