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Tynemouth Software

@tynemouthsoftware.co.uk
1.5K followers 239 following 663 posts

Making new things for old computers. blog.tynemouthsoftware.co.uk www.tindie.com/stores/tynemouth www.patreon.com/tynemouthsoftware

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Tynemouth Software @tynemouthsoftware.co.uk · 13h
Someone usually asks "how do you do that?", so here is the blog post describing the contraption used to play 30 games in one hour. blog.tynemouthsoftware.co.uk/2025/08/play... It was originally 60 games in one hour, be we're all taking things a bit slower these days as we get older.
Rod's Random ROM Runner Reciprocator.
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Tynemouth Software @tynemouthsoftware.co.uk · 30/09/2026
I was lucky, I bought mine in the 80s before the prices went silly.
My incredibly expensive professionally calibrated tape winding device....
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Tynemouth Software @tynemouthsoftware.co.uk · 30/09/2026
If the tape inside is a write-off, like one of my 3D Monster Maze tapes was, I went for the option of replacing the tape inside the cassette with half a C15. blog.tynemouthsoftware.co.uk/2025/07/3d-m...
Rex transplant underway.
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Tynemouth Software @tynemouthsoftware.co.uk · 27/09/2026
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.
The new Minstrel Joystick V2.0 Multi-Standard 9 way-D interface for Minstrel 4th and RC2014.Minstrel 4th the Minstrel Joystick V2 and ZIP stickPaul Farrow's ZX81 Kong running on ZX81 BASIC for Minstrel 4th supports the Kempston interface standard.David Stephenson's Zevious Seven running on ZX81 BASIC for Minstrel 4th supports the Kempston, Boldfield and ZXpand interface standards.
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Tynemouth Software @tynemouthsoftware.co.uk · 25/09/2026
I don't know, but they're multiplying. (this one was something I built for @futurewas8bit.bsky.social blog.tynemouthsoftware.co.uk/2017/04/divm... )
Mysterious black box with 5 wires and three illuminated buttons.
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Tynemouth Software @tynemouthsoftware.co.uk · 24/09/2026
All the bits I needed have finally arrived. Well, 90% of the bits. 5 bags of 2, one of which only had one part in. DHL had completely wrecked the other parcel. Luckily the parts inside were in IC tubes, so survived. I may consider the £15 delivery by UPS option next time I order anything fragile.
The chip in the bottom bag is singing "All by myself...."What's left of the box.OoooffOh dear.
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Tynemouth Software @tynemouthsoftware.co.uk · 23/09/2026
Update: the order was indeed split into two. The parts I didn't need were dispatched at 2PM, the parts I actually needed were dispatched at 10PM. Both parcels have made it to the local depot and onto a van. It's now past midday, I am not expecting them to go out for delivery, but we will see.
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Tynemouth Software @tynemouthsoftware.co.uk · 22/09/2026
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.
Minstrel 4th V4.52 with Forth keyboard overlayMinstrel 4th kitMinstrel 4th with the new Multi-standard 9 way D joystick interface (Boldfield / ZXpand / Kempston).Minstrel 4th keyboard overlays for Forth, ZX81 BASIC, ZX80 BASIC and Lambda 8300 BASIC.
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Tynemouth Software @tynemouthsoftware.co.uk · 20/09/2026
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...
ZX81 case and membrane in need of some TLC.I don't know why the membrane was covered in tape?The top was all sorts of patchy.The final result, not bad, from a distance of several hundred yards.
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Tynemouth Software @tynemouthsoftware.co.uk · 18/09/2026
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.
Broken ZX81 board with three flaky sockets and a soldered in RAM chip.New sockets all round.Testing with known working original chips.Finished board with 16K RAM upgrade and EPROM ROM replacement, switching regulator and a heatsink on the ULA.
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Tynemouth Software @tynemouthsoftware.co.uk · 13/09/2026
I did look into implementing that in logic as part of the Minstrel 3 design. I think I had it working, set via a DIP switch. It didn't make production as the board was too full and I needed to simplify things, so it got removed from the final version as I was going for ZX81 compatibility.
Minstrel 3 prototype V3.1Minstrel 3 prototype V3.1 assembledMinstrel 3 prototype V3.1 DIP switches, 7 is "Turbo Disable"ZX81 issue one and Minstrel 3 V3.5.2 I think, the first production boards.
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Tynemouth Software @tynemouthsoftware.co.uk · 13/09/2026
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.
ZX81 issue one board, broken.Repaired and upgraded ZX81 board.ZX81 16K RAM upgrade.ZX81 EPROM ROM replacement.
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Tynemouth Software @tynemouthsoftware.co.uk · 09/09/2026
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...
Broken ZX81 board with three empty socketsSockets and RAM chips desoldered.New sockets fitted (and damage from a previous repair fixed.Testing with Minstrel Expansion Bus for power, Minstrel keyboard, ZX81 membrane, and known working chips including a ULA in a ZIF socket.
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Tynemouth Software @tynemouthsoftware.co.uk · 06/09/2026
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?
ZX81 board missing a few chips.Two ZX81 boards with chips.A previous repair attempt.K cursor ready with Minstrel ZXpand II banner.
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Tynemouth Software @tynemouthsoftware.co.uk · 01/09/2026
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
Minstrel ZXpand, Minstrel ZXpand II, ZXpand+Minstrel ZXpand II plugged into Minstrel 3No replacement ROM and wire to jumper block is required.Can also be used with a ZX81 or TS1000, but an internal RAM upgrade is recommended. e.g. https://blog.tynemouthsoftware.co.uk/2017/10/zx81-internal-16k-ram-reversible-version.html
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Tynemouth Software @tynemouthsoftware.co.uk · 30/08/2026
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.
The Minstrel ZXpand II with horizontal pin header connection.The Minstrel ZXpand II with vertical pin header connection, plugged into a Minstrel 2 with 4K BASIC.The Minstrel ZXpand II with horizontal pin header connection soldered direct to a Minstrel 3.The Minstrel ZXpand II with vertical pin header connections in a Minstrel Expansion Bus plugged into a TS1000 with an internal RAM upgrade.
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Tynemouth Software @tynemouthsoftware.co.uk · 28/08/2026
blog.tynemouthsoftware.co.uk/2026/01/mins...
Minstrel joystick, Kempston compatible joystick interface for Minstrel 2, 3, ZX80 or ZX81 (via Minstrel Expansion Bus)
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Tynemouth Software @tynemouthsoftware.co.uk · 28/08/2026
No, not the Minstrel 2. There are some specially written flicker-free games that will run, but most graphical ZX81 games need NMI compute and display (slow) mode, which the ZX80 and Minstrel 2 do not have. You need a Minstrel 3, it runs nicely on there thanks to all the extra chips.
Minstrel 2 (ZX80) and Minstrel 3 (ZX81)
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Tynemouth Software @tynemouthsoftware.co.uk · 23/08/2026
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)
A pile of more parcels ready to ship. From July 2025, when it was a little easier to ship internationally that it currently is and as a result I was getting a lot more orders.
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Tynemouth Software @tynemouthsoftware.co.uk · 21/08/2026
The big magnifier is essential these days. Ten years ago @futurewas8bit.bsky.social and I were running through all sorts of mods like these whilst working on the divMMC future. Don't think either of us would be doing things like that now. From - blog.tynemouthsoftware.co.uk/2018/01/desi...
divmmc future RC1 with bodge wires.divmmc future RC2 with bodge wires.divmmc future RC3 with bodge wires.divmmc future RC5 with bodge wires. (whatever happened to RC4?)
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Tynemouth Software @tynemouthsoftware.co.uk · 16/08/2026
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.
Find out what the Kamaca 8200 is, and also the Mimssqek 4sg.Inverse Ys where they shouldn't be, forming an enigmatic face.Minstrel 4th kit built and ready for testing.
When is a vlist not a vlist? when it's a vlhrt.
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Tynemouth Software @tynemouthsoftware.co.uk · 09/08/2026
New blog post - second part of the VIC20 Timebomb game. This time fixing some bugs and optimising and tidying up the code blog.tynemouthsoftware.co.uk/2026/08/time... Includes looking at how the maze is generated and displayed, and how I slightly broke that when I rewrote it in 6502 assembler.
Debug build showing maze generation.Broken starting screen.Maze and a copy of the mazeBefore and after moving showing the maze below the line changes.
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Tynemouth Software @tynemouthsoftware.co.uk · 06/08/2026
"Hey AI, write me a spam email that definitely doesn't look like I have wedged a keyword into a standard template using mail-merge software from 1993."
Support,

It's clear that THE FUTURE WAS 8BIT LIMITED is making strides in the Cartridge category, and I wanted to connect.

With [REDACTED], you gain access to a network of inspected suppliers. My job is to match you with the right partners for items such as Cartridge without the usual headaches.

I'm curious if Cartridge is a product category you're actively sourcing. If yes, I can help you connect with reliable suppliers. If not, just share what you're currently sourcing and I'll look into it.
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Tynemouth Software @tynemouthsoftware.co.uk · 02/08/2026
Yes, the arrays look right, I couldn't see clearly in the previous photo. Looking at the screen, ZW80 BBSJC suggests you have a problem on the A0 line, a short somewhere? (X=$61, but you see W=$60, A=$38, but you see B $39)
ZW80 BBSJC +> ZX81 BASIC
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Tynemouth Software @tynemouthsoftware.co.uk · 02/08/2026
Check the manual, it looks like you don't have any of the DIP switches on, so there will be no clock.
DIP switch settings for the Minstrel 4th.
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Tynemouth Software @tynemouthsoftware.co.uk · 02/08/2026
New blog post - Speeding Up a Timebomb blog.tynemouthsoftware.co.uk/2026/08/time... Timebomb is a nice little VIC20 BASIC game, but the maze generation at the start was very slow, so I rewrote it in 6502 assembler. This one contains lots of hints and tips for VIC20 BASIC and 6502 assembler coding.
Timebomb, a type in game for the VIC20The original BASIC version took one minute to generate the maze.Memory contents visible at the top of the maze screen.Oops, didn't find it in time. Bang!
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Tynemouth Software @tynemouthsoftware.co.uk · 26/07/2026
New blog post: Changes to international shipping rules mean I now ask you to contact me and tell me what you want (and which options) and your address and I will get you an accurate price. blog.tynemouthsoftware.co.uk/2026/07/game... If you want to know why, read on, otherwise give this one a miss.
Good News says the Royal Mail. Is it? Not for me it isn't.
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Tynemouth Software @tynemouthsoftware.co.uk · 19/07/2026
New blog post - Updates to the PET ROM/RAM board, and the places I sell things. blog.tynemouthsoftware.co.uk/2026/07/pet-... Lots of new options, as well as Tindie, I am starting to list things on Lectronz, SmallRun and SellMyRetro, or contact me and order direct via PayPal or UK bank transfer.
PET ROM/RAM board, 5 switch version, at a jaunty angle on my world famous battered desk top.PET ROM/RAM board, 9 switch version, at a jaunty angle on my world famous battered desk top.PET ROM/RAM board, 5 switch version, installed on a CBM 4016 board.PET ROM/RAM board, 9 switch version, installed on a CBM 4016 board.
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Tynemouth Software @tynemouthsoftware.co.uk · 12/07/2026
New blog post - the repair of a Commodore PET 3032 board with no video output. blog.tynemouthsoftware.co.uk/2026/07/comm... Also a capacitor that is looking decidedly unwell.
Commodore PET 2001N-32 / 3032PET Video Out board plugged into PET 3032.Oooooh nasty.Something is not quite right.
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Tynemouth Software @tynemouthsoftware.co.uk · 05/07/2026
New blog post - Testing a not-quite-a-ZX-Printer on a not-quite-a-ZX81. blog.tynemouthsoftware.co.uk/2026/07/test... But an Alphacom 32 on a Minstrel 3 or Minstrel 4th is close enough, and works impressively well.
A ZX Printer (non-functional as many of them are)A Minstrel 3 (fully working) connected to a ZX Printer (less so)A Minstrel 4th connected to an Alphacom 32 printer via the RC2014 bus.10 LPRINT "Testing a sort-of-ZX-Printer on a sort-of-ZX81 ":
20 GOTO 10
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Tynemouth Software @tynemouthsoftware.co.uk · 30/06/2026
The ZX81 is missing a \ character, which stops it doing the standard 10 PRINT maze program. The Lambda 8300 is based on the ZX81, but does have two diagonal black and white boxes. That turned out quite nicely, not optimised for speed or anything. From blog.tynemouthsoftware.co.uk/2026/06/lamb...
10 PRINT Maze program on Lambda 8300 for Minstrel 4th, in ZX81 colours.10 PRINT Maze program on Lambda 8300 for Minstrel 4th, in emulator in Jupiter Ace colours.Listing of 10 PRINT Maze program on Lambda 8300 for Minstrel 4th, in emulator in Jupiter Ace colours.Minstrel 4th V4.52 which includes Lambda 8300 for Minstrel 4th.
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Tynemouth Software @tynemouthsoftware.co.uk · 28/06/2026
As well as Jupiter Ace Forth, the Minstrel 4th can also run * Enhanced Ace Forth with support for serial comms * ZX80 BASIC * ZX81 BASIC * Lambda 8300 BASIC * ZX-Forth * Microprossor MPF-I and I am sure more to follow github.com/tynemouthsof... www.tindie.com/products/tyn...
ZX80 4K integer BASIC running on Minstrel 4thZX81 8K Floating Point BASIC running on Minstrel 4th (yes it supports slow mode so you can run 3D Monster Maze)Lambda 8300 8K Floating Point BASIC running on Minstrel 4th.Minstrel 4th V4.52
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Tynemouth Software @tynemouthsoftware.co.uk · 28/06/2026
I think this is the relevant section. If block count > 10, decrease padding. If > 100, decrease padding again.
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Tynemouth Software @tynemouthsoftware.co.uk · 28/06/2026
New blog post - Adapting Lambda 8300 BASIC to run on the Minstrel 4th. blog.tynemouthsoftware.co.uk/2026/06/lamb... Getting it running, loading and saving, making sounds, playing games and even a 10 PRINT maze. Happen to need an excessively long blog post to read? then this is the one for you.
Lambda 8300 BASIC running on a Minstrel 4th.Loading programs on Lambda 8300 BASIC for Minstrel 4th with data lines in the border and a bytes remaining countdown.Playing three C's10 PRINT maze using Lambda 8300 graphics characters.
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Tynemouth Software @tynemouthsoftware.co.uk · 28/06/2026
It took me a while to work that one out when I was going through the Commodore directly listings. Sometimes one or two fewer spaces before the filenames to make up for the 1-3 character line numbers that are used to represent block count. blog.tynemouthsoftware.co.uk/2023/12/comm...
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Tynemouth Software @tynemouthsoftware.co.uk · 27/06/2026
Lovely Minstrel 2 build by Electron Greg with added perspex covers and ZX80 logo. How are you going to customise your Minstrel 2? www.tindie.com/products/tyn...
Minstrel 2, a Z80 based 8 bit computer kit which is based on the Sinclair ZX80 with modern parts and a Z80 from the last batch every made.Also Minstrel 2, but now with black pillars.
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Tynemouth Software @tynemouthsoftware.co.uk · 25/06/2026
Any chance of a Lambda 8300 version of Altairis? (The original ROM, not the colour/READY version, of the more ZX81 compatible ROM) I could use the ZX81 Altairis, but the grey squares are missing and I want sound :) Lambda 8300 now runs on Minstrel 4th blog.tynemouthsoftware.co.uk/2026/06/lamb...
Lambda 8300 ROM modified to run on the Minstrel 4th. Part 1 link below, Part 2 coming Sunday. 
http://blog.tynemouthsoftware.co.uk/2026/06/lambda-8300-reverse-engineering.htmlLambda 8300 for Minstrel 4th boot screen.
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Tynemouth Software @tynemouthsoftware.co.uk · 21/06/2026
New blog post - Reverse Engineering the ROM on the Lambda 8300, a sort of ZX81 clone. blog.tynemouthsoftware.co.uk/2026/06/lamb... It is sort of a ZX81, but with quite a few differences. Full disassembly on github if you are interested. github.com/tynemouthsof...
10 PRINT "LAMBDA 8300 (plus some graphics)" 20 GOTO 10Lambda 8300 boot screen (with flashing cursor)10 PRINT "HELLO WORLD" 20 ...TIMEX PC 8300 alternate ROM
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Tynemouth Software @tynemouthsoftware.co.uk · 20/06/2026
Any recommendations for some good ZX81 programs which are written purely in BASIC? Nothing generated by Z88DK or similar. Nothing with machine code in REM statements etc. I have been using Perilous Swamp as an example, as this is BASIC only and quite a good game, but I am looking for some more.
The start of the BASIC listing for Perilous SwampPerilous Swamp game playThe start of 3D Monster Maze showing machine code.The only like of BASIC in a Z88DK program.
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Tynemouth Software @tynemouthsoftware.co.uk · 16/06/2026
Every time I see this post in my feed, it reminds me of something.
Some bike pedalsSutekh the destroyer, not some bike pedals.
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Tynemouth Software @tynemouthsoftware.co.uk · 15/06/2026
Well, not to give any spoilers, but I did spend a lot of time loading and testing various versions of Zevious Seven by @zx81keyboardadventure.com and Altairis by @loudscotsbloke.bsky.social
Zevious Seven by David Stephenson - https://zx81keyboardadventure.itch.io/zevious-sevenZevious Seven by David Stephenson - https://zx81keyboardadventure.itch.io/zevious-sevenAltairis For Jupiter Ace by Roy Templeman - https://loudscotsbloke.itch.io/altairis-jupiter-aceAltairis For ZX80 by Roy Templeman - https://loudscotsbloke.itch.io/altairis-sinclair-zx80
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Tynemouth Software @tynemouthsoftware.co.uk · 14/06/2026
New blog post - Improving Tape Loading on Minstrels Episode 4 - A New Hope blog.tynemouthsoftware.co.uk/2026/06/impr... Which tape loading circuit did I finally go for, and how well does it work? The new Minstrel 4th with this circuit is shipping this week. www.tindie.com/products/tyn...
The new Minstrel 4th V4.52 - looks rather splendid, doesn't it?
Available to order now, shipping this week.Triangle waves showing input filtering and hysteresis.Loading a ZX81 game from tape with source signal, processed signal and clean digital output.Loading a Jupiter Ace game from a PC sound card with source signal, processed signal and clean digital output.
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Tynemouth Software @tynemouthsoftware.co.uk · 12/06/2026
I think this is one of the nicest looking breadboards layouts I have created. This was to test out a brilliant idea I had in this week's blog post. blog.tynemouthsoftware.co.uk/2026/06/impr...
Breadboard circuit which is a lot neater than my usual breadboard test circuits.
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Tynemouth Software @tynemouthsoftware.co.uk · 07/06/2026
New blog post - I've had this great idea to improve tape loading on the Minstrels, using a rather unexpected chip. blog.tynemouthsoftware.co.uk/2026/06/impr... Includes the neatest thing I have ever assembled on a breadboard. The new Minstrel 4th is now available to pre-order, shipping next week.
Obvious click-bait, sorry, but you might be interested to see the design I have come up with.That has to be the neatest looking breadboard circuit I have ever assembled.This is the same circuit, somewhat less neatly assembled.Oh look pretty wiggly lines and spikes which look like the icing on a Mr Kipling iced slice.
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Tynemouth Software @tynemouthsoftware.co.uk · 03/06/2026
I tend to default to typing "KILL JESTER" when I get bored of a text adventure. I must have typed it into a dozen different games. Only one responded correctly ... (also honorable mention for "FIND LIGHTSWITCH" from watching too much @robbotron.bsky.social )
Colossal Caves for the PETAdventureland for the VIC20Planet of Death for the ZX81Kingdom of the Seven Stones
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Tynemouth Software @tynemouthsoftware.co.uk · 03/06/2026
Maybe they forgot to put it into fast mode to do the thinking?
ZX81 keyboard showing SLOW and FAST keywords.
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Tynemouth Software @tynemouthsoftware.co.uk · 31/05/2026
New blog post - Second part of Improving Tape Loading on Minstrels. blog.tynemouthsoftware.co.uk/2026/05/impr... This time looking at the circuits used on the BBC Micro / Acorn Electron and the Oric-1 / Oric Atmos.
Acorn Electron 3 stage tape input circuit.Nice clean output from the Elk.Look at all those parts.Acorn Electron loading from ANF-03 cassette data recorder.
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Tynemouth Software @tynemouthsoftware.co.uk · 24/05/2026
New blog post - The first post in a series looking at improving tape loading future revisions of the Minstrel 2, 3 and 4th. blog.tynemouthsoftware.co.uk/2026/05/impr... See the end of the post for discounts on Tindie and Patreon that have both landed at the same time.
Loading a tape into a Minstrel 4th from a Sony TCM-818 cassette player.The Jupiter Ace tape input schematic, redrawn in Circuit Labs3KHz data from a ZX81 tape fed through the Jupiter Ace input circuit.ZX81 tape data fed through one of my prototype tape loading designs giving a clean train of pulses below (although gaining one extra pulse in the process)
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Tynemouth Software @tynemouthsoftware.co.uk · 22/05/2026
If you login in and have a UK account, it will show the prices in GBP. UK postage is for special delivery for larger items. Cheaper items go tracked 24.
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Tynemouth Software @tynemouthsoftware.co.uk · 22/05/2026
I am told it is a bank holiday weekend. So why not have 10% off everything in my Tindie store - www.tindie.com/stores/tynem... DIY computer Kits and upgrades for ZX80, ZX81, Jupiter Ace, Commodore PET. Test tools, USB keyboard adapters, RC2014. Shipping worldwide, US orders with tariffs paid.
Minstrel 3 with keyboard and Minstrel ZXpandPET ROM RAM boards, smaller 5 switch and large 9 switch versions.Mini PET 40/80 - PET replacement motherboard.Minstrel 2 ZX80 compatible to fit in ZX81 case (also available with keyboard)
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