Serial Box 64K Printer Buffer

  • The Serial Box 64K Printer Buffer is a transparent printer buffer for the IEC bus. Normally, a Commodore computer will be tied up until a slow printer on the IEC bus has accepted all of the data for printing. This device buffers data in RAM and then spools the data to the printer as it will accept it, allowing the computer to be freed more quickly.

    LEDs on the top of the unit alert when it is running, paused, or when the 64K buffer is full. Momentary pushbuttons allow printing to be paused or the unit to be reset.

    This device connects inline between the computer and IEC printer using permanently cabled male and female 6-pin DIN connectors. It derives its power from the computer’s cassette port, like many printer interfaces.


    The Serial Box uses a 65C02 microprocessor with a 2732 EPROM for its firmware. Eight 64Kx1 DRAMs hold the buffer. It contains no I/O device such as a 6522 VIA, and instead uses only 74xx series devices to control the IEC ports.


    The 2732 EPROM had no label covering its window or other identification. Text inside the EPROM identifies it as version 6.06.

    Serial Box Firmware 6.06


    User Manual