[HP48] Kermit setup

[Christoph Giesselink]

(03-23-2023 06:56 PM)cdmackay Wrote:  Nice!

My notes tell me that Kermit also has the advantage of CRC, unlike the XMODEM client in the 48?

Yes the HP48 Kermit protocol support CRC with the fallback of checksum.

Recently I made some tests with Hyperterminal as Kermit Server and a HP48 as sender. The Kermit packets used the CRC for error checking. Same situation, but now Tera Term as Kermit Server. The request from the HP using CRC was denied by Tera Term and so the 6 bit checksum mode was used.

Yes, that's correct that the XSEND and XRECV commands inside the HP48 G-series only support the checksum method. But some 3rd party libraries, also my CARDUPL and CRDDWL HP48 programs are supporting XMODEM with CRC. Also the HP48 S-series calculators with it's 2MHz CPU are fast enough calculating the CRC instead of checksum without speed loss.

I just published a small article in the article section about connecting a HP48 and my experiences about speed and Terminal software.