Mitsubishi Electric Apricot User manual

apricot
Qi 486
ADD-ON INSTALLATION GUIDE
MITSUBISHI ELECTRIC

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doesnot represent a commitment on thepart of Apricot Computers Limited. The
softwaredescribedinthis manual is furnished under a license agreement. The
software may be used or copied only in accordance with the terms of this
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Copyright©ApricotComputersLimited1992
Publishedby
ApricotComputersLimited
3500Parkside
BirminghamBusinessPark
B377YS
MITSUBISHIELECTRIC
PrintedintheUnitedKingdom
Partno.15007631

1
Contents
Introduction 2
Anti-static precautions 3
Installing extra memory 4
Installing an 80487SX in Qi 486SX 11
CPU module upgrades 18

2
Introduction
This guide contains instructions on installing extra memory
in Qi 486 and 486SX, and an 80487SX coprocessor in a
Qi 486SX. This document should be your only source of
information when installing extra memory or a
coprocessor.
You should read this document before purchasing extra
memory or a coprocessor. If, having read the relevant
instructions, you are not confident about installing the
upgrade, you may wish to have your supplier or service
organisation install it for you.
Warning
Never carry out any work on the computer with power
applied. Always switch off at the mains and remove the
power lead from the system unit before starting work.
Before you start installing the upgrade you should be
thoroughly familiar with all the relevant instructions in this
guide and the appropriate sections of your
Owners
Handbook
.
CPU module upgrade
The system boards in Qi 486SX and Qi 486 have
removable CPU modules. These modules can be removed
and replaced without replacing the entire system board.
80486SX CPU modules can be removed and replaced
with a CPU module fitted with an 80486DX. This upgrade
is not user installable. Contact your supplier or service
organization for details.

3
Anti-static precautions
All electronic components and equipments are sensitive to
static electricity. Even small electrostatic discharges can
render components useless or severely shorten their
working life, therefore you should always take preventative
measures.
No work should be carried on any item unless it is in a
Special Handling Area (SHA) as defined in BS CECC
00015:Part 1. In general this involves:
* a common earth point
* an earthed bench or bench mat
* an earthed wrist strap

4
Installing extra memory
The system board in your computer has eight sockets for
Single Inline Memory Modules (SIMMs). The system board
treats these sockets as two sets of four. Each set of four
sockets must either be all occupied, or all empty. SIMMs
are supplied in sets of four.
How much memory
Three different capacities of SIMM are available:
256kbyte, 1Mbyte and 2Mbyte, giving upgrade kit
capacities of 1, 4 and 8 Mbytes. The system board does
not support all possible combinations of these three
capacities. The following table shows the RAM capacities
supported:
Memory Fitted SIMM Capacity
Set 0 Set 1
1 Mbyte 256k -
2 Mbyte 256k 256k
4 Mbyte 1M -
5 Mbyte 256k 1M
8 Mbyte 1M 1M
12 Mbyte 2M 1M
16 Mbyte 2M 2M
If you do not know how much memory is fitted to your
system, you can find out when you switch your computer
on. During the power up sequence on-board memory is
tested and the capacity is displayed on the screen.
On the start up screen two memory capacities will be
shown: base and extended. By adding the base and
extended memory capacities together and dividing by
1024 you will arrive at the amount of RAM (in Mbytes)
fitted to your system board. The result should always be
an integer.
If the result of the calculation is not an integer you
probably have ROM BIOS shadowing enabled and you
should add 384kbytes to the total you arrived at before
dividing by 1024.

5
The following diagrams show which type of SIMM should
be fitted in each slot for each possible memory capacity.
The memory sockets are labelled ‘MM1’ to ‘MM8’, note
that the sockets are not numbered in sequence.
TOWARDS REAR OF MACHINE TOWARDS REAR OF MACHINE
TOWARDS REAR OF MACHINE TOWARDS REAR OF MACHINE
256 KBYTE MODULES
1 MBYTE MODULES256 KBYTE MODULES
Orientation 1 Mb
2 Mb 4 Mb
MM4 MM8 MM3 MM7 MM2 MM6 MM1 MM5

6
TOWARDS REAR OF MACHINE TOWARDS REAR OF MACHINE
TOWARDS REAR OF MACHINE TOWARDS REAR OF MACHINE
1 MBYTE MODULES
2 MBYTE MODULES2 MBYTE MODULES
5 Mb 8 Mb
12 Mb 16 Mb
1 MBYTE MODULES
256 KBYTE MODULES
1 MBYTE MODULES

7
Obtaining access
The SIMM sockets are accessible with the system unit
cover removed. To obtain access:
1. Take suitable anti-static precautions.
2. Remove the system unit cover as described in your
Owner’s Handbook .
3. Identify the SIMM sockets from the illustration
below.
SWITCHES
SIMMS

8
Removing and replacing SIMMs
If you are fitting additional SIMMs remove those already
installed.
Removing SIMMs
Starting with the SIMM nearest the front of the system unit
and working towards the rear:
1. Note which socket the SIMM is in.
2. Lever the metal clips on each side of the socket
gently away from the SIMM using your thumbnails.
When the clips are far enough apart the top edge
of the SIMM will move forward until the SIMM is at
an angle of about 15°.
3. Taking care to avoid touching any of the
components on the SIMM grip the top corners of
the SIMM between thumb and first finger and
carefully pull the SIMM out of the socket.
4. Repeat steps 1 to 3 for all the other SIMMs.

9
Inserting SIMMs
From the illustrations showing the possible SIMM
combinations decide which SIMM capacity will be installed
in each slot. Then, working from the socket nearest the
rear of the system unit towards the front, install the
SIMMs.
To fit a SIMM:
1. Hold the SIMM so that the memory chips are facing
the rear of the system unit with the metal connector
strip nearest the system board.
2. Position the SIMM above the socket at an angle of
about 15°.
3. Lower the SIMM towards the socket. The right edge
of the SIMM will be prevented from reaching the
connector by the securing clip.
4. Allow the left edge of the SIMM to drop into the
connector.
5. Push the SIMM gently to the right and lower the
right edge into the connector.
6. Ensure that the SIMM is properly located in the
connector.

10
7. Rotate the SIMM into the vertical position by
pushing gently on the top corners.
8. If the SIMM is properly located the SIMM should
remain in position held by the securing clips, and
with a small plastic lug through the holes on either
side of the SIMM.

11
Installing an 80487SX in Qi 486SX
The 80486SX CPU module provides a co-processor
socket for an 80487SX. The socket can be configured to
accept either an 80486SX or an 80487SX. Normally, the
socket will be free, the 80486SX will be soldered directly
to the CPU module, and the socket will be configured for
an 80487SX.
It is possible however, that the 80486SX may be installed
in the socket. If so, the 80486SX will have to be removed
and the socket reconfigured before the 80487SX can be
installed.
Identifying the 80487SX socket
1. Take suitable anti-static precautions as described
in your
Owner’s Handbook .
2. Obtain access to the system board as described in
your
Owner’s Handbook .
3. Identify the tape drive mounting plate at the front
left of the system unit.
4. Remove the four screws that secure the plate and
lift it clear of the system unit.
Notes
1. If there is an adapter card fitted in slot 3 you
may find the removal of the mounting plate
easier if you first remove the adapter card.
2. If a tape drive is fitted it must be removed with
the mounting plate. See the instructions on
page 17.

12
5. Identify the 80487SX socket.
80487SX SOCKET
80486SX
From the illustration above, you will be able to identify the
80487SX socket. If the socket is unoccupied, and an
80486SX is soldered to the CPU module as shown, you
can install the 80487SX as described in
Installing the
80487SX
.
If the socket is occupied by an 80486SX before you install
the 80487SX you will have to remove the 80486SX, using
a suitable extraction tool, and reconfigure the socket.

13
Configuring the 80487SX socket
If the 80486SX is soldered directly to the CPU module the
socket will already be configured for an 80487SX.
If an 80486SX is installed in the socket it must be removed
and the socket reconfigured, before the 80487SX can be
installed. The socket is configured by a four pin jumper
block and two position switch alongside the socket.
SYSTEM
BOARD
JUMPER
SWITCH

14
If the socket is configured for an 80487SX two jumpers will
be fitted and the switch will be away from the socket, as
shown in the following illustration.
SYSTEM
BOARD
If the jumpers and switch are not as shown above,
reconfigure the socket by moving the jumpers and switch
to the correct positions.
Note
If the socket is configured for an 80486SX a second
jumper should be fitted to one of the unused posts on the
jumper block. This allows the socket to be reconfigured for
an 80487SX.

15
80486SX configuration
If the socket is configured for an 80486SX one jumper will
be fitted and the switch may be in either position. The
switch will normally be away from the socket, as shown in
the following illustration.
SYSTEM
BOARD
Note
A second jumper should be fitted to one of the unused
posts on the jumper block. This allows the socket to be
reconfigured for an 80487SX.

16
Installing the 80487SX
With the co-processor socket empty and correctly
configured you can install the 80487SX as follows:
1. Identify the 80487SX socket.
SYSTEM
BOARD
PIN 1
2. The 80487SX has a positioning guide in the form
of a small dot of paint. Carefully position the
80487SX above the socket with the positioning
guide at pin 1.
3. Gently insert the 80487SX making sure that it is
correctly aligned with the socket and that you do
not bend or otherwise damage the pins.
4. Reassemble the computer.
5. Reboot the computer with the Reference/SETUP
diskette and reconfigure it for the co-processor.
Warning
Always ensure that the system unit is fully
reassembled before powering it up.

17
Removing a tape drive
If your computer has a tape drive fitted this must be
removed to allow access to the CPU module. To remove
the drive follow the procedure below.
1. Remove the four screws that secure the drive
cover, drive and earth tag.
ADAPTER POWER
CABLE TAPE DRIVE
TAPE DRIVE
COVER
SIGNAL CABLE
2. Lift the drive cover clear.
3. Lift the drive far enough to allow access to the
power and signal cables at the rear of the drive and
disconnect them.
4. Lift the drive clear.
5. Once the 80487SX has been installed the drive
may be replaced by reversing the removal
procedure.
Note
Ensure that the earth tag is secured by the screw at
the left rear of the drive.

18
CPU module upgrades
If your computer is fitted with an 80486SX CPU module it
can be upgraded by fitting an 80486 CPU module.
depnding the the processor clock speed it may also be
possible to upgrade an 80486DX based system to a faster
processor.
Contact your Apricot supplier for information about the
availability of such modules.