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.

iPhone mount for monitor top - 3D print

In a video call with a friend recently I noticed that the video was noticably clearer than normal. They were using an iPhone as the camera rather than the camera in the monitor. 

It didn't take long to use TinkerCad to design a simple mount for my monitor. I've made it public here. 

The phone sits nicely with the camera used in this mode just above the monitor's build-in camera.

Here's the device. After the first prototype I went back and angled the phone forward a few degrees.

I use two of these but you can get by with one. My monitor is about 18mm thick so you might need to adjust the hook part for your monitor.

3D printers are such a useful thing in the world.

PicoRX SDR software for a Raspberry Pi PICO

Amazing work by Jon Dawson at 101 Things and others to bring a very capable SDR to the RaspberryPi PICO.

I've forked the project here and had claude write some very useful documentation on the user interface operation.

It sounds great:

You might notice that my display is offset two pixels to the left. The solution is to select the OLED type of SH1106 instead of the default SSD1306. (It seems they are frequently substituted).

Jon's blog post here is very good reading.

If you're interested in building one of these, I'm not aware of anyone selling these boards - you might try contacting the Manly Warringah Radio Society or it's pretty easy and low cost to upload the gerbers from VK2ARH (he designed this board) git repository and get them made.

I've recently ordered Jon Dawson's board from JLCPCB and the price for 5 was US$5 + shipping. (Shipping costs significantly more than boards).

Sunday FreeDV net - diversity of software

A terrific net this morning on 40m here in VK3. We had stations in VK2, VK3, VK5 and VK7. Stations were using not just FreeDV 2.3.1 but also the macOS FreeDVNeo and the Thetis SDR software. One was listening on an SDR that decodes RADE at the Nepean Men's Shed.

There was some SSB partly overlapping our normal frequency of 7.177 so I moved up 2kHz to 7.179. Most people realised but at least one didn't and when they transmitted interfered. In future I'll be careful to move at least 3kHz away. Lesson learned.

Here's some of the stations on the net, if you haven't heard RADEV1 this will give you a good idea of how it typically sounds.

Stations on the net included: VK2AWN, VK2BLQ, VK2DWG, VK3FAR, VK3FC, VK2KNC, VK3GTP, VK3JCO, VK3JF, VK3KEZ, VK3ZTR, VK5ABE, VK5FD, VK5RA, VK7HOB and me, VK3TPM.

Thanks to Stephen, VK2BLQ, for sending this clip of his reception of me in Sydney (about 1000km away).

Tech Talk on ABC Radio - Apple's developer announcements

This week on Nightlife Tech we discus the announcements at Apple's Worldwide Developer Conference. iOS 27, macOS 27 and the others will ship to users in a few months. The Siri features Apple showed two years ago seem to be real this time and the overreach in the Liquid Glass user interface design is being dialled back to be more usable.

In other AI news, after the success of the SpaceX IPO, based largely on future profit from their AI component, the other AI companies - OpenAI and Anthropic - are also planning their own IPOs. One model, "Fable 5", from Anthropic was released and then withdrawn for non-US citizens and this highlights a risk to Australians who rely on AI cloud services not controlled by us. Listen here: https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/106805414 

Sunday FreeDV net - very interesting discussion

A terrific net this morning in south east Australia. Amazingly there has been mobile FreeDV activity during the week! Most people are now on 2.3.1 which resolved a Windows audio issue.

Stations heard included VK2BLQ, VK3APG, VK2AWN, VK3FAR, VK3FC, VK3GTP, VK3KEZ, VK3PTR, VK3YSA, VK5ABE, VK5JPL, VK5RA, VK2DWG, VK2KNC, VK5FD, VK3JCO, and me, VK3TPM.

Several stations said that they'd like an option in the FreeDV app to auto-start the Modem at launch. This is particularly helpful when operating on headless, or small screen Raspberry Pi. I've raised a feature request here but it needs some more backers. Please add your email if you support this.

FreeDV Neo - native macOS client for FreeDV RADE V1

Built for my own entertainment but might be of interest to other macOS hams. FreeDV Neo is enough of an implementation of FreeDV RADE V1 to be usable on air. More info here including a download link. 

This app is not officially supported and you should first use the official FreeDV app from the project.

Tech talk on ABC Radio - SpaceX IPO, emergency communications & PCs going ARM

This week on Nightlife Tech Talk with Philip Clark, we discussed the US$1.7 Trillion valuation of SpaceX (if their IPO goes as planned), NVIDIA's announcement that they're getting in to the personal computer CPU market with an ARM based chip that seems influenced by Apple Silicon, and if you go in to the Australian outback there's a good saftey reason to carry a recent cell phone from Google or Apple. Listen here: https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/106751536 

Used AI to assist Bill from Soldersmoke

I'm a big fan of Bill Meara's Soldersmoke podcast and blog.  It's always a pleasure to hear from Bill and last week he contacted me asking for help with the website where he keeps an archive of the past editions of the podcast. 

Bill has been editing the HTML of the page manually using a web editor that had hit a page size limit of 1MB and would no longer let him add new podcasts so it had fallen behind. Here's how the page looked:

At first glance I thought this was an easy little job, get in via FTP and paste in the new episodes. When I looked more closely at the HTML, and ran a validator on it, my heart sank. It's a credit to the robustness of web browsers that they managed to render this as well as they did. The podcast has been around for 20 years and while some of the HTML was obsolete, worse was that Bill's copy pasting from his blog had all sorts of errors in it. Mostly table tags that weren't balanced etc.

The HTML had ballooned out and had parts that looked like they'd been generated in Microsoft Word's export to Web - huge runs of fonts and styles repeated over and over.

I thought this would take many days of manual clean up and editing so I turned to Claude code for the project. I downloaded the various existing pages to a local folder, explained what we wanted and mentioned the blog as a place to get missing information.

Claude installed BeautifulSoup and proceeded to write python scripts to extract just the needed information from the existing broken HTML. It also looked at the blog to get missing info, looked at YouTube and even got the modification dates of the mp3 files to figure out publish dates. The result is at soldersmoke.com and now looks like this:

The HTML now validates without any complaint and it's much more efficient and compact than before.

AI will put web developers out of work to some extent. On the other hand it's fantastic at doing what would have been an incredibly time consuming menial task. This kind of job might not have been done at all except for this marvelous new technology. It's not perfect but it's amazing what can be achieved.

Thanks to Bill for all his great content, it's great to see the podcast archive remains available and up to date.

Away from home but monitoring the FreeDV net

My wife unfortunately broke her arm a few weeks ago and can't drive so I've been away from home looking after her. Normally on a Sunday morning I would conduct a FreeDV RADE V1 net on 7.177. 

I tuned in this morning via the excellent Ironstone Range WebSDR and was pleased to hear that stations can chat without my help ;-).

This screen recording was made by using Loopback to pipe audio from the Safari Web browser into my home brew FreeDV app for macOS called FreeDVneo.

Tech Talk on ABC - Google I/O preview and software updates

This week on ABC Nightlife Phil and I preview what's coming up in this week's annual Google I/O conference. Headline topics include AI, Android 17, the Chrome browser and a new operating system for laptops dubbed "GoogleBooks". 

We make a call for RCS messaging which will smooth out messaging between Android and iOS. 

There have been an unusual number of security updates from both Microsoft and Apple - are these vulnerabilities being found by AI? 

Listen here: https://www.abc.net.au/listen/programs/nightlife/nightlife-tech-talk-with-peter-marks/106698692

Incidentally, I was in Melbourne this week so took the opportunity to talk to Phil in Sydney from the Southbank studio.