Hard disk drive exchange

What kind of effects will you gain, if you exchange a genuine hard disk drive like 80MB or 160MB to a high capacity hard disk?
The effects include not only an increase in the disk capacity but also accelerated r/w speed of the disk. For example, system boot up time will be shortened as well as that of application booting or data searching.
You may be surprized to the feeling of speedup. Even you may feel this is better than CPU upgrade.
So, at first I recommend you to exchange an existing hard disk drive to a high capacity and more speedy one, if you want to accelerate your Color Classic. Of course the exchanged disk drive will be available after CPU upgrade.
It is rather difficult to exchange HDD of Color Classic. If you remove the analog board, HDD will be easily exchanged. However, it is more difficult to remove analog board. ;-(
It may be a good idea to perform HDD and high-resolution conversion at the same time. Please read the description below thoroughly and try it carefully.
Tools needed

This is a tip of torx screw driver. You may use a minus screw driver as a su bstitute, you'd better to get a torx screw driver.

At fist, you have to set up new HDD.

At least, you must establish a SCSI ID and a terminator.

These establishment is typical method. The establishment may different from typical one by each marketing HDD. You had better to read spec sheet of the HDD.
Normally, an internal HDD is set to No. 0 of SCSI ID.

There are jumper switches on the side of an HDD circuit board.

Pins A0, A1, A2 express the SCSI ID as a binary number.

SCSI ID is established by installing jumper-tip.

The table below shows the relationship between jumpers and ID number.

HDD boardA0***

Apply a jumper tip on each *.
SCSI ID Zero is coded with no jumpers.

A terminator will be enabled by setting a jumper switch or installing on-boa rd terminating resistors. You must enable a terminator on when using as a internal drive. You can enable a terminator either setting a jumper switch or installing terminating resistors.

Disassembly of Color Classic!

Place a Color Classic on the front bazel. Loosen 4 screws, don't lose them, though.

Lift a rear cover.

Rear view without a rear cover.

  1. CRT
  2. analog board
  3. speaker (locating FDD inner this part)
  4. HDD
  5. logic board

Some thousands volts of electrical charge may still remain around a CRT andsome parts on the analog board. It is very, very dangerous. Never touch them!
Zoom up of HDD. (6) is SCSI cable, and (7) is power supply cable.
Remove these two cables. A narrow-tipped plier is useful to remove these parts.

Speaker cables may prevent you from removing HDD, so put them aside first.

Remove the SCSI cables with a narrow-tipped plier. Take care not to damage cables.

(8) is a claw of the carrier. HDD is fixed by hooking this claw on the chassis.

Remove HDD installed on a carrier from the chassis. HDD is a fixed on the HDD carrier with some screws.

Pull the claw upward with a narrow-tipped plier and pull the carrier out.

Detach the carrier from HDD loosening 4 screws.

You finished disassembly. Replace a large capacity HDD with old one. The assembly is a quite reverse manner of the disasembly. Do not attach the carrier to wrong direction.