You mean these?
https://www.exxosforum.co.uk/atari/store2/#0137
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DO NOT USE DEVICES WHERE THE IP CHANGES CONSTANTLY!
At this time it is unfortunately not possible to white list users when your IP changes constantly.
You may inadvertently get banned because a previous attack may have used the IP you are now on.
So I suggest people only use fixed IP address devices until I can think of a solution for this problem!
At this time it is unfortunately not possible to white list users when your IP changes constantly.
You may inadvertently get banned because a previous attack may have used the IP you are now on.
So I suggest people only use fixed IP address devices until I can think of a solution for this problem!
Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
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jurassicman
- Posts: 22
- Joined: Thu Jan 26, 2023 7:08 pm
Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
Yes... they seem exactly the same I ordered... I'm still waiting for them, though.
In the meantime, is there somewhere a list of the axial capacitors needed in order to recap this model of mainboard?
In the meantime, is there somewhere a list of the axial capacitors needed in order to recap this model of mainboard?
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frank.lukas
- Posts: 795
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Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
-7 = 70ns
-10 = 100ns
... for a standard 8Mhz 68000 Atari ST 100ns is fast enough. Atari use 150ns or 200ns.
-10 = 100ns
... for a standard 8Mhz 68000 Atari ST 100ns is fast enough. Atari use 150ns or 200ns.
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rubber_jonnie
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Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
In my experience the ST generally doesn't need recapping, I personally wouldn't worry too much unless you can see capacitors that look like they're leaking or are bulging, I wouldn't bother.jurassicman wrote: Sat Oct 18, 2025 12:13 pm
In the meantime, is there somewhere a list of the axial capacitors needed in order to recap this model of mainboard?
In any event, just read the values off the caps on the board. My personal preference is to go for 105c caps instead of 85c as it means you have a better temperature range from any replacements.
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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jurassicman
- Posts: 22
- Joined: Thu Jan 26, 2023 7:08 pm
Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
Thanks for your replies... the capacitors look ok but I was wondering if it would have been wise to replace them as I did with those in the PSU.
I had a look online and axial capacitors are a bit more expensive than the radial ones and not so common so probably it would be just a waste of time at the moment... I'll patiently wait for the memory chips...
I had a look online and axial capacitors are a bit more expensive than the radial ones and not so common so probably it would be just a waste of time at the moment... I'll patiently wait for the memory chips...
Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
Are you sure Atari ever used 200ns RAM chips in any ST machine? At least in theory, 200ns RAM chips are not fast enough.frank.lukas wrote: Sat Oct 18, 2025 9:11 pm ... for a standard 8Mhz 68000 Atari ST 100ns is fast enough. Atari use 150ns or 200ns.
http://github.com/ijor/fx68k 68000 cycle exact FPGA core
FX CAST Cycle Accurate Atari ST core
http://pasti.fxatari.com
FX CAST Cycle Accurate Atari ST core
http://pasti.fxatari.com
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frank.lukas
- Posts: 795
- Joined: Fri Jan 19, 2018 11:52 am
Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
ROM chips 200ns and RAM 150ns I think but I might have mixed something up?
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jurassicman
- Posts: 22
- Joined: Thu Jan 26, 2023 7:08 pm
Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
I finally got the chips, I did mount them on the sockets but my system still sees only 512 KB of RAM... Am I missing something?
The R73, R72 and R71 were already populated as the C25, C26, C27 and C28... please help...
The R73, R72 and R71 were already populated as the C25, C26, C27 and C28... please help...
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jurassicman
- Posts: 22
- Joined: Thu Jan 26, 2023 7:08 pm
Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
Here some pictures...
As visible I did replace the Axial C49 capacitor with a Radial one 'cause it seemed a bit swollen. I've been using the computer for two weeks and I haven't had any issues so far so I think it's ok. It passes all tests and I was able to play all games I did try.
As visible I did replace the Axial C49 capacitor with a Radial one 'cause it seemed a bit swollen. I've been using the computer for two weeks and I haven't had any issues so far so I think it's ok. It passes all tests and I was able to play all games I did try.
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jurassicman
- Posts: 22
- Joined: Thu Jan 26, 2023 7:08 pm
Re: Upgrading C103175 Rev. 1 520STFM to 1MB - how exactly?
As per the RAM speed, as visible in my picture and as you can read here the original chips speed is 100ns like those I did buy.