EXT-1
ISA Bus Extender Card
User Manual
EXT-1
User Manual
Document Part N° 127-177 Document Reference EXT-1\..\127-177.Doc Document Issue Level 1.2
Manual covers PCBs identified EXT-1 Rev A
All rights reserved. No part of this publication may be reproduced, stored in any retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopied, recorded or otherwise, without the prior permission, in writing, from the publisher. For permission in the UK contact Blue Chip Technology.
Information offered in this manual is correct at the time of printing. Blue Chip Technology accepts no responsibility for any inaccuracies. This information is subject to change without notice.
All trademarks and registered names acknowledged.
Blue Chip Technology Ltd. Chowley Oak, Tattenhall Chester, Cheshire CH3 9EX. Telephone : 01829 772000 Facsimile : 01829 772001. Amendment History
Issue Issue Author Amendment Details Level Date 1.0 15/5/89 JSD Document Reference was EXT1013 1.1 21/1/96 EGW First approved issue, new front sheet. Addition of EMC information to Technical Section. 1.2 30/6/97 SEJ Window front cover and logo. See ECN97/087. Contents
OUTLINE DESCRIPTION...... 1
TECHNICAL SPECIFICATION ...... 2 Electrical ...... 2 Physical...... 2
ELECTROMAGNETIC COMPATIBILITY (EMC) ...... 3
ELECTRICAL OPTIONS...... 4 Signal Isolation ...... 4 Test Points...... 4
APPLICATION NOTES...... 5 Bus Characteristics...... 5 Current Capacity...... 5
Blue Chip Technology Ltd. 127-177.doc
Outline Description Page 1
OUTLINE DESCRIPTION
The board is an extender unit which allows the PC bus to be extended above the height of the PC housing to facilitate servicing and development of other boards.
The board is suitable for both AT and XT (16 and 8-bit) buses.
Blue Chip Technology Ltd. 127-177.doc Page 1 Page 2 Technical Specification
TECHNICAL SPECIFICATION
Electrical
Maximum current per track 1 Amp Typical capacitance 50pF
Physical
Board:
Height 217 mm Depth 172 mm Width 14 mm
Overall:
Height 236 mm Depth 187 mm Width 25mm
Page 2 127-177.doc Blue Chip Technology Ltd. Electromagnetic Compatibility (EMC) Page 3
ELECTROMAGNETIC COMPATIBILITY (EMC)
The extender card is a service tool only for personal computers. It is benign, and has no function other than to allow a card to sit outside of the PC to facilitate service or development work.
As such it is excluded from the scope of the EMC Directive and is not required to be CE marked.
Blue Chip Technology Ltd. 127-177.doc Page 3 Page 4 Electrical Options
ELECTRICAL OPTIONS
Signal Isolation
Each of the bus signals may be isolated from the unit under test (UUT) by cutting the track between the two pads on the rear of the board. The pads are provided to accept dual row pin strip headers (on a 0.1 inch pitch). If the tracks between these pads are cut and pin headers fitted, the bus signals may be re-connected by fitting shorting links.
Optionally, the headers may be used as convenient test points.
Test Points
Two test points are provided on the board which are connected to Ground and +5V. These are useful for providing power to a logic probe and a ground connection for an oscilloscope lead, etc.
Page 4 127-177.doc Blue Chip Technology Ltd. Application Notes Page 5
APPLICATION NOTES
Bus Characteristics
When a card is connected to the PC bus using a card extender the bus timing is altered slightly due to the additional length of signal path and capacitance. This effect is notorious in that a board which works in a slot may not work when fitted on an extender. Conversely a board which works on an extender may not work when fitted directly into the bus slot.
However, boards and computers which both follow the bus specifications perfectly should always work together either with or without an extender.
Current Capacity
The printed circuit tracks on this board are relatively small in places and a massive fault on the UUT can cause the tracks to be damaged. The maximum currently rating must be observed to avoid damages.
Blue Chip Technology Ltd. 127-177.doc Page 5