Tynemouth Software

GRAVZRONOX (VIC-20 +32k) by Misfit

I released a new gravity cave thrust game for VIC-20 + 32k
GRAVZRONOX
misfit.itch.io/gravzronox

Your little TV has good taste.

The ZX81 was my first computer, and it certainly had a massive impact on the 6 year old me.
I am sure I don't need to tell you all, but if you want to see why the ZX81 was so important, you can build a ZX81 compatible kit from basic logic chips.
www.tindie.com/products/tyn...

You can divide or multiple by any of the numbers, 1, 2, ....
OK, that's it, but you can do those.
It's just all the other numbers that require a bit of extra effort.

New blog post - The repair of an Acorn A5000 RISC PC where the CMOS battery leaked not once, but twice in the last 30 years.
blog.tynemouthsoftware.co.uk/2026/03/acor...
Plus a seemingly unrelated hard drive access problem.

I should have saved all the old dust and tipped out the hoover bag over the board once I was finished.

New blog post - The repair of an Acorn A5000 RISC PC where the CMOS battery leaked not once, but twice in the last 30 years.
blog.tynemouthsoftware.co.uk/2026/03/acor...
Plus a seemingly unrelated hard drive access problem.

RIP Rob Grant.

RIP Rob Grant. I'm sure I'm not alone in saying that, along with Doctor Who, Red Dwarf quite simply defined my teenage years and I was utterly obsessed with it. The six series he co-wrote with Doug Naylor remain pure gold. I hope he knew how much the show meant to us.

See you, Smeghead.

I have been using gimp for raster work and inkscape for vector work for such a long time now, I am happy to stick with those.
Who would have though eh? me? afraid of change?

I am still using gimp for artwork, and I recently spent far too long making black and white line drawings of some TFW8b stuff. I am sure an AI could have done it instantly and probably better, but my workflows are still firmly rooted in the past.

I don't have much tolerance for things like that or obviously click-bait titles or AI thumbnails, or anything negative, "the 10 worst.....", "the tragic story of....", "why x hates y" etc. It's a simple "don't recommend channel". Sorry to those channels, but they are not for me.

New blog post - A look at writing a simple hello world LED flasher in C for the AVR series of microcontrollers.
blog.tynemouthsoftware.co.uk/2026/02/avr-...
Trying to minimise things to be able to see what is going on and test a feature in isolation without being swamped by auto-generated code.

New blog post - A look at writing a simple hello world LED flasher in C for the AVR series of microcontrollers.
blog.tynemouthsoftware.co.uk/2026/02/avr-...
Trying to minimise things to be able to see what is going on and test a feature in isolation without being swamped by auto-generated code.

I am surprised that no one has commented on the serial number of the PET 2001-8 in this week's blog post.
Or maybe no one read far enough through to see it?
Potentially the first 240V PET?
Or at least the first with that style of serial number, with a 1 prefix indicating a 240V model. (115V was 0)

I had never thought about it before, but River Race is just Scramble with a roof on.

Looks taller than I remember.

Eurovision 2026: Electronic artist and YouTuber Look Mum No Computer to represent UK in Vienna The synth artist and Eurovision fan says he finds it

Well done, Sam.
www.bbc.co.uk/news/article...

I can only presume that my use of Sam's video building one of my Mini PET kits on the Tindie listing has raised his profile sufficiently, but I don't think I should take all the credit.

www.tindie.com/products/tyn...

www.youtube.com/watch?v=wCOF...

Looking good, but you need to add a mode where it randomly crashes after a few seconds like Tornado used to before I fixed it.

It did indeed require some deep thought to pinpoint the issue.

New blog post: Remote diagnosing a PET 2001 video fault from one photograph.
blog.tynemouthsoftware.co.uk/2026/02/diag...
Includes a look at how the PET video system works with redrawn schematics.
It also turns out to be a surprisingly early PET 2001.

Red and blue PCBs from JLCPCB arranged in a heart shape.

JLCPCBs are Red
JLCPCBs are Blue
Here is my affiliate link
So you can get some too

jlcpcb.com/download?fro...

My blog is now sponsored by JLCPCB, although this was not quite how I planned to announce that.

Red and blue PCBs from JLCPCB arranged in a heart shape.

JLCPCBs are Red
JLCPCBs are Blue
Here is my affiliate link
So you can get some too

jlcpcb.com/download?fro...

My blog is now sponsored by JLCPCB, although this was not quite how I planned to announce that.

I think those would have been 4108's 8K x 1 bit, although the board usually takes 4116 for 16K or 32K if you fit all 16.
But the 6550's yeah, nice idea, but they didn't work out.

It is possible this was a dealer thing, rather than a Commodore thing.
If they were selling to businesses, they would be more likely to go for upgrading by buying a whole new machine every couple of years.

If only they could have had a Mini PET replacement board :-)

Something you don't see very often.
Inside an 8K Commodore PET model 2001-8N.
Notice the 4 holes drilled in the front of the PCB to stop you buying the cheaper model and upgrading the RAM yourself.
Yes, they actually did that.
Although it wasn't too hard to add bodge wires, I have seen that done.

New blog post - blog.tynemouthsoftware.co.uk/2026/02/10-y...
Something a little different this week, looking back at 10 years and 10,000 miles with my 2016 Nissan Leaf, how much has that cost me?
Normal service will be resumed next week with a PET repair post.

With hindsight maybe, but when I bought it, I did not know that 6 months later, the investors in the company I was working for were going to pull the plug overnight and I would no longer need to commute.
I clocked up 9000 miles in 3 years on the previous Leaf, and had expected to continue like that.

I work from home now, so I was only commuting for the first year of that.
My commute these days involves walking down the stairs.

No different than if I had bought a new diesel Golf for a similar price at the time. If anything the Leaf is probably worth a bit more now than a Golf would have been.
But it really owes me nothing and keeping it going as long as possible seems the best option as it suits me and my needs perfectly.

New blog post - blog.tynemouthsoftware.co.uk/2026/02/10-y...
Something a little different this week, looking back at 10 years and 10,000 miles with my 2016 Nissan Leaf, how much has that cost me?
Normal service will be resumed next week with a PET repair post.