Answers to a few questions

["John Kim" <jokim@chs.cusd.claremont.edu>]

I'm too lazy to edit this down.  Hope Ken doesn't mind.  He's answered some
questions, and brought up a few new questions.  Oh well.  :)

Oh, and I've already forwarded this to the software.watson.ibm.com ftp site
administrator.  It looks like this stuff *will* be available via ftp, it's
just a question of when.

Send any other questions to me and I'll queue them up and forward them.
----------------------------------------------------------------------------
From: Ken Inoue <xxxxxxxxxxxxxxxxxxx>
Tue, 26 Apr 94 13:09:53 JST
To: John Kim <jokim@jarthur.cs.hmc.edu>
Subject: Who at IBM is in charge of TP750 stuff?

John,
My apologies for the delay in responding to you. I have been waiting for
news on the IBM Internet FTP site.

To cut a long story short, we (ThinkPad development) can authorize the
FTP site coordinator to make the drivers package available to public,
*IF* she/he agrees. The Watson FTP site coordinator hasn't returned our
calls... if you know her/his Internet ID you may want to try alerting
the coordinator to the situation.

Now to answer your questions as best I can:

>1. Somebody who asked IBM tech support about installing a larger hard drive
>was told that the BIOS won't support a hard drive larger than 340 MB.  Is
>this true?  And if it isn't, how do you configure the BIOS to recognize,
>say, a 500 MB hard drive with x cylinders, y sectors, etc?

The tech support is correct in that the BIOS has not been tested with
anything larger than the 340MB drive that we offer. Also, as you know,
there is a magic number (528 million bytes) imposed by current IDE drive
interface spec. To go beyond that magic number would require changes to
BIOS. As for drives between 340M and 528M, anything goes; the drive may
work if the drive supports the IDE identity command that returns drive
parameters such as cyls/sectors/heads. Please note however that your
warranty will be void if your 750 fails (e.g. fuse blowout due to too
much peak power drain) as a result of using an unsupported drive.

>2. Is there any way to increase the tracking speed of the Trackpoint II
>under OS/2?  The OS/2 mouse control is already at maximum sensitivity and
>it's still too slow.

Sorry but this is an OS/2 issue; as you know, the OS/2 development is
in Boca Raton, FL - on the wrong side of the Pacific pond :) Your best
bet might be to patch the OS/2 mouse driver. I understand the source
code CD-ROM is availble from IBM. You may want to call OS/2 tech
support or try OS/2 support forums on CompuServe.

>3.  Where's a better source of TP750 technical info? The technical manuals
>are terrible.

Perhaps the technical reference manuals for individual chipsets (e.g.
Intel 486SL, Western Digital WD90C24) might be better at describing the
in-depth details that interest you. However, please note that programs
written directly to the hardware registers will not be guaranteed to
work in future models of ThinkPads.

>4. Is there a way to turn the backlight off without turning off the LCD?
>When I'm typing in the sunlight, I can see the screen just fine and I'd like
>to save some power by turning off the backlight.

I am afraid turning off the backlight would make the screen unreadable,
the ambient light notwithstanding. The screen has to be of a type
called 'transflective' to begin with, to make it feasible; it takes
something like a half mirror which passes through backlight but at the
same time reflects the incoming light to some degree. None of the 750
line features a transflective panel.

(In case you are wondering why: just as a half mirror can't do as good
a job of reflecting light as a normal mirror or of passing light as a
transparent window, transflective mono LCDs are generally not quite as
bright as normal backlit LCDs of comparable power consumption, because
the reflecting part absorbs the backlight. To the best of my knowledge
no manufacturer produces a transflective color LCD, because the color
filters absorb so much light (approx. 2/3 - e.g. the Red filter blocks
Green and Blue) that any reflected light, reduced to about 1/9 of the
original intensity after passing through the filters twice, just isn't
enough to make the screen readable.)

>5. What's different about the floppy drive?  What gap values, etc, are used
>for 2.88 Mb drives, and why does the drive change line act differently?

The diskette drive controller is configured to be compatible with PS/2
Model 30, the first AT bus PS/2.

> 6. How do I read the battery capacity from a program?

One way to do this in DOS is to use APM BIOS. The APM specification
version 1.1 (by Intel et al.) is on CompuServe PLUGPLAY forum; the 750
supports version 1.0 but if I remember correctly the battery status
interface should be the same between 1.0 and 1.1. Please be careful
about some of the APM BIOS calls that control system power state, as
improper use of these calls can result in system crash (the APM BIOS
calls were not meant to be used by two power managers). I am afraid
that currently there is no easy way to do this in OS/2 without
interfering with the operation of the standard power manager.

Hope this answers your questions.

Sincerely,
Ken Inoue
--
John H. Kim              | "Just try telling the IRS you don't feel like
jokim@jarthur.cs.hmc.edu | 'contributing' this year come April" - Bob Dole
This mail sent by NUPop  | on Bill Clinton's avoidance of the word "taxes"