Semiconductor History

The IBM System/360 mainframe development which started in 1961 was the biggest product development in corporate history. Costing $5B at the time ($44B today), it was a huge gamble, but it paid off handsomely for IBM. They dominated the market for the remainder of the mainframe computer era. There were several big innovations which created its success, including, upwards/downwards software compatibility across the range, standard interface for many different peripherals, emulation of other platform developed software, adoption of the 8-bit byte and Solid Logic Technology. Seen in close up, SLT was a ceramic substrate technology with printed resistors and mounted transistors, creating Resistor Transistor Logic (RTL) blocks. The resistors were trimmed before the lid was put on the modules. IBM gambled in large part because they were facing increasing stiff competition. One of their competitors launched a product with early logic integrated circuits. IBM had considered this but felt the te...

IBM Standard Modular System (SMS) Card The Standard Modular System for mainframes was introduced by IBM in the late 50s for the 7030 Stretch program. The card on the left is an IBM SMS card post 1969 even though the card format had changed with the System/360. This card is from a 2420 tape reader. Tape machines and other peripherals kept the SMS format and the component technology longer. The NPN transistors are date code 1970 but are IBM 030 and 044 transistor models defined in the late 1950s. The IBM chrome coloured module on the right of the card is SLT (Solid Logic Technology) format. Later IBM Format Card Monolithic System Technology (MST) was introduced by IBM in 1968 and first appeared in the System/370. It replaced the earlier discrete transistor and diode logic SLT, SLD and ASLT hybrid logic with monolithic circuits, still on ceramic substrates in the same IBM package format.