Vonada's Engineering Maxims - Revision history

Jnc: /* Related observations */ rm dup

2023-12-03T10:36:09Z

‎Related observations: rm dup

Jnc: /* Related observations */ +Maxim #12 at work

2023-03-26T12:38:49Z

‎Related observations: +Maxim #12 at work

Jnc: Add link to meta-stability for #10

2022-12-06T21:52:18Z

Add link to meta-stability for #10

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2021-03-21T16:11:00Z

+book details

Jnc: best cat I can come up with

2018-12-30T13:53:23Z

best cat I can come up with

Jnc: Add links

2018-11-26T00:35:01Z

Add links

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2017-10-05T20:24:18Z

Add ref to example

Jnc at 06:31, 8 July 2017

2017-07-08T06:31:16Z

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2016-12-02T14:05:22Z

mention typo

Jnc: Useful to have!

2016-12-02T14:03:18Z

Useful to have!

New page

'''Vonada's Engineering Maxims''' are a group of pithy observations about computer engineering compiled by Don Vonada, an engineer at [[DEC]], and reproduced in:

* C. Gordon Bell, J. Craig Mudge, John. E. McNamara, "''Computer Engineering''"

They are:

# There is no such thing as ground.
# Digital circuits are made from analog parts.
# Prototype designs always work.
# Asserted timing conditions are designed first; unasserted timing conditions are found later.
# When all but one wire in a group of wires switch, that one will switch also.
# When all but one gate in a module switches, that one will switch also.
# Every little pico farad has a nano henry all its own.
# Capacitors convert voltage glitches to current glitches (conservation of energy).
# Interconnecting wires are probably transmission lines.
# Synchronizing circuits may take forever to make a decision.
# Worse-case tolerances never add - but when they do, they are found in the best customer's machine.
# Diagnostics are highly efficient in finding solved problems.
# Processing systems are only partially tested since it is impractical to simulate all possible machine states.
# Murphy's Laws apply 95 percent of the time. The other 5 percent of the time is a coffee break.

← Older revision		Revision as of 10:36, 3 December 2023
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	: "A digital circuit is like a tame animal, the analogue circuit is a wild animal. Every so often the tame animal reverts to the wild."		: "A digital circuit is like a tame animal, the analogue circuit is a wild animal. Every so often the tame animal reverts to the wild."
−
−	~~(See, for instance, [[meta-stability]].)~~

	==External links==		==External links==

← Older revision		Revision as of 12:38, 26 March 2023
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	(See, for instance, [[meta-stability]].)		(See, for instance, [[meta-stability]].)
		+
		+	==External links==
		+
		+	* [https://fritzm.github.io/unix-v6-trouble-1.html PDP-11/45: V6 Unix Troubleshooting, Part I] [https://fritzm.github.io/unix-v6-trouble-2.html Part II] - a wonderful, lengthy and painful example of Maxim #12 at work

	[[Category: Basics]]		[[Category: Basics]]

@@ Line 20: / Line 20: @@
 # Murphy's Laws apply 95 percent of the time. The other 5 percent of the time is a coffee break.
-(The typo in #11 - "Worse" - is in the original.)
+(#10 is apparently a reference to [[meta-stability]]. The seeming typo in #11 - "Worse" - is in the original.)
 ==Related observations==

← Older revision		Revision as of 13:53, 30 December 2018
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	(See, for instance, [[meta-stability]].)		(See, for instance, [[meta-stability]].)
		+
		+	[[Category: Basics]]

← Older revision		Revision as of 06:31, 8 July 2017
Line 21:		Line 21:

	(The typo in #11 - "Worse" - is in the original.)		(The typo in #11 - "Worse" - is in the original.)
		+
		+	==Related observations==
		+
		+	Maurice Wilkes is reported to have said something like:
		+
		+	: "A digital circuit is like a tame animal, the analogue circuit is a wild animal. Every so often the tame animal reverts to the wild."

@@ Line 1: / Line 1: @@
-'''Vonada's Engineering Maxims''' are a group of pithy observations about computer engineering compiled by Don Vonada, an engineer at [[DEC]], and reproduced in:
+'''Vonada's Engineering Maxims''' are a group of pithy observations about computer engineering compiled by Don Vonada, an engineer at [[Digital Equipment Corporation|DEC]], and reproduced in:
-* C. Gordon Bell, J. Craig Mudge, John. E. McNamara, "''Computer Engineering''"
+* C. Gordon Bell, J. Craig Mudge, John. E. McNamara, "''Computer Engineering: A DEC View of Hardware Systems Design''" (Digital Press, Bedford, 1978)
 They are:

@@ Line 5: / Line 5: @@
 They are:
-# There is no such thing as ground.
+# There is no such thing as [[ground]].
-# Digital circuits are made from analog parts.
+# [[Digital]] [[circuit]]s are made from [[analog]] parts.
 # Prototype designs always work.
 # Asserted timing conditions are designed first; un-asserted timing conditions are found later.
-# When all but one wire in a group of wires switch, that one will switch also.
+# When all but one [[conductor|wire]] in a group of wires switch, that one will switch also.
-# When all but one gate in a module switches, that one will switch also.
+# When all but one [[gate]] in a module switches, that one will switch also.
 # Every little pico farad has a nano henry all its own.
-# Capacitors convert voltage glitches to current glitches (conservation of energy).
+# [[Capacitor]]s convert [[voltage]] glitches to [[current]] glitches (conservation of energy).
-# Interconnecting wires are probably transmission lines.
+# Interconnecting wires are probably [[transmission line]]s.
-# Synchronizing circuits may take forever to make a decision.
+# [[Synchronizer|Synchronizing circuits]] may take forever to make a decision.
 # Worse-case tolerances never add - but when they do, they are found in the best customer's machine.
-# Diagnostics are highly efficient in finding solved problems.
+# [[Diagnostic]]s are highly efficient in finding solved problems.
 # Processing systems are only partially tested since it is impractical to simulate all possible machine states.
 # Murphy's Laws apply 95 percent of the time. The other 5 percent of the time is a coffee break.

← Older revision		Revision as of 14:05, 2 December 2016
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	# Processing systems are only partially tested since it is impractical to simulate all possible machine states.		# Processing systems are only partially tested since it is impractical to simulate all possible machine states.
	# Murphy's Laws apply 95 percent of the time. The other 5 percent of the time is a coffee break.		# Murphy's Laws apply 95 percent of the time. The other 5 percent of the time is a coffee break.
		+
		+	(The typo in #11 - "Worse" - is in the original.)