Model:    Heathkit ET-3400a
Release Date:    1976
Original Price:    $200 (kit) and $280 (assembled)
Processor:    Motorola 6802 @ 1 MHz
Memory:    1KB RAM (2 x 2114 ICs) / 1KB ROM

I found this at a HamFest this past weekend. It was one of four that the guy had for sale and, unfortunately, I only bought the one. As usual, upon retrospection I wish I had bought at least one more, if not all four. Ah well... que sera sera.... Although this was once sold as a kit to teach microcomputer skills, mine was already assembled. I think it would be fun to put one of these together.

I couldn't find much information about this nifty computer trainer, except that it was designed for use in universities. It seems like there were several software ROMs written including an Assembler and a Tiny BASIC Interpreter. A memory expansion module was also sold that increased the available RAM to 4 KB.

Programs are entered through the 17 button keypad and are displayed on the 6 seven-segment LED displays. There are also eight LEDs available for output. A large breadboard and several connection points allow you to design and build your own peripheral circuits to use with your programs. Even by itself, without programming, the breadboard area is very useful and makes this worth the price of admission!

NOTE: The manuals that I have for download here are for the original ET-3400. While they may be useful, understand that there are some differences in the original design and this the later 3400A. If you happen to have a copy of the 3400A manual(s) that you would like to share, please let me know.

   >> Click here to download the User Manual (9.5 mb)
   >> Click here to download the Schematic (ET-3400A) (1.4 mb)
   >> Click here to download the ROM image file (.HEX) (2 kb)
   >> Click here to download the Memory I/O Accessory Manual (5.2 mb)
   >> Click here to download the Memory and Input/Output Manual (7.2 mb)
   >> Click here to download the manual for the Modification Kit (498 kb)

Back to the Top