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Cyhist Feb 07 1997 C
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Date: Fri, 7 Feb 1997 11:14:51 -0800
Reply-To: les@cs.stanford.edu
Sender: "CYHIST Community Memory: Discussion list on the History of
Cyberspace" <CYHIST@SJUVM.STJOHNS.EDU>
From: Les Earnest <les@Steam.Stanford.EDU>
Subject: CM: Emulation vs microcode
X-cc: efrem@acm.org
In-Reply-To: Efrem Lipkin's message of Wed, 5 Feb 1997 02:12:57 -0800
<199702060008.QAA29255@Steam.Stanford.EDU>
______________________________________________________________________
Community Memory: Discussion List on the History of Cyberspace ______________________________________________________________________
Efrem Lipkin writes:
Does anyone know the first machine to use microcode?
I'm not sure what machine was the first, but an early example was the TX-0 computer built at MIT Lincoln Lab around 1956, primarily to test the use of transistor circuits for digital logic. This machine originally had just four instructions: store, add, unconditional jump and "operate." In "operate" instructions the address field was interpreted as microcode, to do various I/O operations, internal register transfers, shifts and sign changes as well as conditional skips based on the contents of the accumulator. Thus, subroutines were needed for such things as multiplication and division.
The main designer of TX-0 was a young engineer named Ken Olson, who a short time later started a small company called Digital Equipment Corporation.
Coolly,
-Les Earnest
______________________________________________________________________
Reply-To: les@cs.stanford.edu
Sender: "CYHIST Community Memory: Discussion list on the History of
Cyberspace" <CYHIST@SJUVM.STJOHNS.EDU>
From: Les Earnest <les@Steam.Stanford.EDU>
Subject: CM: Emulation vs microcode
X-cc: efrem@acm.org
In-Reply-To: Efrem Lipkin's message of Wed, 5 Feb 1997 02:12:57 -0800
<199702060008.QAA29255@Steam.Stanford.EDU>
______________________________________________________________________
Community Memory: Discussion List on the History of Cyberspace ______________________________________________________________________
Efrem Lipkin writes:
Does anyone know the first machine to use microcode?
I'm not sure what machine was the first, but an early example was the TX-0 computer built at MIT Lincoln Lab around 1956, primarily to test the use of transistor circuits for digital logic. This machine originally had just four instructions: store, add, unconditional jump and "operate." In "operate" instructions the address field was interpreted as microcode, to do various I/O operations, internal register transfers, shifts and sign changes as well as conditional skips based on the contents of the accumulator. Thus, subroutines were needed for such things as multiplication and division.
The main designer of TX-0 was a young engineer named Ken Olson, who a short time later started a small company called Digital Equipment Corporation.
Coolly,
-Les Earnest
______________________________________________________________________
