🚀 go-pugleaf

   Does anyone know what the maximum speed is for sending and
   receiving on Sparc-Station 1+ or SLC?

Look in <sys/ttydev.h>, which shows B38400 as the maximum, at least under
4.0.3c and 4.1.1.  We run PPP at that speed with fine results.  On a
Sun-4/60 (SPARCStation-1) running 4.0.3c and with two T1600s attached,
things look like

	8:59am> eeprom | egrep ttya
	ttya-mode=38400,8,1,n,h
	ttya-rts-dtr-off=false
	ttya-ignore-cd=false
	8:59am>

My /etc/ttytab entries are simply

ttya	"/usr/etc/getty std.38400"	unknown		on # in/outbound PPP

where that gettytab entry looks like

h|std.38400|38400-baud:\
	:sp#38400:nx=std.19200

My devices look like

9:01am> ls -Failg /dev/{cu,tty}[ab]
   493 crw-rw-rw-  1 root     staff     12, 128 Jan 17 17:52 /dev/cua
   507 crw-rw-rw-  1 root     staff     12, 129 Jan 17 17:56 /dev/cub
    93 crw--w--w-  1 root     wheel     12,   0 Jan 18 00:43 /dev/ttya
    94 crw--w--w-  1 root     wheel     12,   1 Jan 17 17:52 /dev/ttyb
9:01am>

This may be more detail than you asked for, but I hope it's useful.