Expand an ALTAIR 8800 PRO v1.5 with a BUS board.

[Mike Tailor]

Hello Chris..
I bought two ALTAIR 8800s from you and both are running very well now.
The first was the "PRO" with a blue housing (also with VT100 and VGA output), unfortunately there was no BUS connection back then.
I then also bought the experimental Altair 8800 and used it with an LED board and floppy controller.

But I also wanted to use the first ALTAIR PRO with floppy.
A friend drew me a daughter board for the Arduino DUE, to which I can connect a ribbon cable and SUB-D25 connector.
I simply soldered this board onto the Arduino from behind. All I had to do was send the unused pin headers back with the soldering iron so that the distance was smaller

So I now have the first ALTAIR 8800 with additional BUS interface modules.

If anyone is also interested,

[Mike Tailor]

The board simply gets the necessary signals from the DUE from above.
Originally the board was intended to be soldered between the Arduino and the ALTAIR board.
Now you can solder them on more easily from above. You just have to press down the annoying pin headers with a little heat.
The board looks like this from above and below:

[Chris Davis]

That looks great!

[Mike Tailor]

Use at your own risk :)
Note: I crimped a male SUBD-25 connector onto a 25-pig ribbon cable.
On the other side a 26-pin "socket strip". (here, so the correct PIN must remain free!)

I also heated up the unused pins on the ALTAIR DUE and pushed them up a little so that they don't get in the way and the board lies flat. (This is easier than cutting it off, except for the three-pin power plug, where I shortened the 3 pins a bit).

And the black USB plug from the kit to the programming port is a bit too thick.
I cut this off a little to the side.
(This could perhaps be simplified if the plug was positioned a little more to the side), but I'm happy with that.

Attached is the Gerber file
Greetings Mikel

[John Kennedy]

Haha that PCB is a LOT neater than my solution :)