Briel Computers



by on Dec.31, 2009, under Micro-KIM

Introducing the micro-KIM. The micro-KIM is a clone of the KIM-1 created by MOS Technology in 1975 as a development board for the 6502 CPU. The micro-KIM uses many of the same components as the KIM-1 to give it that authentic vintage feel. No custom components are used and the micro-KIM is designed with off the shelf parts. As an improvement to the original KIM-1 the RS-232 interface is included onboard to make I/O easier. Some components on the original KIM-1 are no longer available. The 6530 RIOT included a custom programmed ROM and has been replaced by a 6532 RIOT and an external ROM. The custom 23 key keypad is onboard with tactile switches giving the micro-KIM a compact size. A total of 5K RAM is on board with an expansion header for future expansion of memory or add-on boards. With a projected selling price of $99 the micro-KIM is one of the most affordable 8 bit computer kits available today. As a matter of fact, the micro-KIM was designed around the student market in an effort to offer students and schools a low-cost 8 bit CPU trainer.


  • 6502 CPU running at 1Mhz
  • 2K EPROM replacing built in ROM on 6530′s
  • 5K RAM using the KIM-1 memory map
  • RS-232 interface made to work with TTY interface built in KIM-1
  • Single-Step mode for debugging
  • Debounced RESET and STEP switches
  • 40 pin header for future expansion
  • I/O of the 6 digit display and keyboard are memory mapped exactly like the KIM-1 for full program compatibility.

  • Most pins are standard 8 bit signals but a few are custom signals. DEN is Decode Enable. It is the enable line for the onboard Memory. This is connected to JP1 onboard.
  • IO3 is the decode line for the 2nd 6532 as an option. Preaddressed at $1700-173F
  • TAPE is a required line for finishing the cassette tape interface
  • PB7 is the 7th bit of I/O port B on the onboard 6532

Add-on Accessories:

32K RAM CardThe 32K RAM card is an optional card that increases the total RAM on your micro-KIM from 5K to 37K. The extra 32K is addressed from $2000-9FFF in memory because most of the programs available including floating point BASIC reside in $2000-up. When installed, JP1 jumper needs to be removed so the RAM card can decode memory. Current price is $25 for the kit that you solder yourself and $35 for the assembled and tested board.


Micro-KIM user manual:

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