3 ms·
except it really isn't an operating system - i used it back in the 1980s, and it is really just a static library you can call into - same as msdos. there is no
by zabzonk 2y ago
except it really isn't an operating system - i used it back in the 1980s, and it is really just a static library you can call into - same as msdos. there is no OS process running things.
- riku_iki 2y agoI think everything was running in the same address space in those CPUs, thus no separate processes. But I am not an expert.
- zekica 2y agoThere is no separate per-process address space on 8080 or Z80, for that you need an MMU/protected mode.
- mjg59 2y agoThere are plenty of multitasking operating systems with a strong concept of processes without any memory protection being involved - it just means any single process can overwrite resources belonging to others, or the OS itself.
- pjmlp 2y agoBy that definition RTOS aren't OSes either.
- zabzonk 2y agoi would say that is right - an OS should be managing multiple processes. cp/m certainly did not do that - but i know nothing about RTOSs.
- pjmlp 2y agoMany of the early 1950 - 1970 OSes did not had the notion of multiple processes, only jobs processed in batch. Many RTOS don't have processes, only tasks, which depending on the nature of the OSes can be cooperatively or preemptively scheduled. Also everything is linked together and deployed as a single execution unit into the hardware firmware. So again, by the same definition, when using cooperative scheduling, they aren't OSes.
- Rochus 2y ago“Language is the source of misunderstandings.” (Antoine de Saint-Exupéry)