15 Mar
2023
15 Mar
'23
12:59 a.m.
From: Ken Unix
I have mknod but need the (c,b) major/minor numbers
for /dev/lp
It looks like SysV still has conf.c; you're looking for 'cdevsw'.
Noel
15 Mar
15 Mar
8:05 a.m.
New subject: UNIX System V Release 2.2 gdts Vax-780
jnc(a)mercury.lcs.mit.edu (Noel Chiappa) wrote:
To be more explicit, you need to find the index in cdevsw of the lp
device. You will then want to run
mknod c <index> 0 /dev/lp # I think that's the right argument order
That is, 'c' for character device, major device is the index in cdevsw,
and minor device indicates which physical one to use. Since you only
have one, it should be 0.
If the above is not correct, someone will correct me, I'm sure. :-)
HTH,
Arnold
From: Ken Unix
I have mknod but need the (c,b) major/minor
numbers for /dev/lp
It looks like SysV still has conf.c; you're looking for 'cdevsw'.
Noel 
8:52 a.m.
New subject: UNIX System V Release 2.2 gdts Vax-780
On Wed, 15 Mar 2023, arnold(a)skeeve.com wrote:
[...]
That is, 'c' for character device, major
device is the index in cdevsw,
and minor device indicates which physical one to use. Since you only
have one, it should be 0.
There's also the possibility of using the upper-order bits to pass flags,
although there's not a lot that you can do with a printer (control of page
throw, etc).
-- Dave
11:09 a.m.
New subject: UNIX System V Release 2.2 gdts Vax-780
In: /usr/src/uts/vax/cf
This is what is in conf.c:
struct cdevsw cdevsw[] = {
/* 0*/ conopen, conclose, conread, conwrite,
conioctl, 0,
/* 1*/ dzopen, dzclose, dzread, dzwrite, dzioctl,
dz_tty,
/* 2*/ syopen, nulldev, syread, sywrite, syioctl, 0,
/* 3*/ nulldev, nulldev, mmread, mmwrite, nodev, 0,
/* 4*/ gdopen, gdclose, gdread, gdwrite, nodev, 0,
/* 5*/ htopen, htclose, htread, htwrite, nodev, 0,
/* 6*/ nodev, nodev, nodev, nodev, nodev, 0,
/* 7*/ nodev, nodev, nodev, nodev, nodev, 0,
/* 8*/ erropen, errclose, errread, nodev, nodev, 0,
};
In "master" sample entries are:
ts11 4 36 115 ts 4 1 5 1 5
tu78 1 36 515 hu 0 1 5 4 5
rm05 1 76 515 hm 0 0 4 8 5
nsc 4 77 5 nsc 8 0 10 1 5
ndb ct
*lp11 4 73 5 lp 4 0 6 1 4*
dn11 4 32 6 dn 8 0 7 4 5
vp 4 33 5 vp 16 0 14 1 5
vp
dmc11 8 37 6 dmc 8 0 19 1 5
Those numbers do not mean much to me.
Does this help in determining major/minor number for lp?
Thanks
Ken
On Wed, Mar 15, 2023 at 4:53 AM Dave Horsfall <dave(a)horsfall.org> wrote:
On Wed, 15 Mar 2023, arnold(a)skeeve.com wrote:
[...]
--
End of line
JOB TERMINATED
That is, 'c' for character device,
major device is the index in cdevsw,
and minor device indicates which physical one to use. Since you only
have one, it should be 0.
There's also the possibility of using the upper-order bits to pass flags,
although there's not a lot that you can do with a printer (control of page
throw, etc).
-- Dave
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days inactive
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3 comments
4 participants
participants (4)
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arnold＠skeeve.com -
Dave Horsfall -
jnc＠mercury.lcs.mit.edu -
KenUnix