Re: Footnote RE: Legacy Terminology RE: DMA across PCI

[Kevin Normoyle <Kevin.Normoyle@Eng.Sun.COM>]

Just to show how old DMA concepts are:

I suspect there may be earlier references, but this
patent, from work in 1969, seems to capture
the flavor of what's commonly talked about as DMA, with
respect to I/O systems. (he references the phrase "direct memory 
access" between computer memories in his description, so there 
may have been some other uses at the time. )
 
Note the mention of most of the important issues related to what
we now refer to as DMA.
 
US3673576: PROGRAMMABLE COMPUTER-PERIPHERAL INTERFACE
Inventor(s):   Donaldson, Jr.; John C. , Peabody, MA
Applicant(s):   E.G. & G., Inc., Bedford, MA
Issued/Filed   June 27, 1972 / July 13, 1970
 
Abstract:   
An interfacing network for providing asynchronous data transfers directly
with a computer memory and external devices. Computer instructions from the
computer arithmetic unit are decoded in an executive control unit. Certain
instructions ready an input or output channel control unit which thereafter
controls data transfers with a selected external device. 
 
Each transfer is made directly with the computer memory and does not 
require interruption of the program being processed in the arithmetic unit. 
Once the input or output channel control unit assumes control of the transfer, 
the executive control unit is immediately available to perform other functions 
independently and concurrently. 
 
It may ready the other channel control unit and monitor external device and 
interface conditions including the readiness of an external device to transmit 
data. Certain monitored conditions cause the interfacing network to interrupt 
normalcomputer operation. 
 
Various control signals in the executive control unit are translated to and 
from control signals in the computer and external devices to permit the 
utilization of common instructions.