
Casio FX-880P Personal Computer Teardown - neilpanchal
https://neil.computer/notes/casio-fx-880p-personal-computer-teardown/
======
donio
I started looking around for other cool models. First I found this beauty, the
fx-890p, programmable not just in BASIC but also in C (interpreted) and
assembler:

[https://www.thimet.de/CalcCollection/Calculators/Casio-
fx-89...](https://www.thimet.de/CalcCollection/Calculators/Casio-
fx-890P/Casio-fx-890P-M.JPG)

And then there is this pocket Lisp machine:

[https://casio.ledudu.com/images/pockets/casio/machines/zoom/...](https://casio.ledudu.com/images/pockets/casio/machines/zoom/AI1000.jpg)

There are a couple of emulators out there, this one supports the AI-1000 Lisp
version too:

[http://www.pisi.com.pl/piotr433/pb2000ee.htm](http://www.pisi.com.pl/piotr433/pb2000ee.htm)

~~~
fit2rule
I have a pair of Atari Portfolios' in my retro collection, one of which is my
original from the release, and the other was a contribution - and they're
simply delightful little machines.

My original still has Turbo C on it, and all the programs I wrote during
flights all over the place back in the 90's, keeping myself awake in obscure
airports.

Very fun to dig it out, put in fresh batteries, and go back to where I was
editing, ~30 years ago .. ;)

My GPD Pocket is still a better dev machine in that regard, though..

(I also have an Olivetti M10, which is like a Tandy Model 100 .. another
delightful machine with saved state that goes back decades, instantly
available with the insertion of a couple of ol' trusty AA's ..)

------
tomhoward
I think I first saw one of these devices in our house when I was a kid in the
mid 80s.

My dad was (still is) an electronics engineer, and started a company making
data logging devices for weather and environmental data, and was using these
for data download and display.

His own computer was a self-built machine with a Motorola 6809 processor, with
all the boards/parts mounted into an old Hoover Keymatic washing machine
chassis [1].

It was funny for ~8yo me to learn that this tiny pocket-sized Casio thing and
the Hoover monstrosity in the garage were both "computers".

Fond memories.

[1] [https://www.ssplprints.com/image/83554/hoover-keymatic-
washi...](https://www.ssplprints.com/image/83554/hoover-keymatic-washing-
machine-1963)

------
nullc
> If somone designed a calculator today, they would most likely be made from
> ABS plastic, in a clamshell case.

Not so-- calculators are now such a niche market that it again makes sense to
build for quality. You're not going to get any of the price shopper to begin
with.

[https://www.swissmicros.com/dm42.php](https://www.swissmicros.com/dm42.php)

~~~
reaperducer
Absolutely so. There were at least a dozen plastic calculators available to
buy at the office supply store when I was last there earlier this year.

------
saagarjha
> If somone designed a calculator today, they would most likely be made from
> ABS plastic, in a clamshell case. An ARM microcontroller that replaces
> essentially 70% of the chips, and it would be impossible to repair.

Interestingly, my Casio fx-115ES PLUS (which I love, BTW) uses a obscure but
cute little architecture called nX-U8/100\. Although I am a bit sad that it's
hidden by epoxy like most cheaper calculators :(

~~~
RealityVoid
I don't agree with the author here. The ARM replacing the chips is not bad,
just the nature of what technical possibilities we have now. And having some
funky chips in an old design does not help with repairing it.

I think OP has some sort of nostalgia that is not always well placed for old
electronics.

~~~
neilpanchal
OP here, I didn't phrase that right. It was meant along the lines of "Look at
all these mechanical linkages, its all replaced by relay logic now-a-days".
Indeed, a SoC + PMIC and a few stray bypass caps will replace the whole
motherboard - that's a great thing.

It's sort of like appreciating old timers for doing what they had to do with
the tools they had at the time - how NES game developers had 40KB of space to
fit their game in which lead to some incredible resourceful hacks [1].
Obviously, today's game engines are "better" in every metric possible if by
"better" we measure those metrics as higher/faster/easier == better. There is
also a fascinating reason why a game engine like Pico8 [2] exists when we have
almost unlimited compute/storage resources and if everything was "better" in
the modern age :)

OP does have nostalgia, otherwise why would he purchase old useless gadgets?
;)

[1]
[https://news.ycombinator.com/item?id=21213840](https://news.ycombinator.com/item?id=21213840)
[2]
[https://www.lexaloffle.com/pico-8.php](https://www.lexaloffle.com/pico-8.php)

------
pjmlp
Loved my Casio.

Back in the late 80', throughout the 90's, the Casio FX models were the high
school and university beloved models.

With 850 and 880 being the wished for models of engineering university
students.

Our education system did not had any kind of monopoly agreement like TI seems
to have in US.

So I hardly can relate to the usual TI stories, it was all about Casio and
some lucky ones got HP-48 variants.

------
anonymousiam
I believe that Radio Shack marketed and sold these as the TRS-80 Pocket
Computer. I was probably in my 20's then.

~~~
pengaru
[https://en.wikipedia.org/wiki/Tandy_Pocket_Computer](https://en.wikipedia.org/wiki/Tandy_Pocket_Computer)

~~~
WalterGR
“Although named after the TRS-80 line of computers, they were not compatible
with it and didn't use the Z-80 CPU. Computers in the line were actually
rebadged Sharp and Casio devices with different model names.”

~~~
tyingq
The Casio FX-880P uses a Hitachi HD62002A01 CPU, which is a Z80 with a built
in MMU. I suspect the _" didn't use the Z-80 CPU"_ part may not be right for
the Casio OEM'ed ones.

------
guidedlight
I have one of these, but the LCD is bad (terribly faint).

How would I go about fixing it?

~~~
opencl
The most likely culprit for display issues on these old calculators in my
experience is the ribbon cables. You can take a multimeter and check the
resistance of each connection, if any of them read too high you can solder a
thin wire in parallel with it.

Or it could be the contrast potentiometer giving too high of a resistance, you
can try cleaning the internal contacts or replacing it.

------
jcun4128
It only uses those two cell batteries? Wonder what it can do.

