New PCBs and assembly

A project log for Single Chip AVR BASIC Computer

A computer running the BASIC programming language, generating composite video and reading PS/2 keyboard input using a single AVR.

danDan 08/14/2014 at 17:050 Comments

I have received the new PCBs and assembled one of them which can be seen in the above image. A few changes have been made to the design of the PCB compared to the previous PCB including:

- Changing of the naming of the computer (now V0.x - this PCB is v0.3)

- Added a USBasp programming header

- Added a female header labelled "Storage" which allows a small PCB containing a 25LC640 EEPROM IC to be connected (see below images). A male pin header labelled "MEM Select" allows the user to select between the internal and external EEPROM for saving BASIC programs to. This feature was added to allow larger programs to be saved as the ATmega 1284P only has 4KB internal EEPROM.

- Mapped all GPIO pins which are not in use to male pin headers (except analogue reference).

- This PCB was also designed in KiCAD rather than Fritzing.

The remaining PCBs have been put on eBay and can be found at the following link:

I have started a new HaD projects page which focuses only on this new PCB (single chip computer V0.3); this new page will contain a link to the firmware, the schematic, some details and possibly more. The following link is for the new project page: