The TI 83+' hardware
Although it's
out since more than a year and a half, I don't think anybody has
shown its hardware in pictures. So here it is...
First part: a general view
The TI 83 + Silver Edition is distinguishable
by its translucent sequined case (Quite beautiful, I must say...).
Except from this quite attractive looking, nothing tells the
differences with the traditional TI 83+. If you remove the battery
cover, you'll see a small inscription indicating that similarities
stop there;
Under a small triangle, you'll see an inscription (I enlarged it so
you can see better...even if that's not perfect yet :p) which says
">PC<". These letters
indicate the case's material. Here, it's polycarbonate, yeah, the
same plastic that makes bulletproof sunglasses for hunting. Yeah, the
TI 83+SE can resist to lead shots (ok, I won't test that...:)
So don't worry about the calc's durability, the internal components will probably be dead before the case.
Another advantage of this translucent case, we can easily locate where the two halves of the case snap into each other (see this page for details), so no risky attempts if you want to open it.
...And that's what we are going to do...
Second part: the opening
Make sure you have the right tools for this work (there should be no problem, considering there's only a few.):
- Torx #6 screwdriver For those who cannot find one, I sell some for $10CDN ($7US, 9€). Caution it's not the same as the regular TI 83+!
- Flat screwdriver, with rounded corners if possible
- A cable compatible with your computer, and the correct software. In fact, when you will remove the back cover of the TI, you will be forced to remove also the RAM auxiliary battery. So you have two choices: either you archive in ROM all data you want to keep; or, if you don't have enough room in archive memory (which is highly unlikely to happen considering it's enormous size - more than 80% larger than the one on the TI 89/92+) or want increased security, you'll have to copy data to the computer.
Data backup
I won't rewrite all about this, it's already on the overclock page
Third part: opening the calculator
I won't tell the details about removing the batteries, it's already on the overclock page (again!)
Before starting to unscrew blindly, please note that some of these screws are particularly hard to unscrew, because polycarbonate is stiffer than ABS, in which are built most electronic appliances. Don't try to force them, you could mess them up if you do (all the more there's no Torx the exact size of the screws: only #6 seems to fit best).
To avoid destructing the screws, thoroughly
clean the screwdriver's tip as well as the
screw head. In fact, dirt makes the screw head slippery. If you're
clumsy, I recommend you use some anti-slipping compound for vinyl
disk decks, you can find some at most electronic parts retailers (but
this is not cheap). Once you have ended with the preparation of the
two parts, push the tip of the screwdriver in the screw's head, and
if it doesn't fit properly, grind the screwdriver, as indicates this
page.
Click on the picture for a zoom. Beware it's a heavy one !
Fourth part: The main components
The RAM:
It is a SRAM one, a type of RAM which holds data as long as current
is applied to the circuit.
One advantage of this RAM is its speed; it is much faster than DRAM we can find in computers, and requires less work from the system, which is crucial considering the relatively low power of a calculator.
Capacity
128KB (only 24 are available to the user, the other part is accessible via notably Virtual Calc, the virtual TI 83+ application for TI 83+SE - see the archives for more information)
Pin assignment
/WE Write Enable, allows data to be wrote in memory when in
low state (active) while /CE1 is at the same logical
state
/OE Output Enable, allows data reading when in low
state while /CE1 is active and
/WE is inactive
/CE Chip Enable
Vcc Power supply +3V
(2,7~3,6V)
Vss 0V
Current consumption in activity: 20mA (40mA max.) standby: 0,4µA (100µA max.)
This memory is equipped with a function which automatically places it in standby mode when inputs are inactive. (In our application it doesn't change anything when the calculator is on :-/ )
Underlined in red: Manufacturer's
code; here, CY = Cypress
Framed in yellow
62128V: memory's reference
Underlined in orange:
access time to memory in nanoseconds, here 70= 70ns; the lower
the value, the faster the memory :)
Underlined in grey:
Case code (useful only if you want to change it)
Underlined in
green: temperature range, here, C
= commercial; 0°C to +70°C
Other information on TI
83+SE's RAM (you need Acrobat
Reader to read them (while you wait for the HTML version))
You have other infos ? Mail-me
!
The Flash ROM:
Capacity
2MB (512KB are used by the AMS, 1,5MB are available to the user)
Framed in yellow 29LV160:
integrated circuit reference
Underlined red:
manufacturer's abbreviation; here,
= Fujitsu
Underlined violet: boot
sector location; here, T = Top (vs. B = Bottom)
Underlined
in mauve: memory's speed; not faster
than 70 ns to access data
Underlined in grey:
case code; PFTN = TSOP (Thin Small Outline
Package) normal pin assignment
Power supply: +3V
Current consumption in read mode:30 mA; in
standby: 5 µA
Number of write/erase cycles before memory
becomes corrupt: 100 000
The microcontroller:
It seems that it contains the z80 microprocessor and other control
circuits.
This circuit is proprietary, so it is unlikely (unfortunately) I can find detailed information about it :(