Z80 Turns 50

In this morning's news a great piece about the Zilog Z80 CPU chip turning 50. This triggers many happy memories. I had a Tandy/Radioshack TRS80 clone called a Dick Smith System 80 that I programmed to key the cassette deck motor relay to send Baudot to a teletype. Later I had other boards and even a Sinclair ZX80. 

CP/M with Wordstar was my writing environment for too many years - although I kept using it and some indexing tools I wrote using BDS-C - a fast compiler that I recall arrived on 8 inch floppy disks I had to get a friend to copy over to 5 inch.

My first paid programming work was in DBase II on CP/M. It was such a rich time in home computing with many fine alternatives and new machines on the covers of magazines every other month.

Tech talk on ABC Radio - Telstra outage, smartphone replacement battle & smart TV shenanigans

This week on ABC Nightlife Tech we discussed how the recent Telstra network outage which affected all sorts of things including country trains in Victoria seems somewhat similar to the Y2K bug. The battle to invent the tech product that will displace the smartphone is getting nasty with Apple suing OpenAI over stolen hardware secrets. Your smart TV apps may be using your home internet connection to scan the internet - perhaps it's time to use a set top box for streaming? Listen here: https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/106915290

101 Things Pi PICO sideband transmitter

The uSDX transceivers are not great but it's amazing that they work at all. An under-powered Atmel processor being able to demodulate and modulate single sideband is incredible. Hans at QRP-Labs has turned polar modulation in to an incredibly well performing radio in the form of the QMX.

What's missing is the technology of the uSDX ported to a more capable CPU and Jon has done that. It's one of a group of amazing bits of code documented here and shared here.

I've taken just on bit of it, the transmitter example and forked it here.

Not sounding great at this point but it does work. What's incredible to me is that there's no Si5351 being rapidly phase shifted, it's all done in the PICO. The circuit is very simple, even more simple than an NE602 based qrp transmitter.

I can well understand why QRP-Labs keeps their software closed source - they'd be put out of business by clone makers in minutes. Having said that, I hope we can one day have an open source equivalent to hack on. Thanks to Jon for his great work.

My analog switch chips, the FST3253, arrived smaller than I expected. My fault! I have some carrier boards but struggle to solder the tiny chips to them. Second attempt worked today.

FreeDV Sunday net - 17 stations, good discussion

Once again I had to move frequency to avoid analog traffic. Not a problem with the Reporter though and we had 17 stations on the frequency today. There was some selective fading but conditions improved as we went along. This morning we were back on 7.177Mhz.

VK2BLQ, VK2KNC, VK2ZB, VK3AOK, VK3EY, VK3FAR, VK3FC, VK3GTP, VK3JCO, VK3KEZ,  VK3PCC, VK3TPM, VK3UBK, VK5AG, VK5FD, VK5RA, ZL2IT. Unfortunately Error in NZ couldn't hear us.

I was using my FreeDV client for macOS. I've been adding some more fancy graphs. (Click to enlarge).

Thanks everyone who joined in.

AI - The god we made

I highly recommend the feature essay in the latest Quarterly Essay titled "The God we made - the threat and promise of artificial intelligence" by Anna Goldsworthy.

My newsagent's penchant for placing their price stickers over the title makes this look like "Arterly Essay" which is somewhat appropriate as Anna is a music academic but is impressively well read in the AI realm including the amazing Dwarkesh podcasts. 

She talks about the impact on writing, music, art, education and work "the bottom rungs of the career ladder have been knocked out".

On education she observes something that I've also thought, that the current crisis in students using AI to answer their assessments is not to be blamed on AI but rather the mass production of assessment.

Apart from her alarm at the high chance that we'll all be wiped out by artificial super intelligence in its quest to make paperclips, she celebrates the capability of AI to help us all educate ourselves.

Spelling checkers didn't make us good spellers. Grammar checkers don't improve our grammar. Will AI Chatbots dumb down our thinking or raise us up to a higher level of enquiry?

Postscript

After reading this I re-watched Spike Jonze 2013 Movie "Her". If Apple ever makes a folding phone he will have been correct in pretty much everything.

Updates to FreeDV Neo

Work continues on my little FreeDV RADE V1 native app for macOS. Feedback from some users bemoaned the lack of fancy visualisations so I've addressed that. The latest version also improves the operation of the Reporter window quite a bit and adds a filter by my frequency option.

More information and a download link is here.

It's great to see all the third party FreeDV RADE apps starting to appear. We have a list of known ones on the FreeDV site here. Let me know of others that I've missed.

Tech talk on ABC Radio - AI is costing us in more ways than one

This week on ABC Nightlife we discussed new data from a study by the University of Newcastle, published in the British Medical Journal, that concludes that more than 80% of teens under 16 are still accessing social media sites banned in Australia. The government has moved to increase penalties but our teens are technically pretty advanced it seems. 

Social media is currently awash with AI generated content designed to encourage division and presumably promote far right politics. 

Finally, Apple has increased prices due to shortages and price rises of components used to build out AI server farms. Other manufacturers have signalled significant price rises as well. AI is costing us all in ways we never expected. Listen here: https://www.abc.net.au/listen/programs/nightlife/ai-is-about-to-cost-us-more-than-we-anticipated/106862726 

Mems microphone to USB Audio

A PDM (Pulse Density Microphone) and a Raspberry Pi Pico. It appears on the computer as an audio input (I changed the name from the original).

All credit for this project to Sandeep Mistry here. 

A recording of how it sounds (pretty good) is here. There's a bit of mic popping - perhaps a pop filter would help.

Applications of this technology are swirling in my mind...

Strain relief for RG58U coax - 3D print

I've been a bit slack with my dipoles here in the bush, the coax just hangs from the PL259. It's been fine until kangaroos catch the coax and rip the coax out. The repair isn't too hard but I thought I'd look for a way to relieve the strain on the connection and ended up with my own design for 3D printing.

It has a channel that the coax fits in to and two cable ties to grip it.

3mm cord lifts the coax slightly so that there's no weight on the PL259. 

I designed it in Tinkercad and you're free to grab it for printing for further modification here. It will be interesting to see what breaks when a Kangaroo goes through it next time.

FreeDV Sunday net - moved to 7.197

For a few weeks we've run in to analog traffic when using 7.177 so today we moved to 7.197 and the frequency was clear so I think we might stay here in future. Most stations figured out that we'd moved so we had a good rollup and an interesting discussion about the proposal to report centre frequency rather than dial frequency in future.

It was noted that Icom radios have an option to tune to the centre but most of us have turned that off.

FreeDV reporter was a little unstable today.

Stations on the net included VK2AWN, VK2BLQ (combination digital voice and valve audio with 6AU6 and 6AQ5), VK2KNC, VK3FC, VK3GTP, VK3JCO, VK3KEZ, VK3ZTR, VK5AG, VK5ABE, VK5FD, VK5JPL, VK5RA and me, VK3TPM.