Serial analyzers (was Re: VAX 11/730 quickie)

Marc wrote.... -------- I was not sure what I would getting that a laptop with a good terminal emulator and a serial port would give me. Can you convince me otherwise? What do you guys use it for? --------- Perhaps there are terminal emulators out there that can do the following, but I'm not aware of any that do these things that are the most common use cases.... 1) Display transmit on one line and receive on the other line, positionally correct. Very easy to visually see what one side sent, and what the other side replied. 2) Display the characters not just in ascii text, but in ascii mnemonics, and better yet... binary, octal, hex. FAR easier to see what is REALLY being transmitted and received. Ex - so if the unit is set to 81N, are the parity bits right? You can tell visually at a glance without really thinking. 3) And given the display can be in binary, it's easy to see field values that do not align on even count positions - ex: 8 bits where the first 3 bits mean something in the protocol, and the next field is 5 bits, etc. 4) Automatically trigger on events - ex. Watch the line until you see this sequence from the DCE. Then insert this string as a reply, wait for this response, then let the DTE continue. Oh, and start logging if this pattern occurs 3 times. 5) Automatically calculate checksums by any one of a designated set of algorithms, and verify the checksums being sent and received. Start logging, up to 2K size, once a checksum mismatch occurs. 6) Run BERT tests to either side. 7) Often provide a breakout box to jumper and/or reroute wires. 8) Save data to a disk for later review, or print to paper. 9) Easily deal with async, sync, bsync, x.25, etc. When writing your own communications protocols, a datascope makes testing/troubleshooting a very quick process. The alternative ... not so much. Many decades ago, I had a program for DOS (that I have since lost) called "Breakout II". It came with a cable and required two serial ports. It was a "software" breakout box. It was sorta handy... but it was no datascope. J