Tell me a lot more and maybe I can help. I have never had to adjust the buffer size in over 2 decades.
Bob
I have a dell laptop with XP Pro SP3. I download a dos palm pilot of text data using a serial to usb adapter on com port 1. If there is too much data to download, or if it goes too fast, I get a " buffer overflow error suggest increasing buffer size" error message. I already did adjust the virtual memory and that didn't help. (My old win 98 laptop didn't have this problem before it went belly up). Any suggestions? Don't see any option to slow down the transfer rate. Thanks.

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