As most of you probably don't know, two years ago I wrote flash editor utility for the TI-84+/SE. The TI-84+CSE has prompted me to revive the project and rewrite most of it. MicrOS now functions on the TI-84+CSE and has the three vital utilities you'd want to see in a Calcsys replacement: port monitor, hex editor, and disassembler. Additionally, MicrOS, once loaded into RAM, does not use ANY B_CALLs; MicrOS has its own set of keyboard, screen, memory, and flash routines. Thus, you can use MicrOS to edit any part of the OS without fear of crashing MicrOS.

To run MicrOS, copy both MICROS and MILO to your calculator. Make sure MICROS is archived! Unarchive MILO and run it with the Asm( command. MILO will archive itself, load MicrOS into RAM, and transfer control to MicrOS. You'll notice that, because MicrOS doesn't use the OS display routines, it feels faster than the OS.

This initial beta release of MicrOS does not feature full functionality of the hex editor. In particular, the user interface side of the flash editor has not been implemented, nor has the find feature, nor the text mode of the hex editor. Currently, I am requesting comments before continuing major development. In particular, I would like opinions on whether to keep the existing font, or move to a 5x7 font with 2x upscaling. The 5x7 font would make displaying text about 40-50% faster, reduce the size of the font data set by over 1.5 KB, and be a lot uglier.

That is awesome, CalcSys is such a useful utility and it is nice to see it on the cse

The ONLY reason I'm even considering a 2x upscaled font is for use with the 2x width mode. I tried making a font with 2x wide pixels but 1x high pixels, and I didn't like it. (The logic for vertically up-scaling by 2 is dead simple, because MicrOS scans pixels for the font top-down, the left-to-right. Thus, it's a simple matter of outputting each value twice.) The old 6x8 font would be less ugly, but would reduce the text mode to 26 columns and 15 rows. The speed improvement would be closer to 30%. And I'd have to adjust the hex editor and disassembler layout---there'd be no label at the start of each row.

The "small" letters definitely look great... But yeah, if the speed is so slow that it's becoming a pain for the user, well...

Not at all. Like I said, it feels faster than the OS, and the screen repaint time feels like it matches the key repeat rate. It doesn't, but MicrOS feels more responsive than the OS because it can queue a keypress that's registered while the screen is still painting, thanks to improved, interrupt-based keyboard routines. I also optimized some of the screen handling routines. For example PutSClrWind displays a string, and writes whitespace into any unused area; thus, when displaying a new menu, it doesn't need to clear the whole screen at once (including areas that are already blank anyway), then display the string, because PutSClrWind takes care of both, such that each pixel need only be visited once.

(Also, could you actually leave the font choice to the user, or would that be too much trouble to make ?)

It's not technically impossible, but it's definitely not something I would implement. The most you might get is support for it being a compile-time switch.

If you have questions about the internal architecture of MicrOS, I suggest looking in the source code. MicrOS is fairly modular, and the routines are actually documented, so you shouldn't have too much trouble figuring out how to add your own code. You're also free to use MicrOS code in other projects. For example, you can rip the interrupt and keyboard routines out and copy them into another project without much trouble. The convoluted logic of the keyboard debouncing code is probably the best example of well-commented code in the entire Z80 community.

I'm confused; how does this stand-alone, low-level calculator management utility relate to a shared programming/graphics library like Ion? To me, they seem to serve different purposes, and one can't really be molded to serve the purpose of the other.

[stupid comment]what exactly is CalcSys, an OS on top of an OS? I have no idea.[/stupid comment]

Looks awesome, though I have no idea what it is

Nifty

Relayed to TI-Planet (in French), so that hopefully, more people can comment on the matter of the font: https://www.tiplanet.org/forum/viewtopic.php?t=11692