Re: Proposed open operating system/gui/shell (CalcOS-82,83,85,86)
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Re: Proposed open operating system/gui/shell (CalcOS-82,83,85,86)
On Mon, 13 Oct 1997 18:34:57 -0400, Daniel Reed <djr@NARNIA.N.ML.ORG>
wrote:
>On Mon, 13 Oct 1997, Riley McArdle wrote:
>) I am proposing a new operating system. Unlike anything any other TI
>) calculator has seen (other than the 92). I have attached my notes so far.
>) Nothing is started yet so don't ask for a download site. I have been
>) looking at the state of ti calculators for a while and I have been thinking.
>) It is so hard for someone to get started programming. Once they do get
>) programming, there are so many operating systems (at least two for each
>) calculator) and twice as many gui/shell/apis. Most of them are also closed
>) source code. What I am proposing is an open operating system with
>) reasonable portability and SMALL size. The way I think that we can make it
>) small is with compression. If we had a small kernel and a compression
>) library, we could load and unload programs from RAM (or even a memory
>) expander like the ones for the TI-85) and dynamically decompress them.
>/usr/src/zlib-1.0.4/README:
>zlib 1.0.4 is a general purpose data compression library. All the code
>is reentrant (thread safe). The data format used by the zlib library
>is described by RFCs (Request for Comments) 1950 to 1952 in the files
>ftp://ds.internic.net/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate
>format) and rfc1952.txt (gzip format). These documents are also available in
>other formats from
>ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html
>...
>root@narnia:~# ls -l /usr/local/lib/libz.so.1.0.4
>-rw-r--r-- 1 root root 49952 Sep 5 18:58
> /usr/local/lib/libz.so.1.0.4
>root@narnia:~#
>
>I'm, uhm, pretty sure the TI-85 only has 32k of RAM, while the stripped,
>maximally optimized zlib library that I have on my computer is 48.78k
>alone...
>
>) I
>) also think that the operating system needs to have dynamic linked libraries
>) so that common code can be shared (which would also help with size). I am
>) starting with the TI-82 (because that is what I have) and TASM (not the one
>) from Borland). I don't know a whole lot about assembly (especially Z80) but
>) I definitely know a lot about programming and operating systems.
>
>--
>Daniel Reed <n@narnia.n.ml.org>
>System administrator of narnia.n.ml.org (narnia.mhv.net [199.0.0.118])
>The two most common elements in the Universe: Hydrogen and Stupidity...
A complete compression and decompression function program isn't really
worthwhile. The smallest compression algorithm would be a fixed tree
Huffman coding, and that would be abou 2000 bytes for the whole thing.
That will run fairly quickly but will not compress better than 30%,
which is only about 8k, which is not much, because you need space for
the decompressed file. A better algorithm like arithmetic coding might
get 70% or so, but It would be pretty big.
Richard
References: