310derive_3 1 360 1018
310derive_3.dat 310 200 10 0 -5 62172 0 ch1
# 1020 samples * 4/3 = 1360 bytes
# 1019 samples would still need 1360 bytes since it extends. This file tests 1018.
# 1018 samples * 4/3 bytes/sample = 1357+1/3 bytes. The last sample extends into 1358.
# The dat file is 1358 bytes. 
# wfdb c CAN read this.