From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 References: <65cd39f4d41d55c39717cb717a9582ac@felloff.net> In-Reply-To: From: Skip Tavakkolian Date: Thu, 5 May 2016 15:38:25 +0000 Message-ID: To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: multipart/alternative; boundary=001a1147fc729731ee05321a222f Subject: Re: [9fans] A couple questions about /dev/draw and /dev/kbmap Topicbox-Message-UUID: 8e9b256a-ead9-11e9-9d60-3106f5b1d025 --001a1147fc729731ee05321a222f Content-Type: text/plain; charset=UTF-8 The beauty of it is the uniformity and not making any assumptions about the specifics of what's underneath; notice starting rio inside a rio window. http://herpolhode.com/rob/lec5.pdf On Thu, May 5, 2016 at 6:12 AM Dave MacFarlane wrote: > In that case, is there any way to get the current max packet size that 9p > will allow for > a read or write, or to determine if you're drawing to a local machine or > not? I'm not seeing anything obvious under /dev or /env. > > On Wed, May 4, 2016 at 10:45 PM, wrote: > >> you wont have that limitation on devdraw on the local machine. but >> over 9p, your reads and writes are limited by the iounit of the >> channel over which 9p is transfered. >> >> the reson for having a iounit is that you'r not the only one doing >> stuff over the channel. you chunk stuff up in packets, so multiple >> things can appear as simultanious even tho theres only one serial >> channel. the bigger you make the packets, the bigger the latency >> for concurrent packets wanting to be transmitted. >> >> for the keyboard stuff. you cant do that with /dev/cons. drawterm >> only gives you runes, but no kbmap (you'r probably seeing the cpu >> servers kbmap, not the one in drawterm). in 9front [1,2], theres >> /dev/kbd [3] which also gives you button states. >> >> [1] http://9front.org/ >> [2] http://drawterm.9front.org/ >> [3] http://man.9front.org/8/kbdfs >> >> -- >> cinap >> >> > > > -- > - Dave > --001a1147fc729731ee05321a222f Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
The beauty of it is the uniformity and not making any assu= mptions about the specifics of what's underneath; notice starting rio i= nside a rio window.

http://herpolhode.com/rob/lec5.pdf

On Thu, May 5, 2016 at 6:12 AM Dave MacFarlane &l= t;driusan@gmail.com> wrote:
=
In that case, is ther= e any way to get the current max packet size that 9p will allow for
a r= ead or write, or to determine if you're drawing to a local machine or n= ot? I'm not seeing anything obvious under /dev or /env.
=

On Wed, May 4, 2016 at 10:45 PM, <cinap_lenrek@fe= lloff.net> wrote:
you wont= have that limitation on devdraw on the local machine. but
over 9p, your reads and writes are limited by the iounit of the
channel over which 9p is transfered.

the reson for having a iounit is that you'r not the only one doing
stuff over the channel. you chunk stuff up in packets, so multiple
things can appear as simultanious even tho theres only one serial
channel. the bigger you make the packets, the bigger the latency
for concurrent packets wanting to be transmitted.

for the keyboard stuff. you cant do that with /dev/cons. drawterm
only gives you runes, but no kbmap (you'r probably seeing the cpu
servers kbmap, not the one in drawterm). in 9front [1,2], theres
/dev/kbd [3] which also gives you button states.

[1] htt= p://9front.org/
[2] http://drawterm.9front.org/
[3] http://man.9front.org/8/kbdfs

--
cinap




--
- Dave
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