FLIP CHIP
Flip-Chip was a DEC registered trademark, named after the "flipchip" component mounting technique which quite rapidly faded from fame. The name was retained although the majority of Flip-Chips never really were flipchip-mounted as it became apparent that the flipchip mounting technique was highly unreliable. Flip-chips were used in the DEC PDP-7 (Referred to in documentation as the "FLIP CHIP"), PDP-8, PDP-9 and PDP-10, beginning on August 24, 1964.
In practice, they performed generic, simple functions, similar to an integrated circuit. They were approximately 4 inches long and 2.5 inches wide. Each had 36 connectors, 18 on each side.
Contents
[hide]Naming
There appeared to be some confusion inside DEC at the time, as various manuals refer to it as "FLIP CHIP", "Flip Chip", "FLIP-CHIP", "Flip-Chip" and "Flip Chip", with trademark and registered trademark symbols.
Flip-Chip families

The various families were colour-coded, and the first letter denoted a colour, which was also visible on the handle.
A series
See the list of DEC parts.
The A stands for Amber. The A series were used for analog functions - ADCs, DACs, amplifiers etc.
B series
The B stands for Blue. The B series were used as core logic in the higher-end CPUs.
G series
The G stands for Green. The G series were used for "anything with non-standard voltages", I think.
M series
See the list of DEC parts.
The M stands for magenta. Part of this line is simple TTL-level logic, while later on, it became quite complex, see list of DEC part numbers. They replaced the R series which used discrete transistors with integrated circuits.
- Power supply: 5 V
- Operate at up to 6 MHz
R series
The R stands for Red. Slower logic than the B series, but cheaper. Used extensively in the I/O circuitry of computers.
- Slower logic than B series, cheaper
- Used in a variety of systems, e.g. PDP-8
- Power supply 10 and -15 volts
- Operational to 2 megahertz
- Signal level 0 volts, logic 0 and -3 volts, logic 1
- Typical price $20 to $30
S series
The S series is identical to the R seriese except that its transistors switch faster and lower resistance resistors, allowing more cards to be wired in series and operate somewhat faster.