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
I had a question about making sounds on the Commodore PET and Mini PET, so I have updated one of my old blog posts:
blog.tynemouthsoftware.co.uk/2022/05/pet-...
This covers various ways to make music on the PET, as explained by someone with little understanding of proper musical terminology (sorry).
blog.tynemouthsoftware.co.uk/2022/05/pet-...
This covers various ways to make music on the PET, as explained by someone with little understanding of proper musical terminology (sorry).
January 13, 2026 at 1:23 PM
I had a question about making sounds on the Commodore PET and Mini PET, so I have updated one of my old blog posts:
blog.tynemouthsoftware.co.uk/2022/05/pet-...
This covers various ways to make music on the PET, as explained by someone with little understanding of proper musical terminology (sorry).
blog.tynemouthsoftware.co.uk/2022/05/pet-...
This covers various ways to make music on the PET, as explained by someone with little understanding of proper musical terminology (sorry).
New blog post - part 1 of a series looking at replacing the microcontroller used as the CRTC in the Minstrel 4th.
blog.tynemouthsoftware.co.uk/2026/01/a-ne...
This time looking at various options I considered.
blog.tynemouthsoftware.co.uk/2026/01/a-ne...
This time looking at various options I considered.
January 11, 2026 at 1:35 PM
New blog post - part 1 of a series looking at replacing the microcontroller used as the CRTC in the Minstrel 4th.
blog.tynemouthsoftware.co.uk/2026/01/a-ne...
This time looking at various options I considered.
blog.tynemouthsoftware.co.uk/2026/01/a-ne...
This time looking at various options I considered.
A mini setup on the bench today, I needed to do some PET stuff and my main bench is full of a different project.
One of the first batch of SD2PETs (2019).
The first Mini PET (2020).
The first Deluxe Keyboard (2020).
Definitely not the first mini LCD from Amazon (2024).
All still working nicely.
One of the first batch of SD2PETs (2019).
The first Mini PET (2020).
The first Deluxe Keyboard (2020).
Definitely not the first mini LCD from Amazon (2024).
All still working nicely.
January 7, 2026 at 9:53 AM
A mini setup on the bench today, I needed to do some PET stuff and my main bench is full of a different project.
One of the first batch of SD2PETs (2019).
The first Mini PET (2020).
The first Deluxe Keyboard (2020).
Definitely not the first mini LCD from Amazon (2024).
All still working nicely.
One of the first batch of SD2PETs (2019).
The first Mini PET (2020).
The first Deluxe Keyboard (2020).
Definitely not the first mini LCD from Amazon (2024).
All still working nicely.
New blog post - a round up of the current range of modules and backplanes for the Minstrel Expansion Bus:
blog.tynemouthsoftware.co.uk/2026/01/mins...
Also a look at some of the things you can use them for on the Minstrel 2, Minstrel 3, ZX81 or TS1000.
blog.tynemouthsoftware.co.uk/2026/01/mins...
Also a look at some of the things you can use them for on the Minstrel 2, Minstrel 3, ZX81 or TS1000.
January 4, 2026 at 12:14 PM
New blog post - a round up of the current range of modules and backplanes for the Minstrel Expansion Bus:
blog.tynemouthsoftware.co.uk/2026/01/mins...
Also a look at some of the things you can use them for on the Minstrel 2, Minstrel 3, ZX81 or TS1000.
blog.tynemouthsoftware.co.uk/2026/01/mins...
Also a look at some of the things you can use them for on the Minstrel 2, Minstrel 3, ZX81 or TS1000.
New blog post - Fitting Perilous Swamp into 8K on a PET 2001:
blog.tynemouthsoftware.co.uk/2025/12/fitt...
When I converted the ZX81 game last month, it was 8.5K. It should be easy to fit that into 8K, right?
Lots of things you can do to make your BASIC programs smaller, faster (and less readable).
blog.tynemouthsoftware.co.uk/2025/12/fitt...
When I converted the ZX81 game last month, it was 8.5K. It should be easy to fit that into 8K, right?
Lots of things you can do to make your BASIC programs smaller, faster (and less readable).
December 28, 2025 at 1:31 PM
New blog post - Fitting Perilous Swamp into 8K on a PET 2001:
blog.tynemouthsoftware.co.uk/2025/12/fitt...
When I converted the ZX81 game last month, it was 8.5K. It should be easy to fit that into 8K, right?
Lots of things you can do to make your BASIC programs smaller, faster (and less readable).
blog.tynemouthsoftware.co.uk/2025/12/fitt...
When I converted the ZX81 game last month, it was 8.5K. It should be easy to fit that into 8K, right?
Lots of things you can do to make your BASIC programs smaller, faster (and less readable).
I can't guarantee address or R/W are valid until the 1 MHz clock goes high, and I need the data on the bus before it goes low.
The red line is about 8-10 cycles at 24 MHz.
I don't see where a latch would help?
I did try lots of things to make this work, but it wasn't to be. It's sorted now anyway.
The red line is about 8-10 cycles at 24 MHz.
I don't see where a latch would help?
I did try lots of things to make this work, but it wasn't to be. It's sorted now anyway.
December 22, 2025 at 6:13 PM
I can't guarantee address or R/W are valid until the 1 MHz clock goes high, and I need the data on the bus before it goes low.
The red line is about 8-10 cycles at 24 MHz.
I don't see where a latch would help?
I did try lots of things to make this work, but it wasn't to be. It's sorted now anyway.
The red line is about 8-10 cycles at 24 MHz.
I don't see where a latch would help?
I did try lots of things to make this work, but it wasn't to be. It's sorted now anyway.
Looks like a flat version of Wordy.
December 22, 2025 at 11:40 AM
Looks like a flat version of Wordy.
New blog post: Faster isn't always better - A Cautionary Tale.
blog.tynemouthsoftware.co.uk/2025/12/fast...
An unexpectedly seasonal post, the red and green in the first photo looking very festive, piles of presents, and the feature charts from Microchip looking like they got them out of a cracker.
blog.tynemouthsoftware.co.uk/2025/12/fast...
An unexpectedly seasonal post, the red and green in the first photo looking very festive, piles of presents, and the feature charts from Microchip looking like they got them out of a cracker.
December 21, 2025 at 1:38 PM
New blog post: Faster isn't always better - A Cautionary Tale.
blog.tynemouthsoftware.co.uk/2025/12/fast...
An unexpectedly seasonal post, the red and green in the first photo looking very festive, piles of presents, and the feature charts from Microchip looking like they got them out of a cracker.
blog.tynemouthsoftware.co.uk/2025/12/fast...
An unexpectedly seasonal post, the red and green in the first photo looking very festive, piles of presents, and the feature charts from Microchip looking like they got them out of a cracker.
Yeah.... it's always fun trying to source decent NOS chips these days. I went through quite a few with mixed results.
blog.tynemouthsoftware.co.uk/2023/01/test...
blog.tynemouthsoftware.co.uk/2023/01/test...
December 21, 2025 at 12:24 AM
Yeah.... it's always fun trying to source decent NOS chips these days. I went through quite a few with mixed results.
blog.tynemouthsoftware.co.uk/2023/01/test...
blog.tynemouthsoftware.co.uk/2023/01/test...
I did try that once....
"Obviously, with a kit like this, detailed instructions would normally be required. The foremost technical authors of the land have provided such a manual ....... they would be grateful if you could fill it in as you go."
blog.tynemouthsoftware.co.uk/2022/04/mini...
"Obviously, with a kit like this, detailed instructions would normally be required. The foremost technical authors of the land have provided such a manual ....... they would be grateful if you could fill it in as you go."
blog.tynemouthsoftware.co.uk/2022/04/mini...
December 14, 2025 at 4:05 PM
I did try that once....
"Obviously, with a kit like this, detailed instructions would normally be required. The foremost technical authors of the land have provided such a manual ....... they would be grateful if you could fill it in as you go."
blog.tynemouthsoftware.co.uk/2022/04/mini...
"Obviously, with a kit like this, detailed instructions would normally be required. The foremost technical authors of the land have provided such a manual ....... they would be grateful if you could fill it in as you go."
blog.tynemouthsoftware.co.uk/2022/04/mini...
New blog post, that moment when it goes from "Yay! I sold one" to "Oh, now I have to write the documentation"
blog.tynemouthsoftware.co.uk/2025/12/i-so...
Or, how many times do I need to redraw this schematic until I am happy with it?
blog.tynemouthsoftware.co.uk/2025/12/i-so...
Or, how many times do I need to redraw this schematic until I am happy with it?
December 14, 2025 at 12:34 PM
New blog post, that moment when it goes from "Yay! I sold one" to "Oh, now I have to write the documentation"
blog.tynemouthsoftware.co.uk/2025/12/i-so...
Or, how many times do I need to redraw this schematic until I am happy with it?
blog.tynemouthsoftware.co.uk/2025/12/i-so...
Or, how many times do I need to redraw this schematic until I am happy with it?
I think the GI processors of the day were the first generation PIC microcontrollers. I think they did OK, specially when they split off into Microchip.
December 8, 2025 at 4:22 PM
I think the GI processors of the day were the first generation PIC microcontrollers. I think they did OK, specially when they split off into Microchip.
The full family.
December 8, 2025 at 10:07 AM
The full family.
New blog post - "Can I Add Games to the Penultimate Cartridge?"
blog.tynemouthsoftware.co.uk/2025/12/can-...
(quick answer is yes, that's why we made the PU+3)
blog.tynemouthsoftware.co.uk/2025/12/can-...
(quick answer is yes, that's why we made the PU+3)
December 7, 2025 at 12:36 PM
New blog post - "Can I Add Games to the Penultimate Cartridge?"
blog.tynemouthsoftware.co.uk/2025/12/can-...
(quick answer is yes, that's why we made the PU+3)
blog.tynemouthsoftware.co.uk/2025/12/can-...
(quick answer is yes, that's why we made the PU+3)
Disappointing response to the new Software Serial card. A lot of work went into that, I was hoping there might have been a bit more interest. I guess those days are gone, the state the world is in right now, people have other priorities, and things have moved on. Oh well.
December 2, 2025 at 10:16 AM
Disappointing response to the new Software Serial card. A lot of work went into that, I was hoping there might have been a bit more interest. I guess those days are gone, the state the world is in right now, people have other priorities, and things have moved on. Oh well.
I used 4 channels as there were only a few traces to display, if you read the post you will also see 8 channel captures.
And these are not cheap Chinese knocks offs, these are quality bits of kit from the actual designers, Ikalogic in France. Great products and support.
www.ikalogic.com
And these are not cheap Chinese knocks offs, these are quality bits of kit from the actual designers, Ikalogic in France. Great products and support.
www.ikalogic.com
December 1, 2025 at 10:25 AM
I used 4 channels as there were only a few traces to display, if you read the post you will also see 8 channel captures.
And these are not cheap Chinese knocks offs, these are quality bits of kit from the actual designers, Ikalogic in France. Great products and support.
www.ikalogic.com
And these are not cheap Chinese knocks offs, these are quality bits of kit from the actual designers, Ikalogic in France. Great products and support.
www.ikalogic.com
New blog post - a new serial card for Minstrel 4th and RC2014 - blog.tynemouthsoftware.co.uk/2025/11/soft...
Yes, that's it. No UART, no ACIA, no DART, no SIO no microcontroller, no Raspberry Pi.
How did I do it?
Yes, that's it. No UART, no ACIA, no DART, no SIO no microcontroller, no Raspberry Pi.
How did I do it?
November 30, 2025 at 12:14 PM
New blog post - a new serial card for Minstrel 4th and RC2014 - blog.tynemouthsoftware.co.uk/2025/11/soft...
Yes, that's it. No UART, no ACIA, no DART, no SIO no microcontroller, no Raspberry Pi.
How did I do it?
Yes, that's it. No UART, no ACIA, no DART, no SIO no microcontroller, no Raspberry Pi.
How did I do it?
There is a "Contact Store" button on Tindie, a "Contact Me" button on my blog and a DM button on my profile.
blog.tynemouthsoftware.co.uk
blog.tynemouthsoftware.co.uk
November 28, 2025 at 12:25 PM
There is a "Contact Store" button on Tindie, a "Contact Me" button on my blog and a DM button on my profile.
blog.tynemouthsoftware.co.uk
blog.tynemouthsoftware.co.uk
New blog post - Converting a ZX81 BASIC game to run in Commodore BASIC on the VIC 20 (and the PET, C64 and TED)
blog.tynemouthsoftware.co.uk/2025/11/peri...
BASIC is quite a portable language, so let's see how easily it ports.
blog.tynemouthsoftware.co.uk/2025/11/peri...
BASIC is quite a portable language, so let's see how easily it ports.
November 23, 2025 at 2:42 PM
New blog post - Converting a ZX81 BASIC game to run in Commodore BASIC on the VIC 20 (and the PET, C64 and TED)
blog.tynemouthsoftware.co.uk/2025/11/peri...
BASIC is quite a portable language, so let's see how easily it ports.
blog.tynemouthsoftware.co.uk/2025/11/peri...
BASIC is quite a portable language, so let's see how easily it ports.
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