Difference: RaspiElf (17 vs. 18)

Revision 182017-12-18 - PeterSchmid

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title="Raspberry Pi Interface to Cosmac Elf" titlestyle="color:#F00000;" }%

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Intro

The Unix philosophy

emphasizes building simple, short, clear, modular, and extensible code that can be easily maintained and repurposed by developers other than its creators. The Unix philosophy favors composability as opposed to monolithic design.

This is a good opportunity to merge old SBC technology (COSMAC Elf) with a new one (Raspberry Pi and GNU/Linux). If you are new to GNU/Linux get involved! I always admire the UNIX philosophy, I hope this project fulfill the UNIX concept.

Contents

elf2bin (download tool)

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bin2elf (upload tool)

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bin2elf (upload tool)

NAME: bin2belf - Copies the content of binary file on the Raspberry Pi to Elf (Membership Card) memory .

SYNOPSIS: bin2elf [-s hexadr] [-e hexadr] [-w] [-r] [file]

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elf (command line tool)

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elf (command line tool)

NAME: elf - Controls the mode, sets data switches and gets LED data of an Elf (Membership Card).

SYNOPSIS: elf [-s hexadr] [-i] [-n] [-v] [load|run|wait|reset|read|get|put] [switch]

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Wiring

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The Raspberry Pi ARM processor supply voltage is 3.3 V and the GPIOs are not 5 V tolerant. The Elf supply voltage is 5 V. This means that the GPIOs (input) has to be protected from Elf. The easiest way is to use diodes e.g. 1N4148 to protect the GPIOs from the 5 V, but the GPIOS need then a pullup resistors. Thankfully the Raspi GPIOs have internal pullup and can be controlled by software. The cathode has to be on the Elf side.

It is possible that the Elf works with 3.3 V supply voltage, but this is not within the specifications. In this case the diodes are not needed. Connect the Raspi Pin 1 to P4 Pin 3 (do NOT connect Raspi Pin 2!).

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Peter Schmid - 2017-11-26

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Comments

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Comments

META FILEATTACHMENT	attachment="gpio-numbers-pi2.png" attr="" comment="" date="1511721965" name="gpio-numbers-pi2.png" path="gpio-numbers-pi2.png" size="54469" user="PeterSchmid" version="1"

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META FILEATTACHMENT	attachment="harness.jpg" attr="" comment="" date="1513619169" name="harness.jpg" path="harness.jpg" size="282878" user="PeterSchmid" version="1"
META FILEATTACHMENT	attachment="raspi-elfmemcard.jpg" attr="" comment="" date="1513620002" name="raspi-elfmemcard.jpg" path="raspi-elfmemcard.jpg" size="406259" user="PeterSchmid" version="1"

META TOPICMOVED	by="PeterSchmid" date="1512077728" from="Cosmac.RaspberryElf" to="Cosmac.RaspiElf"

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