0b10

Two-Bit History

Computing through
the ages

Simulating the Altair

02 Dec 2017

The Altair 8800 was a build-it-yourself home computer kit released in 1975. The Altair was basically the first personal computer, though it predated the advent of that term by several years. It is Adam (or Eve) to every Dell, HP, or Macbook out there.

Some people thought it’d be awesome to write an emulator for the Z80—a processor closely related to the Altair’s Intel 8080—and then thought it needed a simulation of the Altair’s control panel on top of it. So if you’ve ever wondered what it was like to use a computer in 1975, you can run the Altair on your Macbook:

Altair 8800

Installing it

You can download Z80 pack from the FTP server available here. You’re looking for the latest Z80 pack release, something like z80pack-1.26.tgz.

First unpack the file:

$ tar -xvf z80pack-1.26.tgz

Move into the unpacked directory:

$ cd z80pack-1.26

The control panel simulation is based on a library called frontpanel. You’ll have to compile that library first. If you move into the frontpanel directory, you will find a README file listing the libraries own dependencies. Your experience here will almost certainly differ from mine, but perhaps my travails will be illustrative. I had the dependencies installed, but via Homebrew. To get the library to compile I just had to make sure that /usr/local/include was added to Clang’s include path in Makefile.osx.

If you’ve satisfied the dependencies, you should be able to compile the library (we’re now in z80pack-1.26/frontpanel:

$ make -f Makefile.osx ...
$ make -f Makefile.osx clean

You should end up with libfrontpanel.so. I copied this to /usr/local/lib.

The Altair simulator is under z80pack-1.26/altairsim. You now need to compile the simulator itself. Move into z80pack-1.26/altairsim/srcsim and run make once more:

$ make -f Makefile.osx ...
$ make -f Makefile.osx clean

That process will create an executable called altairsim one level up in z80pack-1.26/altairsim. Run that executable and you should see that iconic Altair control panel!

And if you really want to nerd out, read through the original Altair manual.

If you enjoyed this post, more like it come out every two weeks! Follow @TwoBitHistory on Twitter or subscribe to the RSS feed to make sure you know when a new post is out.