🚀 go-pugleaf

In <1993Jan5.104013.2925@brandonu.ca> guelzow@brandonu.ca writes:

>Does anybody know how I can increase the size of the portbuffer in ZTerm0.9?
>It is currently 4K and I occasionally receive data that fast that the buffer
>runs over and data is lost. (This happens if large amounts of text are 
scrolled
>onto the screen, e.g. when listing file information.)

I suspect there is a better solution. I can't say for sure how Zterm handles 
port reading, but a little simple math says to me that it should be hard to 
overrun that buffer, because for any connections over 2400 bps (240 cps max) 
you should be using RTS/CTS flow control (which does a fine job of preventing 
overflow) and for 2400 or less you're talking about over 17 seconds worth of 
data backing up. Now that doesn't necessarily mean that you are getting a 17 
second stall, but the problem is NOT likely in a too-small buffer. More likely
is loss because something else on the computer is turning off interrupts for 
too long, so the little tiny buffer on the serial chip is getting overrun. This
is very possible if you have an older mac running lots of tweaky little INITs 
that have the arrogance to turn off interrupts for 1/80th of a second (long 
enough to overrun the 3-byte buffer before the driver gets a chance to read it)
Obviously you can also have serious problems if you have things running 
alongside Zterm, but that is all too obvious a problem...

As for how to change it, the only way is to get some serious hacking tools and
start searching for code equating to the allocation of that buffer and the 
passing of it to SerSetBuf. Does that sound fun?