Re: [M100] m100 maximum baud rate without flow control
The hardware is capable of 76,800 baud and if the other end supports it then John's Hterm can run at that speed. Using XON/XOFF handshaking and minimal buffer size the native apps BASIC, TEXT and TELCOM will run at 19,200bd. Without handshaking the maximum speed depends on the software and what it has to do between characters received; BASIC is the slowest because it has to interpret incoming text. TELCOM is next because it has to display each character and possibly scroll the screen. Download is slower because it also has to store the characters. TEXT is the fastest because it only has to store the characters. I did some tests years ago but don't remember the results; why not try it yourself? Create a large (20K) text file, send it to and from the M100 and compare it to the original. 600 bd is probably the fastest in all cases while TEXT may be happy with 1200. On Thu, Nov 30, 2023 at 1:30 AM runrin wrote: > > hey all, > > i was wondering if anyone has done any work determining the maximum baud > rate the m100 supports without xon/xoff flow control? i assumed it was > 9600 because thats what most of my machines from that era support > (usually with a 8250 uart). > > i've been working on a homebrew computer for some time now, and even > with a dead stable serial clock at 9600 hz i'm dropping characters on > the m100. i thought it was a software issue, but it works perfectly with > my heathkit terminal, so i'm thinking its an m100 problem. > > 300 baud worked fine, but even as slow as 2600 seemed to be an issue. > > thanks!
Re: [M100] m100 maximum baud rate without flow control
It's largely a problem of the m100... it has a small receive buffer, 64 bytes, and highly software driven display. But it also depends on the peer and the degree to which it is expeditiously monitoring and possibly "looking ahead" in incoming data for xoff to flow off its sending process when the model t request it. So a single answer is not possible since it is potentially different for every peer system. Add in issues with the m100 doing anything else... like displaying text on the screen and it can be quite slow. Linux in particular is a poor peer in this regard. To get reasonable speeds xon xoff isn't really appropriate and you should really roll your own hardware flow control. With hardware flow control you can use even 38400 or 76800 speeds without data loss. Windows seems to allow higher than usual baud rates with software flow control. Probably still 9600 or lower I would think. -- John.
[M100] m100 maximum baud rate without flow control
hey all, i was wondering if anyone has done any work determining the maximum baud rate the m100 supports without xon/xoff flow control? i assumed it was 9600 because thats what most of my machines from that era support (usually with a 8250 uart). i've been working on a homebrew computer for some time now, and even with a dead stable serial clock at 9600 hz i'm dropping characters on the m100. i thought it was a software issue, but it works perfectly with my heathkit terminal, so i'm thinking its an m100 problem. 300 baud worked fine, but even as slow as 2600 seemed to be an issue. thanks!
