Woodstock Chipset Decapped (HD Photograph)

[andylithia]

Greetings forum
I've recently acquired an old metallurgic microscope that is good enough for micro-meter scale chip analysis. The first thing I set out to do is to decap and obtain a complete photograph of HP ACT - the second generation calculator chipset seen in the Woodstock series.

https://lithcore.cn/decaps


For those wanting to know more about the circuit design, a good way to start is by reading the Verilog source code of Monte's 41CL that he kindly provides. This implementation is almost identical to the original design, and HP-41's architecture is basically an enhanced version of that of the earlier chipsets.

Also, years ago, I wrote three articles on my blog, exploring the details of HP's bit serial design. To me, a student who was born in the CMOS VLSI era, bit-serial calculator chip design is totally exotic. The adventure was quite enjoyable.

https://lithcore.cn/2103

[TomC]

Nice photo!

The BitSerial articles are well written and most informative.

Thank you,
TomC

[EdS2]

Very nice Andy - thanks!