Date: Thu, 6 Apr 95 00:27:44 EDT
From: Bill Flynn 

with modifications by Philip Wilk

I just upgraded my Aero 4/33c's hard drive from 170mb to 720mb. This process
was remarkably simple. The new drive is an IBM DBOA2720, 12mm 13ms. It was $699
from Micro Sense, CA (800)544-4252. I run Linux and the X Window system on this
and maintain a small dos partition for maintenance tasks not accesible to
PC-UNIX (essentially, a 640k PROM ;-<). I summarize the process below.

These is a procedure that I followed to replace my drive. Use at your own risk.
Replacing your own hardware may likely interfere with your Compaq warranty. I
can not be responsible for any damages incurred should you set out on this
course.

Before removing drive

  1.  Go into Compaq setup by pressing F10 on bootup when the cursor goes to
     the upper right corner of the screen.
  2.  Select the option to "Create a Diagnostics Diskette". From here feed the
     required diskettes and then feel safe that you will be able to restore
     this neat little setup partition. NOTE: The setup partition must be the
     fist partition on the hard drive so it must be installed before making any
     other partitions!
  3.  Go into "Computer Setup", then into "Storage", then "Configure Fixed Disk
     Drives". Write down the all information under "Fixed Disk Drive
     Information".
  4.  Back up any data you need to secondary media ;*)

Drive installation

  1.  I strongly suggest using a grounding strap. These should be available
     from local electronics or hobby shops, if you dont have on already.
  2.  Carefully disassemble the Aero. There are 4 screws on the bottom, and two
     in the rear. All the screws to be removed are black.

!!!!Note!!!!
Date: Tue, 18 Jun 1996 17:05:05 -0500 (CDT)
From: Peter Barrette 

   I would like to make a correction in the HDD replacement instructions. 
Step 2 has the user removing both of the rear screws. Only removal of the 
top screw is neccessary while removing both can create difficulty in 
handling the screen. 


  3.  There is a "shell" surrounding the keyboard which snaps apart in the
     front. Be careful not to scratch the case if prying this with a sharp
     object. This peice is somewhat difficult to remove from the hinges of the
     display. BE CAREFUL with the ribbon connecting the LCD display to the
     internal assembly.
  4.  The system board and hard drive are located under the keyboard. Unscrew
     this again being careful with the ribbon cables connecting the keyboard to
     the system board. The keyboard can be laid toward the front, out of the
     way.
  5.  The hard drive can now be accessed. It slides away from the system board(
     to the right). Once disconnected, it can be lifted out. Lift it out front
     first or the screws on the back may put too much pressure on one of the
     circuit boards. There is a vertical tab on the disk mount which has to
     clear the ridge across the front of the aluminum system board mount.
  6.  My IBM drive came with one jumper installed. Without this jumper, the
     system didn't recognize the drive at all. I left it off as the 170mb
     Segate had pins in the same position non-jumpered. I suspect this has to
     do with the IDE master/slave stuff. (my drive expertise is more with SCSI
     drives on UNIX workstations and servers).
  7.  If you are using the IBM DBOA2720, it's drive parameters should be on the
     drive label. Mine are as follows: Type: 65
     Cylinders: 1400
     Heads: 16
     Sectors: 63
     ECC: 4
     Capacity resulting from above = 722.0 MBytes
     1400cyls * 16heads * 63sectors/track * 512k blocks = 722534400bytes
  8.  Switch the drive bracket to the new drive.
  9.  The installation is the reverse of removal keeping in mind the following
     points:

AGAIN, BE CAREFUL WITH THE RIBBON CABLES. Be sure they are all fully seated in
the sockets. When I put mine back together, the display cable was not fully
seated and upon power on, the screen went blue with BRIGHT yellow lines. I then
reseated the cable and when the system came up, the yellow lines were etched
into the display. Fortunately, these gradually went away by the next day. The
display was only up for about 5 seconds like this. I suspect much more may have
fried it so again, please be careful.

      Use caution reassembling the "shell" surrounding the keyboard.
      The first time the system is booted, it will notice the drive and ask for
      confirmation before updating the CMOS drive parameters. Allow this.

Reinstalling setup Boot system the first time from the "setup" diskette. It
will notice that the new hard disk has no diagnostics partition, and suggest
that you create one. Select the option to do so.

Good Luck.