The Naked Atari 800
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stephen_usher
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- Posts: 7376
- Joined: 13 Nov 2017 19:19
- Location: Oxford, UK.
Re: The Naked Atari 800
When I used an ATTiny85 I used the Arduino IDE to generate a file which I then used the TL866 to program onto the chip.
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
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- Posts: 14888
- Joined: 17 Aug 2017 19:40
- Location: Essex
Re: The Naked Atari 800
Mine has a USB interface so I should be able to do it directly. I hope...stephen_usher wrote: 11 Jan 2026 18:43 When I used an ATTiny85 I used the Arduino IDE to generate a file which I then used the TL866 to program onto the chip.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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stephen_usher
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- Posts: 7376
- Joined: 13 Nov 2017 19:19
- Location: Oxford, UK.
Re: The Naked Atari 800
Oh, you've got it on a board with USB boot code built in. I just use the stock chips. :-)
Intro retro computers since before they were retro...
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
ZX81->Spectrum->Memotech MTX->Sinclair QL->520STM->BBC Micro->TT030->PCs & Sun Workstations.
Added code to the MiNT kernel (still there the last time I checked) + put together MiNTOS.
Collection now with added Macs, Amigas, Suns and Acorns.
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rubber_jonnie
- Site Admin

- Posts: 14888
- Joined: 17 Aug 2017 19:40
- Location: Essex
Re: The Naked Atari 800
Yeah I'm a cheater 😁stephen_usher wrote: 11 Jan 2026 20:02 Oh, you've got it on a board with USB boot code built in. I just use the stock chips. :-)
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Maximilian
- Posts: 407
- Joined: 28 Feb 2019 17:02
Re: The Naked Atari 800
Code: Select all
print("Si5351 programmed successfully.")Code: Select all
print("Tape backup made successfully.")(I was able to get their software and databases running again after a lot of work)
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rubber_jonnie
- Site Admin

- Posts: 14888
- Joined: 17 Aug 2017 19:40
- Location: Essex
Re: The Naked Atari 800
Well this is only for programming via RPi so it doesn't really matter that much as that isn't the long term plan :)Maximilian wrote: 12 Jan 2026 15:22LOL, I have a funny memory of this kind of code, it went like this:Code: Select all
print("Si5351 programmed successfully.")
They thought tape backups were really quick because the backup never took more then one or two seconds..Code: Select all
print("Tape backup made successfully.")
(I was able to get their software and databases running again after a lot of work)
If only I could get my ATTiny85 to play ball it might actually go somewhere!
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Maximilian
- Posts: 407
- Joined: 28 Feb 2019 17:02
Re: The Naked Atari 800
Should be pretty simple with Arduino and a scope that can decode I2C.
Nice project!
Just ordered a few of those SI chips.
Nice project!
Just ordered a few of those SI chips.
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rubber_jonnie
- Site Admin

- Posts: 14888
- Joined: 17 Aug 2017 19:40
- Location: Essex
Re: The Naked Atari 800
Thanks. I think my ATTiny has died so I'll just wait for replacements to arrive. I2C is working on the clock generators and for programming via the RPi, which is fine for testing but I want to add the ATTiny so that it will run code on boot to inject the config to the clock generator on power up with no need for the RPi, so all autonomous.Maximilian wrote: 12 Jan 2026 17:09 Should be pretty simple with Arduino and a scope that can decode I2C.
Nice project!
Just ordered a few of those SI chips.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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Maximilian
- Posts: 407
- Joined: 28 Feb 2019 17:02
Re: The Naked Atari 800
They normally do not die. (that quick)
Did you perhaps disable the internal clock on your last project?
You can feed a clock(1 mhz) in CLKI (PB3) to make sure.
Set the programmer to 250kHz. (not more than 1/4 of the clock)
Or use a high voltage programmer to reset it.
If you really killed it, you get a badge with "Killer of AVR's"
Did you perhaps disable the internal clock on your last project?
You can feed a clock(1 mhz) in CLKI (PB3) to make sure.
Set the programmer to 250kHz. (not more than 1/4 of the clock)
Or use a high voltage programmer to reset it.
If you really killed it, you get a badge with "Killer of AVR's"
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rubber_jonnie
- Site Admin

- Posts: 14888
- Joined: 17 Aug 2017 19:40
- Location: Essex
Re: The Naked Atari 800
I've had a lot of trouble getting both my Mac and Windows machines to work with it and it half programmed at one point (As far as I can tell) and then after that it stopped playing nicely. I pulled the ATTiny off the USB board and it seemed to behave when soldered to an adapter in my TL866. I reset the fuses but it wouldn't play after after I resoldered it to the USB adapter board.Maximilian wrote: 12 Jan 2026 22:30 They normally do not die. (that quick)
Did you perhaps disable the internal clock on your last project?
You can feed a clock(1 mhz) in CLKI (PB3) to make sure.
Set the programmer to 250kHz. (not more than 1/4 of the clock)
Or use a high voltage programmer to reset it.
If you really killed it, you get a badge with "Killer of AVR's"
Will have another look to see if I've jostled some other component when using hot air. I'm not desperately upset as they are cheap and I have some more coming tomorrow.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
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