Author: Before 15 years ago, Internet was hard to search/reach and there were no quality info (Google wasn't invented) so I spent lot of time digging out the specifications of various electronic circuits. All data collected is summarized on these pages. Nowdays, all this information is almost obsolete, and I kinda lost interest in electronics, but nevertheless I will leave these pages as they were.

Documents:

• Basic characteristic of digital integrated circuits (74xxx and 4xxx family)
• ISA bus (pin description)
• Parallel port by Kris Heidenstrom (pins and description of PS/2,EPP,ECP mode)
• How to make your own AT card (PIO & DMA data transfer,connecting IRQ lines,..)
• EPROM, EEPROM and GAL programmable logic devices(simple and high performance programming theory)

Links:

• Tomi Engdahl page: very useful page at which you can find docs on various things such as:
  electronic circuits (audio,video,computer,data communication circuits,..),
  description of opamps (LMxxx), 555 timer chip,MAX232 chip for RSs232 communication, there is also description of PC-hardware: ISA,PCI bus, Plug'n Play technology...
• Electronic WorkBench 5.0. Software for designing electronic circuits