Ah!

I wrote:
> % man 4 pty
> 	:
>      In configuring, if an optional count is given in the specification, that
>      number of pseudo terminal pairs are configured; the default count is 32.
> 	:

The "default count" doesn't mean that of GENERIC kernel.

sys/kern/tty_pty.c has

	#if NPTY == 1
	#undef NPTY
	#define	NPTY	32		/* crude XXX */
	#endif

and "the default count" is 32.
That is, a line

	pseudo-device	pty

is equivalent to

	pseudo-device	pty	32

I'd say to

>  1. fix manpage,

as

<      number of pseudo terminal pairs are configured; if the count is
<      omitted it defaults to 32.

Comments / corrections?
-- 
ITOH, Yasufumi <itohy@netbsd.org>