[net.micro.trs-80] 16/6000 C

dab@myrias.UUCP (Danny Boulet) (03/25/86)

Buy the Tandy 6000 Software Development System (probably arouund $700US).
It has a reasonable C compiler.  Also, you don't have to worry about swapping
and such as the system takes care of all that for you.  One warning:  the
Tandy 6000 is limited to 256K per user process (I sure wish I'd known this
BEFORE buying the machine...).  Also, A Tandy 6000 (or model 16B) with only
512K is usable but not much fun (the system ends up swapping a lot).  If that
is all you have then you should seriously consider buying more memory (you
don't need the memory to be able to use the development system but it sure
is a more pleasant environment if you've got it).

ron@dsi1.UUCP (03/27/86)

In article <230@myrias.UUCP> dab@myrias.UUCP (Danny Boulet) writes:
>Buy the Tandy 6000 Software Development System (probably arouund $700US).
>It has a reasonable C compiler.  Also, you don't have to worry about swapping
>and such as the system takes care of all that for you.  One warning:  the
>Tandy 6000 is limited to 256K per user process (I sure wish I'd known this
>BEFORE buying the machine...).

 Below is an adb session that will allow you to change the amount of
 per process memory allowable.  This patch works for Xenix versions
 2.x as well as 3.x on the Tandy version of the kernel.

 Note on the 3.1 Tandy kernel the per process size is already set to
 512k per user process, so this patch is not needed.  I guess The Small
 Computer Co. finally bugged them enough :-)

 One additional note, you need the development system to apply this
 patch since you need 'adb' which is distributed with that product.

 (at your prompt (the '%' below is a typical C-Shell prompt) you would type):

   % cp /xenix /xenix.256k
   % adb -w /xenix
   _Maxmem?D
   	(to display current allocation)
   _Maxmem?W	512
   	(to set allocation to 512k per user process. [NOTE: You should have
   	available at least 1 meg of swap per user on your system! Also note
   	that you could use a number greater than 512 however keep in mind
   	how much memory you are dealing with, the most you can possibly
   	have is 1 meg. It is not recommeded that you go higher than 512k
   	unless you are the only user on the system and you don't mind alot
   	of large process swapping. (lots of overhead!!!)])
   $q
   	(to quit adb)
   	(you must now re-boot Xenix to have the patch take effect.)

--
Ron Flax  (ron@dsi1.UUCP)
ARPA:	dsi1!ron@seismo.arpa
UUCP:	..!{seismo, rlgvax, prometheus}!dsi1!ron

iv@trsvax (04/02/86)

>> /* Written 11:00 pm  Mar 24, 1986 by myrias.UU!dab in net.micro.trs- */
>> [ . . . ]  One warning:  the
>> Tandy 6000 is limited to 256K per user process (I sure wish I'd known this
>> BEFORE buying the machine...).
>> /* End of text from trsvax:net.micro.trs- */

This is changable.  If you have the development system login as  root,
make a copy of /xenix (for example, "cp /xenix /xenix-"), and then adb
/xenix as follows:

    Type:	adb -w /xenix
    Type:	_Maxmem?X
		_Maxmem:	0x100
    Type:	_Maxmem?w 0x0 0x1000
		_Maxmem:	0x0	0x1000
    Type:	$q

XENIX will then be set for 1 meg maximium process size (obviously, you 
can set it to whatever you wish, as long as it is a multiple of 4k...)

				IV  (aka John Elliott IV)
				Tandy Systems Software; Fort Worth, TX
				... {convex!ctvax,microsoft}!trsvax!iv
				... cu-arpa.trsvax!iv@Cornell.ARPA


[This information was provided by an individual and is not  nor  should
 be  construed  as  being provided by Radio Shack or Tandy Corporation.
 Radio Shack and/or Tandy Corporation have no obligation to support the
 information  provided.    The  author will, however, cheerfully accept
 mail.  This information will self-destruct in 5 seconds. ]

jmturn@lmi-angel.UUCP (James Turner) (04/03/86)

In article <> dab@myrias.UUCP (Danny Boulet) writes:
>							 One warning:  the
>Tandy 6000 is limited to 256K per user process (I sure wish I'd known this
>BEFORE buying the machine...).  Also, A Tandy 6000 (or model 16B) with only
>512K is usable but not much fun (the system ends up swapping a lot).  If that
>is all you have then you should seriously consider buying more memory (you
>don't need the memory to be able to use the development system but it sure
>is a more pleasant environment if you've got it).

Well, I can't talk for Xenix 3.0, but 2.3 (V7) works just fine with 512K. I
guess I have different expectations of a $3500 machine. The real performance
break seems to come between 256K (thrash city) and 512K. I do notice a
substantial degradation of performance if a lot of jobs start up (UUCP, for
example, when it is spawned by uux). Things have recently gotten better, now
that I have /usr and / on different drives, with / sharing with swap.
-- 

James

Helping Computers With Speech Impediments
LISP Machine, Inc.

{harvard|cca|mit-eddie}!lmi-angel!jmturn

dab@myrias.UUCP (Danny Boulet) (04/08/86)

>Well, I can't talk for Xenix 3.0, but 2.3 (V7) works just fine with 512K. I
>guess I have different expectations of a $3500 machine. The real performance
>break seems to come between 256K (thrash city) and 512K. I do notice a
>substantial degradation of performance if a lot of jobs start up (UUCP, for
>example, when it is spawned by uux). Things have recently gotten better, now
>that I have /usr and / on different drives, with / sharing with swap.

Using 1.3.5 (based on V7 UNIX), I found that the system would swap out my
vi task once a minute whenever cron woke up to check crontab.  I found
this to be sufficiently annoying that I felt that I had to have more
memory (if cron actually did anything useful then the pause could be
as long as 10 or 20 seconds).
Note that in addition to the standard XENIX background processes,
I always have an extra background task running (it's a fairly crude but
effective screen saver program that wakes up once an hour to see if
/dev/console has been idle for the past hour.  If so it clears the screen
to avoid burn-in if I forget to turn down the brightness).  Also, if I
recall correctly, 1.3.5 XENIX uses up more memory for the kernel and such
than any of the 1.2.x versions.

-Danny
P.S. It cost me only $167 Canadian to add the extra 512K of memory myself.
I would have probably lived with the pauses if I'd had to pay the $1,250 (Can)
that Radio Shack wanted at the time (the price is now down to around $500
(Can) but that is STILL pretty expensive).