Apple IIe Mainboard Question

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clockchip's picture
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Apple IIe Mainboard Question

Hello,

I am new here in the forum and have a question about my recently purchased APPLE IIe.

Switches are soldered to the back of the motherboard via a long cable.

Can anyone explain the purpose of these switches?

Thank you for your help

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speedyG's picture
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This seems to be a incomplete

This seems to be a incomplete attempt with target to switch
adressing between slot 5 and slot 6.
But this seem also to be not completed correct.
Lets first analyze the singanls picked from slot to switch.

wire-color:=slot-signal
white=DevSel-Slot6
violet=IO_Sel-Slot6
orange=IO_Sel-Slot6
btown=DevSel-Slot6
black=IO_Sel-Slot5
grey=DevSel-Slot5
green=IO_Sel-Slot5
yellow=IO_Sel-Slot5

The target seeems to be the ability to change the commands PR#5 and PR#6
and the selection of the Interfacecards inserted in that slots.
BUT:
At the other hand this mod is incomplete. There is no "clearance" between the
"source-signals"(from the chips at mainboard ) and the "target-pins" at slot !
If the switch is in position "reverse / switch" the still remaining intact
traces ( i.e. IO-Sel orange wire and violet wire ) at the mainboard might
cause a shortcut hetween the signals:
orange wire and green wire as well as brown wire and yellow wire.
At the other hand adding additional wire path of wires to the paths at the
mainbaoard is probably also a time critical add to that signals.

Finaly nearly all important chips of clocking are missing in their sockets....
Warning:
Any attemt to power up this mainbgoard at the moment will harm the chips
if they are inserted and trying to test the current mod.

clockchip's picture
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Hi thanks for the info I will

Hi thanks for the info I will revert the motherboard back to its original state before I put the chips back in and try to start a first power on attempt.

speedyG's picture
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probably not a bad idea to

probably not a bad idea to visit this page:
http://www.appleii-box.de/D06b_resurectionIIe.htm
before attempting the resurection....

clockchip's picture
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thank you is thats a good

thank you that is a good hint.

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