I thought it was time for an update on the progress of my 6303 computer build, now officially named Retro63. To complete the build I have added a keyboard. I looked around at the readymade options but decided to go DIY for the moment. To keep things simple I used a Arduino Nano to scan the matrix of keys (there is an existing library to use for this). The 6303 is simply presented with 7bit ascii and a data available flag. Initially I am scanning for the keypress flag but can easily change over to have it create an interrupt each time a key is pressed.

To keep things together I build a simple wooden frame for the keyboard and processor board to sit in. The only other hardware change is the addition of a simple buzzer driven from a processor port.

With the keyboard working my focus changed to getting a basic monitor program up and running. You can see this booting in the following video.

The monitor functions are:-

• display memory
• modify current memory address
• move one address forward or backwards
• jump to memory address
• execute program at current memory address
• basic search

There are also quite a lot of sub-routines to make doing ‘stuff’ easier.

The next iteration of the monitor will include the ability to load and save via the serial port but I’m not planning a lot beyond that – I may well in time implement one of the existing monitors others have written but that is a way off currently.

I have been a little distracted by the arrival of the new Pi Pico for the last couple of days, thinking about how I can usefully use one on the Retro63 project !