Tandy Professional Forum   Section: Tandy 2000
Subject: 2500sx/20 jumpers?   Total messages: 2
===============================================

#62396   1 Reply   08/28/96   14:57:28
From: Dan Taysom, 76376,2403
To:   all

I've got a Tandy 2500sx/20 that I'd like to understand better. 2 sets of
questions:

Jumpers on the motherboard:
E11/12/13 is for [onboard]VGA enable/disable

E14/15 says something about IRQ9 as near as I can make out (it's currently
open) what does it do?

E16/17/18 says PS2/AT it is currently set to PS2, what does the other
setting do?

E19/20/21 says multisync/std - currently set to std - what's the difference,
when would I use multisync?

E23 is open - what does it do?

E24/25/26 is line/mike - currently set to mike - when should each setting be
used and how do I make use of the input jack, i.e. software drivers, etc.?

E28/29/30 is line/phone - currently set to phone - when should each setting
be used and how do I make use of it, i.e dirvers, software, is it compatible
with 3rd part soundcard standards such as SoundBlaster, etc.??


Expansion VGA RAM - there are 2 sets of sockets labeled u48 & u50, each is
composed of 2 rows of 20 pinholes (SIPP style) offset by one.  If looks sort
of like this:
       U48
 ...................
...................
       U50
 ...................
...................

What type of chips will work here? (and what base memory do I have if these
are empty? any idea of the cost to fill these, or whether it is even worth
it?


Thanks,
Dan










#62431   Reply to #62396   09/04/96   02:57:09
From: Horace Ory, 71625,1006
To:   Dan Taysom, 76376,2403

Probably the E16/17/18 jumper is to select either an AT type or a
PS/2 type mouse, depending on which you are using.  The E19/20/21
jumper is for the type monitor you are using.  If you are using a
multisynch (higher frequency) monitor, use that setting;
otherwise, stick with the standard setting.


