Mainboard 81-110 - Revision history

FrankRahman: /* 81-110A */

2026-03-04T21:00:09Z

81-110A

← Older revision		Revision as of 21:00, 4 March 2026
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	==81-110A==		==81-110A==
	The 81-110A is notable for 4 unpopulated chips locations from the Ferguson Big Board design (CTC, Monitor ROM, and 2 74LS chips).		The 81-110A is notable for 4 unpopulated chips locations from the Ferguson Big Board design (CTC, Monitor ROM, and 2 74LS chips). It was proceeded by at lest one 81-110 in serial number.
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FrankRahman: /* 81-110 */

2026-03-04T20:57:46Z

81-110

← Older revision		Revision as of 20:57, 4 March 2026
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	==81-110==		==81-110==
	This ~~image was shared with a friend~~ is an 81-110(no letter) board. Note the C21, R37, and R38 are silk ~~screen~~ for components that are not installed. The U88 was intended to be a 16 pin chip but was replaced by the FDC9216 which only has 8 pins so the footprint extends beyond the chip. There are sockets on the board for the chips not present on the 81-110A boards but these could have been added after production. Both ROMS appear to be Intel D2816 EEPROMs. On other boards they would usually be EPROMs which are not electronically erasable.		This is an 81-110(no letter) board. Note the C21, R37, and R38 are silk screened for components that are not installed. The U88 was intended to be a 16 pin chip but was replaced by the FDC9216 which only has 8 pins so the footprint extends beyond the chip. There are sockets on the board for the chips not present on the 81-110A boards but these could have been added after production. Both ROMS appear to be Intel D2816 EEPROMs. On other boards they would usually be EPROMs which are not electronically erasable.

	The board's number is 1145 which is earlier than 1353 which was the earliest 81-110A board seen. The QC Sticker is dated 26JL82 which is after the three earliest 81-110A boards so ~~the machine~~ may have ~~been shipped later~~.		The board's number is 1145 which is earlier than 1353 which was the earliest 81-110A board seen. The QC Sticker is dated 26JL82 which is after the three earliest 81-110A boards so this board may have required additional rework delaying it's use. The chassis that it is in does not have a serial number but the power switch implies it is not among the first machines delivered.
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FrankRahman: /* 81-110 General Info */

2026-03-04T20:49:48Z

81-110 General Info

← Older revision		Revision as of 20:49, 4 March 2026
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	It was exclusively used in the Kaypro II and for the most part was replaced by the [[Mainboard 81-240\|81-240]] sometime in 1983.		It was exclusively used in the Kaypro II and for the most part was replaced by the [[Mainboard 81-240\|81-240]] sometime in 1983.

			Most of the oldest machines used the 81-110A board but an 81-110(no letter) board has appeared and appears to be the oldest known board.

	The 81-110B, B1 and B2 represent a cost reduced version of the 81-110A board since they use fewer chips. It is likely that the 81-110B board had an issue since it was replaced very quickly making that board relatively rare.		The 81-110B, B1 and B2 represent a cost reduced version of the 81-110A board since they use fewer chips. It is likely that the 81-110B board had an issue since it was replaced very quickly making that board relatively rare.

FrankRahman: /* 81-110 */

2026-03-03T22:41:38Z

81-110

← Older revision		Revision as of 22:41, 3 March 2026
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	[[File:81-110 bottom small.jpg\|600px]]<br>		[[File:81-110 bottom small.jpg\|600px]]<br>
	Source: ~~Stargeezer~~		Source: Stargeezerlabs
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	===81-110 Machines===		===81-110 Machines===
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	-->		-->
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	==81-110A==		==81-110A==

FrankRahman at 22:40, 3 March 2026

2026-03-03T22:40:32Z

@@ Line 24: / Line 24: @@
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+|
-[[File:81-110 bottom small.jpg|600px]]
+[[File:81-110 bottom small.jpg|600px]]<br>
 |}
 ==81-110A==

FrankRahman: /* 81-110? */

2026-03-03T22:33:11Z

81-110?

← Older revision		Revision as of 22:33, 3 March 2026
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	* ROMs are as labeled		* ROMs are as labeled

	==81-110?==		==81-110==
	This image was shared with a friend ~~and may be of~~ an 81-110(no letter) board. Note the C21, R37, R38 ~~and an IC chip~~ silk screen for components that are not installed. There are sockets on the board for the chips not present on the 81-110A boards but these could have been added after production. Both ROMS appear to be Intel D2816 EEPROMs. On other boards they would usually be EPROMs which are not electronically erasable.		This image was shared with a friend is an 81-110(no letter) board. Note the C21, R37, and R38 are silk screen for components that are not installed. The U88 was intended to be a 16 pin chip but was replaced by the FDC9216 which only has 8 pins so the footprint extends beyond the chip. There are sockets on the board for the chips not present on the 81-110A boards but these could have been added after production. Both ROMS appear to be Intel D2816 EEPROMs. On other boards they would usually be EPROMs which are not electronically erasable.

	The board's number is 1145 which is earlier than 1353 which was the earliest 81-110A board seen. The QC Sticker is dated 26JL82 which is after the three earliest 81-110A boards so the machine may have been shipped later.		The board's number is 1145 which is earlier than 1353 which was the earliest 81-110A board seen. The QC Sticker is dated 26JL82 which is after the three earliest 81-110A boards so the machine may have been shipped later.
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	[[File:81-110 unk MB small.jpg\|600px]]		[[File:81-110 unk MB small.jpg\|600px]]
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			[[File:81-110 bottom small.jpg\|600px]]
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FrankRahman: /* 81-110? */

2026-03-03T20:27:07Z

81-110?

← Older revision		Revision as of 20:27, 3 March 2026
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	==81-110?==		==81-110?==
	This image was shared with a friend and may be of an 81-110(no letter) board. Note the C21, R37, R38 and an IC chip silk screen for components that are not installed. There are sockets on the board for the chips not present on the 81-110A boards but these could have been added after production. The board's number is 1145 which is earlier than 1353 which was the earliest 81-110A board seen. The QC Sticker is dated 26JL82 which is after the three earliest 81-110A boards so the machine may have been shipped later.		This image was shared with a friend and may be of an 81-110(no letter) board. Note the C21, R37, R38 and an IC chip silk screen for components that are not installed. There are sockets on the board for the chips not present on the 81-110A boards but these could have been added after production. Both ROMS appear to be Intel D2816 EEPROMs. On other boards they would usually be EPROMs which are not electronically erasable.

			The board's number is 1145 which is earlier than 1353 which was the earliest 81-110A board seen. The QC Sticker is dated 26JL82 which is after the three earliest 81-110A boards so the machine may have been shipped later.
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FrankRahman at 20:20, 3 March 2026

2026-03-03T20:20:32Z

← Older revision		Revision as of 20:20, 3 March 2026
Line 13:		Line 13:
	* Q1 = Q1 and C6 are present		* Q1 = Q1 and C6 are present
	* ROMs are as labeled		* ROMs are as labeled

			==81-110?==
			This image was shared with a friend and may be of an 81-110(no letter) board. Note the C21, R37, R38 and an IC chip silk screen for components that are not installed. There are sockets on the board for the chips not present on the 81-110A boards but these could have been added after production. The board's number is 1145 which is earlier than 1353 which was the earliest 81-110A board seen. The QC Sticker is dated 26JL82 which is after the three earliest 81-110A boards so the machine may have been shipped later.
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			[[File:81-110 unk MB small.jpg\|600px]]
			\|}

	==81-110A==		==81-110A==

FrankRahman: /* 81-110 General Info */

2025-11-27T03:22:51Z

81-110 General Info

← Older revision		Revision as of 03:22, 27 November 2025
Line 5:		Line 5:

	The 81-110B, B1 and B2 represent a cost reduced version of the 81-110A board since they use fewer chips. It is likely that the 81-110B board had an issue since it was replaced very quickly making that board relatively rare.		The 81-110B, B1 and B2 represent a cost reduced version of the 81-110A board since they use fewer chips. It is likely that the 81-110B board had an issue since it was replaced very quickly making that board relatively rare.

			Also note that the floppy controller chip was changed when they switched from the 81-110A to the 81-110B board.

	Legand/Info:		Legand/Info:

FrankRahman at 03:20, 27 November 2025

2025-11-27T03:20:09Z

← Older revision		Revision as of 03:20, 27 November 2025
Line 1:		Line 1:
	==81-110 General Info==		==81-110 General Info==
	The 81-110 Mainboard was the original Kaypro board and debuted with the first Kaypro II machines. It's design was based on the Ferguson Big Board. ([https://retrocmp.de/kaypro/kay-p2_hrdw.htm#mb-kII Thomas Brase])		The 81-110 Mainboard was the original Kaypro board and debuted with the first Kaypro II machines, including the Kaycomp machines. It's design was based on the Ferguson Big Board. ([https://retrocmp.de/kaypro/kay-p2_hrdw.htm#mb-kII Thomas Brase])

	It was exclusively used in the Kaypro II and for the most part was replaced by the [[Mainboard 81-240\|81-240]] sometime in 1983.		It was exclusively used in the Kaypro II and for the most part was replaced by the [[Mainboard 81-240\|81-240]] sometime in 1983.

			The 81-110B, B1 and B2 represent a cost reduced version of the 81-110A board since they use fewer chips. It is likely that the 81-110B board had an issue since it was replaced very quickly making that board relatively rare.

	Legand/Info:		Legand/Info: