VFD Output Filtering

[Susquatch]

I hesitate to dive in and figure out what it would cost to update all of the above. Likely the price of a small car.

Your lab is better equipped than mine by a wide margin even if it is old. The newest piece of electronics test equipment I have is a 150MHz 2 channel Tectronix 2430A Digital Storage Scope. I also have a 400MHz 4 channel 2465B Analog.

I do have a few signal generators but they are home made.

I'd love to have a few of the toys you have (especially the Discovery 2 multi function) but the truth is that I'd prolly never use it. I just don't do things like that anymore. Old age keeps relentlessly slowing me down.

I love reading your posts though. They make me laugh and remember days gone by with a big huge smile.

 

[jcdammeyer]

I forgot to mention I also have a 300 MHz Tektronix TDS3032 but it saves screen captures to floppies. And those are getting harder and harder to read even with new floppy readers. The probe plastic is also disintegrating. But it sits at the other workstation and/or gets dragged into the shop to look at encoder signals etc on the CNC stuff.

And then there's my analog 30MHz Gould 2 channel scope. Haven't powered that one up in a couple of decades. It's what moved me from being a sales guy for Cardinal and Bowtek into going back to school but taking Comp. Sci. I used it to develop a wire wrapped 48K dynamic memory board for my S100 computer. Back when all the EE's were telling me that you can't wire wrap dynamic memory boards.

Oh and I have one of these that I used to capture CAN bus data streams and decode into CAN bus messages. That was before scopes could do this. And I why I prefer integrated test gear rather than something with a PC based user interface. I have a prom/pal programmer where support stopped working when WIN-95 showed up. Cost me $1K back in 1994. Became useless with WIN-95 and WIN98.
As did this after WIN-XP and the vanishing parallel port.

NCI Gologic Logic Analyzer with Parallel 25 Pin Interface | eBay

If we have made a mistake we do apologize, we are only human.

www.ebay.com

 

[Susquatch]

And I why I prefer integrated test gear rather than something with a PC based user interface.

Damn good point John. I keep a few old computers around for certain software. As you may recall, I wish I had kept my S100 System.

An old boss of mine used to say that "Many the impossible thing has been done by someone who didn't know it couldn't be done.".

But ya, I never wire wrapped a dynamic memory board either. In fact, I hated that tool so I seldom wire wrapped anything.

 

[jcdammeyer]

The secrets to a 48K dynamic ram board for S100 are:
1. Use a Z80 not 8080 because the Z80 provides the refresh signal for the rams.
2. Use 22g stranded wire for the +/-5 +12 voltages instead of 30g kynar WW wire.

As for old computers. Pretty well a requirement. The processor that runs my foundry was programmed with a specific Kanda dongle. There is still the company resurrected from the original but they for some reason never bothered upgrading support for it and now it only works on WIN-98 machines. Luckily I have a laptop with that software and OS. Not functional on batteries but boots well enough that if I wanted to make a change to the code I could.

Likely what I'll do is make a new board that uses something more current or programmable. The code is in C. Pretty simple. Runs spark plug, fan, gas solenoid and can interface to a flame detector and air flow sensor. Just never added the flame and air flow stuff so the code has #ifdefs around that.

 

[Dabbler]

I only wire wrapped small projects. When I bought all my S100 stuff, it was on double sided PCBs. I never got around to designing any S100 boards, so no wire wrapping them... I still have a tube or 2 of 2101 dynamic memory chips for making a 4KX12 S100 memory board. Oh the memories!

 

[Former Member]

The secrets to a 48K dynamic ram board for S100 are:
1. Use a Z80 not 8080 because the Z80 provides the refresh signal for the rams.
2. Use 22g stranded wire for the +/-5 +12 voltages instead of 30g kynar WW wire.

As for old computers. Pretty well a requirement. The processor that runs my foundry was programmed with a specific Kanda dongle. There is still the company resurrected from the original but they for some reason never bothered upgrading support for it and now it only works on WIN-98 machines. Luckily I have a laptop with that software and OS. Not functional on batteries but boots well enough that if I wanted to make a change to the code I could.

Likely what I'll do is make a new board that uses something more current or programmable. The code is in C. Pretty simple. Runs spark plug, fan, gas solenoid and can interface to a flame detector and air flow sensor. Just never added the flame and air flow stuff so the code has #ifdefs around that.

View attachment 27610

Reminds me of building my first memory expansion on a KIM from 1K to to 2k

 

[cjmac]

Your lab is better equipped than mine by a wide margin even if it is old. The newest piece of electronics test equipment I have is a 150MHz 2 channel Tectronix 2430A Digital Storage Scope. I also have a 400MHz 4 channel 2465B Analog.

I do have a few signal generators but they are home made.

I'd love to have a few of the toys you have (especially the Discovery 2 multi function) but the truth is that I'd prolly never use it. I just don't do things like that anymore. Old age keeps relentlessly slowing me down.

I love reading your posts though. They make me laugh and remember days gone by with a big huge smile.

I have a 2465A in working order, but I also have a 2445A that need that U800 chip and a 2430A that has power supply problems. The 2430A could be potential parts if something fails in yours. I don't envision ever trying to do anything with it myself. Also have a 1240 logic analyzer and a bunch of S-100 stuff like John.

Chris

 

[whydontu]

Jeez. You guys are all old as me. 2102 chips, wire wrapped, to bump my RCA COSMAC from 256 bytes of RAM to a whopping 1.2kb! Built from plans published in Pop Tronics.

Used the COSMAC to drive R2R D/A converter for an analog modular synthesizer. Checked waveforms on my 10MHz Eico scope.

Hated my Hantek scope. PITA to have a scope that needs a PC. Too many wires.

For quick-n-dirty I have a couple of pocket DSOs
DSO213 4-channel
DSO211 single-channel
For $100 if I fry them it’s not too painful.

I tried a touch-screen DSO FNIRSI 1013D, ok but touch-screen isn’t intuitive for someone who grew up with Tek gear

I don’t do critical stuff, just need to see if the signal exists and how much noise. mostly audio. My current real(ish) scope is a Siglent SDS1052, a decent compromise between price and usefulness.

 

[Susquatch]

The 2430A could be potential parts if something fails in yours. I don't envision ever trying to do anything with it myself.

THANK YOU!

I have book marked this thread. You never know how the story might evolve......