[C] date: 2001
from: Rick

First let me say that there is a lot more that I don't know about the Aero than
what I do. I have picked up a large number of these units and have
five of the 4/25 and two of the 4/33 working at this point. All of these units
have accepted the Toshiba MK1926FCV  814MB hard drives without partitioning.

[C] from Ingo Ralf Blum
date: March 2001

I'm not Javier, however I had a UDMA-66 harddisk running well. The Aero doesn't
support UDMA, but the hard disks are compatible with earlyer standards, and so
they operate at PIO mode, which the Aero supports. Make sure you have the Compaq
setup disk available to tell the Aero the new harddisk size. The size of mine
was not automatically detected and I had to manually set the
cylinder/tracks/head values by hand. Have them at your hands. In some cases they
are printed on the harddisk, but sometimes you'll have to look at the
appropriate internet pages of your harddisk vendor.

Regards Ingo

[C] from Ingo Ralf Blum
date: March 2001

> What size (gigas) is your hard drive?

It's 12 MB. When you ask, if the Aero can handle such drives, that depends on
which operating system you are using.
Usually there are the following dependencies.

Windows 95 -> BIOS -> harddisk
Linux -> harddisk

So you see Linux directly accesses the hraddrive and so supports all current
hard disk sizes. Windows 95 relies on the BIOS, and the Aero BIOS supports only
8 GB. This doesnÄt mean, that you can't use larger disk on Windows 95, but
Windows only sees the lower part
of the drive.

Lets assume a 12 GB drive.

################++++++++

where each character is 512 KB. The # specifies the part which win 95 can see,
the rest is only accessable by other os which use direct acces, e.g. Linux.
So you can partition as follows.

wwllllllllllllllllllllll

where Windows has a partition in a lower part and linux in the upper. Contary
this doesn't work:

wwwwwwwwwwwwwwwwwwwwllll.

> What do you mean with earlier standars?

There are different operation modes of harddrives, PIO (programmed input
output), where the processor transfers the data, and DMA (direct memory access),
where the disk controller transfers the data (The terminology may not be 100 %
correct). These operation modes were introduced in the following order:

PIO 1
PIO 2
PIO 3
PIO 4
... perhaps the thats not fully correct
UDMA 33
UDMA 66
UDMA 100

The current drives are usually UDMA 66 or 100, mine is UDAM 66

If a controller operates only e.g. on PIO2 and you have a UDAM 100 drive, both
parties agree to the largest common protocol, which results in a PIO 2
operation. I think (however I do not know for sure) that all the older PIO modes
are also covered by the newest UDAM standards, so every drive should work.

> Does this mean that aero can manage an actually 6 gigas hard drive?

6 GB is no problem. As you can see 6 GB is well below 8GB so you can use it with
no restriction both in Windows 95 and Linux.

> And at last, you refer to a rompaq to set up the new disk, no?

Yes and no, I referred to a setup disk for the Aero. I can't remeber the fixpack
number, but it is named "Compaq Setup & Diagnostics". I is the same software as
usually installed on the harddisk, which you can execute by pressing DEL when
booting (I think it was DEL, but I have removed it, so that's a guess), but when
you install a new harddisk, there is usually nothing installed.

> (Somebody talked about don't touch the parameters and let the aero define them
by itsel, also if they're wrong, so the hard drive will work fine ?:)

That depends. Last month I replaced the 12 GB drive in the Aero with the old 170
MB, because I had to capture some video on my desktop and needed a drive. After
rebooting the Aero displayed "Bad system disk, press F1". This was, because the
hard disk layout was NOT automatically detected, and NO it was not an empty
clock-bios-backup-battery. So what I had to do was to go to Compaq's homepage,
find the disk layout (heads, cylinders, tracks), boot the Aero from floppy with
the setup disk and enter the values.

So be sure to have the disk layout of your current and old drive at your hands,
as well as a setup disk.

Another problem you should be aware of (Its not a really problem, howver it can
be annoying)

ATA drives don't distinguish heads, cylinders and tracks. They number the blocks
on the disk straightforward. However the BIOS does not and needs to map the CHT
values to block numbers. Unfortunately there are different mapping modes called
"NORMAL" and "LBA". If you have a desktop computer you can see these word
domwhere in your BIOS setup, where you can change them.

Here is the pitfall. When you format a drive in LBA mode, you can't read it in
NORMAL mode. Of course the data is still on the disk, but the block numbers map
to different positions, and so you'll likely get a "no system disk" error, when
booting. So make sure to always use the same mode. (In fact the mode is not the
problem, but the layout. Changing from LBA to NORMAL or the other way round
simply changes
the CHS values, so e.g. in one you have 8 sectors, 8 cylinders and 8 heads, and
in the other you have 2 cylinders, 2 heads and 128 sectors.
Both drives have the same size, but not the same layout.

If you format and install on your desktop and then put the drive into the Aero,
make sure you enter the values from your desktio into the Aero setup, if the
Aero doesn't detect the drive.

Formatting large drives > 8GB:

DOS fdisk (=Windows fdisk) relies on the BIOS to format drives, so you can't
format such drives on the Aero using the BIOS. Either install Linux first (or
use a Linux install disk, where a Linux partitioning program is on) or format
the disk in your desktop (which usually has a newer BIOS which supports larger
disks than 8 GB). Since noth methods don't know your Aero BIOS setting you'll
have to write down the CHS settings for your drive, for the case you have to
enter them into the Aero BIOS.

Nothing is more annoying than to have your computer in pieces and then find,
that you need some data which is on your pc's harddisk or in the internet.

[C] from Edgard ONO
date: March 2001

Yeh! I've just installed a Fujitsu MHD2032AT disk (3.2 gigas) in the litle
Aero! now it is a big boy!
Somebody told that Fujitsu discs were a little bit problematic to fit in the
aero because of the drills of the cady. He was right! but I had already
ordered de disk ;) But it wasn't a mission impossible! I just used car
painter tape (Sorry for the literal translation), to make the "paper
Spacers" that evite the disk from moving off its place.
Thanks everybody for the advices about bios, and setup floppys (Uf!). The
setup program just detected the disk, size, cylinders... and if I tried to
modify them, they reset to 0 (Oh my God what a fright!). So I reset and
didn't touch the parameters (That were right by themselves), and it worked.
After I used the W95 instalation disk to format the drive. I must say I've
just left 500 megs to windoze, and the rest for LINUX (I said the AERO is
now a big boy, no? :)
What a dream! Is a little dificult to know when it writes (Because it is
less sonour than the original quantum daytona). It wakes up faster. Tomorrow
I'll install de OS, so one day of thees I'll measure the performance of the
drive, ok?
Bye Aeronauts of XXI Century!




[C] Date: Dec 23, 1998

Modern harddrives are much faster that the factory installed 84mb and
170mb drives that were shipped with the aero. They are also much more
reliable, hours-of-operation-wise. Two good reasons to upgrade, in
addition to the obviuos gain in storage space. The increase in disk
access time can make the aero run much faster. 

If you are installing a large harddrive, you will also want to upgrade
the system ROM to SP1992 so that the Aero can recognize the larger
drives. If you do not, you will have to use some interleaving software to 
access the larger harddrive.

[C] Date: Fri, 25 Jun 1999 16:22:42 -0400 (EDT)
From: bfeitell 
Subject: Re: Upgrade HD without floppy

It can be done.  The suspend/maintenance partition may be a problem and
since you don't have a floppy that will be necessary.  You can install an
operating system byu using a 2.5 -> 3.5 adapter and set up the drive in a
desktop computer.  The carriers are listed in the aero faq and also are
now available from www.computersurplusoutlet.com.

[Q]From: DOUGLAS KOCHER 
Subject: fdisk and Partition Magic only see the first 500 MB or so.

Aeronauts--Help, please, with this one.  Many of you have reported installing
drives of various manufacturers greater than 540 MB, even > 1G, _without_
having to resort to Disk Mangler to overcome that barrier.

I had a Toshiba MK 1924FCV 540 MB that I needed to replace as it was full.
This is a _dog_ of a drive, so I was eager to do so.

I have it replaced with a Maxtor MobileMax 1.35G drive, but guess what?  
Even with the latest Compaq bios, and even though the bios sees all 1.35G,
both fdisk and Partition Magic only see the first 500 MB or so.

What gives?  BTW, the diagnostic partition installed perfectly.  The drive,
based on its interactions with the diag. partition, is much quicker and
quieter than the Toshiba it replaced.

[A] From: John David Steffes 
Subject: RE: fdisk and Partition Magic only see the first 500 MB or so.
Date: Mon, 17 Feb 1997 12:23:39 -0500

First wipe all fdisk stuff off. NO Diag Partition no MSDOS/windows Partition
NOTHING!. Then Boot with first Diag disk in. and set the drive up under the
setup there is a disk icon under that there is advanced under that there is
another tab which specifies which operating system. Click if DOS/WINDOWS
click Other. Then exit and let the machine reboot. Then go back and reset
the tab to DOS/WINDOWS this feature is what turn on LBA translation which is
what ONTRACK Overlay manager does. I also want you to know you must be on the
latest and greatest BIOS and DIAG utilities other wise things may not work. 

JDS

PS Just a suggestion I am not liable for anything that may go wrong from
following these directions.



  -- Ed. Note: For those of you who wonder why you can not get much more than
500 Mb of HD on your Aero: The BIOS when running DOS or windows 3.x can 
only recognize 1024 cylinders. This usually works out to about 502 or 512 Mb
depending on the rest of the hard drive parameters. You can get around this
by using either a special driver or a utility. If your hard drive needs this,
then one then contact the distributor or you can use the previously described
method for gaining full access. It is interesting to note that LINUX is not
limited in this way.    - Philip

  -- Ed. Note: The harddrive can be no thicker than 12.7 mm.  - Philip

[A] I would like to share my success in swapping out the original 170 MB disk
for a 353 MB disk in my 4/33C. I just carefully took the Aero apart (take care
with the clip on the right side), pulled the Seagate ST9190AG drive from its
carrier, put in the new one, and put it all back together (and fixed a slightly
erratic graphics cable along the way). I was mighty impressed with the
technology in there.

Now for the setup. I had made a floppy version of the Setup and Diags
partitions ahead of time and proceeded to use these to set up the
cylinders/heads/sectors and run a full diags sweep of the disk. I made three
partitions on the new drive -- 50M for DOS, 30 MB for shared swap and the
remaining 273 MB for Linux. I didn't make the diags partition; I'll just use
the floppies again if I ever need something from the there again some day.

So, it can be done. I was a little hesitant at first after calling Laptop
Solutions in Houston because they tried to tell me the BIOS wouldn't support
different sized drives without their proprietary changes. Well, maybe there are
cases where their changes are needed but I've not found them yet.

The drive is a Toshiba 1824FCV (682 cyl, 16 heads, 63 sectors); I just
reprogrammed the drive type 65 entries with these values. Only down side is
that it seems to spin up a bit slower than the old drive. But I'm convinced the
battery life is better, at least a little. The noise is distinctly different
too; maybe a little lower pitched but still as loud.

Warranty? Well, yes, compaq tech support told me what I did voids the
warranty.He said my only option, if I need service, is to put back the old
drive and tryto convince them the problem is not related to the change. I'm not
worried about it but it might be a factor for some.

[A] I can second Elwood's story. I have had the Toshiba disk in my Aero for
about 2 weeks now. Its great to have 330 MB of disk. Also, I think Elwood is
correct, in that the battery lasts longer with the Toshiba disk. Seems to draw
less power.

The difficulties I had in doing the exchange were much the same as Elwood
related. Namely the clip on the right hand side next to the mouse buttons. In
addition, I could not get the cable unplugged that feeds the trackball, mouse
buttons and speaker. So, it was easy enough to unscrew the track ball assembly.
The speaker, buttons and trackball could then be lifted out of the way while
still plugged in. Also, Ali, your instructions to me on not removing the lower
screw supporting the screen were correct. It is not necessary and helps keep
the assembly stable while trying to pry the cover off!

The Toshiba drive cost about $400 with tax. I bought it from Micro Sense in San
Diego, CA. (Micro Sense's Phone number is 1-800-544-4252.) They were very
helpful in telling me that the drive would work in the Aero without any BIOS
mods. They also told me I could put in a bigger capacity drive, but I would
need some BIOS mods to do that.

[Q] After saving the automatically recognized drive parameters, how did you get
FDISK to run on the PCMCIA FDD? I thought the PCMCIA drive needed drivers
loaded before it was recognized or is that something that's built into the BIOS
already?

[A] Yes. The FDD runs out of the BIOS. You can boot from it with nothing on the
hard disk. This assumes you have a current COMPAQ BIOS too. Very old ones did
not support the FDD correctly.

A word of warning. When I took apart the case it took me 2 1/2 hours. I was
very careful. I stopped twice during the process because of frustration.
However, once the top of the machine is off, then removing the old disk is not
a big deal. You move the drive holder from one driver to the other. Push the
new drive into place on the connector.

You can then power up the machine and test it to make sure the disk works.
(Have a boot floppy with FDISK.) If you have done it correctly, you will see
lots of disk space. Putting the cover on only took 10 minutes. The hard part is
prying the cover over the screen support rods. Also, do NOT remove the bottom
screw as seen from the back of the Aero which supports the screen. The screen
is really loose if you do this and as Ali told me, you can tear the flexible
cable that goes to the screen!

As has been said before, this is not for the faint of heart. If you take your
time, walk away from it if you get frustrated, and do not force anything very
hard you should be OK. The most difficult part is the clip near the mouse
buttons. If you do not have the original case disassembly instructions, I can
resend them.

[Q] Which brand(s) and model(s) can replace the 84Mb and 170Mb drive in the
Aero 4/25...anyone know if the drives are higher than the drives sitting in the
4/33c or is the height difference merely the colour screen as opposed to the
mono screen?

[A] Correct. The height difference is in the screen and not in the base. The
Toshiba MK1824FCV was an exact fit at 12.5mm. The Toshiba has 335MB on it. It
should also work in the 4/33c. The drive in the color model is the same size as
in mono. They're both 2,5" slim IDEs.

[C] From: "Steve Sims" 
Date: Mon, 29 Jul 1996 06:44:30 -0400

> From: Erik A Hansen 
> 
> Anyone deal with Drive Outlet Center?
> They have Toshiba notebook drives:
>       540MB   TOHDDNB540      $199
>       810MB   TOHDDNB810      $239

I've dealt with them on some SCSI stuff.  They we somebody I'd buy again
from.