Collapse OS Documentation Browser


asm/ code/ hw/ algo.txt arch.txt avr.txt blk.txt blksrv.txt bootstrap.txt cross.txt design.txt dict.txt dis.txt drivers.txt ed.txt emul.txt faq.txt grid.txt grok.txt impl.txt intro.txt me.txt mspan.txt ps2.txt rxtx.txt sdcard.txt sega.txt selfhost.txt spi.txt usage.txt wordtbl.txt

Design considerations

The primary goals of Collapse OS are to:

* Run on minimal and improvised machines.
* Interface through improvised means.
* Edit text and binary contents.
* Compile assembler source for a wide range of MCUs and CPUs.
* Read and write from a wide range of storage devices.
* Assemble itself and deploy to another machine.
* Achieve this with as little external means as possible, for
  example, internet or a functional global supply chain.

It follows, from these goals, the following priorities in code

* Simplicity
* Compactness
* Speed

It is paramount that this project stays understandable in its
whole by a single person so that it can be adapted to as many
contexts as possible.

However, it also needs to stay compact so that it can run on as
many machines as possible, however small. So far, there's a few
hard limits that have been identified:

* The ROM for the RC2014 port with SD card has to fit in 8K.
* Self-hosting must stay possible on the Sega Master System with
  its 8K of RAM.

If these limits are respected, we consider the compactness crit-
eria met.

Lastly, Collapse OS should be usable on its target machines. If
it's slow, it's less usable. Efforts should be made towards this
as long as it doesn't break the two other constraints.

That last part is hard to remember. When going through the code,
there are some obvious inefficiencies and when we look at them,
the mind immediately thinks of ways to smooth them out. But
those ways add complexity. If the solution you're thinking about
adds significant complexity compared to the speedup, then it has
likely been considered already and dismissed.

The idea behind this is that those easy pickings can easily be
picked by the post-collapse user. Simplicity is paramount and,
besides, why not leave this pleasure to them, those poor souls?

Collapse OS and its documentation are created by Virgil Dupras and licensed under the GNU GPL v3.

This documentation browser by James Stanley. Please report bugs on github or to

This page generated at 2022-05-19 21:05:03 from documentation in CollapseOS snapshot 20220509.