mirror of https://github.com/hsoft/collapseos.git
146 lines
4.9 KiB
Plaintext
146 lines
4.9 KiB
Plaintext
# TI-84+
|
|
|
|
The TI-84+ is a machine with many advantages, one being that
|
|
it's very popular. It also has a lot of flash memory and RAM.
|
|
|
|
Its builtin keyboard and screen, however, are hard to use,
|
|
especially the screen. With a tiny font, the best we can get is
|
|
a 24x10 console.
|
|
|
|
There is, however, a built-in USB controller that might prove
|
|
very handy.
|
|
|
|
I haven't opened one up yet, but apparently, they have limited
|
|
scavenging value because its z80 CPU is packaged in a
|
|
TI-specific chip. Due to its sturdy design, and its ample RAM
|
|
and flash, we could imagine it becoming a valuable piece of
|
|
equipment if found intact.
|
|
|
|
The best pre-collapse ressource about it is WikiTI[1].
|
|
|
|
As it is now, with its tiny screen and cumbersome keyboard,
|
|
Collapse OS is not really usable on the TI-84+. One could
|
|
imagine a scenario where one has a terminal and uses the TI-84+
|
|
through the link for its large amount of flash and RAM. But
|
|
using it standalone? Nah, not even post-collapse.
|
|
|
|
Therefore, this recipe is more of a "look, I run!" demo.
|
|
|
|
# Gathering parts
|
|
|
|
* A TI-84+
|
|
* A USB cable
|
|
* tilp[2]
|
|
* mktiupgrade[3]
|
|
|
|
# Build the ROM
|
|
|
|
Running "make" in /arc/z80/ti84 will result in "os.rom" being
|
|
created.
|
|
|
|
# Emulate
|
|
|
|
Collapse OS has a builtin TI-84+ emulator using XCB for display
|
|
in emul/hw/ti. You can invoke it with "make emul".
|
|
|
|
You will start with a blank screen, it's normal, you haven't
|
|
pressed the "ON" key yet. This key is mapped to tilde (~) in the
|
|
emulator. Once you press it, the Collapse OS prompt will appear.
|
|
See emul/hw/ti/README.md for details.
|
|
|
|
# Upload to the calculator
|
|
|
|
# Background notes
|
|
|
|
Getting software to run on it is a bit tricky because it needs
|
|
to be signed with TI-issued private keys. Those keys have long
|
|
been found and are included in keys/. With the help of the
|
|
mktiupgrade, an upgrade file can be prepared and then sent
|
|
through the USB port with the help of tilp.
|
|
|
|
That, however, requires a modern computing environment. As of
|
|
now, there is no way of installing Collapse OS on a TI-8X+
|
|
calculator from another Collapse OS system.
|
|
|
|
Because it is not on the roadmap to implement complex
|
|
cryptography in Collapse OS, the plan is to build a series of
|
|
pre-signed bootloader images. The bootloader would then receive
|
|
data through either the Link jack or the USB port and write that
|
|
to flash (I haven't verified that yet, but I hope that data
|
|
written to flash this way isn't verified cryptographically by
|
|
the calculator).
|
|
|
|
As modern computing fades away, those pre-signed binaries would
|
|
become opaque, but at least, would allow bootstrapping from
|
|
post-modern computers.
|
|
|
|
# Instructions
|
|
|
|
WARNING: the instructions below will wipe all the contents of
|
|
your calculator, including TI-OS.
|
|
|
|
To send your ROM to the calculator, you'll need two more tools:
|
|
mktiupgrade and tilp.
|
|
|
|
Once you have them, you need to place your calculator in
|
|
"bootloader mode", that is, in a mode where it's ready to
|
|
receive a new binary from its USB cable. To do that you need
|
|
to:
|
|
|
|
1. Shut down the calculator by removing one of the battery.
|
|
2. Hold the DEL key
|
|
3. But the battery back.
|
|
4. A "Waiting... Please install operating system now" message\
|
|
will appear.
|
|
|
|
Once this is done, you can plug the USB cable in your computer
|
|
and run "make send". This will create an "upgrade file" with
|
|
mktiupgrade and then push that upgrade file with tilp. tilp will
|
|
prompt you at some point. Press "1" to continue.
|
|
|
|
When this is done, you can press the ON button to see Collapse
|
|
OS' prompt!
|
|
|
|
# Validation errors
|
|
|
|
Sometimes, when uploading an upgrade file to your calculator,
|
|
you'll get a validation error. You can always try again, but in
|
|
my own experience, some specific binaries will simply always be
|
|
refused by the calculator. Adding random "nop" or reordering
|
|
lines (when it makes sense, of course) should fix the problem.
|
|
|
|
I'm not sure whether it's a bug with the calculator or with
|
|
mktiupgrade.
|
|
|
|
# Usage
|
|
|
|
The shell works like a normal BASIC shell, but with very tight
|
|
screen space.
|
|
|
|
When pressing a "normal" key, it spits the symbol associated to
|
|
it depending on the current mode. In normal mode, it spits the
|
|
digit/symbol. In Alpha mode, it spits the letter. In Alpha+2nd,
|
|
it spits the uppercase letter.
|
|
|
|
Special keys are Alpha and 2nd. Pressing them toggles the
|
|
associated mode. Alpha and 2nd mode don't persist for more than
|
|
one character. After the character is spit, mode reset to
|
|
normal.
|
|
|
|
Pressing 2nd then Alpha will toggle the A-Lock mode, which is a
|
|
persistent mode. The A-Lock mode makes Alpha enabled all the
|
|
time. While A-Lock mode is enabled, you have to enable Alpha to
|
|
spit a digit/symbol.
|
|
|
|
Simultaneous keypresses have undefined behavior. One of the keys
|
|
will be registered as pressed. Mode key don't work by
|
|
simultaneously pressing them with a "normal" key. The presses
|
|
must be sequential.
|
|
|
|
Keys that aren't a digit, a letter, a symbol that is part of
|
|
7-bit ASCII or one of the two mode key have no effect.
|
|
|
|
[1]: http://wikiti.brandonw.net/index.php
|
|
[2]: http://lpg.ticalc.org/prj_tilp/
|
|
[3]: https://github.com/KnightOS/mktiupgrade
|