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stephen_usher
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Re: General Stuff(tm)

Post by stephen_usher »

Here's a picture showing the 50Hz light strobing on the dials on the bottom of drive B.

IMG_3568.jpeg
IMG_3568.jpeg (179.19 KiB) Viewed 183 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: General Stuff(tm)

Post by rubber_jonnie »

stephen_usher wrote: Wed Feb 07, 2024 11:34 pm Here's a picture showing the 50Hz light strobing on the dials on the bottom of drive B.


IMG_3568.jpeg
They look huge, more like 8" drives.

Are the dead spots due to the belt, or is it a problem with dry grease in the bearings? If so could you put in some light oil and keep them spinning to break up the dry grease?
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: General Stuff(tm)

Post by stephen_usher »

The motors aren't even trying the turn (there's no hum or jitter from them) until I put some pressure on them. Once they kick in they go fine. I s'pose one set of windings in the stepper motor cold have gone, but I don't know it they're even stepper motors.

They've been oiled and spinning for most of the evening.
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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stephen_usher
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Re: General Stuff(tm)

Post by stephen_usher »

Right, plan of action to test the A drive... Use a BBC Micro.

I should be able to hook these drives up to a BBC and read 40 track disks. If that works then I know that the drive is working OK.

I can test if the disk image(s) I have are OK using a Gotek and converting the IMD format files into HFE files. It will also verify that the Kaypro's floppy interface is working correctly.

That will get rid of most of the variables, leaving just the writing stage from the Win98 PC.
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: General Stuff(tm)

Post by rubber_jonnie »

stephen_usher wrote: Thu Feb 08, 2024 9:15 am Right, plan of action to test the A drive... Use a BBC Micro.

I should be able to hook these drives up to a BBC and read 40 track disks. If that works then I know that the drive is working OK.

I can test if the disk image(s) I have are OK using a Gotek and converting the IMD format files into HFE files. It will also verify that the Kaypro's floppy interface is working correctly.

That will get rid of most of the variables, leaving just the writing stage from the Win98 PC.
Good luck!
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: General Stuff(tm)

Post by stephen_usher »

"Drive A" doesn't work properly. The motor seems very weak for a start.

I found a whole load of broken joints on the motor power board but even after reflowing those it made no difference.

I reconfigured "Drive B" to be a "Drive A" and that worked fine after a few tries getting the head stepper to run. Loaded Elite no problem.

So, I've put the drives back onto the Kaypro with them swapped. Now the system starts to boot but freezes after printing the banner.

'Scoping the data bus after the system has crashed all the lines except for the one for U26 have a very similar pattern. The U26 data line is going hell for leather.

When the floppy drive motor stalls and the machine is waiting for the data all the data lines except the one for U26 are high. The one on U26 is mostly low with a short spike up to 5V every 1600uS. Doesn't look right at all.

All the memories are Intel 4164 equivalents so I have spares, but I'm not looking forward to desoldering that chip as all the solder and chip legs are tarnished and slightly corroded around there so desoldering is going to be an issue. Anyway, it'll have to wait until the weekend now.
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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stephen_usher
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Re: General Stuff(tm)

Post by stephen_usher »

OK, it can't be the RAM chip as it's on the Data-in line and that's separated by the 8216 transceiver. The spike must be on the data bus D1.
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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stephen_usher
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Joined: Mon Nov 13, 2017 7:19 pm
Location: Oxford, UK.
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Re: General Stuff(tm)

Post by stephen_usher »

On the "Drive A" front, it's probably the servo board which has a problem, either the LM2917 or the TIP110 or both.
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: General Stuff(tm)

Post by rubber_jonnie »

Sounds like good progress, very much looking forward to seeing this running.
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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PhilC
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Re: General Stuff(tm)

Post by PhilC »

@stephen_usher how's it been getting hold of service manuals for those drives? I've had a couple I had to fix and lets say Unicorn Poo was more easier to find.
If it ain't broke, test it to Destruction.
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