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Cyhist Feb 02 1997 A
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Date: Sun, 2 Feb 1997 23:36:44 -0500
Reply-To: dsenzig@execpc.com
Sender: "CYHIST Community Memory: Discussion list on the History of
Cyberspace" <CYHIST@SJUVM.STJOHNS.EDU>
Comments: Authenticated sender is <dsenzig@mail.execpc.com>
From: Don Senzig <dsenzig@mail.execpc.com>
Subject: CM> re: VN computers
______________________________________________________________________
Community Memory: Discussion List on the History of Cyberspace ______________________________________________________________________
On 1 Feb 97 at 23:54, A. Padgett Peterson P.E. Info wrote:
>>The essential difference between von Neumann machines and
>>others, as I understood it, what that a single shared memory was used for programs and data in von Neumann machines, whereas programs where kept in different hardware in other architectures.
>By that definition, a Mil-Std-1750 ISA is not a von Neumann architecture. For that matter neither would a PC using MS-DOS to run an .EXE file. Both have separate data and executable code structures.
Not having any experience with Mil Std 1750 I cannot comment but a PC running MS-DOS is definitely a von Neumann architecture. The data and executable structures may indeed be different (questionable in many cases) but the physical memory used by both is the same.
In contrast, the Harvard architecture has physically separate code memory and data memory. The data memory cannot be executed as there is no path to the program execution elements of the processor. This architecture is used in many if not most DSP chips.
>>The von Neumann architecture made it possible to write self-modifying programs and to use a number of other sleazy programming tricks.
>"Sleazy" !?! Please look at the first 64 bytes in my 1994 Christmas Card. - have always felt that was my most "elegant" code and have been at it for a while.
IMHO sleazy is probably kind, unwise comes to mind, how about obsfucated.
Elegant does not describe self-modifying code for me and I have been at it for a while too. It's too hard for someone else to maintain. Granted a Christmas Card will probably not be maintained by someone else, but almost anything else...
Don Senzig, Jr - dsenzig@execpc.com - http://www.execpc.com/~dsenzig
______________________________________________________________________
Reply-To: dsenzig@execpc.com
Sender: "CYHIST Community Memory: Discussion list on the History of
Cyberspace" <CYHIST@SJUVM.STJOHNS.EDU>
Comments: Authenticated sender is <dsenzig@mail.execpc.com>
From: Don Senzig <dsenzig@mail.execpc.com>
Subject: CM> re: VN computers
______________________________________________________________________
Community Memory: Discussion List on the History of Cyberspace ______________________________________________________________________
On 1 Feb 97 at 23:54, A. Padgett Peterson P.E. Info wrote:
>>The essential difference between von Neumann machines and
>>others, as I understood it, what that a single shared memory was used for programs and data in von Neumann machines, whereas programs where kept in different hardware in other architectures.
>By that definition, a Mil-Std-1750 ISA is not a von Neumann architecture. For that matter neither would a PC using MS-DOS to run an .EXE file. Both have separate data and executable code structures.
Not having any experience with Mil Std 1750 I cannot comment but a PC running MS-DOS is definitely a von Neumann architecture. The data and executable structures may indeed be different (questionable in many cases) but the physical memory used by both is the same.
In contrast, the Harvard architecture has physically separate code memory and data memory. The data memory cannot be executed as there is no path to the program execution elements of the processor. This architecture is used in many if not most DSP chips.
>>The von Neumann architecture made it possible to write self-modifying programs and to use a number of other sleazy programming tricks.
>"Sleazy" !?! Please look at the first 64 bytes in my 1994 Christmas Card. - have always felt that was my most "elegant" code and have been at it for a while.
IMHO sleazy is probably kind, unwise comes to mind, how about obsfucated.
Elegant does not describe self-modifying code for me and I have been at it for a while too. It's too hard for someone else to maintain. Granted a Christmas Card will probably not be maintained by someone else, but almost anything else...
Don Senzig, Jr - dsenzig@execpc.com - http://www.execpc.com/~dsenzig
______________________________________________________________________
