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ERNIE Mark I was the first large-scale use by the Post Office of transistors, rectangular-hysteresis-loop ferrites and printed circuit board techniques. |
ERNIE is fitted onto five double-sided Post Office telephones racks which are bolted together and mounted on a plinth. Prior to 1960, Post Office equipment racks were painted 'battleship grey'. The racks were once enclosed by 12 removable doors with identical locks.
"ERNIE is controlled by an officer of the Savings Department seated at a control desk or console. Although the machine is switched on some time before the commencement of a draw, the draw is started by the operation of a key on the console, whereupon printing of potential winning numbers commences. At the same time a draw-serial-number generator is started. Each printed message consists of the bond number followed by a draw serial number to enable the prize winning numbers to be arranged in order of drawing for subsequent allotting of appropriate prizes. These messages are printed as a master copy on teleprinters on the console as well as on appropriate pairs of teleprinters distributed among the files."
Layouts
In the exhibit, ERNIE is somewhat 'unplugged' with spare connector blocks hanging loose. Some of these may have been redundant wiring as the design of the kit was modified over the many years of operation. The ERNIE racks (shown) were part of a much larger set up which included power feeds, alarm equipment, a Main Distribution Frame (MDF), remote teleprinters as well as the (missing) control desk and console (dais).
External connections:
80 wire cable (tape feed) from ERNIE to MDF in Maintenance Room
80 wire cable (teleprinter signalling) from ERNIE to MDF in Maintenance Room
100 wire cable from Console to MDF
100 wire cable from Console to MDF
Additional wiring between Console and ERNIE
Additional wiring between Console and Power Room
Additional wiring between ERNIE and Power Room
The MDF carried connections out to Teleprinter Signalling, Control Signalling and Tape Feed, and Alarm Bells
ERNIE 1: Front racking layout
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Racks are lettered left to right, A B C D and E. |
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Descriptions subject to further research |
| Rack B Front | |
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Descriptions subject to further research |
| Rack C Front | |
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Descriptions subject to further research |
| Rack D Front | |
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Descriptions subject to further research |
| Rack E Front | |
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Descriptions subject to further research |
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Racks are lettered left to right, A B C D and E. |
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Descriptions subject to further research |
| Rack B Rear | |
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Descriptions subject to further research |
| Rack C Rear | |
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Descriptions subject to further research |
| Rack D Rear | |
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Descriptions subject to further research |
| Rack E Rear | |
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Descriptions subject to further research |
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It is essential that there should be no break in the a.c. supply to the electronic equipment and emergency lighting nor in the d.c. supply to the telegraph equipment whilst a draw is in progress. The power plant consists essentially of a battery with its centre point earthed, which supplies 80 + 80 V d.c. to the telegraph equipment and feeds two motor-alternators in parallel. The motor-alternators provide 240 V 50 c/s supply to the electronic equipment and emergency lighting. |
"A teleprinter 7B fits into a locked drawer at each pedestal of the console such that it can be readily removed for maintenance (see Plate 6) while leaving the upper surface of the console flush except for a sunken well in a hinged cover over the teleprinter which enables the printing on the paper to be seen by the controller seated at the console. The hinged cover can be raised to enable paper changing to be carried out."
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The numbers generated by ERNIE 1 were printed on a pair of teleprinters No.7B. One was set up for page printing, the other a tape machine. Several sets of teleprinters were distributed among the files of photocopied bonds. |
PO Research Reports:
14093 ERNIE
14214 D.C. Power Supply Units for use with ERNIE
14218 ERNIE - Console Equipment
14219 ERNIE - Design of Cyclic Tester
14220 ERNIE - Noise Generator Output Tester
14221 ERNIE - Design of Redundancy Table
12864 Design of an artificial traffic machine (Part 2)
14108 ERNIE - Mathematical theory
Diagrams:
EX 29960 to EX 29999
EX 44745 Noise Generator Assembly
EX 60088 Random Number Generator Rack Wiring
EX 60123 to EX 60132
EX 60297
EX 60436/7
Acknowledgements
Disclaimer: These pages are an unofficial review of ERNIE and Premium Bonds. Photos copyright Light Straw Archives, as marked. Other photos and images used with kind permission of National Savings and Investments (NS & I). With thanks to the Science Museum, NS & I, and BT Heritage.
If you have a query about money or bonds held in National Savings, please visit the National Savings and Investments site.
All logos and trade marks are the property of their respective owners and are used on the Light Straw site(s) for review only. Students and researchers are recommended to make their own independent enquiries as to the accuracy of the information contained therein.