UNIBUS boot ROMs - Revision history

Jnc: +cat

2018-12-16T23:12:37Z

+cat

Jnc: Handle BM873 correctly

2016-03-27T11:45:46Z

Handle BM873 correctly

Jnc: consistent page naming

2016-03-26T18:55:32Z

consistent page naming

Jnc: Fix M873 description

2016-03-26T18:54:52Z

Fix M873 description

Jnc: typo

2016-03-26T18:13:20Z

typo

Jnc: +M793

2016-03-26T18:10:52Z

+M793

Jnc: A start....

2016-03-20T02:50:01Z

A start....

New page

DEC produced three generations of '''[[UNIBUS]] [[Read-only memory|ROM]] boot''' cards.

The first was the [[BM792 ROM]] card, which used individual diodes in an array to represent individual bits; it contained only 32 words of memory. The second was the [[M9301 ROM]] card; it had a capacity of 512 words, using [[PROM]] chips. The third was the [[M9312 ROM]] card, which also had a capacity of 512 words.

In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window.

← Older revision		Revision as of 23:12, 16 December 2018
Line 10:		Line 10:

	In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window, unlike later, larger [[QBUS]] ROM cards.		In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window, unlike later, larger [[QBUS]] ROM cards.
		+
		+	[[Category: UNIBUS ROMs]]

@@ Line 1: / Line 1: @@
 DEC produced several generations of '''[[UNIBUS]] [[Read-only memory|ROM]] boot''' cards.
-The first was the [[BM792 ROM]] card, which used individual diodes in an array to represent individual bits; it contained only 32 words of memory. The second was the [[M9301 ROM]] card; it had a capacity of 512 words, using [[PROM]] chips. The third was the [[M9312 ROM]] card, which also had a capacity of 512 words.
+* The first was the [[BM792 ROM]] [[DEC card form factor‎|quad]] card, which plugged into an [[Small Peripheral Controller|SPC]] slot; it used individual diodes in an array to represent individual bits, and contained only 32 words of memory.
-In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window.
+* The second was the [[BM873 ROM]], also a quad card used in an SPC slot; it contains 128 words, using 2 [[PROM]] chips.
-There was also another early [[DEC card form factor‎|quad]] ROM card, the [[M873 ROM]], but almost next to nothing is currently known about it; apparently it contains 128 words, using 2 of the ROM chips like those in the M9301.
+* The third was the [[M9301 ROM]] card, a dual card intended for use in the top two rows of a [[Modified UNIBUS Device|MUD]] slot; it had a capacity of 512 words, using four chips like those in the BM873.

← Older revision		Revision as of 18:55, 26 March 2016
Line 5:		Line 5:
	In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window.		In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window.

−	There was also another early [[DEC card form factor‎\|quad]] ROM card, the [[M873]], but almost next to nothing is currently known about it; apparently it contains 128 words, using 2 of the ROM chips like those in the M9301.	+	There was also another early [[DEC card form factor‎\|quad]] ROM card, the [[M873 ROM]], but almost next to nothing is currently known about it; apparently it contains 128 words, using 2 of the ROM chips like those in the M9301.

@@ Line 1: / Line 1: @@
-DEC produced three generations of '''[[UNIBUS]] [[Read-only memory|ROM]] boot''' cards.
+DEC produced several generations of '''[[UNIBUS]] [[Read-only memory|ROM]] boot''' cards.
 The first was the [[BM792 ROM]] card, which used individual diodes in an array to represent individual bits; it contained only 32 words of memory. The second was the [[M9301 ROM]] card; it had a capacity of 512 words, using [[PROM]] chips. The third was the [[M9312 ROM]] card, which also had a capacity of 512 words.
@@ Line 5: / Line 5: @@
 In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window.
-There was also a specialized card for use in the [[PDP-11/40]] machines,
+There was also another early [[DEC card form factor‎|quad]] ROM card, the [[M873]], but almost next to nothing is currently known about it; apparently it contains 128 words, using 2 of the ROM chips like those in the M9301.

← Older revision		Revision as of 18:13, 26 March 2016
Line 6:		Line 6:

	There was also a specialized card for use in the [[PDP-11/40]] machines,		There was also a specialized card for use in the [[PDP-11/40]] machines,
−	the [[~~M793~~-YA]].	+	the [[M873-YA]].

← Older revision		Revision as of 18:10, 26 March 2016
Line 4:		Line 4:

	In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window.		In both of the latter two cards, the entire ROM contents were directly visible on the UNIBUS, not through a window.
		+
		+	There was also a specialized card for use in the [[PDP-11/40]] machines,
		+	the [[M793-YA]].