We explore the 1975 HP 1607 Logic State Analyzer, one of the first logic analyzers, while noisy construction is going on in the background. And we conduct a completely impartial test on how it stacks up with a modern reincarnation.
Ya... I was a bit confused until I saw it happen. Then when he hit blanking , and I saw crisp clean 1's and 0's - I was amazed. You could have used that display in a 1970's James Bond movie, with a "nameless henchman" dressed in a blue jumpsuit, monitoring the data.
Around 1980 I worked with a Z80 development system that connected to an analog scope in the same way to display a trace. It displayed data and addresses in hexidecimal. Sorry I can't recall any more details.
I had one of those but ended up selling it as it was just too limiting BUT the qualifier bits actually make this better than the cheap analyzers in respect of triggering and I rather wish I hadn't sold it and kept it purely for triggering a more modern device. The clips on these HP analyzers are the best ever
@@AllElectronicsGr I'm pretty sure what he's saying is that it's much simpler because it's just ones and zeros A quadrature oscillator makes a sin wave and that same sine wave shifted 90 degrees (a cosine). If you let the X coordinate be the sin output and the Y coordinate be the cos output , you'll get a circle/0. To get a one you just have to surpress the X output. So you negate the input and use that to enable the X output, and you'll get something that displays a 1 when the input is 1 and 0 when the input is zero. You then level shift the X output once per cycle of the oscillator to shift where on screen the 0/1 is displayed, and thus make a line of 0/1, and level shift vertically at 1/16th the frequency to make multiple lines. You the. Put a signal to display nothing on screen while you're doing the shift, and voila, nice display of 1/0. This method makes the bit inversion really easy, instead of disable x oscillator output when held high, you enable it This is only so simple because 1/0 are easier, you could probably also make an 8, but the other numbers/letters would be challenging The top and bottom of the 1 probably look a little brighter than the middle because the electron beam lingers there a little longer due to the sinusoidal nature of the output, as well as being just brighter overall because the beam moves pi times further in the same time for the 0 than the 1 Edit: or level shift every so many cycles looking at the unblanked output a bit more
Dylan Davies Other shapes are possible via Fourier decomposition and you only need maybe 6 frequencies (fundamental + 5 harmonics) to draw OK characters. 12 signals total, with on-off gating, per each component (X and Y). For some harmonics you may wish more than one amplitude so, say, you may end up with 24-48 bits of switch control signals. But that would be for a general case - surely one can choose the harmonics and amplitudes that work best for whatever subset of alphabet/digits you want, possibly with less than 32 control signals. It’s a rather efficient representation of characters - 2-4 bytes/character, depending on how you design the font. And since it’s all relatively fast AC, you can do switching using diodes and AC couple everything - cheap, way cheaper than analog muxes.
Coolest piece of test gear I've seen since my buddy's plaid generator (crosshatch generator) We never did tv repair but he found it and we used to turn it on at parties to throw up on the TV lol. But this is awesome!!!
My freshman year at Ga. Tech in 1988-89 I took a class on TTL circuitry, and we used an HP logic analyzer very similar to that one. I don't remember the exact model we used, but that thing looks very familiar.
that's amazing- i didn't know test equipment that displayed the output as drawn characters on a sillyscope existed- I thought only early broadcast tv equipment did displays like that. I assumed any logic test equipment would just be rows of leds or counters showing oct or hex
Look into 7L logic analyzer plugins for the Tek 7k mainframes. Same principle. Heck, those mainframes have a built-in analog character generator for labeling vertical and horizontal scales. And the characters are passed from plugins to the mainframe as… analog voltages, none of that digits rubbish :) Well, to be frank, they are IIRC base 12 digital signals in a multi-level logic (vs base-2 on-off).
Ingenious use of a scope for display purposes! The comparison wasn't really very fair. It was like comparing a vintage Rolls Royce with a recent Tata Nano! Yes, they do the same basic job but one's a delight to drive whilst the other really just gets you from A to B! Great to see such beautiful old kit, though.
What? Apple to oranges? Not fair? The only rule on this channel is that the old HP unit always win. Apart from that, expect 100% objective and impartial evaluation.
What is the mainframe (or is it a mainframe?) in background? I mean the thing with dials that looks like IBM IPL device selector dials and keyboard that looks like many HP desktop computers. I mean the thing to the left of this large reel to reel.
That would be my HP 5451C Fourier Analyzer. A combo computer and ADC and measurement instrument and programmable Fourier calculator. One of the earliest DSP really. To be restored.
Wow, I didn’t realize people were ripping off the Salae brand for those little crap units. Real Salae Logic units are $100~200, but are way nicer. They’re based out of South SF, and are nice folks. It’s still impressive what you can get for $12 on eBay, though.
To be fair the "real saleaeaeae logic" is just a copy and paste of Cypress EZ-USB FX2LP application note from datasheet, and it wasnt even the first logic analyzer build this way. Salaleaeeaeea itself is a company founded on ripping off USBee.
I would love to have those switches for the pattern. It is either a rotary dial or touchscreen on my 45000$ desk device. I am thinking of making a gpib control panel with rocker switches only ;)
rasz: They were originally, the newer ones are a little bit more complicated. I still think they are overpriced, but you're really paying for the software.
Very cool. I have a pair of 1670A's. I had a feeling you'd go for a 74LS90 and discover to your horror a little later that the VCC & GND pins aren't where you'd assume they normally are.
What type of connector is the 3-lug TRIG BUS connector that is smaller than the BNC connectors? My best guess is that a Trompeter / Cinch PL50 "TPS" might be a mating connector. I have an HP 1600A and would need to build a TRIG BUS cable to connect an HP 1607A to it if I pick up one of those.
Seems to me that with 256 LEDs, the 'scope display could have been dispensed with. Even in 1975, 256 LEDs would have been cheaper than all that display driving circuitry. Maybe it really came into its own when used as an extra 16 channels to the other logic analyser.
Oh man I have that same scope... It worked for a while after I got it... Then something popped and well... Edit: Oops maybe not... Mine was a memory scope... Extra set of buttons up above the knobs
CuriousMarc I wonder whether the percussion electric tool is more or less auditorily disagreeable than the manual alternative. A good demo person would develop a steady rhythm on the chisel so that wouldn’t be as disturbing as a more random pattern by someone inexperienced. Stucco should fall off with a fairly wide chisel and once you find the suitable angle it can be a fairly quickly progressing job, with a steady hammering tempo. I’ve seen a pro in action doing something similar and I swear they kept the 4-4-3 pattern going at 1/4=70 tempo for minutes on end. It could almost make one fall asleep!
Absolute porn for nerds are these HP equipments! I own a HP LCR bridge (1984) and it works like a charm! Downrange to fF (femtofarads). Never required any adjustments, all measurements are spot on!
