[Simh] A terminology question

[Shoppa, Tim]

Rather than "convolution", maybe "parity", "check", "hash", or "fingerprint"? Like "command parity" and"number parity" plus two "invalid parities"?

Many buses have multiple parity bits already (e.g. "address parity" and "instruction parity" or "upper parity" and "lower parity").

Tim.

Sent from my PDP-8/E
________________________________
From: Leo Broukhis<mailto:leob at mailcom.com>
Sent: ‎2/‎9/‎2015 3:33 PM
To: simh at trailing-edge.com<mailto:simh at trailing-edge.com>
Subject: [Simh] A terminology question

Dear colleagues,

There is an implementation detail in the BESM-6 architecture the name of which we've struggled to translate adequately.  There is a feature preventing execution of arbitrary data as instructions implemented using two parity bits per word, for the upper and the lower half-word. The overall parity must be odd, and one of the valid parity bit configurations denotes an instruction, and the other denotes data. In the original documentation this mechanism was called https://translate.google.com/#ru/en/%D1%81%D0%B2%D0%B5%D1%80%D1%82%D0%BA%D0%B0 (the two forms were called literally "command convolution" and "number convolution").

Unlike a tagged architecture, there isn't a fixed tag value to indicate instructions or data.

Is there a standard term for this? "Convolution" sounds too mathematical.

Thanks,
Leo

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