#: 3618 S12/OS9/68000 (OSK)
20-May-90 02:21:29
Sb: #3607-OS9 for Embedded System?
Fm: Kevin Darling (UG Pres) 76703,4227
To: Charles H. Murray 73707,1752 (X)
Hi Charles. From a Microware file I got a while back...
The Host system for porting may be:
a. A 68000-based computer with 256K RAM and OS-9/68000.
b. A VAX computer running UNIX/BSD 4.2 or VMS.
c. A SUN 3 Workstation running UNIX/BSD 4.2.
The Target (embedded) system requires:
a. A 68000 family CPU.
b. At least 64K RAM.
c. At least 16K ROM capacity. Alternatively,
use an emulator with 16K of overlay memory.
d. Two serial I/O ports; one for a terminal and
one for communications with the host system.
I think once you get it ported over, you can drop back the RAM. At the same
time, the ROM will need to go up to around 32K, as now you'll burn in the whole
OS (original ROM holds a debugger to help porting). You can also drop the
serial ports, of course. Hmmm. You can get by with (1) during porting, I think
also. I could be far off here. Anyway, as you go along you can ROM each
application, and OS-9 will find it automatically on the next restart (or you
can load into RAM on the fly, of course).
Wait. Let me look on my system: kernel is 25K; a serial port manager and driver
maybe 4K total. System RAM use maybe 8-12K on startup? That doesn't count any
shells or apps or more drivers, of course. OS-9 may be slightly larger than
other realtime kernels, because it's a more full-fledged OS. You could easily
switch to doing development on your target if you wished (and added some mass
storage).
For far better and later details, call Microware at 515-224-1929. And, if you
wish, do a "GO MSC" here on CIS and download the files on OS-9 from the
Microware Systems Corp (msc) display area. Loads of info there. You'll find
stuff on IPC, multitasking, etc. Drivers are pretty easy to write. Be sure to
also read their "Pipelines" newsletter there.
Judging from what I've been told by others with your same background, you'll
enjoy working with OS-9 quite a bit. best - Kevin
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