Apricot Diamond Motherboard

Cache SIMM Socket

If your computer came without any cache fitted you can install a 256Kb module of either of the following types:-

256KB Async Cache Module
256KB 55MHz Pipelined Sync

If you have a 75MHz motherboard it will not have a cache SIMM, due to the performance benefits of EDO RAM. If you upgrade the processor at a later date you may require a cache upgrade to improve performance further.

Video RAM

If your machine came with 1MB video RAM then it can be upgraded as follows (depending on your Video Card) -

GD5434 1MB to 2MB Video RAM Upgrade
GD5436 1MB to 2MB Video RAM Upgrade

If your machine came with 2MB already installed then it cannot be upgraded further.

RAM Configuration

The SIMM sockets are located at the front of the motherboard. Each pair of sockets can be fitted with SIMMs. SIMMs with capacities of 2, 4, 8, 16 or 32 Mbytes are supported, giving a maximum capacity of 128 Mbytes.

Socket Location

SIMMs must be fitted in pairs and the pair must be identical. The system does not require Parity checking (36-bit) SIMMs. Conventional 32-bit SIMMs with a refresh rate of 70ns is the specification. The newer Extended Data Output (EDO) type SIMMs are supported and will give enhanced performance.

Note: MS530 has only Banks 0 & 1 available for memory expansion.

Processor Upgrade

These are is the processor upgrades for MS530's and MS540's with the model number prefixes MK or MT.To use the tables below, select the processor you wish to upgrade to and confirm that the upgrade is possible. Then check additional requirements such as BIOS upgrades & processor speed jumper settings.

BIOS Upgrade

For MK (MS530) and MT (MS540) model machines, the latest version of the BIOS is 5.09.

BIOS Installation Instructions

Once the BIOS update file has been downloaded & saved in your C:\WINDOWS\TEMP folder:

Click on START
Click on RUN
Type in c:\windows\temp\D509COMB.EXE
Press RETURN, then click on UNZIP (this will create three files in your C:\WINDOWS\TEMP folder).
Place a blank formatted disk into the floppy drive A:
Click on START
Click on RUN
Type C:\WINDOWS\TEMP\IMAGE 509BIOS.IMG A: /M /B
When the boot disk has been created, restart the computer and boot from the diskette. From the menu press 1 to detect the type of video controller, and then press 2 or 3 to upgrade the BIOS for your type of video controller.

Jumper Settings

Internal speaker operation

Next to outer SIMM socket, default position link pins 4 and 5 gives audio output to the internal speaker in mono. Only to be removed in a system having internal stereo speakers.

Internal 'audio' modem

Just along from the CD audio connection, default position if no internal modem is fitted, link pins 3 and 4. Remove only when fitting an internal modem supporting sound.

BIOS reprogramme

These links are for special purposes. Only to be used for an official upgrade to the system BIOS. DO NOT move for any other reason.

Floppy disk control mode

Next to floppy disk ribbon connector, default position link pins 3 and 4.

PL13	2 mode =
	3 mode =

Clear BIOS settings

Next to outer video upgrade socket, default position linkpins 1 and 2.Moving the link to pins 2 and 3 disconnects the battery from the BIOS memory, and will cause all the user settings to be lost. To be used with caution and only in the event of an access password being lost.

Video / VESA option

A single jumper may be the only one fitted, at the end nearest PL21.Only needs to be removed if fitting a new high feature 'plug-in' video card and serious problems are encountered. If taken out, it must be replaced if the extra video card is subsequently removed.

Sound Blaster Address

PL24, PL28

This range of pins is not exactly for jumpers, but is used to connect various features around the system case to the motherboard.

Rear Panel

Expansion Slots

Clear BIOS Settings / CMOS Discharge

To clear the BIOS. you need to move jumper PL21, which is situated next to outer video upgrade socket.By default the jumper should be set to 1-2.

Moving the link to pins 2 and 3 disconnects the battery from the BIOS memory, and will cause all the user settings to be lost. To be used with caution and only in the event of an access password being lost.

BIOS Screens

When this appears in the top right of the screen press the F1 on the keyboard and in a few seconds you will be presented with the BIOS setup screen see below)

Interrupts, Memory & I/O Ports

Interrupts (IRQ)

I/O Ports

Direct memory access (DMA) channel

Error Codes