Talk:Mainframe - Revision history

Jnc: +link; have page now

2021-07-18T19:32:53Z

+link; have page now

Jnc: /* Contemporary idiots */ new section

2021-04-20T19:15:39Z

‎Contemporary idiots: new section

Larsbrinkhoff: /* When is a computer not a mainframe? */ Thanks!

2021-04-10T07:45:21Z

‎When is a computer not a mainframe?: Thanks!

Jnc: /* When is a computer not a mainframe? */ Yes, PDP-8 front ends on PDP-10

2021-04-10T02:10:01Z

‎When is a computer not a mainframe?: Yes, PDP-8 front ends on PDP-10

Jnc: Nah, channels aren't it

2021-04-09T11:11:24Z

Nah, channels aren't it

Larsbrinkhoff: /* When is a computer not a mainframe? */ It's the channels, man!

2021-04-09T04:44:59Z

‎When is a computer not a mainframe?: It's the channels, man!

Jnc: Hmm, good question

2021-04-08T20:14:23Z

Hmm, good question

Larsbrinkhoff at 17:04, 8 April 2021

2021-04-08T17:04:52Z

Larsbrinkhoff: Long rant.

2021-04-08T17:03:51Z

Long rant.

New page

===When is a computer not a mainframe?===

A not too opinionated discussion around various ideas about what constitutes a "real" mainframe, and what doesn't, might be interesting. As an example, in the DEC world, the PDP-10 family of computers are usually regarded as mainframes (probably excepting the DEC-2020). But IBM people seem to regard it as minicomputer. That is not to say one definition is more correct than any other. The PDP-8 and 11 are usually regarded as squarely in the mini category even though some of he larger PDP-11s could rival a 10 in some respects. The VAX was often referred to as a "super mini"; maybe later larger models nudged into the mainframe category? [[User:Larsbrinkhoff|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff|talk]]) 19:03, 8 April 2021 (CEST)

@@ Line 12: / Line 12: @@
 : Hah. Then by ''their own'' definiton, the PDP-10 was a 'mainframe'; they had [[DF10]] channels. If one uses an alternative definition where a 'mainframe' has associated smaller front end machines to do I/O, then again the PDP-10 counts, because of the [[DL10]] and associated PDP-11[s]. (I think there was some earlier PDP-8 equivalent of the DL10, but I forget the details.)
-:: There was; the DA10 (although unlike the DL10, it didn't do DMA, just programmed I/O). I've substantially upgraded the [[PDP-10]] article, to talk about the busses, devices, and front ends. [[User:Jnc|Jnc]] ([[User talk:Jnc|talk]]) 04:09, 10 April 2021 (CEST)
+:: There was; the [[DA10]] (although unlike the DL10, it didn't do DMA, just programmed I/O). I've substantially upgraded the [[PDP-10]] article, to talk about the busses, devices, and front ends. [[User:Jnc|Jnc]] ([[User talk:Jnc|talk]]) 04:09, 10 April 2021 (CEST)
 ::: Thanks! [[User:Larsbrinkhoff|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff|talk]]) 09:45, 10 April 2021 (CEST)

← Older revision		Revision as of 19:15, 20 April 2021
Line 18:		Line 18:
	: I'm not big on using that definition, though, because it's too tied to that generation of technology. (And later PDP-11 I/O devices such as the [[DEUNA]] and [[DELUA]] and the later multi-serial line cards all had micros on them.) Now that it's 'trivial' to throw a bazillion transistors at things as small as a handheld, we need to look elsewhere than internal organizational stuff - other than things like reliability via replication, maintainability via hot-swapping, etc. I think one/some of the other external attributes might be better.		: I'm not big on using that definition, though, because it's too tied to that generation of technology. (And later PDP-11 I/O devices such as the [[DEUNA]] and [[DELUA]] and the later multi-serial line cards all had micros on them.) Now that it's 'trivial' to throw a bazillion transistors at things as small as a handheld, we need to look elsewhere than internal organizational stuff - other than things like reliability via replication, maintainability via hot-swapping, etc. I think one/some of the other external attributes might be better.
	: Oh, I don't think floating point comes into 'mainframe' at all (but I guess you were just talking about supercomputers, there); for 'supercomputer', absolutely, that's ''key''; but for many mainframe uses (e.g. large online transaction systems), they aren't heavy on floating point. Overall computing crunch, yes, but not floating point. Mainframes also had a lot of I/O capability, including a lot of mass storage. [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 13:11, 9 April 2021 (CEST)		: Oh, I don't think floating point comes into 'mainframe' at all (but I guess you were just talking about supercomputers, there); for 'supercomputer', absolutely, that's ''key''; but for many mainframe uses (e.g. large online transaction systems), they aren't heavy on floating point. Overall computing crunch, yes, but not floating point. Mainframes also had a lot of I/O capability, including a lot of mass storage. [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 13:11, 9 April 2021 (CEST)
		+
		+	== Contemporary idiots ==
		+
		+	[https://www.ebay.com/itm/203250339708 PDP-11/23 Mainframe Computer]. Nitwit. [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 21:15, 20 April 2021 (CEST)

@@ Line 13: / Line 13: @@
 :: There was; the DA10 (although unlike the DL10, it didn't do DMA, just programmed I/O). I've substantially upgraded the [[PDP-10]] article, to talk about the busses, devices, and front ends. [[User:Jnc|Jnc]] ([[User talk:Jnc|talk]]) 04:09, 10 April 2021 (CEST)
 : I'm not big on using that definition, though, because it's too tied to that generation of technology. (And later PDP-11 I/O devices such as the [[DEUNA]] and [[DELUA]] and the later multi-serial line cards all had micros on them.) Now that it's 'trivial' to throw a bazillion transistors at things as small as a handheld, we need to look elsewhere than internal organizational stuff - other than things like reliability via replication, maintainability via hot-swapping, etc. I think one/some of the other external attributes might be better.
 : Oh, I don't think floating point comes into 'mainframe' at all (but I guess you were just talking about supercomputers, there); for 'supercomputer', absolutely, that's ''key''; but for many mainframe uses (e.g. large online transaction systems), they aren't heavy on floating point. Overall computing crunch, yes, but not floating point. Mainframes also had a lot of I/O capability, including a lot of mass storage. [[User:Jnc|Jnc]] ([[User talk:Jnc|talk]]) 13:11, 9 April 2021 (CEST)

@@ Line 11: / Line 11: @@
 : Hah. Then by ''their own'' definiton, the PDP-10 was a 'mainframe'; they had [[DF10]] channels. If one uses an alternative definition where a 'mainframe' has associated smaller front end machines to do I/O, then again the PDP-10 counts, because of the [[DL10]] and associated PDP-11[s]. (I think there was some earlier PDP-8 equivalent of the DL10, but I forget the details.)
 : I'm not big on using that definition, though, because it's too tied to that generation of technology. (And later PDP-11 I/O devices such as the [[DEUNA]] and [[DELUA]] and the later multi-serial line cards all had micros on them.) Now that it's 'trivial' to throw a bazillion transistors at things as small as a handheld, we need to look elsewhere than internal organizational stuff - other than things like reliability via replication, maintainability via hot-swapping, etc. I think one/some of the other external attributes might be better.
 : Oh, I don't think floating point comes into 'mainframe' at all (but I guess you were just talking about supercomputers, there); for 'supercomputer', absolutely, that's ''key''; but for many mainframe uses (e.g. large online transaction systems), they aren't heavy on floating point. Overall computing crunch, yes, but not floating point. Mainframes also had a lot of I/O capability, including a lot of mass storage. [[User:Jnc|Jnc]] ([[User talk:Jnc|talk]]) 13:11, 9 April 2021 (CEST)

← Older revision		Revision as of 11:11, 9 April 2021
Line 9:		Line 9:

	:: IBM types clam one defining characteristic is that a mainframe must have subordinate I/O processors, i.e. "channels". As for supercomputer I think you're right about computing power, or specifically floating-poing throughput. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 06:44, 9 April 2021 (CEST)		:: IBM types clam one defining characteristic is that a mainframe must have subordinate I/O processors, i.e. "channels". As for supercomputer I think you're right about computing power, or specifically floating-poing throughput. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 06:44, 9 April 2021 (CEST)
		+
		+	: Hah. Then by ''their own'' definiton, the PDP-10 was a 'mainframe'; they had [[DF10]] channels. If one uses an alternative definition where a 'mainframe' has associated smaller front end machines to do I/O, then again the PDP-10 counts, because of the [[DL10]] and associated PDP-11[s]. (I think there was some earlier PDP-8 equivalent of the DL10, but I forget the details.)
		+	: I'm not big on using that definition, though, because it's too tied to that generation of technology. (And later PDP-11 I/O devices such as the [[DEUNA]] and [[DELUA]] and the later multi-serial line cards all had micros on them.) Now that it's 'trivial' to throw a bazillion transistors at things as small as a handheld, we need to look elsewhere than internal organizational stuff - other than things like reliability via replication, maintainability via hot-swapping, etc. I think one/some of the other external attributes might be better.
		+	: Oh, I don't think floating point comes into 'mainframe' at all (but I guess you were just talking about supercomputers, there); for 'supercomputer', absolutely, that's ''key''; but for many mainframe uses (e.g. large online transaction systems), they aren't heavy on floating point. Overall computing crunch, yes, but not floating point. Mainframes also had a lot of I/O capability, including a lot of mass storage. [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 13:11, 9 April 2021 (CEST)

← Older revision		Revision as of 04:44, 9 April 2021
Line 7:		Line 7:
	: I don't thing even large -11's were anything more than super-minis (although a large one, with a bunch of [[MK11]]s, might be borderline). Likewise even the larger VAXen - although maybe the VAX 9000 could count. A VAXCluster of VAX 9000's would be a mainframe, to me.		: I don't thing even large -11's were anything more than super-minis (although a large one, with a bunch of [[MK11]]s, might be borderline). Likewise even the larger VAXen - although maybe the VAX 9000 could count. A VAXCluster of VAX 9000's would be a mainframe, to me.
	: There's no way a big KL10 system was a minicomputer. [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 22:14, 8 April 2021 (CEST)		: There's no way a big KL10 system was a minicomputer. [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 22:14, 8 April 2021 (CEST)
		+
		+	:: IBM types clam one defining characteristic is that a mainframe must have subordinate I/O processors, i.e. "channels". As for supercomputer I think you're right about computing power, or specifically floating-poing throughput. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 06:44, 9 April 2021 (CEST)

← Older revision		Revision as of 20:14, 8 April 2021
Line 1:		Line 1:
−	===When is a computer not a mainframe?===	+	==When is a computer not a mainframe?==

	A not too opinionated discussion around various ideas about what constitutes a "real" mainframe, and what doesn't, might be interesting. As an example, in the DEC world, the PDP-10 family of computers are usually regarded as mainframes (probably excepting the DEC-2020). But IBM people seem to regard it as a minicomputer. That is not to say one definition is more correct than any other. The PDP-8 and 11 are usually regarded as squarely in the mini category even though some of the larger PDP-11s could rival a 10 in some respects. The VAX was often referred to as a "super mini"; maybe later larger models nudged into the mainframe category? [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 19:03, 8 April 2021 (CEST)		A not too opinionated discussion around various ideas about what constitutes a "real" mainframe, and what doesn't, might be interesting. As an example, in the DEC world, the PDP-10 family of computers are usually regarded as mainframes (probably excepting the DEC-2020). But IBM people seem to regard it as a minicomputer. That is not to say one definition is more correct than any other. The PDP-8 and 11 are usually regarded as squarely in the mini category even though some of the larger PDP-11s could rival a 10 in some respects. The VAX was often referred to as a "super mini"; maybe later larger models nudged into the mainframe category? [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 19:03, 8 April 2021 (CEST)
		+
		+	: Hmmm. I'll have to go away and think about what 'mainframe' means. (And the meaning may have changed a bit over time, to make it a bigger problem.) One definition might include physical size ('it fills a whole room'), but that's less relevant today. Another might talk about what it does (e.g. big online system), and how it was run (e.g. secured machine room with operators). Another might talk about computing power ('the biggest thing smaller than a supercomputer'), and internal characteristics (e.g. duplication for reliability, ability to hot-swap, etc).
		+	: It can get fuzzy at the edges, though. E.g. hot-swapping - IIRC old Tandem's could do that, but I think of them as super-minis.
		+	: I don't thing even large -11's were anything more than super-minis (although a large one, with a bunch of [[MK11]]s, might be borderline). Likewise even the larger VAXen - although maybe the VAX 9000 could count. A VAXCluster of VAX 9000's would be a mainframe, to me.
		+	: There's no way a big KL10 system was a minicomputer. [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 22:14, 8 April 2021 (CEST)

← Older revision		Revision as of 17:04, 8 April 2021
Line 1:		Line 1:
	===When is a computer not a mainframe?===		===When is a computer not a mainframe?===

−	A not too opinionated discussion around various ideas about what constitutes a "real" mainframe, and what doesn't, might be interesting. As an example, in the DEC world, the PDP-10 family of computers are usually regarded as mainframes (probably excepting the DEC-2020). But IBM people seem to regard it as minicomputer. That is not to say one definition is more correct than any other. The PDP-8 and 11 are usually regarded as squarely in the mini category even though some of he larger PDP-11s could rival a 10 in some respects. The VAX was often referred to as a "super mini"; maybe later larger models nudged into the mainframe category? [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 19:03, 8 April 2021 (CEST)	+	A not too opinionated discussion around various ideas about what constitutes a "real" mainframe, and what doesn't, might be interesting. As an example, in the DEC world, the PDP-10 family of computers are usually regarded as mainframes (probably excepting the DEC-2020). But IBM people seem to regard it as a minicomputer. That is not to say one definition is more correct than any other. The PDP-8 and 11 are usually regarded as squarely in the mini category even though some of the larger PDP-11s could rival a 10 in some respects. The VAX was often referred to as a "super mini"; maybe later larger models nudged into the mainframe category? [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 19:03, 8 April 2021 (CEST)