What was a Terminal Concentration Device in DEC's products?

Noel Chiappa jnc at mercury.lcs.mit.edu
Sat Jan 29 14:58:53 CST 2022


    > From: Paul Koning

    > DH-11 is unusual in that it has DMA in both directions

McNamara's DH11? (I don't know of another DECdevice of that name.) Per:

  http://www.bitsavers.org/pdf/dec/unibus/EK-ODH11-OP-002_DH11_Asynchronous_16-line_Multiplexer_Users_Manual_Sep76.pdf

it's DMA on output only; the input side has a FIFO that has to be emptied by the CPU.

	Noel

PS: I am familiar with the term 'terminal concentrator' from the networking
world, but as a generic term, not the name of a particular product. (Although
Cisco's first boxes may have included a terminal concentrator, so named.)

	Noel



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