Mainboard 81-110

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. (Thomas Brase)

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

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).

81-110A Machines

Serial Num	Board Num	QC Sticker	Monitor ROM	Char ROM	Notes
#2775	1457	30 Jn 82 29 NLS	81-149	81-146	Drive Fix Mod
#3590	2220	6 Au 1982 4 Aug 1982 NLS QA 115	?	?	Drive Fix Mode Monitor pin 21 -> U59 pin 2 U60 pin 1 ->pin 8 Speed up mod w/switch RTC board QC dated 4 & 6 Aug 1982
#4207	2997	"R" NLS 3	81-149	81-146	no mods
#4222	3057	"R" NLS 3	81-149	81-146	no mods
#4223	3051	"R" NLS 3	81-149C	81-146	Drive Fix Mod

81-110B

The B board in extremely rare. It apparently had some technical problems that required the rapid update to the B1 board. It's design allowed for the total chips used to be reduced from 83 (A board) to 72 (B board).

81-110B Machines

Serial Num	Board Num	QC Sticker	Monitor ROM	Char ROM	Notes
#7872	5372	NLS 16 FT	MC K8 ProMonitor	MC Clean ProCHAR	This board was swapped for #93481 since it is a rare board

MC= MicroCornucopia

81-110B1

81-110B1 Machines

Serial Num	Board Num	QC Sticker	Monitor ROM	Char ROM	Notes
#7954	6992	NLS 16 FT	MC ProMonitor	MC Clean ProCHAR	Drive Fix Mod

81-110B2

81-110B2 Machines

Serial Num	Board Num	QC Sticker	Monitor ROM	Char ROM	Notes