Category: hardware


power mosfet

The power supply in the PC has evolved over time however the basic technology has remained the same. Most of the changes over the years were driven by many different forces. BRIDGE RECTIFIER It takes 4 power diodes to covert the 115V AC to about 150VDC.  The reason the voltage is higher is that DC …

Continue reading


The Intel C8080A microprocessor was released circa April 1974. The CPU replaces the earlier Intel 8008 processor, Once CP/M was ready, the 8080 became a successful platform for business machines. As the 1970s unfolded large numbers of machines were designed and built. The C8080A is largely 8-bit however it does add some 16-bit instructions not available …

Continue reading



Networking got its start back in the 1950s with RADAR systems and mainframe systems. Ethernet came from Robert Metcalf’s PhD dissertation in 1973. Eventually this was standardized by the IEEE as 802.3 working group. In the early days DOS machines used coaxial cables to wire up a group of machines into a local area network, …

Continue reading


In the early days the first printer we had used was the IBM 1403. In 1970,  the model 7 was in use with the IBM System 360 mainframes. The 1403 used a chain and a bank of solenoid hammers to print letters on a line. The ink ribbon was a long roll the width of …

Continue reading


Back in the early 1980s the use of a 32-bit MBR index was believed to adequate. Hard disks from the 1956 to 1981 had not even made it much past 1GB with mainframes. The IBM 350 Disk Storage Unit (image), released in 1956, consisted of the magnetic disk memory unit with its access mechanism, the …

Continue reading