There are some 89Sxx development board, here is another one. I have designed this single side development board to be used as a tool for learning MCS-51 Microcontrollers, and for easy microcontroller project development.
The 89Sxx development board features :
89Sxx 40-DIL based design, 89S51/52/53
In System Programming (ISP) through the 6-pin header
RS-232 and RS-485 serial port (shared pin) for communicating with serial devices like PC
HD44780 compatible alphanumeric LCD connectivity with backlight control
4 on-board tact switch
16 general purpose IO port pins on 5x2 header (Port0 and Port2)
24Cxx I2C EEPROM
DS1302 serial Real Time Clock (RTC) with battery backup
On-board supply rectifier and voltage regulator
Single side development board with In System Programmable Flash based microcontroller, 89Sxx series.
