NitrOS-9 FAQ v1.01

NitrOS-9 FAQ v1.2

1. What is NitrOS-9?

NitrOS-9 is a 99% OS-9 compatible operating system for the HD6309. It can be simply 'dropped in' to replace the OS-9 you currently use.

The current version of NitrOS-9 is v1.22n.

2. Why is it 99% compatible, and not 100% compatible?

Because NitrOS-9 runs in 6309 native mode, the CPU itself behaves in a slightly different manner than the 6809. The two differences are:

The CPU runs faster. Software timing loops must be adjusted. e.g. The SIO, and Printer drivers.
Programs that use interrupts have to be patched to use 6309 mode instead of 6809 mode. e.g. Home Publisher.

NitrOS-9 includes patches for all known programs to ensure they work correctly on the 6309. If you have a program that NitrOS-9 does not patch, send it to the distributor, and a patched program will be returned to you at no cost.

All other programs may be used as they are, and their behaviour will not change after installing NitrOS-9.

3. Why should I use NitrOS-9 instead of OS-9?

The main reason to use NitrOS9 is speed. Any OS-9 application running under NitrOS9 will run a minimum of 10-15% faster than the identical application running under stock OS-9. This speed increase is due to the 6309 native mode.

The kernel of NitrOS-9 has been written using the new capabilities of the 6309. As the 6309 is much more powerful than the 6809, NitrOS-9 is much more efficient and powerful than OS-9.

Many of the algorithms OS-9 used internally have been changed in NitrOS-9. The new algorithms execute much faster than the previous ones, but are otherwise identical in behaviour.

The graphics drivers (WindInt, Grfdrv) were also optimized for the 6309. Speed tests show that text screen updates are performed more than four times as fast under NitrOS9 as under stock OS-9. Even the 'Xmas grfdrv' patches lag far behind NitrOS9 in terms of raw graphics speed.

The latest version of NitrOS-9 speeds up the entire system by 2 to 10 times over stock OS-9. Text writes, graphics fonts, line drawing, flood filling, system call overhead, serial I/O, and pipes are much faster than all previous versions of OS-9 or NitrOS-9. The difference is so large now that as a developer, I refuse to use anything less than NitrOS-9 v1.22. Even v1.16 of NitrOS-9 is so slow as to be more comparable to a stock system than to v1.22.

These are not the only reasons to move to NitrOS9. Another advantage is that all of the bugs that existed in stock OS-9 have been found and fixed. This includes bugs that had not been discovered previously. All publicly available kernel 'fixes' and 'enhancements' are included in NitrOS9.

4. Does NitrOS-9 implement any of the rumored 'OS-9 Upgrade'?

Yes and no.

Many of the same features in the upgrade have been included in NitrOS-9, but they were developed independently of the upgrade. Other features in the upgrade may be added in the future.

5. What level of support is there for NitrOS-9?

Both the authors and the distributors are fully committed to supporting NitrOS-9. Any questions may be relayed to:

Software support: aland@physics.carleton.ca

Distributor support: aland@physics.carleton.ca

With NitrOS-9, you find a level of support that was never possible with OS-9. Any software problems should be relayed to Software Support. You will be contacted about the problem, and a fix will be shipped as soon as possible.

6. Are there hardware problems with installing NitrOS-9?

You must replace the 6809 chip inside the Color Computer with a 6309. Directions for doing this are given in the NitrOS-9 manual. If you do not feel comfortable performing this modification yourself, any electronics shop can de-solder and replaces chips for a charge.

NitrOS-9 pushes the hardware of the Color Computer much closer to its limit that did OS-9, or DECB. It is very important that the installation procedure is followed carefully and exactly in order to have a complete and therefore stable system.

No hardware modifications other than installing the 6309 (any rating B, C) are required.

7. How hard is it to install NitrOS-9?

NitrOS-9 is much easier than to install stock OS-9. You must be able to build a boot disk, and as version 1.20 ships with the needed modules on the disk, minimal patching is required. You simply replace the OS-9 modules with the equivalent NitrOS-9 modules. The executable modules should NOT be mixed between OS-9 and NitrOS-9, as they are incompatible. Device descriptors can be copied over unchanged.

If you have an OS-9 module and there is no NitrOS-9 equivalent, contact the distributor, and one will be shipped to you as soon as possible. After more than two years of shipping, however, we believe there are few, if any modules that do not have NitrOS-9 equivalents.

Once NitrOS-9 is installed, you may want to reformat your disks with a smaller interleave factor. NitrOS-9 can handle much higher data rates than OS-9.

8. Is other 6309 specific software available?

There is a 6309 version of rma, and two 6309 versions of asm. There is not, however a 6309 C compiler.

Most authors appear to be continuing to be writing mainly 6809 software. This ensures that their software will run on ALL OS-9 LII platforms, although their software will run much faster under NitrOS-9.

NitrOS-9, therefore, benefits you the most. No one else has to be aware that you are running it, and you can buy any OS-9 software in the confidence that it will work on your NitrOS-9 system.

Contact:

                 Northern Xposure
                 PO Box 30057
                 NEPEAN  ON  K2H 1A3
                 Canada

Last updated: Mon Mar 11 14:47:22 EST 1996 by Alan DeKok