Tynemouth Software
@tynemouthsoftware.co.uk
Making new things for old computers.
http://blog.tynemouthsoftware.co.uk/
https://www.tindie.com/stores/tynemouth/
https://www.patreon.com/tynemouthsoftware
http://blog.tynemouthsoftware.co.uk/
https://www.tindie.com/stores/tynemouth/
https://www.patreon.com/tynemouthsoftware
New blog post - I have designed a new serial card for the Minstrel 4th and RC2014 bus. More on that next week, but first a look back at some of the things I tried before settling on this design.
blog.tynemouthsoftware.co.uk/2025/11/a-ne...
blog.tynemouthsoftware.co.uk/2025/11/a-ne...
November 16, 2025 at 11:49 AM
New blog post - I have designed a new serial card for the Minstrel 4th and RC2014 bus. More on that next week, but first a look back at some of the things I tried before settling on this design.
blog.tynemouthsoftware.co.uk/2025/11/a-ne...
blog.tynemouthsoftware.co.uk/2025/11/a-ne...
New blog post - a simple LED tester for PET, VIC20 and C64 Userports.
blog.tynemouthsoftware.co.uk/2025/11/user...
#blinkenlights
www.tindie.com/products/tyn...
blog.tynemouthsoftware.co.uk/2025/11/user...
#blinkenlights
www.tindie.com/products/tyn...
November 9, 2025 at 12:54 PM
New blog post - a simple LED tester for PET, VIC20 and C64 Userports.
blog.tynemouthsoftware.co.uk/2025/11/user...
#blinkenlights
www.tindie.com/products/tyn...
blog.tynemouthsoftware.co.uk/2025/11/user...
#blinkenlights
www.tindie.com/products/tyn...
New blog post - the second part of the 4016 repair.
blog.tynemouthsoftware.co.uk/2025/11/cbm-...
The board is working with a PET ROM/RAM and video RAM replacement, let's get back to as many original chips as possible.
After all, they can't all be bad, can they......
blog.tynemouthsoftware.co.uk/2025/11/cbm-...
The board is working with a PET ROM/RAM and video RAM replacement, let's get back to as many original chips as possible.
After all, they can't all be bad, can they......
November 2, 2025 at 11:51 AM
New blog post - the second part of the 4016 repair.
blog.tynemouthsoftware.co.uk/2025/11/cbm-...
The board is working with a PET ROM/RAM and video RAM replacement, let's get back to as many original chips as possible.
After all, they can't all be bad, can they......
blog.tynemouthsoftware.co.uk/2025/11/cbm-...
The board is working with a PET ROM/RAM and video RAM replacement, let's get back to as many original chips as possible.
After all, they can't all be bad, can they......
What better way to spend Halloween than playing 3D Monster Maze on the green screen CRT of a PET in the dark.
I fixed this one last week, it was quite a horror show when it arrived.
blog.tynemouthsoftware.co.uk/2025/10/cbm-...
Get my PET 3DMM remake from itch.io
tynemouth.itch.io/pet-3d-monst...
I fixed this one last week, it was quite a horror show when it arrived.
blog.tynemouthsoftware.co.uk/2025/10/cbm-...
Get my PET 3DMM remake from itch.io
tynemouth.itch.io/pet-3d-monst...
October 31, 2025 at 2:48 PM
What better way to spend Halloween than playing 3D Monster Maze on the green screen CRT of a PET in the dark.
I fixed this one last week, it was quite a horror show when it arrived.
blog.tynemouthsoftware.co.uk/2025/10/cbm-...
Get my PET 3DMM remake from itch.io
tynemouth.itch.io/pet-3d-monst...
I fixed this one last week, it was quite a horror show when it arrived.
blog.tynemouthsoftware.co.uk/2025/10/cbm-...
Get my PET 3DMM remake from itch.io
tynemouth.itch.io/pet-3d-monst...
Hmm, an AVR microcontroller at 24MHz runs 24 million single cycle instructions in a second.
Yet a PIC microcontroller at 64MHz runs only 16 million of their "single cycle" instructions, as 1 "cycle" is 4 clock cycles.
Well that was a waste of time and money, thank you @microchip-makes.bsky.social
Yet a PIC microcontroller at 64MHz runs only 16 million of their "single cycle" instructions, as 1 "cycle" is 4 clock cycles.
Well that was a waste of time and money, thank you @microchip-makes.bsky.social
October 30, 2025 at 6:01 PM
Hmm, an AVR microcontroller at 24MHz runs 24 million single cycle instructions in a second.
Yet a PIC microcontroller at 64MHz runs only 16 million of their "single cycle" instructions, as 1 "cycle" is 4 clock cycles.
Well that was a waste of time and money, thank you @microchip-makes.bsky.social
Yet a PIC microcontroller at 64MHz runs only 16 million of their "single cycle" instructions, as 1 "cycle" is 4 clock cycles.
Well that was a waste of time and money, thank you @microchip-makes.bsky.social
I've just been checking back on some old repairs and I found this 8032 repair from 2017. That was a similar date to the 4016 in this weeks post.
It had sockets on all main chips apart from the 6545, might explain why that had been desoldered on the 4016.
blog.tynemouthsoftware.co.uk/2025/10/cbm-...
It had sockets on all main chips apart from the 6545, might explain why that had been desoldered on the 4016.
blog.tynemouthsoftware.co.uk/2025/10/cbm-...
October 29, 2025 at 2:31 PM
I've just been checking back on some old repairs and I found this 8032 repair from 2017. That was a similar date to the 4016 in this weeks post.
It had sockets on all main chips apart from the 6545, might explain why that had been desoldered on the 4016.
blog.tynemouthsoftware.co.uk/2025/10/cbm-...
It had sockets on all main chips apart from the 6545, might explain why that had been desoldered on the 4016.
blog.tynemouthsoftware.co.uk/2025/10/cbm-...
Also useful for testing. That's why I made these "joystick emulators".
October 29, 2025 at 2:04 PM
Also useful for testing. That's why I made these "joystick emulators".
The "Advanced Level" kit for the Mini PET was like that. Who needs legends on the keycaps or silkscreen on the PCB? That's for the amateurs.
blog.tynemouthsoftware.co.uk/2022/04/mini...
blog.tynemouthsoftware.co.uk/2022/04/mini...
October 29, 2025 at 11:54 AM
The "Advanced Level" kit for the Mini PET was like that. Who needs legends on the keycaps or silkscreen on the PCB? That's for the amateurs.
blog.tynemouthsoftware.co.uk/2022/04/mini...
blog.tynemouthsoftware.co.uk/2022/04/mini...
New blog post - CBM 4016 Repair - blog.tynemouthsoftware.co.uk/2025/10/cbm-...
Since Halloween is approaching, this is a bit of a horror show special. Those of a nervous dispositions should look away now.
Since Halloween is approaching, this is a bit of a horror show special. Those of a nervous dispositions should look away now.
October 26, 2025 at 1:08 PM
New blog post - CBM 4016 Repair - blog.tynemouthsoftware.co.uk/2025/10/cbm-...
Since Halloween is approaching, this is a bit of a horror show special. Those of a nervous dispositions should look away now.
Since Halloween is approaching, this is a bit of a horror show special. Those of a nervous dispositions should look away now.
New blog post - The Minstrel ROM Cart for the Minstrel Expansion Bus.
blog.tynemouthsoftware.co.uk/2025/10/mins...
Replace the ROM on a Minstrel 2, 3, ZX81 or TS1000 with an 8K or 16K ROM image.
blog.tynemouthsoftware.co.uk/2025/10/mins...
Replace the ROM on a Minstrel 2, 3, ZX81 or TS1000 with an 8K or 16K ROM image.
October 19, 2025 at 11:23 AM
New blog post - The Minstrel ROM Cart for the Minstrel Expansion Bus.
blog.tynemouthsoftware.co.uk/2025/10/mins...
Replace the ROM on a Minstrel 2, 3, ZX81 or TS1000 with an 8K or 16K ROM image.
blog.tynemouthsoftware.co.uk/2025/10/mins...
Replace the ROM on a Minstrel 2, 3, ZX81 or TS1000 with an 8K or 16K ROM image.
For the dual port RAM on the Mini PET, I generate gated read and write signals and use those for the /WR and /OE signals respectively. Those are generated from CPU R/W and PHI2.
October 18, 2025 at 6:34 PM
For the dual port RAM on the Mini PET, I generate gated read and write signals and use those for the /WR and /OE signals respectively. Those are generated from CPU R/W and PHI2.
New blog post - Changing SD2IEC Device IDs
blog.tynemouthsoftware.co.uk/2025/10/chan...
Several techniques you can use to change the device ID of your SD2IEC from ID #8 to ID #9, and several reasons why you shouldn't do it.
blog.tynemouthsoftware.co.uk/2025/10/chan...
Several techniques you can use to change the device ID of your SD2IEC from ID #8 to ID #9, and several reasons why you shouldn't do it.
October 12, 2025 at 11:42 AM
New blog post - Changing SD2IEC Device IDs
blog.tynemouthsoftware.co.uk/2025/10/chan...
Several techniques you can use to change the device ID of your SD2IEC from ID #8 to ID #9, and several reasons why you shouldn't do it.
blog.tynemouthsoftware.co.uk/2025/10/chan...
Several techniques you can use to change the device ID of your SD2IEC from ID #8 to ID #9, and several reasons why you shouldn't do it.
The vertical ones don't fit in Spectrum cases as you say, but you can get horizontal 7805 switching regulator replacements which do fit.
blog.tynemouthsoftware.co.uk/2023/08/zx-s...
blog.tynemouthsoftware.co.uk/2023/08/zx-s...
October 11, 2025 at 10:45 PM
The vertical ones don't fit in Spectrum cases as you say, but you can get horizontal 7805 switching regulator replacements which do fit.
blog.tynemouthsoftware.co.uk/2023/08/zx-s...
blog.tynemouthsoftware.co.uk/2023/08/zx-s...
Or you could build a fully ZX81 compatible DIY kit if you still have a hankering to play 3D Monster Maze on real hardware.
www.tindie.com/products/tyn...
The kit is also available from z80kits.com so you can pick one up when you're getting your RC2014 bits.
z80kits.com/shop/tynemou...
www.tindie.com/products/tyn...
The kit is also available from z80kits.com so you can pick one up when you're getting your RC2014 bits.
z80kits.com/shop/tynemou...
October 8, 2025 at 6:12 PM
Or you could build a fully ZX81 compatible DIY kit if you still have a hankering to play 3D Monster Maze on real hardware.
www.tindie.com/products/tyn...
The kit is also available from z80kits.com so you can pick one up when you're getting your RC2014 bits.
z80kits.com/shop/tynemou...
www.tindie.com/products/tyn...
The kit is also available from z80kits.com so you can pick one up when you're getting your RC2014 bits.
z80kits.com/shop/tynemou...
The numbers aren't exactly consistent, but two separate D-type flip flops is a 74, four with a common clock is a 175, six is a 174, and eight is a 273 (or 374 if you want /OE instead of /CLR, or a 574 if you want that and also want all the inputs on one side and the outputs on the other)
October 7, 2025 at 12:57 PM
The numbers aren't exactly consistent, but two separate D-type flip flops is a 74, four with a common clock is a 175, six is a 174, and eight is a 273 (or 374 if you want /OE instead of /CLR, or a 574 if you want that and also want all the inputs on one side and the outputs on the other)
There is no competition, has to be 3D Monster Maze.
October 6, 2025 at 7:30 PM
There is no competition, has to be 3D Monster Maze.
New blog post. Something a little different, a look at the wonderful 74HC74 (and 74LS74, 74HCT74 etc.) and some of the many and varied things you can do with it.
blog.tynemouthsoftware.co.uk/2025/10/the-...
It all started when I had this brilliant idea.......
blog.tynemouthsoftware.co.uk/2025/10/the-...
It all started when I had this brilliant idea.......
October 5, 2025 at 12:49 PM
New blog post. Something a little different, a look at the wonderful 74HC74 (and 74LS74, 74HCT74 etc.) and some of the many and varied things you can do with it.
blog.tynemouthsoftware.co.uk/2025/10/the-...
It all started when I had this brilliant idea.......
blog.tynemouthsoftware.co.uk/2025/10/the-...
It all started when I had this brilliant idea.......
Your daily reminder that AI is dangerous nonsense and should not be trusted with even the simplest of tasks. I wish everyone would hurry up and release that, and stop wasting ridiculous amounts of money and energy on something that will never be fit for purpose.
September 29, 2025 at 6:03 PM
Your daily reminder that AI is dangerous nonsense and should not be trusted with even the simplest of tasks. I wish everyone would hurry up and release that, and stop wasting ridiculous amounts of money and energy on something that will never be fit for purpose.
Does your C128 not do that?
September 25, 2025 at 8:31 PM
Does your C128 not do that?
Anyone know how to decode Texas Instruments date codes?
The one of the left is the standard old school 5th week 1980, but the ones on the right I don't understand. You might think 24 was a year, but I have seen all sorts of numbers there, so I don't think it is.
2022 4th month? or 2nd month 2024?
The one of the left is the standard old school 5th week 1980, but the ones on the right I don't understand. You might think 24 was a year, but I have seen all sorts of numbers there, so I don't think it is.
2022 4th month? or 2nd month 2024?
September 25, 2025 at 2:21 PM
Anyone know how to decode Texas Instruments date codes?
The one of the left is the standard old school 5th week 1980, but the ones on the right I don't understand. You might think 24 was a year, but I have seen all sorts of numbers there, so I don't think it is.
2022 4th month? or 2nd month 2024?
The one of the left is the standard old school 5th week 1980, but the ones on the right I don't understand. You might think 24 was a year, but I have seen all sorts of numbers there, so I don't think it is.
2022 4th month? or 2nd month 2024?
New blog post - What can you do to fix "?device not present error" on the Commodore PET, including an 8032 repair. blog.tynemouthsoftware.co.uk/2025/09/sd2p...
Warning: also includes awful screenshots and an analogy involving a Ford Cortina.
Warning: also includes awful screenshots and an analogy involving a Ford Cortina.
September 21, 2025 at 2:15 PM
New blog post - What can you do to fix "?device not present error" on the Commodore PET, including an 8032 repair. blog.tynemouthsoftware.co.uk/2025/09/sd2p...
Warning: also includes awful screenshots and an analogy involving a Ford Cortina.
Warning: also includes awful screenshots and an analogy involving a Ford Cortina.
I talk about the AVR Curiosity Nanos in the blog post, the integrated programmer on those makes things a lot easier, and they are about £15, so cheap enough to integrate into a development board or small run project.
You can probably get clones for $1 from Ali Express, but I try to avoid that.
You can probably get clones for $1 from Ali Express, but I try to avoid that.
September 14, 2025 at 3:38 PM
I talk about the AVR Curiosity Nanos in the blog post, the integrated programmer on those makes things a lot easier, and they are about £15, so cheap enough to integrate into a development board or small run project.
You can probably get clones for $1 from Ali Express, but I try to avoid that.
You can probably get clones for $1 from Ali Express, but I try to avoid that.
New blog post - a look at how things have changed since I first used microcontrollers in the early 1990s, and some of the new features they have managed to cram into the latest versions.
blog.tynemouthsoftware.co.uk/2025/09/new-...
blog.tynemouthsoftware.co.uk/2025/09/new-...
September 14, 2025 at 12:08 PM
New blog post - a look at how things have changed since I first used microcontrollers in the early 1990s, and some of the new features they have managed to cram into the latest versions.
blog.tynemouthsoftware.co.uk/2025/09/new-...
blog.tynemouthsoftware.co.uk/2025/09/new-...
New blog post - making some new clip leads for my logic analysers.
blog.tynemouthsoftware.co.uk/2025/09/logi...
Time for a new set which are the right colour, have nice silicone cables and clips that work on ICs.
blog.tynemouthsoftware.co.uk/2025/09/logi...
Time for a new set which are the right colour, have nice silicone cables and clips that work on ICs.
September 7, 2025 at 1:33 PM
New blog post - making some new clip leads for my logic analysers.
blog.tynemouthsoftware.co.uk/2025/09/logi...
Time for a new set which are the right colour, have nice silicone cables and clips that work on ICs.
blog.tynemouthsoftware.co.uk/2025/09/logi...
Time for a new set which are the right colour, have nice silicone cables and clips that work on ICs.