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7D14: Difference between revisions
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The counter outputs are multiplexed onto a common 4-bit bus using open-collector NAND gates under control of the mainframe's [[7000 series readout system|readout system]]. The multiplexed digit value feeds a D/A converter (Tek [[155-0038-01]]) that in turn drives the analog row and column returns to the readout system. A separate blanking logic eliminates leading zeroes and displays a ">" sign in the leftmost column if the counter overflows. | The counter outputs are multiplexed onto a common 4-bit bus using open-collector NAND gates under control of the mainframe's [[7000 series readout system|readout system]]. The multiplexed digit value feeds a D/A converter (Tek [[155-0038-01]]) that in turn drives the analog row and column returns to the readout system. A separate blanking logic eliminates leading zeroes and displays a ">" sign in the leftmost column if the counter overflows. | ||
In early 7D14 units (board 388-1825-00), U329 was a Tek made IC, [[155-0046-00]], | |||
which was not used in other instruments. | |||
From SN B050000 on, an MC12090P was used on a redesigned circuit board (670-0993-01). | |||
==Links== | ==Links== | ||