The Newbear 77-68 was a kit of parts from which a purchaser could construct a first generation home computer based around a Motorola 6800 microprocessor. Because it was designed to be assembled by its owner at home, it was also a homebuilt computer. The 77-68 was designed by Tim Moore and was offered for sale by Bear Microcomputer Systems of Newbury, Berkshire, England from June 1977. It was among the first, if not the first, of British home computers and was featured in the launch edition of Personal Computer World magazine in February 1978. The Newbear 77-68 was both a home computer and a homebuilt computer, since it was designed to not only be used at home (hence a home computer), but also be assembled at home by its owner (hence a homebuilt computer). Description The basic 77-68 comprised an 8-inch square printed circuit board accommodating the microprocessor, Static RAM of 256 8 bit words and the bare essentials in terms of input/output and timing logic to make a working computer. The processor ran with an instruction cycle time of around 1.25 microseconds with most instructions executing in 3 to 7 microseconds. In the short time for which the 77-68 represented an economic and reasonably current technology for home computing, an active user group distributed designs for additional components such as memory cards, video display cards and teletype interfaces which enthusiasts could, and did, construct themselves. It was even possible to run BASIC. All the components to build the basic machine could be bought for around £50 with additional elements added later. This was a sensible approach at a time when, for example, 16K x 1 bit dynamic memory chips cost £7 each and 8 chips plus a significant amount of support logic were required to build a memory card. Operation The 77-68 was programmed in its most basic form with toggle switches and LEDs. With the microprocessor's operation suspended in "HALT" mode, memory words could be accessed and their contents observed in binary. The word could then be modified directly using an additional 8 binary toggle switches to specify the data required. Once a complete program had been "toggled in" using this method, the "HALT" condition could be removed using another switch and the microprocessor would look for an address at which to start executing the program in the last two words of the address space. This technique, called