That was a rather interesting read. It's like a combination of archeology and technology. - Joe Oprysko
Right. That's what early vintage computing looks like - kinda. ;) Editorial follows, for those interested. Otherwise: thanks for this glimpse into a corner of chip-collecting. - H Doing some Web "archeology" found the originator of the decapitated chip. It's part of a recent project by Robert Baruch which he calls "Project 54/74" and hosted on YouTube and a wiki at project5474.org, and his Twitter account. He extracts chip die from original 7400 (and the industrial/military version 5400) logic chips, for annotation and imaging; then reverse engineers the schematic. He seems to be doing other vintage-computing stuff as well, with new S-100 boards and 3D printing, very 21st century. Tracing out chip-die sounds like rocket-science; but it's a matter of knowledge and tedium, recognizing visual patterns and following the likely logic. That's what the "fake" poster Ken Shirriff performed in his deconstruction Web post. TTL gate-level logic is usually described in 7400 documents, but not in detail. EE's in the 70's era (like me) were trained in semiconductors at almost the die level; the detailed knowledge is/was available in other textbooks for IC design specialists. And, it's something done in the microprocessor collecting world; tracing out early CPU dies. There may well be other such projects, for other chips including TTL. And it was professionally done in the era as literal reverse-engineering; competitors looking for ways to produce copies, learn design techniques, and so on. "Archeology and technology" overlap considerably; archeologists try to reverse engineer how structures or tools, homes, weapons were made. To me this is another example of what I call preservation by restoration and repair and Web publishing. I work at the S-100 board and chip level, not at the die level. As do others in this email list. Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net