If you are fed up with unreliable S51 parallel port programmers, this programmer is the one you want.  Perfect for BULK Programming! Program the devices in the list below without the use of a computer.**** Files to be programmed are stored in the programmer's memory. Programmer takes power from the target (5V) or uses it own power from a 9VDC power adapter with positive center (not included). This can easily be changed using a simple jumper setting (J3). Standalone operation is invoked when jumper J2 is installed. Perfect for programming off site without having to bring your computer, programmer, cables and power supply. This is the most reliable method for programming AT89 devices in ISP mode!  Similar to the above avr programmer, except this one programs the 8051 devices in circuit listed below:

AT89S2051
AT89S4051
AT89LP2052
AT89LP4052
AT89S51
AT89S52
AT89S53
AT89S8252
AT89S8253

More devices will be included in the very near future. 

**** A computer is required to load the hex file to the memory, (up to 12K flash file, 2K eeprom) Once loaded, the file remains in memory and the unit will perform as a standalone unit. Connection can be made through a 9 pin straight through serial cable (not included) to any serial port. Any terminal program can be used to upload the hex file. For best results, download Tera Term here, and follow the instructions on setting up the terminal carefully. You can download the instruction manual here.  If your computer does not have a serial port, our USB to Serial cable has been tested works well with this programmer.