diff --git a/doc/README.md b/doc/README.md index 01aa08d..6b29599 100644 --- a/doc/README.md +++ b/doc/README.md @@ -13,3 +13,11 @@ * [Using block devices](blockdev.md) * [Using the filesystem](fs.md) * [Assembling z80 source from the shell](zasm.md) + +## Hardware + +Some consolidated documentation about various hardware supported by Collapse OS. +Most of that information can already be found elsewhere, but the goal is to have +the most vital documentation in one single place. + +* [TI-83+/TI-84+](ti8x.md) diff --git a/doc/ti8x.md b/doc/ti8x.md new file mode 100644 index 0000000..590a12c --- /dev/null +++ b/doc/ti8x.md @@ -0,0 +1,38 @@ +# TI-83+/TI-84+ + +Texas Instruments is well known for its calculators. Among those, two models +are particularly interesting to us because they have a z80 CPU: the TI-83+ and +TI-84+ (the "+" is important). + +They lack accessible I/O ports, but they have plenty of flash and RAM. Collapse +OS runs on it (see `recipes/ti84`). + +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](http://wikiti.brandonw.net/index.php). + +## Getting software on it + +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 `recipes/ti84`. With the help of the +[mktiupgrade](https://github.com/KnightOS/mktiupgrade), an upgrade file can be +prepared and then sent through the USB port with the help of +[tilp](http://lpg.ticalc.org/prj_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. diff --git a/recipes/ti84/README.md b/recipes/ti84/README.md index 3f58001..a445db7 100644 --- a/recipes/ti84/README.md +++ b/recipes/ti84/README.md @@ -8,6 +8,8 @@ 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. +[Further reading](../../doc/ti8x.md) + ## Recipe This recipe gets the Collapse OS BASIC shell to run on the TI-84+, using its LCD