The LED would change state each time a 256-byte block of data was successfully transferred. The Z80 interrupt line was connected to the keyboard PIO and the "Non Maskable Interrupt" line was not connected. Software The Super-80 came with a 2kB machine code monitor program in ROM. A BASIC interpreter could be purchased either on cassette tape or on a set of three 4kB EPROMs. The first 4kB BASIC EPROM replaced the 2kB monitor EPROM supplied with the computer and contained the first 2kB of BASIC, plus the monitor program. The BASIC interpreter was based on Tiny BASIC rewritten and modified by Ron Harris. In its November 1981 edition (p93), Electronics Australia announced a programming competition with the chance to win one of two dot matrix printers. EA later compiled the better programs submitted by readers into a book called "Software for the Super-80 Computer". Accessories and Options B-3600 Super-80 Technical Manual B-3602 Super-80 BASIC Handbook H-3200 Metal Case K-3602 BASIC Interpreter on Cassette Tape K-3603 I.C. Socket Kit K-3604 BASIC Interpreter in EPROM K-3606 S-100 Expansion Unit K-3607 Lower Case Character Generator Modifications Many Super-80 owners chose to modify their machines to address the limitations of the original machine. The El Graphix kit added the ability to display lower case characters and "chunky" graphics. The Printer Interface was an S-100 Bus card giving the Super-80 a Centronics parallel printer port. The VDU Expansion Board (VDUEB) was an enhanced video display board for the Super-80 developed by Microcomputer Engineering (MCE). The VDUEB gave the Super-80 an 80×25 video display with limited graphics capabilities. It was based on a 6845 CRTC I.C. and had its own 2kB of video RAM and 2kB of character generator RAM. Installation of the VDUEB board was a one-way process, as it required major modifications to the Super-80 printed circuit board including cutting of tracks and soldering in many wire links between various parts of the board. The VDUEB was then connected via three I.C. sockets formerly occupied by the original video display circuitry. Removal of the original DMA based video display effectively doubled the performance of the computer, since the CPU was no longer being disabled 50 times per second for video display refreshes. The board gave the Super-80 similar video display capabilities to the Applied Technology Microbee computer, released about six months after the Super-80. This led to many Microbee games being ported to