[comp.sys.tandy] Tandy TL/2, memory upgrade?

mh@csd4.csd.uwm.edu (Matthew M Holtz) (03/09/90)

Does anybody have any recommendations on if I should upgrade my TL/2 to 728k
or leave it at 640k? It seems that the video memory is taking up some of the
space, so to ease things a bit I thought of doing this, but can't decided.
Also, I have a 20M IDE drive in it, can I put a hard card into it?
Thanks,
Matt

JAP131@psuvm.psu.edu (John A. Pelna) (03/12/90)

  mh@csd4.csd.uwm.edu (Matthew M Holtz)  writes:

>Does anybody have any recommendations on if I should upgrade my TL/2 to 728k
>or leave it at 640k? It seems that the video memory is taking up some of the
>space, so to ease things a bit I thought of doing this, but can't decided.
>Also, I have a 20M IDE drive in it, can I put a hard card into it?
>Thanks,
>Matt

As for the video upgrade, I really can't say much about.  As for as the
20M drive goes, the main difference between the TL and the TL/2 is that
the TL/2 does require a hard disk controller (as you probably already know).
You might think that you can then add another hard disk in one of the expansion
slots.  This would be a big mistake.  The TL/2's power supply isn't strong
enough to handle both drives safely.  If you ask a Radio Shack employee
the same question, they would tell you the same thing.  Although I have
heard of some one running two 40M cards for over three years without a problem.
But I would recommend against it.

No problem,
John

djh9381@ultb.isc.rit.edu (D.J. Halko) (03/14/90)

> I have a 20 meg IDE drive, can I put a hard card into it also?

People say that the power supply isn't big enough to handle it... well folks,
I was running my 40 Meg st251 (I think it was a 251 now... been a long time
now) with a power supply that delivered 1 amp at 12 V and 1 at 5 V... it heated
it up alot, but as long as it was heat-sinked down, there was no problem
(I never shut the machine down either... always stayed running...)

Now, you have to remember, the largest draw from that hard drive is during
startup and during seeks... as long as you don't do 2 simultaneous seeks
with both hard drives, you won't be straining anything. 

A fine example of this is my current hard drive now. I have a Priam 519
running 191.2 Megabytes... the power consumption at startup is 64 Watts 
(peak startup) and 57 Watts (peak seeking) with an average consumption
of 35 Watts and an idle of 29 Watts. In other words, an idle hard drive
(just spinning) will draw about 1/2 as much as 1 drive spinning up or
seeking... 2 drives in idle pull as much as 1 starting up. If the 
power supplies were designed right in the TL/2, it should give MORE than
required for 1 hard drive spining up/seeking, which means with one drive
idle at any one time, you should not be having any problem. 

Now, since you are probably running MSDos on the TL/2, you should not have
a problem with 2 drives seeking simultaneously often. With a slight strain
of something like that happening occasionally, you will not do any damage.
The power supplies are made with a good margin of "beat-on-ability" since
they have no idea how many cards you will be popping in there. With 5 slots
(I think it is 5 slots, eh? I forget sometimes...) there should be adequate
power... I have seen 2 drives run in several 1000's before.  The IDE drive
should take even less power since you don't have a separate controller card.
Your hard cards are miniscribes (if not, just 3 1/2" hard disks) and you
can run those off of batteries... they don't really pull alot...

Now my system, I have to worry about simultaneous seeking on drives all
the time (running OS9 with 191.2 Meg drives and DMA floppies and other
DMA hard drives simultaneously, there are always simultaneous seeks going
on.... I have to be a little more careful... but then again, there is another
OS9 system running in Rochester that was running a 191.2 Meg, 150 Meg, and
2 80 track drives on a 65 Watt power supply with lots of simultaneous seeks
for about 1 year... never any problems... he was running a BBS!

You would be suprised how well that equipment is built that you buy at Shack.

djh9381@ritvax.bitnet
David J. Halko

mdchewni@vela.acs.oakland.edu (Mark D. Chewning) (03/15/90)

Having to be working for the corporation, unoficcialy, no.  But you can because Ihave it done to the one working in our front of our store.  A 20 Meg IDE, and a 20 Meg Hard Card do work.

Mark Chewning
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