The latest member of the family

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rubber_jonnie
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Re: The latest member of the family

Post by rubber_jonnie »

JezC wrote: Fri Jan 31, 2025 2:04 pm @rubber_jonnie I'll also try to test my expansion (no RTC) and see how that goes...just in case!
Good idea.
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
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stephen_usher
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Re: The latest member of the family

Post by stephen_usher »

I'd fit the expansion, look up the address range it should have and then run Amiga Test Kit memory tester on that address range. It's possible one of the 41256 chips has become faulty. This is the least invasive test.

Then again, you know me. I try to exhaust all diagnostics before getting the soldering iron/desoldering gun out. :-) Been bitten too many times.
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.
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rubber_jonnie
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Re: The latest member of the family

Post by rubber_jonnie »

Turns out I'm a numpty.

I was looking at the bloody RAM upside down :dizzy:

So it isn't A2 and A5, it's the data in/data out pins that look all kinds of wrong. D'oh.
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...
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rubber_jonnie
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Re: The latest member of the family

Post by rubber_jonnie »

stephen_usher wrote: Fri Jan 31, 2025 3:00 pm I'd fit the expansion, look up the address range it should have and then run Amiga Test Kit memory tester on that address range. It's possible one of the 41256 chips has become faulty. This is the least invasive test.

Then again, you know me. I try to exhaust all diagnostics before getting the soldering iron/desoldering gun out. :-) Been bitten too many times.
Yeah, I'm off looking for that now...

Also I have loads of 41256 RAM like on the expansion board so I could try piggybacking.
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...
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rubber_jonnie
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Re: The latest member of the family

Post by rubber_jonnie »

Ok, so piggybacking didn't work and when I tried to use the Amiga Test Kit to test the range where the trapdoor RAM should be (08000 to 0ffff) and it recognises it as a 512MB range, but as soon as I start the test it crashes the machine.

Interestingly though, the RTC on the trapdoor board is visible to ATK.
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...
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rubber_jonnie
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Re: The latest member of the family

Post by rubber_jonnie »

Also interesting, I found the RAM I need to do an on board upgrade if it comes to it. It was in a drawer of Atari stuff.
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...
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stephen_usher
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Re: The latest member of the family

Post by stephen_usher »

rubber_jonnie wrote: Fri Jan 31, 2025 3:54 pm Ok, so piggybacking didn't work and when I tried to use the Amiga Test Kit to test the range where the trapdoor RAM should be (08000 to 0ffff) and it recognises it as a 512MB range, but as soon as I start the test it crashes the machine.

Interestingly though, the RTC on the trapdoor board is visible to ATK.
That's weird. It would suggest maybe an addressing problem where the external RAM is also being seen at a low address.
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.
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rubber_jonnie
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Re: The latest member of the family

Post by rubber_jonnie »

stephen_usher wrote: Fri Jan 31, 2025 4:30 pm
rubber_jonnie wrote: Fri Jan 31, 2025 3:54 pm Ok, so piggybacking didn't work and when I tried to use the Amiga Test Kit to test the range where the trapdoor RAM should be (08000 to 0ffff) and it recognises it as a 512MB range, but as soon as I start the test it crashes the machine.

Interestingly though, the RTC on the trapdoor board is visible to ATK.
That's weird. It would suggest maybe an addressing problem where the external RAM is also being seen at a low address.
Definitely is.

I have been wondering if the card is not compatible with this particular issue Amiga, but that would be rather odd.
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...
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stephen_usher
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Re: The latest member of the family

Post by stephen_usher »

Maybe a short between a high and low address line, or maybe one of the higher address lines not reaching the card?
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.
User avatar
rubber_jonnie
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Re: The latest member of the family

Post by rubber_jonnie »

stephen_usher wrote: Fri Jan 31, 2025 4:59 pm Maybe a short between a high and low address line, or maybe one of the higher address lines not reaching the card?
If there is I don't think it's on the card, it's super simple and looking at it with the magnifying glass, it looks just fine.
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...
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