Talk:Fabritek Core Memory - Revision history

Jnc: /* Still here? */ Those dates sound good

2019-07-08T12:36:23Z

‎Still here?: Those dates sound good

Larsbrinkhoff: Info from ITS 848.

2019-07-08T07:50:58Z

Info from ITS 848.

Larsbrinkhoff at 07:34, 8 July 2019

2019-07-08T07:34:12Z

Larsbrinkhoff: Some information about MIT-AI memory limits.

2019-07-08T07:33:50Z

Some information about MIT-AI memory limits.

Larsbrinkhoff: /* Still here? */ I'll keep my eyes peeled.

2019-07-07T17:01:25Z

‎Still here?: I'll keep my eyes peeled.

Jnc: Ah, I'm still dubious

2019-07-07T14:17:35Z

Ah, I'm still dubious

Larsbrinkhoff: /* Still here? */ Some research.

2019-07-06T16:47:51Z

‎Still here?: Some research.

Jnc: Only 2 mobies of actual memory, I'm pretty sure

2019-07-06T13:48:47Z

Only 2 mobies of actual memory, I'm pretty sure

Larsbrinkhoff: /* Still here? */ Mobies.

2019-07-06T05:27:47Z

‎Still here?: Mobies.

Jnc: /* Still here */ Amazed it still exists

2019-07-05T19:22:00Z

‎Still here: Amazed it still exists

New page

==Still here?==

I'm somewhat amazed the one from AI still exists. I would have assumed it would have been junked when HIC did the work to enable LISPM memory to be used on AI to replace the failing core memory. (I forget what hardware was used for the second moby on AI.) [[User:Jnc|Jnc]] ([[User talk:Jnc|talk]]) 21:22, 5 July 2019 (CEST)

← Older revision		Revision as of 12:36, 8 July 2019
Line 24:		Line 24:
	::::: 10-11 support was dropped in 1982.		::::: 10-11 support was dropped in 1982.
	::::: [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 09:34, 8 July 2019 (CEST)		::::: [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 09:34, 8 July 2019 (CEST)
		+
		+	:::: Those all sound plausible; 1981 is about when HIC did the LISPM memory, and the core was de-comissioned. [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 14:36, 8 July 2019 (CEST)

@@ Line 17: / Line 17: @@
 ::::: For what it's worth, here's what I can see in the code.
-::::: IN ITS 785 from 1973, system memory is 272K, and PDP-6 core is mapped right after this.  There is no 10-11 interface.
+::::: In ITS 785 from 1973, system memory is 272K, and PDP-6 core is mapped right after this.  There is no 10-11 interface.
-::::: In ITS 997 from 1975, there is commented-out code to share a moby between the PDP-6 and the 10-11, so I'm guessing they did share a moby at some earlier time.  System memory is 512K, mobies 0 and 1.  The 10-11 moby is 2, and PDP-6 is 3.
+::::: In ITS 848, system and PDP-6 memories remain the same.  The 10-11 interface has been added, and sits in moby 1.  There is code to share moby 1 between the system, PDP-6, and 10-11.
 ::::: PDP-6 support was dropped from ITS in August 1978.
 ::::: In 1981, the system memory limit was increased to 768K.  At this point, the 10-11 moby was also changed from 2 to 3.
 ::::: 10-11 support was dropped in 1982.
 ::::: [[User:Larsbrinkhoff|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff|talk]]) 09:34, 8 July 2019 (CEST)

← Older revision		Revision as of 07:34, 8 July 2019
Line 22:		Line 22:
	::::: In 1981, the system memory limit was increased to 768K. At this point, the 10-11 moby was also changed from 2 to 3.		::::: In 1981, the system memory limit was increased to 768K. At this point, the 10-11 moby was also changed from 2 to 3.
	::::: 10-11 support was dropped in 1982.		::::: 10-11 support was dropped in 1982.
		+	::::: [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 09:34, 8 July 2019 (CEST)

← Older revision		Revision as of 07:33, 8 July 2019
Line 15:		Line 15:

	::::: Thanks, that's worth looking into. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 19:01, 7 July 2019 (CEST)		::::: Thanks, that's worth looking into. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 19:01, 7 July 2019 (CEST)
		+
		+	::::: For what it's worth, here's what I can see in the code.
		+	::::: IN ITS 785 from 1973, system memory is 272K, and PDP-6 core is mapped right after this. There is no 10-11 interface.
		+	::::: In ITS 997 from 1975, there is commented-out code to share a moby between the PDP-6 and the 10-11, so I'm guessing they did share a moby at some earlier time. System memory is 512K, mobies 0 and 1. The 10-11 moby is 2, and PDP-6 is 3.
		+	::::: PDP-6 support was dropped from ITS in August 1978.
		+	::::: In 1981, the system memory limit was increased to 768K. At this point, the 10-11 moby was also changed from 2 to 3.
		+	::::: 10-11 support was dropped in 1982.

← Older revision		Revision as of 17:01, 7 July 2019
Line 13:		Line 13:
	:::: I wouldn't put to much weight on the CONFIG > entries as to what machines had; if something's ''not'' listed, yes, it probably wasn't there, but the other direction... The memory size setting just allowed for ''up to'' that much memory; one could switch memories out at boot time without needing to rebuild the system. (That happened a lot on MC.)		:::: I wouldn't put to much weight on the CONFIG > entries as to what machines had; if something's ''not'' listed, yes, it probably wasn't there, but the other direction... The memory size setting just allowed for ''up to'' that much memory; one could switch memories out at boot time without needing to rebuild the system. (That happened a lot on MC.)
	:::: I really don't recall AI having more than the two mobies before HIC did the LISPM memory; I'm pretty sure if they'd added some it would have been noticeable (physically). Maybe check with Greenblatt, or someone? [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 16:17, 7 July 2019 (CEST)		:::: I really don't recall AI having more than the two mobies before HIC did the LISPM memory; I'm pretty sure if they'd added some it would have been noticeable (physically). Maybe check with Greenblatt, or someone? [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 16:17, 7 July 2019 (CEST)
		+
		+	::::: Thanks, that's worth looking into. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 19:01, 7 July 2019 (CEST)

← Older revision		Revision as of 14:17, 7 July 2019
Line 10:		Line 10:
	::: Some time ago I made notes about how the memory sizes of the ITS machines evolved: https://github.com/PDP-10/its/issues/1585		::: Some time ago I made notes about how the memory sizes of the ITS machines evolved: https://github.com/PDP-10/its/issues/1585
	::: According to this, AI was as you describe at one point. But later a third moby was installed, and the PDP-6 and 10-11 was made to share a moby. ITS has code to accommodate this configuration. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 18:47, 6 July 2019 (CEST)		::: According to this, AI was as you describe at one point. But later a third moby was installed, and the PDP-6 and 10-11 was made to share a moby. ITS has code to accommodate this configuration. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 18:47, 6 July 2019 (CEST)
		+
		+	:::: I wouldn't put to much weight on the CONFIG > entries as to what machines had; if something's ''not'' listed, yes, it probably wasn't there, but the other direction... The memory size setting just allowed for ''up to'' that much memory; one could switch memories out at boot time without needing to rebuild the system. (That happened a lot on MC.)
		+	:::: I really don't recall AI having more than the two mobies before HIC did the LISPM memory; I'm pretty sure if they'd added some it would have been noticeable (physically). Maybe check with Greenblatt, or someone? [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 16:17, 7 July 2019 (CEST)

← Older revision		Revision as of 16:47, 6 July 2019
Line 7:		Line 7:
	:: Generally core maintains its contents for a very long time; I've read of other old core memory being read out decades after last use. But in this case I doubt it would be worth it; the contents would either be i) stuff we have already (ITS system/commands), or ii) junk of no interest (personal data).		:: Generally core maintains its contents for a very long time; I've read of other old core memory being read out decades after last use. But in this case I doubt it would be worth it; the contents would either be i) stuff we have already (ITS system/commands), or ii) junk of no interest (personal data).
	:: AI's pager had a ''hardware address space'' of 4 mobies, but I'm pretty sure only 2 mobies of actual memory. I think the third was the PDP-6 main memory; the 11's had a moby to themselves. (IIRC, they didn't tweak the memory bus cables, the way they did with the I/O bus; the pagers (on all 3 machines) just had 2 or 4 totally stock memory bus cables coming out of them, which were cabled to the appropriate boxes.) [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 15:48, 6 July 2019 (CEST)		:: AI's pager had a ''hardware address space'' of 4 mobies, but I'm pretty sure only 2 mobies of actual memory. I think the third was the PDP-6 main memory; the 11's had a moby to themselves. (IIRC, they didn't tweak the memory bus cables, the way they did with the I/O bus; the pagers (on all 3 machines) just had 2 or 4 totally stock memory bus cables coming out of them, which were cabled to the appropriate boxes.) [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 15:48, 6 July 2019 (CEST)
		+
		+	::: Some time ago I made notes about how the memory sizes of the ITS machines evolved: https://github.com/PDP-10/its/issues/1585
		+	::: According to this, AI was as you describe at one point. But later a third moby was installed, and the PDP-6 and 10-11 was made to share a moby. ITS has code to accommodate this configuration. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 18:47, 6 July 2019 (CEST)

← Older revision		Revision as of 13:48, 6 July 2019
Line 4:		Line 4:

	: I'm amazed too! I had the idea that they should scan the contents, but I suppose the bits have dissapated by now. I think the other moby was an Ampex... but the final configuration had three mobies. The fourth was dedicated to the 10-11 interface and PDP-6. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 07:27, 6 July 2019 (CEST)		: I'm amazed too! I had the idea that they should scan the contents, but I suppose the bits have dissapated by now. I think the other moby was an Ampex... but the final configuration had three mobies. The fourth was dedicated to the 10-11 interface and PDP-6. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 07:27, 6 July 2019 (CEST)
		+
		+	:: Generally core maintains its contents for a very long time; I've read of other old core memory being read out decades after last use. But in this case I doubt it would be worth it; the contents would either be i) stuff we have already (ITS system/commands), or ii) junk of no interest (personal data).
		+	:: AI's pager had a ''hardware address space'' of 4 mobies, but I'm pretty sure only 2 mobies of actual memory. I think the third was the PDP-6 main memory; the 11's had a moby to themselves. (IIRC, they didn't tweak the memory bus cables, the way they did with the I/O bus; the pagers (on all 3 machines) just had 2 or 4 totally stock memory bus cables coming out of them, which were cabled to the appropriate boxes.) [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 15:48, 6 July 2019 (CEST)

← Older revision		Revision as of 05:27, 6 July 2019
Line 2:		Line 2:

	I'm somewhat amazed the one from AI still exists. I would have assumed it would have been junked when HIC did the work to enable LISPM memory to be used on AI to replace the failing core memory. (I forget what hardware was used for the second moby on AI.) [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 21:22, 5 July 2019 (CEST)		I'm somewhat amazed the one from AI still exists. I would have assumed it would have been junked when HIC did the work to enable LISPM memory to be used on AI to replace the failing core memory. (I forget what hardware was used for the second moby on AI.) [[User:Jnc\|Jnc]] ([[User talk:Jnc\|talk]]) 21:22, 5 July 2019 (CEST)
		+
		+	: I'm amazed too! I had the idea that they should scan the contents, but I suppose the bits have dissapated by now. I think the other moby was an Ampex... but the final configuration had three mobies. The fourth was dedicated to the 10-11 interface and PDP-6. [[User:Larsbrinkhoff\|Larsbrinkhoff]] ([[User talk:Larsbrinkhoff\|talk]]) 07:27, 6 July 2019 (CEST)