Hi Paul,
Perhaps. More likely a windows problem.
Your code could be hogging the processor.
In VBA we would put a DOEVENTS after X reads to allow windows to catch up on other business.

Don't know if Cobol has an similar statement.

John


"Paul H" wrote in message ...
I am creating an XLS file from a CSV file using COBOL Net Express, adding
one record at a time. I use various INVOKE statements. After about 1,000
records the speed drops to about 1/4 of the prior rate per minute. I doubt
that the speed of reading the input file changes. Is this because of an
Excel overflow buffer issue? How can I fix this? TIA, Paul