Installing the Smart 16/4 AT Ringnode

TechNote

Number: 00101-2
Date: November 1994

Installing the Smart 16/4 AT Ringnode

1 The Madge Smart 16/4 AT Ringnode

Compatible computers

Any 16- or 32-bit computer which is compatible with the 16-bit ISA specification
8-bit computers which are compatible with the 8-bit ISA specification. The Smart 16/4 AT Ringnode cannot be configured as a bus master when installed in 8-bit expansion slots.
EISA computers. The installation procedure for EISA computers is detailed in TechNote 00102.

Default configuration options

Default settings have been chosen to suit a large proportion of installations. These are:

Configuration item	                                 Controlled by

Interrupt level 3 (IRQ 3)                                Switch 1
I/O address 0A20 - 0A2F                                  Switches 2/1 and 2/2
ROM address CC000 - CDFFF                                Switches 2/1 and 2/2
ROM socket disabled                                      Switch 2/3
Bus master DMA enabled                                   Switch 2/4
Automatic selection between 8- and 16-bit modes enabled  Switch 2/5		
Bus timing method 100% compatible with the AT bus        Switch 2/6		
Clock source asynchronous with the bus                   Switch 2/7		
4Mbit/s network speed                                    Switch 2/8
DMA channel 5                                            Switch 3
Shielded twisted pair cabling                            Link block 1

Carefully check the requirements of your installation against the above list. If any of the settings need to be changed, refer to Section 3 of this document.

2 Installing the Smart 16/4 AT Ringnode in your computer

Handling precautions

Do not remove the Ringnode from its protective antistatic packaging until you are ready to use it.
Discharge the static electricity from your body by touching a protective grounding device or the metal chassis of your computer before handling the Ringnode.
In dry climates or other environments where static electricity is prevalent, wear a grounding strap on your wrist before handling the Ringnode or removing the cover of your computer.
Always handle the Ringnode carefully by its edges and avoid touching any of the components or connections.
Take particular care when installing an optional ROM module into your Ringnode. Use a purpose-designed chip-inserting tool.

Installing the Ringnode

Always turn off the power to your computer before installing or removing any adapter cards.

Remove the cover of your computer.
Select an empty 8- or 16-bit expansion slot in which to install the Ringnode. Use a 16-bit slot if possible.
Remove the blanking bracket. Keep its screw in a safe place.
Push the Ringnode firmly into its socket. Do not force it in. If it does not slide in easily, it may be misaligned.
Secure the Ringnode in place with the retaining screw.
Replace the cover of your computer.
Connect the Ringnode to a working token ring network consisting of at least one Ringhub (or multi-station access unit), with a data cable to connect it to your computer. Connect the data cable to the appropriate connector (STP or UTP) on your Ringnode.
8 Boot up in the normal way. If your computer automatically enters an application program, exit from it and return to DOS. Run the Ringnode diagnostics (see Chapter 2 of the Madge Smart LAN Support Software Installation Guide, part number 100-050) to verify that your Smart 16/4 AT Ringnode is working correctly.

3 Switch settings

Switch block 1: interrupts

The interrupt level corresponding to each switch position is clearly printed on the board next to switch block 1.

Position      Interrupt

1             IRQ 15      
2             IRQ 12      
3             IRQ 11
4             IRQ 10
5             IRQ 7
6             IRQ 5
7 (default)   IRQ 3
8             IRQ 2/9

Note

If the Smart 16/4 AT Ringnode is to be installed in an 8-bit expansion slot, you must use an interrupt level of 7 or lower.

Select an interrupt level which does not conflict with any other boards or devices installed in your computer. Some application programs (such as the IBM 3270 Emulation Program) may also require a particular interrupt level. Several interrupt levels are commonly used for particular purposes as described below: this may affect your choice of interrupt level for your Ringnode.

Interrupt level 2 (IRQ 2/9)

(Sometimes referred to as interrupt 9: interrupt levels 2 and 9 are equivalent to each other.) Interrupt 2 does not conflict with any standard option boards but some manufacturers' communications adapters use this interrupt.

Interrupt level 3 (IRQ 3)

Interrupt 3 is the default interrupt. If your computer has a second serial port built in, or has an alternative asynchronous adapter, this will use interrupt 3. You may be able to disable this serial port using your computer's configuration utility. If not, do not use interrupt 3 for your Smart 16/4 AT Ringnode. If multiple Ringnodes are installed, only one of them can use the default interrupt level 3. We recommend interrupt 12 or 15 as an alternative. Interrupt 3 is also used by several types of IBM communications adapter and by some other manufacturers' network boards. If your computer has one of the following IBM adapters, you cannot use interrupt 3:

SDLC (Synchronous Data Link Control) adapter
BSC (Binary Synchronous Communications) adapter

Interrupt level 5 (IRQ 5)

Used by an alternative parallel port. If one is installed and it is using interrupts, avoid this setting for your Ringnode.

Interrupt level 7 (IRQ 7)

Used by a primary parallel printer port. If your printer is using interrupts, avoid this setting for your Ringnode.

Interrupt levels 10, 11, 12 and 15 (IRQ 10, 11, 12, 15)

Occasionally, one of these interrupts may be used by a device on your computer's motherboard. For example, some Compaq computers use interrupt 12 for the mouse. If you suspect that you have a problem for this reason, information in your computer's technical reference manual may help you decide on the best interrupt level.

Switch block 2: I/O and memory settings and alternative modes of operation

Some text is printed on the reverse of the board to remind you of the function of each of the eight switches in switch block 2.

Each individual switch is identified by a pair of numbers. The first number indicates the switch block, and the second number identifies the particular switch within the switch block. For example, switch 2/1 means block 2, switch 1.

Switches 2/1 and 2/2: I/O and ROM addresses

Ensure that the I/O locations selected to be used by your Ringnode do not conflict with those being used by any other adapter card installed in your computer.

These switches also control the memory address of the ROM socket (if enabled by switch 2/3). If the ROM is disabled this memory area is not used.

Switch   Switch         I/O           ROM 
2/1      2/2            address       address

ON       ON (default)   0A20 - 0A2F   CC000 - CDFFF
OFF      ON             1A20 - 1A2F   DC000 - DDFFF
ON       OFF            2A20 - 2A2F   CE000 - CFFFF
OFF      OFF            3A20 - 3A2F   DE000 - DFFFF

Switch 2/3: ROM enable/disable

Do not set this switch to ON unless you have an optional ROM installed in your Smart 16/4 AT Ringnode.

Switch 2/3      ROM socket

OFF (default)   disabled
ON              enabled

Switch 2/4: bus master DMA enable/disable

The position of this switch has no effect if the Ringnode is installed in an 8-bit slot or if switch 2/5 is OFF - bus master DMA is not possible in these circumstances.

Switch 2/4     Bus master DMA

ON (default)   enabled
OFF            disabled

Switch 2/5: 8-bit mode

The Smart 16/4 AT Ringnode can be used in either 8- or 16-bit bus slots. If the Ringnode is installed in a 16-bit slot, but an 8-bit transfer method (as is used in an 8-bit slot) is required, set this switch OFF.

Switch 2/5     Mode

ON (default)   8/16-bit mode
OFF            force 8-bit mode

16-bit mode must be selected to use the Ringnode in a Novell NetWare 386 server.

The following table summarises the relationship between switch 2/4, switch 2/5 and the choice of expansion slot:

                        8-bit slot      16-bit slot

Switch 2/4 setting      ON      OFF     ON      OFF
Switch 2/5 ON           c       c       a       b
Switch 2/5 OFF       	c       c       c       c

a = 16-bit bus master DMA
b = 16-bit I/O transfer
c = 8-bit I/O transfer

Switch 2/6: AT bus compatibility

If your computer is 100% AT-compatible, switch 2/6 should be set ON. If the Madge Ringnode diagnostics program fails to locate the Ringnode, it may be because of certain incompatibilities in the bus architecture: try setting switch 2/6 to OFF. For example, the IBM PS/2 model 30-286 requires this switch to be OFF.

Switch 2/6     Bus compatibility

ON (default)   normal AT bus timing
OFF            alternative bus timing

Switch 2/7: clock source

This switch defines whether bus master DMA transfers data into the computer using the Ringnode's clock or the host computer's clock. If the host computer has a clock speed of 10MHz or more, this switch should be set to OFF.

Switch 2/7      Clock source

ON              synchronous bus
OFF (default)   asynchronous bus

Switch 2/8: network speed

If you are connecting the Ringnode to a 4Mbit/s token ring network, set switch 2/8 to ON. If the network operates at 16Mbit/s, set switch 2/8 to OFF. The factory setting is ON.

Switch 2/8     Network speed

 (default)   4Mbit/s network
OFF            16Mbit/s network

It is most important that the Ringnode is set to the correct network speed. The operation of your network could be seriously impaired if you attempt to insert a Ringnode set to the wrong speed into your network.

Switch block 3: DMA channel

The DMA channel number corresponding to each switch position is clearly printed on the board next to switch block 3. This switch has no effect unless switches 2/4 and 2/5 are both ON and the Ringnode is installed in a 16-bit expansion slot.

Position      DMA Channel

1             1
2             3
3 (default)   5
4             6

Link block 1: cabling media

The Smart 16/4 AT Ringnode is designed to work with either shielded twisted pair (STP) or unshielded twisted pair (UTP) cabling. See the Madge Smart LAN Support Software Installation Guide for important recommendations about the use of UTP cabling.

The end bracket of the Smart 16/4 AT Ringnode has two data connectors: a 9-pin D-type for use with STP cables and a type RJ45 for use with unshielded twisted pair. The Ringnode's circuitry includes a media filter for UTP, which removes the need for an external filter.

Switching between STP and UTP media is performed using link block LB1. This consists of two parts:

a removable header block which has three rows of holes on its underside and is marked
with a bold arrow on its upper face
a base section fixed to the printed-circuit board which has three rows of pins corresponding to the holes in the header.

The words "UTP" and "STP" are printed on the board, above and below the base section.

The header block can be fitted to the base section in two ways:

With the arrow pointing downwards (towards the word "STP"), shielded twisted pair cabling is supported. The 9-pin D-type connector is enabled.
With the arrow pointing upwards (towards the word "UTP"), unshielded twisted pair cabling is supported. The RJ45 connector and on-board media filter are enabled.

Note

It is essential that the header block is fitted so that it covers all of the pins on the base section. If the header block is misaligned, the Ringnode may not work correctly.

Take care not to bend any of the pins when removing or replacing the header block.