mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-24 04:08:05 +11:00
64 lines
2.3 KiB
Markdown
64 lines
2.3 KiB
Markdown
# Sega Master System
|
|
|
|
The Sega Master System was a popular gaming console running on z80. It has a
|
|
simple, solid design and, most interestingly of all, its even more popular
|
|
successor, the Megadrive (Genesis) had a z80 system for compatibility!
|
|
|
|
This makes this platform *very* scavenge-friendly and worth working on.
|
|
|
|
[SMS Power][smspower] is an awesome technical resource to develop for this
|
|
platform and this is where most of my information comes from.
|
|
|
|
This platform is tight on RAM. It has 8k of it. However, if you have extra RAM,
|
|
you can put it on your cartridge.
|
|
|
|
## Related recipes
|
|
|
|
This recipe is for installing a minimal Collapse OS system on the SMS. There
|
|
are other recipes related to the SMS:
|
|
|
|
* [Interfacing a PS/2 keyboard](kbd/README.md)
|
|
* [zasm and ed from ROM](romasm/README.md)
|
|
|
|
## Gathering parts
|
|
|
|
* [zasm][zasm]
|
|
* A Sega Master System or a MegaDrive (Genesis). (I have only tested on a
|
|
MegaDrive so far)
|
|
* A Megadrive D-pad controller.
|
|
* A way to get an arbitrary ROM to run on the SMS. Either through a writable
|
|
ROM card or an [Everdrive][everdrive].
|
|
|
|
## Build the ROM
|
|
|
|
Running `make` will produce a `os.sms` ROM that can be put as is on a SD card
|
|
to the everdrive or flashed as is on a writable ROM cart. Then, just run the
|
|
thing!
|
|
|
|
## Usage
|
|
|
|
On boot, you will get a regular Collapse OS BASIC shell. See the rest of the
|
|
documentation for shell usage instructions.
|
|
|
|
The particularity here is that, unlike with the RC2014, we don't access Collapse
|
|
OS through a serial link. Our input is a D-Pad and our output is a TV. The
|
|
screen is 32x28 characters. A bit tight, but usable.
|
|
|
|
D-Pad is used as follow:
|
|
|
|
* There's always an active cursor. On boot, it shows "a".
|
|
* Up/Down increase/decrease the value of the cursor.
|
|
* Left/Right does the same, by increments of 5.
|
|
* A button is backspace.
|
|
* B button skips cursor to next "class" (number, lowcase, upcase, symbols).
|
|
* C button "enters" cursor character and advance the cursor by one.
|
|
* Start button is like pressing Return.
|
|
|
|
Of course, that's not a fun way to enter text, but using the D-Pad is the
|
|
easiest way to get started which doesn't require soldering. Your next step after
|
|
that would be to [build a PS/2 keyboard adapter!](kbd/README.md)
|
|
|
|
[smspower]: http://www.smspower.org
|
|
[everdrive]: https://krikzz.com
|
|
[zasm]: ../../tools/emul
|