Bootloader - Updating FW - SIOW works, TeraTerm doesn't

[temtronic]

I'd like to add 'a couple pennies' too....

I'm wondering if which version of Windows matters and 'upgrades' have been installed ?
As a dinosaur, I remember when your PC program (say QuickBasic 4.5) had actual DIRECT access to the PC comports. You read the serial port data buffer and GOT the incoming character. Easy and efficient and it WORKED !
Now, real comports have been replaced with a USB interface and several 'layers ' of muddy software that may or may not get that incoming character.

It'd be interesting (or scary ) to see what's really involved, the actual 'path' that it takes to get that incoming serial byte into a 'terminal' program.