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Expansion
Subsystem
Chapter 4 - Hardware Configuration
Expansion Subsystem Interface Board (A3480)
Host Computer Interface Board (A3470)
DMA Setting
I/O Address Settings
Early "Wait" Signal
This interface board (Figure 4-1) is installed in the Cubix Expansion Subsystem.
This interface board (Figure 4-2) is installed in the host computer.
The Cubix Expansion Subsystem provides support for the 8-bit DMA channels 0, 1, and 3. No special configuration is required to support these channels. In addition, the subsystem may optionally support one 16-bit DMA channel 5, 6, or 7. Channels 2 and 4 are not supported.
If one or more boards installed in the Expansion Subsystem requires 16-bit DMA transfers, the interface board must be configured to support the DMA channel required. Only one 16-bit DMA channel may be selected per Expansion Subsystem.
To configure a DMA channel, select the same channel on both the host interface board and the corresponding Expansion Subsystem interface board. If installing multiple Expansion Subsystems in a single host system, each subsystem may be configured with a unique DMA channel. However, the DMA channel selected for an Expansion Subsystem must match the DMA channel selected on the host interface board connected to it.
DMA channels 5, 6, and 7 are supported. Select the desired channel using switch SW1 on both the host and the subsystem interface boards.
Table 4 - 1
DMA Switch Setting
Channel Switch SW1 Setting
Select
8 7 6 5 4 3 2 1
DMA 5 OFF OFF OFF ON OFF OFF OFF ON
DMA 6 OFF OFF ON OFF OFF OFF ON OFF
DMA 7 OFF ON OFF OFF OFF ON OFF OFF
None* OFF OFF OFF OFF OFF OFF OFF OFF
*Factory default
! The Cubix QL Series processors do not require a 16-bit DMA channel.
Each Cubix Expansion Subsystem must have a unique I/O address. There are three ranges of eight I/O addresses available to allow the installation of up to eight Expansion Subsystems in one host computer. If multiple subsystems are installed, each subsystem must be configured with a unique address. It is recommended (though not required) that these addresses be consecutive. Configure the address using switch SW2.
Table 4 - 2
I/O Address Range 140 - 147 Hexadecimal
Subsystem I/O Switch SW2 Setting
Number Address
7 6 5 4 3 2 1
1 140* ON OFF ON OFF ON ON ON
2 141 ON OFF ON OFF ON ON OFF
3 142 ON OFF ON OFF ON OFF ON
4 143 ON OFF ON OFF ON OFF OFF
5 144 ON OFF ON OFF OFF ON ON
6 145 ON OFF ON OFF OFF ON OFF
7 146 ON OFF ON OFF OFF OFF ON
8 147 ON OFF ON OFF OFF OFF OFF
* Factory default
Table 4 - 3
I/O Address Range 240 - 247 Hexadecimal
Subsystem I/O Switch SW2 Setting
Number Address
7 6 5 4 3 2 1
1 240 OFF ON ON OFF ON ON ON
2 241 OFF ON ON OFF ON ON OFF
3 242 OFF ON ON OFF ON OFF ON
4 243 OFF ON ON OFF ON OFF OFF
5 244 OFF ON ON OFF OFF ON ON
6 245 OFF ON ON OFF OFF ON OFF
7 246 OFF ON ON OFF OFF OFF ON
8 247 OFF ON ON OFF OFF OFF OFF
Table 4 - 4
I/O Address Range 380 - 387 Hexadecimal
Subsystem I/O Switch SW2 Setting
Number Address
7 6 5 4 3 2 1
1 380 OFF OFF OFF ON ON ON ON
2 381 OFF OFF OFF ON ON ON OFF
3 382 OFF OFF OFF ON ON OFF ON
4 383 OFF OFF OFF ON ON OFF OFF
5 384 OFF OFF OFF ON OFF ON ON
6 385 OFF OFF OFF ON OFF ON OFF
7 386 OFF OFF OFF ON OFF OFF ON
8 387 OFF OFF OFF ON OFF OFF OFF
The "RDY" signal can be configured to go false when I/O addresses used by Cubix QL Series processors are accessed. When enabled, the host "RDY" signal is dropped approximately 75 - 80ns, allowing the QL Series processor to assert a wait state if necessary. This helps accommodate host computers which sample "RDY" quickly.
If Cubix QL Series processors are to be installed in the Expansion Subsystem, set this option to ENABLED using position 8 of switch SW2.
Table 4 - 5
Early "Wait" Signal
Early "Wait" Switch SW2 Position 8
Enabled ON
Disabled OFF
This document, and all Web contents, Copyright © 1997
by Cubix Corp., Carson City, NV, USA.