Although EazyLink2 offers more features and is more tolerant of varying serial port hardware configurations, YMODEM file transfers reach triple its maximum speed - achieving 3K/sec at 38400bps regardless of OZ version. This is because the YMODEM implementation does not use the OZ serial driver, so it is not limited to lower baud rates by the driver issues in the original Cambridge ROM versions. Also, by increasing the block size from 128 bytes to 1K and by batching multiple files together into a single session, YMODEM increases communication efficiency.
Transferring the 256KB of OZ 4.7.1 ROM files will take around 1 min 25 secs - something that is an agonising order of magnitude slower on an unmodified Z88 constrained as it is to 9600bps in Eazylink2.
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