DID YOU KNOW: the TI-84+ uses the same CPU as the gameboy (not the advance, the original one)

DID YOU KNOW: that CPU, the zilog Z80, was released in 1976

DID YOU KNOW: despite using a CPU that's over 40 years old on a monochrome screen with a resolution well below 144p, the TI-84+ still costs ~US$120

I was a hobbyist for those things.

Fun fact: if you tried to update the screen within 10μs of the last update, it bugged out and displayed garbage until power cycled.

Fun fact: if the NVRAM didn't have the right sentinel values in the right locations, the thing wiped the NVRAM, erasing all your programs because it refused to let user-written code be loadable from flash. This was easily solved using hobbyist programs that did this loading for you.

Fun fact: The 84 series was programmed to crash (say bye to your NVRAM!) should the program counter exceed 8k. This was a form of DRM: this limit did not apply to native executables run from flash—called "Apps"—which had to be signed.

The 84 series also had a "test mode" that could be activated which would lock the user out of their programs (and some of the native features) until a special key sequence (iirc) was entered. None of my teachers ever used it lol.

The successor to the 84+SE is the 84+Color Edition. It has a higher-res, backlit color screen and a rechargable battery—but the same Z80 at the same clockspeed. This means that just updating the screen takes an enormous amount of time due to all the memory-copying. The maximum full-screen refresh rate of the 85+CE is 5-6FPS. (It did pick up a new trick of partial screen updates, at least).

@Freyaday @lynnesbian That's the 84+CSE that had the same 15 MHz Z80. (Making matters worse, the LCD controller forced you to shove... I think it was 8 bits per pixel, minimum, in? And, hardware-assisted scrolling was only in one direction, as it was intended for the LCD to be vertical, but TI put it horizontally, meaning that text scrolling needed full-screen updates.)

The 84+CE at least has a 48 MHz eZ80 (which is a faster 24-bit Z80 derivative).

@bhtooefr @lynnesbian Oooh. Haven't heard of that model; it's been a while since I left the scene; the CSE had just come out before I stopped paying attention to it entirely (people were wondering why the CSE didn't go straight to the eZ80).

For people unversed in old CPUs, the eZ80 can do nothing four times faster than the original.

@Freyaday @lynnesbian I also wouldn't be surprised if the bill of materials is actually cheaper for the color calcs than the mono calc, just because they're using LCDs meant for those terrible Chinese MP3/WMA/MP4 players.

@bhtooefr @lynnesbian
A screen so shitty you have to pay extra to get it or a CPU they sell by the gallon?

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