I currently have three Symbolics MacIvory CPUs. (Do you, reader, have one to sell? Please leave a comment!)

One is currently installed in a working machine and was not yet molested; the two remaining chips, I obtained in 2017 by bartering away a Symbolics 3620.

At some point I will cut one or more of the “Ivories” [...]

This article is a continuation of “X-Ray Microscopy Kindergarten.”.

Preliminary experiment with multi-energy x-ray (colour channel combination), distinguishing materials by absorption at different wavelengths.

The tube appears to exhibit some “heel effect” at the longer wavelengths.

Exposure: 75 sec. @ 35kV, 21kV, 20kV (R, G, B) [...]

This article is a continuation of “X-Ray Microscopy Kindergarten.”.

Here, we see a stereo pair (approx. +/- 25 deg. one-axis rotation of the object from the horizontal plane, while film is stationary) of the device from before.

The vias are clearly distinguishable.

[...]

This article is a continuation of “PCB Radiography Kindergarten, Continued.”.

The radiography system is equipped with a “microfocus” tube, and its beam has a 30 degree spread cone. So we can get a look at that very same FG TRNG XC9572 CPLD seen earlier, but with 2x magnification:

Click for full resolution (Warning: [...]

This article is a continuation of “PCB Radiography Kindergarten”.

This was a second test-fire of that radiography system, using yet-another board where I already know where everything is (on account of having designed it.)

This time, the victim is a FG TRNG Mainboard:

Click for full resolution (Warning: 16MB)

[...]

Below is the result of test-firing a newly-installed miniature PCB radiography system.
The victim is a standard FG TRNG Analogue Unit:
Click for full resolution (Warning: 14MB)

Detail of left op amp, with bonding whiskers visible:

The substrate, aluminum RF shield frame, SMT contacts, vias, and the two layers of the PCB are clearly distinguishable. Likewise resistors (nearly transparent) [...]

This article is part of a series of hands-on tutorials introducing FFA, or the Finite Field Arithmetic library. FFA differs from the typical “Open Sores” abomination, in that — rather than trusting the author blindly with their lives — prospective users are expected to read and fully understand every single line. In exactly the same [...]

This article is part of a series of hands-on tutorials introducing FFA, or the Finite Field Arithmetic library. FFA differs from the typical “Open Sores” abomination, in that — rather than trusting the author blindly with their lives — prospective users are expected to read and fully understand every single line. In exactly the same [...]

Let’s compare the CPU cost of modular exponentiation performed on Chapter 14 FFA vs ye olde MPI.

V-press the MPI tree to mpi_second_cut.vpatch (or use diana_coman’s cleaned-up variant, this should not affect the result of the test.)

Now, replace the test_mpi.c example I provided, with the following MPIistic implementation of the Ch.14 example test tape:

koch.c:

#include "mpi.h"
#include <stdlib.h>
#include [...]

This article is part of a series of hands-on tutorials introducing FFA, or the Finite Field Arithmetic library. FFA differs from the typical “Open Sores” abomination, in that — rather than trusting the author blindly with their lives — prospective users are expected to read and fully understand every single line. In exactly the same [...]