On Sun, 17 Dec 2000 10:35:59 +0100, Joerg Dietze wrote:
> what is the speed of Your com port? Some time ago I figured out that A.
> loads smoother when speed of com port is set to lower value than modem
> connection. When my com1 was set to 115kbps there were many stallings
> while d/ling files which were totally gone with 38400.
...and then Guenter Bietzig wrote:
> that's also my observation. With a 486/100 Mhz, UART16550 and 56K-Modem
> the best throughput (for me) is with COM-Speed 28800 and Modem line
> speed 33600.
>
I've found (on a DX4-100 VLB with serial card plugged into 8-bit ISA
slot and 56k external modem) that setting Arachne to use 115200 causes
lost characters - noticeable during log-in on terminal screen, so I
must conclude that it is happening elsewhere, too.
Reducing the port speed to 57600 seems to cure it. Before I inserted
a 16550 chip into the serial card in place of the 16450, I couldn't go
faster than 38400 port speed. Maybe if I had a newer 16-bit
ISA serial card (or serial interface built in to motherboard), it would
all go a bit faster still without losing things - which leads me to ask:
with a 16-bit ISA card, will a 486 fetch 2 bytes at a time from the
serial port card by some means of buffering, i.e., getting one byte from
the UART into lower 8 bits and the next into upper 8 bits? If so,
that might make an higher port speed workable.
Even with 57600 port speed, I've seen CARRIER 44000 reported in
PPP.LOG. I assume that this is telephone line speed but my comms
knowledge all gets a bit hazy at this point!
Ron.
