45 votes

Why did the IBM 650 use bi-quinary?

I will just explain what a bit is. It's a binary digit. 0 is numerically zero, 1 is numerically one. If you want to add 1 and 1, in binary it overflows. the result is 0, and a carry out. As you ...
Omar and Lorraine's user avatar
30 votes
Accepted

Why did the IBM 650 use bi-quinary?

Quibbling about the right meaning of "bit" aside, some advantages of the 2-of-7 biquinary representation are: Simpler circuits. In a quinary adder circuit, the output of each of the 5 output lines ...
hmakholm left over Monica's user avatar
18 votes

How does a biquinary adder work?

From a modern chip design perspective, the design of bi-quinary adders is quite simple. The addend inputs are each composed of two 1-hot signals, and the sum output is two 1-hot signals as well. ...
JdeBP's user avatar
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14 votes
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Were any decimal-based computers capable of handling text?

Really early computers like the Mark I and ENIAC didn't have enough memory to attempt to handle text; also the use-case was mostly calculations. A number of decimal IBM computers used characters (with ...
dirkt's user avatar
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5 votes

Why did the IBM 650 use bi-quinary?

Storing a one-of-two selection using vacuum tube technology doesn't require one valve (combination of an anode, cathode, and one or more grids); it requires two. Thus, holding four bits would require ...
supercat's user avatar
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5 votes

Why did the IBM 650 use bi-quinary?

This isn't intended as an answer per se, but I want to provide some support for OmarL's explanation by quoting official documentation for the machine, which speaks of binary values as units of ...
texdr.aft's user avatar
  • 3,495
1 vote

Were any decimal-based computers capable of handling text?

Singer made a series of retail systems which were taken over by ICL and rebranded. The ICL System 10 used 6-bit bytes for decimal and character data. The ICL System 25 used 8-bit bytes, which were ...
Paul_Pedant's user avatar

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