The R-31JP / Reads is the perfect low cost system for those learning the 8051 family and for prototyping applications that use the 8051 for embedded control. 



  • 8031 / 8051 family in the 40-pin DIP format 
  • 32K of SRAM / optional 32K battery backed RAM
  • 32K of monitor EPROM / optional 32K EEPROM
  • 12 general purpose digital input / output bits on terminal blocks
  • All system signals are available on a 40-pin header
  • Address and Data lines of the processor are de-multiplexed on two 23-pin headers
  • Two-way reset feature gives access to all interrupt vectors
  • Fully duplexed RS232 serial port with a MAX 232 driver
  • Serial port terminates at a DB9 connector
  • Power on LED
  • Board operates on +5 volts
  • Power supplied to the board by way of a 2 position terminal block
  • Power consumption is less than 75mA fully populated
  • Operating temperature 0 to 70C
  • Machine screw sockets under all ICs
  • 4" X 3.25" prototyping area for wire-wrapping or soldering your own circuits.
  • 2 layer 4" x 7" board
  • Circuit diagrams
  • Mounting holes in corners
  • May be used as an embedded controller

The R-31JP accepts 8051 microcontrollers in the 40-pin DIP format including the 80C31, 80C32, 80C51, 80C52, 8052AH with Basic, 83C51, 87C51, DS5000, DS80C320 and the SAB C50x series. Normal operating speed is 11.0592MHz, but other speeds are available to accommodate faster processors.  The R-31JP has a large prototyping area to the board for adding your own circuits. 

The system bus is available on two headers where the address and data lines of the processor are de-multiplexed. The system bus facilitates interfacing the R-31JP to external memory-mapped input / output devices. The user may decode the address along with the XIOSEL#, RD#, and WR# signals to select memory-mapped peripherals.

The R31JP board comes standard with an 8052 which contains an 8K ROM with interpreted BASIC. The BASIC interpreter is compiled from Intel's MCS-51 BASIC (version 1.1) source code, which has been released to the public domain as a freeware program. Please note that Intel no longer supports or warrants this interpreter.  Rigel Corporation includes the BASIC interpreter purely as a convenience to its customers. Note that if the R31JP contain an EEPROM version of the 8052, you may erase the BASIC interpreter and reprogram the CPU with your own code. Also, inserting the EA# jumper disables internal code memory so that the 8052 may be used without the BASIC interpreter. 

Software Overview
Reads51 is an integrated applications software development system, which runs on an IBM PC or compatible host. Reads51 allows writing, compiling, assembling, debugging, downloading, and running applications software in the MCS-51 language. Reads51 contains a C compiler, relative assembler, linker/locator, editor,  chip simulator, assembly language debugger, and host-to-board communications in a user-friendly, menu-driven environment.

RbHost is a 32-bit Windows (TM) application, which combines an editor and a terminal emulator. The editor comprises the main window, allowing multiple source files to be viewed and edited. The terminal emulator, referred to as the TTY (teletype) is associated with dockable child window, referred to as the TTY window.  The RbHost editor has BASIC language syntax highlighting. It facilitates writing BASIC programs and downloading them to Rigel's embedded control boards. The BASIC interpreter may be in internal ROM, external ROM, or in RAM.

Tutorial Source Code is provided to quickly familiarize the new user with the R-31JP. 

Documentation for our products includes software and hardware manuals, sample programs, a description of the inner workings of the RROS including user-accessible system calls, and a full set of circuit diagrams. Documentation for kits also includes an assembly manual.  All of our documentation is availabe on the web and the CD ROM shipped with the boards.

Standard Package includes: The R-31JP, 32K EPROM, 32K RAM, Reads software, User's Guides for board and software (download from the web) example programs, software tutorial, and circuit diagrams. An assembly manual may be downloaded to use with the kits and bare boards.

A well-regulated 5-volt (5% @500mA) power supply and a serial cable are to be provided by the user.
Schools, Students (with valid school ID), and US military personal receive a 10% discount on all products.

R-31JP Options Kits Built and Tested
  1-9 1-10 11-24
R-31JP with Basic $ 75 $ 85 $ 75
R-31JP with 80C320 $ 85 $ 95 $ 85
R-31JP Bare Boards $ 20    




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       Last updated 3/18/08