Nix McRetro (Unofficial) / Nix McRetro (Unofficial) is on Nostr

Unofficial automated RSS/Atom links to Nix McRetro's work on retro computing and video-game history. Original work is credited at the source; follow the source links. Zaps support the independent feed operator, not the author.

Last Notes

2026-10-27 04:00:19 GMT

Still Dialling in My Head
The real Avtek MegaPlus V.32bis CD950 dialling 8218 3400. Eight digits, two frequencies for each one.
There’s a particular sound from the dial-up internet days that’s been stuck in my head for more than twenty-five years. Not the modem handshake itself, although I remember that well enough to know it wasn’t V.92. It’s the telephone number being dialled before the connection even gets started.
I can still sing it. Well, I can sing what I think it sounded like, which is an entirely different problem. Rather than leave it alone, I decided to see whether the melody might tell me which Sydney dial-up number I was hearing back in the late 1990s and early 2000s. This became quite the rabbit hole.
Two Numbers, One ISP
I remember using TIG/IHUG in Sydney, and having two numbers to try when the lines were busy. Windows Dial-Up Networking handled the dialling, but if a connection failed we’d have to start it again. I can still remember doing that far too often.
After a trawl through the Wayback Machine, the two Sydney numbers turned up on the archived IHUG access list from March 2000: 02 9373 5100 and 02 8218 3400. They belonged to the same ISP. By April 2002, the archived list showed only 02 8218 3400 for Sydney, although that doesn’t tell us exactly when the other number stopped working.
Both TIG/IHUG numbers reconstructed using the same settings measured from my later Avtek recording. These are synthetic tones, not two historical recordings.
There’s also the question of whether Windows actually dialled the 02. With the local calling rules configured for Sydney, it could dial just the eight-digit number. That gives us two possible starting points before we’ve even looked at the music. Lovely!
Sing It Back
I made six recordings of my best attempts at remembering the dialling sounds. Recordings #1 through #4 and #6 came out as individual little notes. Recording #5 was more of a continuous tune. Apparently my brain has spent two decades working on its own arrangement.
Recording #1 through Recording #6, in order. The bright horizontal stripes are voice harmonics. Nothing has been pitch shifted or time stretched.
Even with the variations, the shape of the melody kept coming back. A little drop around the third sound, a higher group in the middle, then another drop towards the end. Recordings #1, #2 and #3 are especially consistent, despite my singing pitch wandering around a bit.
The same melodies viewed as relative pitch rather than coloured frequency bands. Recording #5 is shown separately because it was sung as a continuous phrase.
We measured the time between the shorter sung notes as well. Across Recordings #1, #2, #3, #4 and #6, which have identifiable note bursts, the median was about 0.225 seconds. My real Avtek modem dialled at about 0.200 seconds between tones. That’s not too bad for something I last regularly heard more than twenty years ago.
The five recordings with distinct notes have a similar cadence to the Avtek dialling. Recording #5 was a continuous melody, so it is not included in this comparison.
The Real Avtek Modem - Well a Real V.32bis Edition
Here’s where the old hardware helped. I had a video of my Avtek MegaPlus V.32bis CD950 attempting a connection, published in 2022. I had manually entered 8218 3400 after finding the number on the Wayback Machine, so it wasn’t a number I’d recovered independently from memory. But it did give us a genuine modem recording to examine.
The eight dialling tones decoded perfectly as 8218 3400. Each digit produces two frequencies at the same time, which makes the spectrogram look like a tidy little ladder. The two eights match one another, and the final two zeroes are identical too.
Measurements taken from the real recording. Every digit contains a lower and an upper DTMF frequency.
After the digits, the recording continues with a series of repeated calling tones at about 1,300 Hz. Those begin around 2.3 seconds apart, rather than every 0.2 seconds. It turns out that the quick notes in my memory have a lot more in common with the dialling part than the waiting part.
One genuine recording, two very different sounds. The eight dialled digits are on the left, followed by the longer calling tones.
Two Frequencies Vs. One Amazing Voice
The catch is that a telephone keypad doesn’t play a conventional single musical note for each digit. DTMF combines two frequencies. When I sing the melody back, I’m producing a vocal fundamental with harmonics above it, which isn’t the same thing at all.
My voice on one side, the real Avtek DTMF on the other. It’s easy to see why a remembered melody doesn’t decode neatly into telephone digits.
We tried comparing the relative rises and dips, differences between DTMF frequencies, and spots where the same digit should make the same sound twice. Some results looked rather good for 9373 5100. Others favoured 8218 3400. The awkward part was that moving the eight-note window by just one or two positions could change the winner.
The earlier comparisons, all shown together. A different starting note can change which number looks best, so I’m not going to pretend we’ve decoded it.
Still Stuck in My Head
So, which one was it? I still don’t know for certain. Both numbers are genuine TIG/IHUG Sydney access numbers, and I do remember switching between them. The rhythm of my recordings is surprisingly close to actual dialling, while the general melodic shape has survived better than I would have expected.
What started with me humming an old dial-up number has turned into a collection of archived ISP pages, six rather questionable singing performances, a real modem recording and some cool-looking graphs.
At least I know it most likely a TIG/IHUG number stuck in my head. Maybe slightly off key. And I can’t tell you exactly which number it was, it was just one of the two. Then again, maybe both. Or maybe… their 0198 number. Hmm… :)
Sources
TIG access numbers, 29 January 1999
IHUG access numbers, 6 March 2000
TIG access numbers, 15 April 2002
TIG access numbers, July 2003
TIG access numbers, January 2004
TIG access numbers, August 2004
Related Posts
2022: Year of the Dial-up Modem
Avtek MegaPlus V.32bis - First Connection Attempt
https://mcretro.net/still-dialling-in-my-head/
https://mcretro.net/assets/images/2026/10/still-dialling-in-my-head/01_actual_avtek_dtmf_spectrogram.jxl
https://mcretro.net/assets/images/2026/10/still-dialling-in-my-head/02_both_ihug_numbers_spectrograms.jxl
https://mcretro.net/assets/images/2026/10/still-dialling-in-my-head/03_six_voice_spectrogram_grid.jxl
#rss #feeds #linksharing #qwibbit

2026-10-27 03:15:04 GMT

VRAMpage MD: Bending Bits
Some of my earlier VRAM experiments on real hardware. The browser version came rather later!
I’ve spent plenty of time persuading Mega Drives to produce pictures they were never asked to draw. Usually this involved a length of wire and a console that wasn’t especially pleased about it. VRAMpage MD brings that experiment into the browser, with considerably less opportunity to damage the actual machine.
I worked with Codex on a modified Genesis Plus GX emulator, compiled to WebAssembly. The faults go into the emulated memory accesses and sound-chip inputs, so the emulator has to deal with the consequences. The work grew into three main parts.
Bending bits, with the soldering iron left in the drawer. Conceptual illustration.
Part 1: SRAM and the Game’s Working Memory
The Mega Drive has 64 KiB of Work RAM, labelled SRAM (Work RAM) above the chip. Bridging two modelled address lines can make normally separate addresses land on the same location. Altering the data lines can change what gets read or stored.
Hooking one convenient write routine wasn’t enough. Instruction fetches, ordinary reads and writes, and DMA can reach memory through different paths, so those needed checking too. Otherwise we’d have a button claiming to bend RAM while part of the emulator quietly carried on around it.
The write-only contacts became particularly useful. There are ten A11 to A15 pairs, held while pressed or applied for eight frames. Letting go disconnects the contact, but anything already written stays changed. A temporary bend can leave a fairly lasting mess inside the running game.
Three requested addresses can land on one location. Disconnecting the bridge does not undo values already written.
Part 2: VRAM and the Picture
VRAM needed two approaches. Frame mode projects the address fault across the frame’s VRAM view. Transaction mode applies it at the emulator’s VRAM access points, including reads, writes and DMA operations.
The awkward part was the renderer. Emulators keep decoded graphics ready to draw, so changing an address doesn’t automatically make every cached tile agree. Those caches had to follow the altered accesses as well. Otherwise the screen could show a mixture of the bent memory view and graphics it had prepared earlier.
The same ROM with faults off, AD3 forced low, and AD2 bridged to AD5. Actual v0.5.0 output using the Transaction model.
Part 3: FM and PSG Sound
The sound controls change writes going into the YM2612 FM and PSG chips before synthesis. Each chip has independent controls. For FM, corrupting an address write can select a different register altogether, which is rather more interesting than simply changing the volume.
Both 68000 and Z80 routes needed coverage, because the sound driver doesn’t have to use the same path as the main CPU. Removing a bridge only fixes future inputs. Earlier register changes can keep making noise, and CPU Reset preserves sound-chip state. Clean Restart is the full reboot when the orchestra refuses to leave.
Where the changes happen. These are simplified digital models, not a physical pinout or a reproduction of every electrical oddity on a real board.
Getting Back to Something Usable
A hard lock is still possible. Force Resume tries to get the CPU moving; CPU Recovery allows one reset if HALT persists for eight further frames. Both can be switched off. There’s also an explicit session checkpoint for saving a clean state and returning to it after an experiment.
We checked the core with small original test programs that produce known pictures, audio and memory changes, then exercised the real WebAssembly build in browsers. That helped separate deliberate corruption from bugs we’d accidentally introduced ourselves.
Try the Test Pattern
The real v0.5.0 workbench running the downloadable colour-test ROM, with all faults off.
VRAMpage MD is now live on McRetro.net. Bring your own ROM; the file stays in your browser. The source and complete browser download are available too. No soldering iron required this time.
Don’t have a game handy? Download the original colour-test ROM, then open it with Load ROM in VRAMpage MD to get the pattern shown above. It uses original code and graphics, with no commercial game assets. It’s silent, so use another cartridge for FM and PSG sound experiments.
Download the ROM and Python source as a ZIP.
https://mcretro.net/vrampage-md-bending-bits/
https://mcretro.net/assets/images/2026/10/vrampage-md/05-bending-bits.jxl
https://mcretro.net/assets/images/2026/10/vrampage-md/03-sram-addresses.jxl
https://mcretro.net/assets/images/2026/10/vrampage-md/04-vram-comparison.jxl
#rss #feeds #linksharing #qwibbit

2026-10-16 03:38:40 GMT

The Newcastle Chapter I Never Got to Finish
I’ve been going through some old messages and notes from 2019 recently. It’s amazing how much you can forget about a particular period of your life, only to have it all come flooding back when you start piecing things together. Some memories are wonderful, others not so much, and this is unfortunately one of the latter.
In December 2018, my relationship ended. At the time, I was living in Newcastle and studying at the University of Newcastle. Things weren’t perfect, but I had somewhere to live, animals I adored, and a reasonably clear idea of where I wanted my life to go. Then January 2019 happened.
The household arrangements changed, and the person I’d been living with was asked to leave. I understood that circumstances had changed and that the people who owned the house wanted their space back. Fair enough. It was their home, after all. What I struggled with was how everything unfolded afterwards.
From the moment that happened, I knew my own time there was probably limited. I didn’t expect to last another six to nine months. The writing was on the wall, even if nobody had explicitly told me to leave. I tried to keep things amicable, offering to change bedrooms, helping with moving arrangements, looking after the dog and generally trying to make myself as little trouble as possible. There were still friendly conversations, shared meals and plenty of ordinary moments, but underneath all of that, I no longer felt particularly secure. It’s a strange feeling, living somewhere you’ve been welcomed for years, suddenly wondering how much longer that welcome will last.
The Birds
Anyone who knows me knows I have a soft spot for animals, birds in particular. I’d raised mine from a young age, and they had their own personalities, little routines and all the peculiar behaviours that make birds such wonderful companions. They were part of my everyday life, and I’d become incredibly attached to them.
Unfortunately, the birds had become an issue within the household, and I agreed to find them new homes. I listed them for sale, but the money wasn’t really the point. Putting a price on them was my attempt to find someone who genuinely wanted them and was prepared to take responsibility for their care. It wasn’t a foolproof method, obviously. Someone paying for an animal doesn’t automatically make them a responsible owner, but giving them away for nothing worried me even more.
I didn’t want someone picking them up simply because they were free, without appreciating the commitment involved. I wanted to take my time, find the right people, and know that the birds would be looked after. Unfortunately, time wasn’t something I had much of.
10th March 2019
By March, the living situation had become something I no longer felt able to manage. On the 10th of March 2019, I left. Nobody physically threw me out that day. I made the decision because I no longer felt comfortable remaining there. The trust I’d previously had in the arrangement was gone, and I couldn’t see that changing.
I ended up at a pet-friendly hotel near the University of Newcastle’s Callaghan campus, spending far too much on temporary accommodation. Pretty much the last of my savings. Not exactly how I’d imagined my university years going! With my circumstances becoming increasingly difficult, I had to make one of the decisions I still regret. I gave the birds away for nothing, the very thing I’d been trying to avoid.
I don’t know whether the people who took them fully appreciated what they were getting, although they seemed nice enough. I hope the birds are still loved and cared for today, and that they’ve had the lives they deserve. What bothers me is that I never wanted to be in a position where desperation dictated what happened to animals I’d raised and loved. I’d been trying to do the responsible thing by finding suitable homes for them, but in the end, circumstances overtook those intentions.
I still miss those birds.
And Then There Was University
The accommodation problems were only part of the story. I’d spent years studying at the University of Newcastle, trying to build something worthwhile for my future. University wasn’t always easy for me, but it mattered, and I wanted to finish what I’d started. Instead, I found myself needing to return to Sydney to work for a boss I wasn’t particularly fond of then, and still aren’t especially fond of now.
I needed an income. The cost of accommodation, the uncertainty surrounding where I would live, and the practicalities of keeping everything together had become too much. My degree was left unfinished, and the future I’d been working towards suddenly looked rather different.
I don’t pretend that one disagreement was responsible for every difficulty I faced. Life is considerably more complicated than that. But the events of early 2019 contributed to circumstances that changed the direction of my life. Sometimes people think moving house is just that. You pack your belongings, find somewhere else and carry on. Unfortunately, when your housing, finances, education and personal circumstances are all connected, losing stability in one area can affect everything else. For me, that’s exactly what happened.
Looking Back
The hardest part of revisiting this period isn’t necessarily the money or even leaving Newcastle. It’s remembering how much trust I once placed in people who had been part of my life for many years. I don’t want to pretend that the kindness I received before 2019 never happened. It did, and I remain grateful for it, but the way things ended changed how I understood those relationships.
I spent a long time wondering whether I’d done something wrong, whether I could have handled things differently, or whether a little more patience might have changed the outcome. Perhaps some things could have been different. I’ll never know. What I do know is that I tried to cooperate, and I eventually reached a point where leaving seemed like the only reasonable option available to me.
It’s possible for someone to have been kind to you for years and still hurt you deeply. Both things can be true, and sometimes accepting that is harder than simply deciding someone was never a good friend in the first place.
The Things We Don’t Get Back
My mother has since died, and losing her has changed the way I look at the past. There are conversations I can never have again, moments I can never revisit, and years I can never reclaim. Her death is a separate loss from what happened in Newcastle, but it has made me think more carefully about how easily parts of our lives disappear.
I can’t go back to 2019 and finish that chapter the way I’d planned. I can’t recreate the circumstances that allowed me to study, and I can’t bring back the birds I raised from youngsters. I can build new things, of course. I’ve done plenty of that over the years, and anyone who’s followed this website knows I’m reasonably good at finding another project to keep myself occupied! But starting something new doesn’t necessarily make the old losses disappear.
I held off writing about all this for years because I wasn’t sure what good it would do. Perhaps I hoped the memories would become less important with time. Some have, others haven’t, and I think that’s okay. This isn’t an attempt to settle an old argument or encourage anyone to take sides. It’s simply a part of my history that I’ve never properly written about.
McRetro.net has been around since February 2012, documenting all sorts of things I’ve done, collected, repaired, broken and occasionally managed to put back together. It seems only appropriate that some of the less enjoyable parts of my life get documented too. Not everything in life comes with a successful repair, or a satisfying conclusion.
If there’s one thing I’ve taken away from revisiting 2019, it’s that a little compassion can make an enormous difference when someone is going through a difficult time. I didn’t expect anyone to solve all my problems. I didn’t expect free accommodation forever, or for circumstances never to change. I just wish things had ended with a little more kindness.
And if, by some chance, the people who took my birds all those years ago ever read this, I hope they’re doing well. I hope the birds have had wonderful lives, and that they’ve been given all the attention and affection they deserve.
I really did love those little creatures.
https://mcretro.net/the-newcastle-chapter-i-never-got-to-finish/
https://mcretro.net/assets/images/2026/newcastle-2019-birds-perch.webp
https://mcretro.net/assets/images/2026/newcastle-2019-birds.webp
https://mcretro.net/assets/images/2026/newcastle-2019-train.webp