Re: TI-H: *Great News* and schematics
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Re: TI-H: *Great News* and schematics
yeah, but the TI-85 and 82 are old and are now replaced by the TI-83/86.
The TI-82 is almost not woth the case, since there isn't even any plans in the
forseable future for a memory expander! Maybe someday, but not today. The
TI-85 does have the most upgrades, but all could be run on the TI-86. The
TI-89 and 73 have a similar shaped case, and though the keys may be different,
the shape seems to be compatible, and even if not, it should be possible to
easily modify it. I think we should stick to the more advanced calcs, cause
they will be the ones that actualy use it! The TI-83 and 86 have built in ASM
support, and they will slowly replace the TI-85 and the 82.
I rarely use my TI-85 any more. My TI-86 and 92 are prety well all I use. My
TI-83 is apart bacause there are two separate versions of the TI-83 board to
map out (schematics). My TI-82 gets used occasionaly, cause of all my TI-BASIC
programs I've written. My TI-81 is sitting on the floor and has never been
used. My TI-80 died, and I'll replac it when I've actualy got cash. I'm going
to use it to map the schematics, and the TI-81.
I finaly have a good TI-82 board (spare one), so I'll finnish mapping it.
Probably the TI-81, then the TI-80, and then the TI-83 (both versions, the 3
and the 4 chip boards)
As for the TI-83, I'd appreciate it if anyone who has ever opened their TI-83
would tell me if it has 4 chips and a few little parts, or tons of little
parts and 3 chips, and let me know the ROM version. The TI-83 I have (working)
is the 3 chip version. The spare board I got is the 4 chip verion. Curiously
enough, the 4 chip TI-83 has the EXACT same chip as the TI-82 does!!! It's the
40-pin chip between the processor and memory chip. Some TI-83's don't have
that chip, but many resistors and capacitors. It'll be interesting to see what
the differences are. Also, the processor is rotated 180° between the two board versions.
This means that I can't use one schematic with modifications between board
versions. I'll have to do two completely different schematics for the two
calcs. Luckily, the TI-86 is fairly standardized. The TI-85 has 2 variations,
but they are mere diffeences in a resistor o two. Easily shown on one
schematic. The TI-85 was designed from the TI-81, and several people have said
their TI-81 has a circuit board that looks like a link port can be added. My
guess is that in the early days of the TI-85, they decided to use one board
for both, sugesting that the TI-81 schematic will be essentialy a TI-85
without a link port. I'll need to test it, but I think it's very likely. I'll
have to test it though. That's why the TI-81 is next.
--
Richard Piotter
richfile@prairie.lakes.com
The Richfiles TI Hardware and BASIC web page:
http://www.geocities.com/SiliconValley/Lakes/5081/Richfiles.html
References: