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Serial EEPROM programmer

EEPROM programmer Programmer and reader of serial EEPROM memories 24CXX, 24LCXX, 93CXX and 93LCXX. But there is a bug in software with the memory 24C32 - see feedback at the end of this page. I have not done any change in schematic, but I've remade PCB. Programmer is connected to PC via parallel port a it doesn't need any external power supply. Driver, programming software and schematic was downloaded from, but in recent days it is impossible so you can download these files on the end of this page.

Schematic :

Connector J1 and diode D2 are not actually placed and used on my programmer. It serves only for external power supply in case of a problem with power supply directly from parallel port. The connector Cannon 25 type is hooked 90 degrees for PCBs. Sockets for ICs should be better ones.


Components :

There is no need of lots of components. The board is better leave without a cover or box to obtain good access to sockets.


Printed circuit board :

The board is bigger, then could be. It is better to hold it and to obtain easy access to sockets. The size is 38.1x53.34 mm. Only one side is used and no additional wire connections are used.


Software of programmer is in file
File consists of following :
eeprom.sch Schematic - format OrCad 386
eeprom.lib Schematic library - format OrCad 386
eeprom.bd1 PCB - format OrCad 386 Schematic - PostScript Components - PostScript 4x bigger PCB - PostScript 4x bigger

List of componets :

   Row  Quantity Ref                      Type
    1       1    C1                        22M/16V            
    2       3    D1,D2,D3                  1N4148             
    3       1    J1                        CON2   ARK120/2
    4       1    P1                        DB25M  CAN 25 V 90
    5       1    R1                        10k R               
    6       1    U1                        I2C_EEPROM DIL8     
    7       1    U2                        3_Wire_EEPROM DIL8  

Feedback :

It looks like there is a bug in software with 24C32 eeprom. I've got next mail:
> I have run
>into a bug concerning the I2C programming of an Atmel 24C32.  The read
>cycle does not appear to be implemented properly in the software and
>actually causes the part to be written!

All the best and good luck from Petr Simandl
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Last change : 13.3. 2000