Re: TI-H: A few ideas

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Re: TI-H: A few ideas

Mikko Kuorelahti wrote:
> 
> 1. Could someone post some info on library and linkport programming or
> even better save me from the trouble of coding and send some sources
> for an I/O lib (possibly a standard serial protocol).

Check out http://www.clinet.fi/~ozone/i2c , you can find my I2C
multimaster
routines there. Also check out www.ticalc.org, it has more general link
port programming guides. My page is only about I2C, which is a standard
serial protocol. I think as many hardware designs as possible should be
built for I2C, because it allows many devices to be connected at the
same
time, including other calculators.

> ---------------------------------------------------------------------
> 2.0. I/O lib+ErrorDetectLib=MassStorageLib for Walkman (or other
> magnetic media). Would it be possible to just record bits (+5v = 1, 0v
> = 0 : or whatever the linkport voltage) to a tape recorder and read
> them back by playing the tape? I do miss those "Press play on tape"
> messages ...

Sorry, it won't work, at least not directly, because the playback
would never reach the about 2.7 volts that the TI counts as a logical 1.
With some sort of a modulator/demodulator it might work. One of the 
problems is that you can't get accurate timing with the TI-85. I guess
the frequencies of the calculators can vary quite much, maybe +- 20 %,
depending on the temperature, battery condition etc. It happens because
the TI has only an RC clock, not a crystal one.

> 2.1. Has anyone done any research on Sony Playstation memorycards and
> their suitability for a mass storage system for the TI85? The
> connector would be excellent for a "disk type" media. The data seems
> to be stored in blocks of 65536 bytes (16 blocks for a normal memory
> card -> 1 Mbyte). It can't be that complicated ...

Not as far as I know...how much do they cost? (In $ and FIM, if you
happen to know...)

> 2.2. I/O lib+h/w adapter=MIDI-TI85. (see my previous message)

The MIDI spec says the frequency should be 31.something kbaud,
+- 1% . I bet you can't do that on a TI (not the accuracy at least), but
you can of course prove me wrong...

> ---------------------------------------------------------------------
> 3. A dynamic memory allocation library has to be published or the
> Z80-asm scene can't evolve. If noone can work it out, we'll just have
> to ask Texas Instruments for it.

Hmm. Mel? Anyone?

> ---------------------------------------------------------------------
> 4. Old games. It would be great if someone could find sources (c,
> pascal, any processor asm) for really old games (w/ ~<10k code?) f.ex
> Rogue, Hack, they shouldn't be too hard to port.

Still, it might be easier to just reprogram them from scratch, even
without the source...there are many "classic" games already for TI's...

> ---------------------------------------------------------------------
> 5. Compilers. GCC, GPC, FPK-pascal - compilers w/ public sources ...
> 
> 5.1. Can anyone get their hands on old Z80 compilers, say for the
> Spectrum Z80?

Hmm...I think I saw a C compiler for Z80 somewhere on the 'Net...
Maybe it had something to do with the UZI project, it's a UNIX for
Z80...but it's probably too large for TI's and would require some
job to port...

> ---------------------------------------------------------------------
> 6.0. Sounds. A 2 bit "soundcard" standard would be great, 1 bit is
> just a little too little.
> 
> 6.1. Serial to parallel chip
> - How complicated an 8 bit soundcard would be?

One to three chips, I'd say. One possible solution is a PCF8574 I2C
expander, a bunch of resistors (Covox style) and perhaps some kind
of an amplifier.

> - How high a frequency would be possible for playback?

My present I2C Multimaster routines transmit at 400 bytes/sec, or
630 bytes/sec if you remove the delays, but then other TI's can't
receive the data. I'm going to optimize them some more, at present
the many CALL_ 's waste lots of processor time. I think it might be
possible to get the speed to about 1 kbyte/sec, but that's not much
if you're going to play sounds with it.

-Ozone

-- 
*** Osma Suominen *** ozone@clinet.fi *** http://www.clinet.fi/~ozone
***
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