TRS-Xenix v01.03.05 Exploration

Obtaining Install Media

A really nice collection of TRS-80 stuff is available here. There's a fair bit of both non-Xenix and Xenix stuff, but for now we only need the Xenix stuff. What we need are all the IMDs (except XNX135FM.IMD) from here.

Setting up our VM

This version of Xenix is for TRS-80 model 16 computers only, thankfully I know an emulator that can run this. Let's set it up by downloading trs80gp.

At first, let's create a hard disk image by simply opening up trs80gp, going to the "Hard Drive" menu and clicking the "unformatted DREM" option in the 4: submenu.

Now, open up the command prompt as in order to run TRS-Xenix 1.x you need a special command line argument which you can't configure in the GUI. I use this command to run trs80gp provided the DREM config file autogenerated with the DREM disk image is stored as "xenix.cfg" and the Xenix install disk is XNX135D1.IMD:

trs80gp.exe -m16 -d0 XNX135D1.IMD -h xenix.cfg -x1hack

Setting up minimal Xenix

It's Xenix time!

The emulator startup command already inserts the boot floppy into the drive. Once you're starting up the emulator, it will attempt to boot from the blank hard drive which will leave you with a garbled screen. In order to boot off the floppy, during startup spam Ctrl+C in the emulator window. Once you're in the bootloader prompt, type "diskutil". It will ask you if you want to deal with the floppy disk or the hard disk - type "h" for hard disk. The unit number is 0. For the disk information, consult the CFG file created by the emulator for the disk image. For me, it generated 256 tracks, 4 sides and 17 sectors. When you're asked "how many heads", type the amount of sides. Once you've passed the formatting, reset the emulator. It will attempt to boot from the hard drive again and since we don't have anything useful there it'll fill the screen with random bootloader data and gibberish. Boot off the floppy the same way.

FIXME: is this amount of hd space actually enough for xenix & friends?

After that, just press Enter. When you're asked to "change the rootdisk" just press Enter again, that is not needed.

Now, let's actually install Xenix and not just partition the HD. Once you're asked to initialize the hard disk, answer with "y". Yes, your hard disk has been formatted with diskutil. Use the same way of finding how much space you have on the hard drive as when you were formatting the drive. It will format the hard drive and copy some basic utilities onto there. Wait until the "Normal System Shutdown" message and power down the emulator.

Setting up the rest of Xenix

After the boot floppy is done copying files, use the following command for running Xenix from here on:

trs80gp.exe -m16 -d0 - -h xenix.cfg -x1hack

At the bootloader prompt, press Enter. It will automatically load the second stage of installation. When you are asked "First floppy?" insert the second disk via Diskette -> :0 and press y. Do the same with the third floppy. This will install the base system. After that, type n. Once you get the message "installation complete", press Ctrl+D. Feel free to set the time if you want but it's probably not Y2K compatible. Log in as root, it has no password.

Adding a user is simple. Once in the root account, just type 'mkuser' to create a user. Home directories are in the /usr folder. If you created a user by the name 'test', then it would be at /usr/test.

Some Xenix manuals are available at this site. Look through the page for mentions of "xenix".

Installing additional software

In order to install software, you need to use the "install" command. Let's install the update from Disk 4 using this method. You can also install other Xenix software from the model2archive but make sure to read the README, some may be incompatible due to being for the Model 6000 running XENIX 3.x.

1. Log in as root
2. Type "install"
3. Press 1
4. Press Enter

And we're done! This particular program wants us to reboot, so eject the floppy and restart the emulator.

Tandy-specific shell

TRS-XENIX comes with a Tandy developed shell called "tshell". You can run it by typing "tsh" in the terminal. It's definitely more advanced than the standard /bin/sh but I have no idea what nice features it has besides builtin help. Might be a nice research subject.

Developing software

Installing the Devkit

The aforementioned archive contains the TRS-XENIX development system except it's a bit broken. If you use 1.2.0a, you'll have a broken as program so you won't be able to compile some stuff. 1.2.0b doesn't have disk 7 and has a broken disk 8. In order to get a nice dev system, install 1.2.0a but replacing Disk 2 with the one from 1.2.0b. The install procedure isn't the same as in any other package: run install, insert disk 1, go through the normal install init, eject disk 1, install devsys only.

For Xenix (pure C)

TRS NOTE: there's cobol in the default install? might be worth writing about

Compiling a Hello World C app for TRS-Xenix natively

The process of creating and compiling a C app on TRS-XENIX is the same as on IBM PC Xenix 1.00, so this is mostly copied from Tox's page.

I created a file named 'hello.c' using the following command:

cat >> hello.c << EOF

This will output the contents of stdin into hello.c until you give it the literal string EOF.

And so, here is the source code of hello.c:

main() {
    printf("hello world\n");
}

Now, we compile it using

cc hello.c -o hello

And then, we simply run it! It gives out the message like we would've expected.

There is also like you might've expected, a linker, by the name of ld -- and a lot of other things, too. There is yacc and lex included, and adb.

For TRSDOS

As far as I know, there is no way to crosscompile TRSDOS apps on Xenix. Maybe someone'll pull out the proper manual which I couldn't find and figure out how to do it, or maybe it's plain impossible without a different compiler. However, an app called "tx" for copying files over to TRSDOS disks is included.

Makefile

The make implementation in TRS-XENIX is the same as in the IBM PC Xenix release, so let's just copy the rest from the IBM PC Xenix page. For the "hello, world!" application under Xenix, you can write this Makefile:

hello: hello.c
    cc hello.c -o hello

and save it as simply 'Makefile'. Oh yeah, by the way, make sure those 4 spaces in front of 'cc hello.c' is actually a tab when you enter it in.

Interesting extra software

WIP