This object is one of the earliest micromputer chips made available on the hobbyist market. It uses the same micro-processor chip that later became the heart of the Apple II computer.

It is part of a collection relating to the history and development of calculating devices assembled by Assoc Professor Allan Bromley of Sydney University, comprising mathematical instruments, slide-rules, mechanical and electronic calculators, electronic analogue computers, computer components, kit computers, education computers, and associated ephemera.

Allan Bromley was a lecturer and researcher at the University of Sydney Basser Department of Computer Science from 1978 until his untimely death in August 2002. He specialised in Computer Architecture, Computer Logic and in particular the History of Computing. He was regarded as the world authority on Charles Babbage's Calculating Engines (instigating the building of the Difference Engine No.2 at the Science Museum London) and the Antikythera Mechanism and had extensive knowledge of calculators, analogue computers, logic, stereopsis, totalisators, clocks and time keeping and mechanical engineering.

Microcomputer Associates Inc, USA, 1975

The Jolt played a part in the development of the prototype Atari 2600 VCS, which was assembled using the Jolt computer board.

Six printed circuit cards assembled into a unit with multicore flat strap IDC cabling between cards. The cards have the electronics required for a small kit computer originally designed to demonstrate the MOS Technology 6502 microcomputer.

The top card is a half-size front panel with input and output patch-plug connectors (eight of each) on either edge of the top card plus two control connectors each and three holes marked 'RESET', 'NMI' (non-maskable interrupt), and 'IRQ' (interrupt request) with wires led through them. The card immediately below this card distributes wires attached to the patch plug input and output connector to the rest of the cards.

The main card carries the processor, port expansion and memory access control chips in IC sockets. These are the MCS6502 central processing unit (CPU) chip in a 40pin "dual-in-line" (DIL) white ceramic package with a gold chip cover, a MCS6530 read only memory (ROM) programmed with a "monitor" - device initialisation and terminal (VDU, or keyboard and character display) software - and debugging software, a Peripheral Interface and Memory control device also in a 40pin DIL white ceramic chip carrier and a Motorola XC6820 (engineering sample version of the MC6820) CPU support chip. It also has 10 MSI (medium scale integration) chips which electronically connect the CPU card to the memory and input/output cards.

Assembled below the CPU card are three identical memory cards each having 32 x AMD 2111 static random access memory (SRAM) chips.

Made: 1975

'Jolt' micro-computer

2010/1/98

1975

134 mm

146 mm