Over the last couple of days I started exploring the TI30X MathPrint Calculator, and found some stuff which I thought might be worth sharing.

First off there exist at least two different PCB revisions, one from the Phillipines (SerialNo. L-0720A) and one from China (SerialNo. N-1121).

Here are some pcb pics of each Version


As can be seen they are quite different, but at least a lot of the test points, marked TP, appear to be labeled the same.
Both versions have identical performance, but the display of L-0720A looks slightly more gray than that of N-1121. Also the D-Pad of L-0720A feels a lot more sturdy (Keys are more difficult to press and have better feedback as a result).
I looked a more closely at the L-0720A version, and below are a bit more details.

The Keypad is connected through TP1-TP16 which are connected to the keys as shown in the picture below.

The Keys "on" logical and "clear" are connected in series and then directly connected to probably either the reset pin or a non mask able interrupt pin, as they cause a Reset and Memory clear. Pulling TP17 to GND results in the same behavior.
The monochrome Display is fairly high resolution (64 * 192 excluding special symbols) and is driven through a parallel connection, with 8 Data Pins (TP28-TP35) and one Clock Pin (Test Point 37). The Clock pin is driven at ~167kHz and for each for each Frame to be transmitted there are 1539 riding/falling Edges. So for every 8 pixels there is a clock pulse. Also frames are only transmitted if there is a change in the displayed Image (so roughly every 500ms when sitting on the home screen).

In Terms of raw Processing Power the Calculator is fairly fast at roughly the speed of a new TI84CET. The Calc draws a maximum of ~1mA at about 3v when calculating summations, and used ~0.2mA idling on the main screen.
Also the Solar cell does not appear to charge the calc, but is instead used to reduce the draw on the two built in CR2032 batteries. It however is possible to use the Calculator without any Batteries installed, but obviously only when there is a bit of Sunlight, otherwise the Screen becomes dim at first, until the CPU glitches, so a reset with ON+CLEAR is required. So presumably there is no built in Brown Out detection which might be handy later. The excess energy produced by the Solar Panel is burned by two LEDs, which is a fairly interesting design decision.

In terms of Firmware the Calculators both advertise themselvesʟ as v1.0.1.21 which appears to be the latest and only public firmware (pls. correct me if I'm wrong). All in all a memory dump is ~744kB in size, with low entropy from 330k-380k and above ~700k so making bold assumptions I'd guess there is like 512kB of Flash/Rom and "lots" of Ram.
The Font used on the Calculator appears to be exactly the same as used on the TI84CE.

The build in SOC is still a big question, but it is definitely very different than the previous 3X lineup.
I kinda made the bold assumption that it might be a ez80 but others like Zeroko made convincing arguments that it's probably not. Other guesses where also unlikely, so that might remain a question for a little longer.

The TI30xMP seems to be destined for modding stuff like the screen (maybe add composite output through an esp32) or keypad mods, as it is very cheap (like 20$) compared to like the TI84CE at 100$
If anybody here is also interested in this calc feel free to message me.
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