Unterschiede
Hier werden die Unterschiede zwischen zwei Versionen gezeigt.
| Beide Seiten der vorigen Revision Vorhergehende Überarbeitung Nächste Überarbeitung | Vorhergehende Überarbeitung | ||
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analyticalengine:retaingreadcell [2015-11-18 21:45] rainer Images added |
analyticalengine:retaingreadcell [2015-11-29 09:55] (aktuell) rainer [Memory Cell with Reataining Readout] Picture added |
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| Zeile 1: | Zeile 1: | ||
| ====== Memory Cell with Reataining Readout ====== | ====== Memory Cell with Reataining Readout ====== | ||
| + | |||
| + | {{ :analyticalengine:merac-model_151129.jpg?direct&300|}} | ||
| Babbage's memory cell in the storage used a reduction-to-zero technique, so it was necessary to restore the values for a retaining read. | Babbage's memory cell in the storage used a reduction-to-zero technique, so it was necessary to restore the values for a retaining read. | ||
| Zeile 6: | Zeile 8: | ||
| From the ENIAC, that used the electronic equvalent of a rotating wheel, i.e. a shift register, I learned that rotating forward one whole rotation | From the ENIAC, that used the electronic equvalent of a rotating wheel, i.e. a shift register, I learned that rotating forward one whole rotation | ||
| allows a non-destructive readout. | allows a non-destructive readout. | ||
| - | So I tried to apply this to the Babbage's basic design, and here is the -- prelimiary -- result: | + | So I tried to apply this to the Babbage's basic design, and here is the -- prelimiary -- result. |
| + | |||
| + | Note that the erasing readout is necessary too, or any other means to zero a storage cell, as writing adds digitwise, so the receiving cell must be zeroed, | ||
| + | see my paper on [[lovelace_noteg_paper]]. | ||
| + | |||
| + | The picture shows a working physical model of two cells: | ||
| ===== Arrangement ===== | ===== Arrangement ===== | ||
| Zeile 15: | Zeile 22: | ||
| * the drive axis (back) | * the drive axis (back) | ||
| - | {{ :analyticalengine:merac-3d-neutral.png?488| Fig.1}} | + | ==== Neutral Position ==== |
| + | |||
| + | {{merac-3d-neutral.png?488 | Fig.1}} | ||
| Both are horizontally arranged and go from the mill | Both are horizontally arranged and go from the mill | ||
| Zeile 44: | Zeile 53: | ||
| The shift is common to all digits of a memory cell. | The shift is common to all digits of a memory cell. | ||
| - | {{ :analyticalengine:merac-3d-add.png?488| Fig. 2}} | + | ==== Add Position ==== |
| + | |||
| + | {{merac-3d-add.png?488 | Fig. 2}} | ||
| In the add position, a pin is engaged with the add gear, | In the add position, a pin is engaged with the add gear, | ||
| Zeile 53: | Zeile 64: | ||
| it to the current digit position even if the digit axis rotates. | it to the current digit position even if the digit axis rotates. | ||
| - | {{ :analyticalengine:merac-3d-send.png?488|}} | + | ==== Send Position ==== |
| + | |||
| + | {{merac-3d-send.png?488 |}} | ||
| In the send position, a pin is engaged with the read cam, | In the send position, a pin is engaged with the read cam, | ||
| Zeile 101: | Zeile 114: | ||
| while inverting their rotation. | while inverting their rotation. | ||
| + | ===== Negative Numbers ===== | ||
| + | |||
| + | By inverting the direction of the driving shaft, the complement of the number will be sent out in reverse direction, | ||
| + | resulting in a subtraction, if the carry mechanism is capable to do so. | ||
| + | And an extras turn is necessary (details to follow) | ||
