Hi, all

Is there anyone who had experience of working with "Paulmon,8051 development board" which is in www.pjrc.com?
I've assembled the board and used an 8951 programmed with PAULMON2 (28F256 ver.). Test step 1 (connecting to computer through serial port) has successfully done but in step 2 of constructing (it is about using an external ram 6264) the download command (downloading ex1_2.obj) reports this error on screen:


PAULMON2 (BETA7) Loc:2000 > Download

Begin ASCII transfer of Intel hex file, or ESC to abort
.................................

Download completed

Summary:
33 lines received
505 bytes received
3 bytes written
Errors:
502 bytes unable to write


In page "Standard command" refer to this type of errors, said that the memory which was specified by the Intel-Hex file is read only, What does it mean? In fact the memory is a SRAM.
As it's also mentioned that in most such case the ram not working properly, I changed the RAM three times from different company (Hitachi 6264,… ) but it still do not work.
Now, could anyone give me some idea about this problem?

I appreciate your kindness in advance.

Best regards,
Mahdi Mahzari