OSBYTE
Misc OS functions specified by accumulator
Categories:
| Function | Address | Vector | Description |
|---|---|---|---|
| OSBYTE | FFF4 | 20A | Misc OS functions specified by accumulator |
OSBYTE calls are a powerful and flexible way of invoking many of the available operating system facilities.
OSBYTE calls are specified by the contents of the accumulator (A register) in the 6502. This means that up to 256 different calls can be made.
The command line interpreter (see section 2.11) performs OSBYTE calls in response to *FX commands. This enables the user to make OSBYTE calls from the keyboard or within BASIC programs. It should be noted however that no results are returned by a *FX call and so it is inappropriate to use certain OSBYTEs in this way.
&72 (114) Shadow ram
*SHADOW equivalent
&8B (139) Select file options
*OPT equivalent
&8C (140) Select tape filesystem
*TAPE equivalent
&8D (141) Select ROM filesystem
*TAPE equivalent
&90 (144) Alter display parameters
*TV equivalent
Last modified October 31, 2021: Fix descriptions on MOS page (d932fb8)