A Key Note

A project log for Melba I

Melba I is an implementation of the Apple I from parts in my collection.

Christian BjelleChristian Bjelle 07/01/2020 at 08:440 Comments

To select a good keyboard for a project like Melba I is no easy task. The style of keyboard sets the look-and-feel of the entire system. At first I intended to use a PS/2 keyboard, with a MiniITX-PCB in a small PC box. That would loose some of the Apple-feel I was after, so I started researching the ADB-port, to connect an old Macintosh keyboard. Maybe a USB-port and a fruity-coloured iMac keyboard with a Pippin-style case in a matching color would be better?

As I dug deeper in my collection of computer pieces I considered

  1. PS/2
  2. ADB
  3. C64
  4. Chinese wireless apple-knockoff
  5. Laptop keyboard
  6. USB

All of these would require some sort of microcontroller to adapt to the keyboard interface in Melba I, and I still don't want to use one just like that, especially since USB and Bluetooth would require some pretty beefy one.

Then I found the perfect keyboard in an old treasure chest in the garage. I really don't know where or when I bought it, but I think I've had it since the mid 80s. Manufactured in 1974, it has no less than four keys labled "tape" with some variations.

After some googling, I found that it was from a TI SILENT 700 MODEL 733, and seems to be a good fit for an Apple I-clone. The link also provided details about the pinout on the card edge connectors. has a complete scan of the original manual.

Now I can start designing a suitable box, and start experimenting with the keyboard :)