Tynemouth Software

I guess I should start off with some links. I write a blog with a new post every Sunday - blog.tynemouthsoftware.co.uk I sell my Z80 and 6502 based kits on Tindie (more soon) - www.tindie.com/stores/tynem... Early access to posts and behind the scenes on Patreon - www.patreon.com/tynemouthsof...

New blog post - looking at Cosmic Snake for the VIC20, which rather unusually for a Commodore BASIC program, contains machine code in REM statements. blog.tynemouthsoftware.co.uk/2026/10/cosm...

New blog post - looking at Cosmic Snake for the VIC20, which rather unusually for a Commodore BASIC program, contains machine code in REM statements. blog.tynemouthsoftware.co.uk/2026/10/cosm...

Ever had a problem loading programs into a ZX81 or ZX Spectrum using a stereo 3.5mm jack? This may be why. Look at the photos, the jack sockets connect to the tip and the ring, not the sleeve. That's fine for a mono TS jack, but a stereo TRS jack connects to left and right, no connection to ground.

Rod Hull Replays: It's the 🐛 Centipede 🐛 Caterpillar 🐛 Millipede 🐛 type 🐛 game 🐛 special! 🐛 #VIC20 🎉 www.youtube.com/watch?v=i8SO... #retrogaming #retrocomputing #commodorevic20 #Commodore #VIC20 #8bit #VIC20Rulez

New blog post - Loading programs into the Timex Sinclair TS1500 - blog.tynemouthsoftware.co.uk/2026/10/load... Some unexpected issues with tape loading, and yes, you can indeed use the Minstrel ZXpand II to load from SD card.

Wow, that's amazing, I didn't know you could solder using an oscilloscope probe. Or maybe it is designed to capture the magic smoke that is released when you accidentally short two pins together with the probe? Or is it an iron that has a 10x better soldering setting?

OK, let's do this. New batch of Mini PET 40/80s stand alone with keyboard. Shipping worldwide end of November. Pre-order now £450 kit / £500 built. PET compatible, 40/80 col, 32K, File Browser. PayPal link for US / EU www.paypal.com/ncp/payment/... Contact me for UK and elsewhere or specific quote.

This was my code to get a pseudo random number from 0-5 from a pseudo random 8-bit number. I count the 1s in the lower 5 bits, giving a number from 0-5. Am I missing an obvious simpler method? From this week's blog post blog.tynemouthsoftware.co.uk/2026/10/vic2... (On entry, X=5, Y=0. A=result)

New Blog Post - VIC20 Bunny Blitz - blog.tynemouthsoftware.co.uk/2026/10/vic2... I have rewritten an old VIC20 BASIC game, Rabbit Blitz by C.Simun in 6502 assembler to fix a couple of bugs and add a few new features and a general spruce up. Source and binary on github - github.com/tynemouthsof...

New Blog Post - VIC20 Bunny Blitz - blog.tynemouthsoftware.co.uk/2026/10/vic2... I have rewritten an old VIC20 BASIC game, Rabbit Blitz by C.Simun in 6502 assembler to fix a couple of bugs and add a few new features and a general spruce up. Source and binary on github - github.com/tynemouthsof...

The rest of the Z80 and eZ80 range is now discontinued. I took a bit of a gamble a few years ago and bought a lifetime's supply of Z80s from the final batch. In the last month, I have sold zero Z80 based kits, therefore according to my calculations, they should last an infinite amount of time.

New blog post - Find out how I managed to squeeze even more games into the latest update to the Penultimate Cartridge, and made it easier to use in the process. blog.tynemouthsoftware.co.uk/2026/10/penu...

New blog post - Find out how I managed to squeeze even more games into the latest update to the Penultimate Cartridge, and made it easier to use in the process. blog.tynemouthsoftware.co.uk/2026/10/penu...

An Hour of Random Commodore VIC20 Games - Via Penultimate+3dcr with an Arduino doing the 2mins 👾🕹️⚡ www.youtube.com/watch?v=7Re3... #RetroGaming #Retrocomputing #8bit #VIC20 #Commodore #commodorevic20 #PenultimateCartridge #NOAI

New blog post - A new multi-standard 9 way D joystick interface for the Minstrel 4th and RC2014. blog.tynemouthsoftware.co.uk/2026/09/tyne... This card can be configured as * Boldfield (Jupiter Ace) * ZXpand IO port (ZX81) * Kempston (ZX81, ZX Spectrum) standards Available as kit or assembled.

New blog post - A new multi-standard 9 way D joystick interface for the Minstrel 4th and RC2014. blog.tynemouthsoftware.co.uk/2026/09/tyne... This card can be configured as * Boldfield (Jupiter Ace) * ZXpand IO port (ZX81) * Kempston (ZX81, ZX Spectrum) standards Available as kit or assembled.

Happy Birthday to the Jupiter Ace. If you fancy a bit of Forth (or ZX81 BASIC, ZX80 BASIC or Lambda 8300 BASIC) with added RC2014 expansion and maxed out 51K of RAM, check out the Minstrel 4th. www.tindie.com/products/tyn... Message me direct if you want to order from outside the UK.

New blog post - Continuing with the ZX81 repairs, this time I turn my attention to the rather tatty case and membrane. blog.tynemouthsoftware.co.uk/2026/09/zx81...

New blog post - Continuing with the ZX81 repairs, this time I turn my attention to the rather tatty case and membrane. blog.tynemouthsoftware.co.uk/2026/09/zx81...

Another ZX81 repair in 4 photos. This is the second board, and was covered in more detail in this weeks blog post. blog.tynemouthsoftware.co.uk/2026/09/zx81... Tune in on Sunday to see part 3, covering restoration of the case and membrane.

New blog post - The second ZX81 board repair. blog.tynemouthsoftware.co.uk/2026/09/zx81... This time with an internal 16K RAM upgrade, an EPROM ROM replacement and a switching regulator 7805 replacement.

New blog post - The second ZX81 board repair. blog.tynemouthsoftware.co.uk/2026/09/zx81... This time with an internal 16K RAM upgrade, an EPROM ROM replacement and a switching regulator 7805 replacement.

A ZX81 repair in 4 photos. Or if you want more details (and another 38 photos), you can check out the full blog post. blog.tynemouthsoftware.co.uk/2026/09/zx81... Part 2 is up on Patreon now if you can't wait (and/or want to support the creation of more of this stuff) www.patreon.com/tynemouthsof...

And how it generates the video is also incredibly bonkers and very Sinclair.

New blog post - The first of a series of ZX81 repairs - blog.tynemouthsoftware.co.uk/2026/09/zx81... I couldn't find any of my ZX81s, but I did find a box with three "untested" boards. They can't all be broken, can they?

New blog post - The first of a series of ZX81 repairs - blog.tynemouthsoftware.co.uk/2026/09/zx81... I couldn't find any of my ZX81s, but I did find a box with three "untested" boards. They can't all be broken, can they?

Where does the new Minstrel ZXpand II fit, compared to the other? * Minstrel ZXpand - SD, ZXpand Joystick, Kempston Joystick - Needs external ROM + wire * Minstrel ZXpand II - SD, ZXpand Joystick, Kempston Joystick, Overlay ROM * ZXpand / ZXpand+ - SD, ZXpand Joystick, Overlay ROM, RAM

New blog post - Introducing the new Minstrel ZXpand II - SD card and joystick interface for the Minstrel 2, Minstrel 3 and a ZX81 or TS1000 with an internal RAM upgrade. blog.tynemouthsoftware.co.uk/2026/08/mins... Shipping worldwide, but as per last week, please contact me if you are interested.

This @tynemouthsoftware.co.uk blog blog.tynemouthsoftware.co.uk/2026/08/time... rekindled my interest in maze generation, and I delved into Eller's Algorithm which generates perfect mazes (weblog.jamisbuck.org/2010/1W2/29/...). Here's my Forth implementation - github.com/markgbeckett...

New blog post - Introducing the new Minstrel ZXpand II - SD card and joystick interface for the Minstrel 2, Minstrel 3 and a ZX81 or TS1000 with an internal RAM upgrade. blog.tynemouthsoftware.co.uk/2026/08/mins... Shipping worldwide, but as per last week, please contact me if you are interested.

Brilliant repair walkthrough on a Minstrel 4th - the ZX81-compatible clone from Tynemouth Software. Tracks down a video display fault through clever debugging with the Lambda 8300 ROM. Love this kind of detective work! https://blog.tynemouthsoftware.co.uk/2026/08/minstrel-4th-repair.html

It amazes me that legislation like this keeps getting through and nowhere along the line do any of our alleged representatives consider how this might impact anything other than large corporations. All I can say is, if you want something from a small seller, buy it now, whilst you still can.

"Slow is smooth, smooth is fast" retrogamecoders.com/minstrel-4th... (Borking my Minstrel 4th)

Finally got around to reading this - an interesting write-up of an almost-working Minstrel and a sound explanation of the diagnostic process involved.

New blog post. I have quite a few posts written and ready, but all waiting on one things or another, so this is an update on the international shipping situation and the best way to order from me. blog.tynemouthsoftware.co.uk/2026/08/upda... (sorry, if it's a bit ranty and a wee bit political)

Zevious Seven has now been release on Cassette by Cronosoft On Tape: cronosoft.fwscart.com/product/zevi... Digital Copy: zx81keyboardadventure.itch.io/zevious-seven #ZX81 #retrogaming #indiedev

New blog post - repairing a Minstrel 4th build that almost worked first time. blog.tynemouthsoftware.co.uk/2026/08/mins... Why the Lambda 8300 ROM was calling itself Kamaca 8200, why the keys were not showing the right thing when pressed, and why bits of the screen weren't quite in the right place.

New blog post - repairing a Minstrel 4th build that almost worked first time. blog.tynemouthsoftware.co.uk/2026/08/mins... Why the Lambda 8300 ROM was calling itself Kamaca 8200, why the keys were not showing the right thing when pressed, and why bits of the screen weren't quite in the right place.