EEVblog Electronics Community Forum
EEVblog => EEVblog Specific => Topic started by: EEVblog on October 08, 2018, 11:34:19 pm
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More Mailbag Monday
https://www.youtube.com/watch?v=cwNBfnNO4AY (https://www.youtube.com/watch?v=cwNBfnNO4AY)
SPOILERS:
A-TEK AT-601 PC ISA Bus Design Breadboarding Tool
Gigatron TTL computer update
https://gigatron.io/ (https://gigatron.io/)
VintageTek museum XY demo board
https://www.ebay.com/str/vintagetek (https://www.ebay.com/str/vintagetek)
1970's Casio CQ-1 Calculator
Zofz PCB Gerber Viewer
https://www.zofzpcb.com/ (https://www.zofzpcb.com/)
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I was just messing with one of those tek boards and some other oscilloscope art stuff last night.
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8:30
Use [Arrows] to select
Press [A] to start program
"Do I have to read the instructions"
:palm:
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8:30
Use [Arrows] to select
Press [A] to start program
"Do I have to read the instructions"
:palm:
They are the same instructions as for the original ROM that used the Nintendo controller thing, so I kinda just subconsciously ignored them assuming that the keyboard version worked more sensibly.
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The programmer* also didn't see that line for months.
https://github.com/kervinck/gigatron-rom/issues/38
*me
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Great Mailbag episode... :)
i would expect that the 244 on the ISA card was probably fried and replaced by a user rather than being mismatched from the factory. I've certainly blown up my share of 244 and 245 chips. :-[
Does the CQ-1 power up at all? It shouldn't be terribly difficult to diagnose basically what is wrong. ;)
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Hey Dave, just noticed this particually on this video
The audio in your video is below the Youtube Reference level by 4.9db Youtube does weird things with normalisaton and stuff, ( you can google this topic ).
You might want to run a loudness meter in your audio, before you push it up to Youtube, to get it up to about -22 LUFS
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Nice video :)
Another demo of the Tektronix logo board by w2aew: https://www.youtube.com/watch?v=1tTeXPmbxW0&t=3s (https://www.youtube.com/watch?v=1tTeXPmbxW0&t=3s)
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Tandy were selling their Radio Shack branded version of that Casio alarm/calculator back in the day. I remember working in their store in Westfield Parramatta when they came in. They were the ants pants.
(https://www.eevblog.com/forum/blog/eevblog-1130-mailbag-monday/?action=dlattach;attach=543320;image)
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Still have my Casio CQ-1 (from 1977 in my case), it stopped working some years ago (the display and one or more switches I think). It's actually not strictly a "4 banger", it can compute with date and time (like number of days between dates). Ok, not super useful but everyone got to know their age in days.
/Lars
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That's a knife!
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I built a circuit back in the day to display the polarization of an RF signal in real-time on an oscilloscope, similar to this Tek device but not quite so fancy. I only drew a polarization ellipse on-screen, and used the z-axis to make the trace look like a dashed line for counter-clockwise polarization (solid was clockwise). I’m surprised the Tek device doesn’t use the z-axis to “pick up the pen”, so to speak, while tracing out the sketch. Without z-axis modulation, it’s like drawing something on an etch-a-sketch.
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It seems Dave missed one special feature of the Vintagetek XY demo board: play tennis on the CRO!
With no jumpers, the board alternates between the logo and the Wizard, a few seconds each. The images are displaced slightly periodically to reduce the possibility of screen burn-in. To draw only the Logo, connect the pad marked “L” to ground. To draw only the Wizard, connect the pad marked “W” to ground. To play tennis, connect two pots to +5 and ground, with wipers to the P1 and P2 pads and ground both W and L pads. The mode is determined at power-on. Thereafter, any changes to the W and L pads have no effect. The pots should be linear-taper and between 1K and 10K.