🚀 go-pugleaf

In article <1992Dec31.162852.2315@hugis.nbg.sub.org>,
hugibaz@hugis.nbg.sub.org (Ingo Kraupa) wrote:
> 
> A few months ago someone posted that there is a patch to get higher bps-rates
> than 38.4kbps on a sun sparcstation. I told this to a friend, and he asked
> me if I can get this patch for him. I forgot the person, but I'm sure he
> posted to this group.  Any hint would be very appreciated.
> 
> -Ingo
Sun Consulting sales a high speed patch but it is pricy. Alternatives is to
get a serial port board from CoSystems(or any other 3rd party company)
which supports higher speed drivers with their product. The latter solution
is supposed to be cheaper.

Who: Kevin D. Sears-searsk@med.ge.com
What: System and Network Admin(a.k.a "Sr. Maintenance Droid")
Where: GE Medical Systems
Disclaimer: I know nothing for sure but I sure try hard!

searsk@med.ge.com (Kevin D. Sears) writes:

>In article <1992Dec31.162852.2315@hugis.nbg.sub.org>,
>hugibaz@hugis.nbg.sub.org (Ingo Kraupa) wrote:
>> 
>> A few months ago someone posted that there is a patch to get higher bps-rates
>> than 38.4kbps on a sun sparcstation. I told this to a friend, and he asked
>> me if I can get this patch for him. I forgot the person, but I'm sure he
>> posted to this group.  Any hint would be very appreciated.
>> 
>> -Ingo
>Sun Consulting sales a high speed patch but it is pricy. Alternatives is to
>get a serial port board from CoSystems(or any other 3rd party company)
>which supports higher speed drivers with their product. The latter solution
>is supposed to be cheaper.

>Who: Kevin D. Sears-searsk@med.ge.com
>What: System and Network Admin(a.k.a "Sr. Maintenance Droid")
>Where: GE Medical Systems
>Disclaimer: I know nothing for sure but I sure try hard!

Here it is:

From: schneck@Physik.TU-Muenchen.DE (Bernhard Schneck)
Newsgroups: comp.sys.sun.admin
Subject: Re: v32bis modems @ 14,400 bps on desktop Sparcs
Date: 6 Jul 92 11:10:19 GMT
References: <1992Jun29.183146.22097@samba.oit.unc.edu> <BOB.92Jun29172708@volitans.MorningStar.Com> <1992Jun29.221236.17474@src.umd.edu> <schneck.709948135@Physik.TU-Muenchen.DE> <1992Jul5.172754.17748@edsr.eds.com>
Organization: Leibniz-Rechenzentrum, Muenchen (Germany)
Content-Length: 2355
Status: RO
X-Lines: 70

cheeks@edsr.eds.com (Mark Costlow) writes:

>Could you be more specific about how you did this?

The following is from two postings from wolfgang@wsrcc.com (Wolfgang S.
Rupprecht) and adrie@ica.philips.nl (Adrie Koolen):

The serial (rs232 / 422) controller in the SparcStation 1, 1+ and IPC is
a Zilog Z8530, driven at 4915200 Hz. The baud-rate depends on a divisor
register, which is calculated as follows:

	divisor = 4915200 / (2 * baud_rate * 16) - 2;
or
	baud_rate = 4915200 / ((divisor + 2) * 2 * 16)

So:     divisor		baud_rate
	510		300
	62		2400
	14		9600
	6		19200
	2		38400
	1		51200
	0		76800

Now take at a look at the zs_speeds table in your /vmunix:

# adb -k /vmunix /dev/mem
physmem 27f4
zs_speeds/16d
_zs_speeds:
_zs_speeds:     0       3070    2046    1394    1140    1022    766     510
		254     126     83      62      30      14      6       2
$q

These are the divisors which are loaded into the Z8530 when you request
a certain baud rate (the first entry is used for B0 == HANGUP which is
handled by special code).  All you have to do is change one of these
fields to the value you want:

# adb -w -k /vmunix /dev/mem
physmem 27f4
zs_speeds+2/w 0
_zs_speeds+2:   0xbfe   =       0x0
zs_speeds/16d
_zs_speeds:
_zs_speeds:     0       0       2046    1394    1140    1022    766     510
		254     126     83      62      30      14      6       2
$q

Now the entry for B50 will load 0 into the divisor register, thus you get
76.8kbaud if you use 'stty 50'.

The adb commands as shown above will only change the running kernel (ie.
/dev/mem), the speed table will be restored to the original at the next
reboot.  You can use "?" to change the table in /vmunix itself, so it
will survive reboots, or you can change /usr/kvm/sys/sun4c/OBJ/zs_async.o
to get the modified table into newly built kernels (be sure to save a copy
of the original).

As always, be careful when tinkering with your /vmunix.  Your mileage may
vary.  I don't know anything, so you can hold me responsible for nothing.
I can't speak for myself most of the time, so I can't speak for my
employer, either.

\Bernhard.
--
Bernhard Schneck        Internet: Bernhard.Schneck@Physik.TU-Muenchen.DE
TU Muenchen Physik
8046 Garching           "There is no problem so big that it cannot be
Germany                 run away from"                  Illusions, Richard Bach

-- 
| ...!unido!ukw!lupe  (German EUNet, "bang")     |  Disclaimer:            |
| lupe@ukw.UUCP       (German EUNet, domain)     |  This is an unofficial  |
| suninfo!alanya!lupe (Sun Germany)              |  opinion of Christoph & |
| Res non sunt complicanda praeter necessitatem. |  Imschweiler Consulting |

In article <1993Jan6.213927.2788@ukw.uucp>, lupe@ukw.uucp (Lupe Christoph) writes:
> searsk@med.ge.com (Kevin D. Sears) writes:
> 
> >In article <1992Dec31.162852.2315@hugis.nbg.sub.org>,
> >hugibaz@hugis.nbg.sub.org (Ingo Kraupa) wrote:
> >> 
> >> A few months ago someone posted that there is a patch to get higher bps-rates
> >> than 38.4kbps on a sun sparcstation. I told this to a friend, and he asked
> >> me if I can get this patch for him. I forgot the person, but I'm sure he
> >> posted to this group.  Any hint would be very appreciated.
> >> 


Please note that I am not speaking for Sun, when it comes to the serial
device driver I'm just a user.

Bear in mind that the 8530 in a SPARCstation is a character-interrupt
device. Every received character causes a CPU interrupt and the processor
must read the chip registers, store the value in memory, etc. Asking it
to do that at >38.4 is asking a lot, especially for an SS1 or 1+. I have
seen SS2s running at 64k, but you can expect that to be quite a load
on the system. If the machine is heavily loaded you may lose characters.


Steve