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Wait state jumper – Measurement Computing CIO-DAC02 User Manual

Page 10

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CIO-DAC02 User's Guide

Installing the CIO-DAC02

10

In the default configuration shown in Figure 2, addresses 9 and 8 are DOWN, and all others are UP.
Address 9 = 200 hex (512 decimal) and address 8 = 100 hex (256 decimal); when added together they equal
300 hex (768 decimal).

Disregard the numbers printed on the switch

When setting the base address, refer to the numbers printed in white on the printed circuit board.

PC I/O addresses

Hex Range

Function

Hex Range

Function

000-00F

8237 DMA #1

2C0-2CF

EGA

020-021

8259 PIC#1

2D0-2DF

EGA

040-043

8253 Timer

2E0-2E7

GPIB (AT)

060-063

8255 PPI (XT)

2E8-2EF

Serial Port

060-064

8742 Controller (AT)

2F8-2FF

Serial Port

070-071

CMOS RAM & NMI mask (AT)

300-30F

Prototype card

080-08F

DMA page registers

310-31F

Prototype card

0A0-0A1

8259 PIC #2 (AT)

320-32F

Hard disk (XT)

0A0-0AF

NMI mask (XT)

378-37F

Parallel printer

0C0-0DF

8237 #2 (AT)

380-38F

SDLC

0F0-0FF

80287 numeric CO-P (AT)

3A0-3AF

SDLC

1F0-1FF

Hard disk (AT)

3B0-3BB

MDA

200-20F

Game control

3BC-3BB

Parallel printer

210-21F

Expansion unit (XT)

3C0-3CF

EGA

238-23B

Bus mouse

3D0-3DF

CGA

23C-23F

ALT bus mouse

3E8-3EF

Serial port

270-27F

Parallel printer

3F0-3F7

Floppy disk

2B0-2BF

EGA

3F8-3FF

Serial port

The CIO-DAC02 Base switch can be set for an address in the range of 000-3E0, so it should not be hard to find
a free address area for your CIO-DAC02. If you are not using IBM prototyping cards, or some other board
which occupies these addresses, then 300-31F HEX are free to use. Addresses not specifically listed, such as
390-39F, are free.

Wait state jumper

The CIO-DAC02 board has a wait state jumper which you can set to enable an on-board wait state generator. A
wait state is an extra delay injected into the processor's clock via the bus. This delay slows down the processor
when the processor addresses the CIO-DAC02 board so that signals from slow devices (chips) will be valid.

This jumper is shown in Figure 3 configured for OFF (wait state is disabled).

O
N

O
F
F

Figure 3. Wait State jumper

The wait state generator on the CIO-DAC02 is only active when the CIO-DAC02 is being accessed. Your PC
will not be slowed down in general by using the wait state.