Below is the output of a new test-fire of the PCB radiography system, this time using FujiFilm “Super HR-T Medium Speed” (25×20 cm) film in place of the earlier self-developing dental Eco-30. However, the time has not yet come to molest the MacIvory — first, we must characterize the film and the pertinent chemistry. This […]

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 […]

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) film: “Eco-30”.

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. Exposure: 70 sec. @ 34kV; 0.3mA + 2x beam spread; film: “Eco-30”.

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: 7MB) This […]

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) For comparison, a visible-light photograph of […]

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. […]

This article is a continuation of the previous, and concludes the series. Let’s try this somewhat different variant of the program, which represents recurring bits of the expansion symbolically (and in a slightly more readable form) : ;; Register bitness. (defconstant +bitness+ 32)   (defun make-reg (reg-name bitness) "Make algebraic representation of a register (bits […]

This article is a continuation of the recent mega-puzzler concerning the experiment. This variant will reduce the equations. We will omit printing the input matrix, for brevity. And so: ;; Register bitness. (defconstant +bitness+ 32)   (defun flatten (l) "Flatten a tree." (cond ((null l) nil) ((atom l) (list l)) (t (mapcan #’flatten l))))   […]

This article is a byproduct of the recent mega-puzzler concerning the Serpent cipher’s key expansion procedure. Behold: ;; Register bitness. (defconstant +bitness+ 32)   (defun make-reg (reg-name bitness) "Make algebraic representation of a register (bits in descending majority)" (loop for i from (1- bitness) downto 0 collect (make-symbol (format nil "~A~A" reg-name i))))   (defun […]