To start with, I suggest that you should try to link your target 8052 board with PC before trying to write your VB6.0 code.

There are a number of Monitor programs available in Internet can be used in your target board. I had tried a program downloaded from Philips FTP site, the file name I believe is MON31.ASM. The program will act as a comm. program and generate a promte on your PC running a terminal program. You are able to edit the memory contents of 8051 from the PC with the program. However, you have to ensure that the baud rate of your monitor and terminal program are the same and the comm. port of 8051 is converted to RS-232 level.

After the above PC/8052 link is tested sucessfully, you can try to use a VB terminal program. Again, there are a number of VB terminal program available in the Internet with source code. VB itself (or at least the older version) comes with sample terminal program. By cut and paste you should be able to create your own version of comm. program very fast.