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800k floppy read-write with Greaseweazel + FluxEngine = Success!


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I used what Greaseweazel project refers to as the F1 "direct-connection" board. It is a STM32F103C8T6 chip also known as bluepill. However, I was not able to source this blue pill board locally, so I used another one (no name) which has the same chip. The pinouts are located elsewhere on the board, but the functionality is the same.

I did not use the recommended firmware upgrade process (https://github.com/keirf/Greaseweazle/wiki/Firmware-Programming) because I did not have the special ST link programmer. However I was able to program it via a generic usb serial (3.3V) adapter I had, together with a programmer called STM32CubeProgrammer.

 

Also, through trial and error I found out that the latest g/w firmware 24 does not work with fluxengine, instead we need to use 2.2.

 

At this point I am trying to figure out how to write custom mini vmac images, as these do not have a header, and fluxengine is complaining about this. Diskcopy 4.2 images that I downloaded from the internet worked fine

Edited by Andrew
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4 hours ago, erichelgeson said:

Well well well! I have about 50 of these for a different project :)(see sig) - Thanks for the tip, I'll be giving it a try.

Yes, I know about your project and I am monitoring it. Good luck with that

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I ordered some PCBs for this project(rather than doing the direct wiring method) which should be here within the next week or 2, so if anyone is interested in a blank PCB or 2 for a few bucks shipped(within the US), let me know

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  • 2 weeks later...
On 2/17/2021 at 4:48 PM, erichelgeson said:

Got my boards from @Torbar
and got it setup. Seems to read the few disks I tried fine, will be trying a few bad disks I couldn't read in my Mac and see if I can salvage the files.

 

 

That's great. I hope you get good results. I found that the Mac drive is better at reading. E.g. when reading some disks with this setup I might get a few bad sectors, whereas the Mac drive can make an image just fine.

 

But nevertheless it gives more choices which is great.

Edited by Andrew
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4 hours ago, Andrew said:

I found that the Mac drive is better at reading

Oh, I was not aware of this - for connecting a mac floppy do you need a straight through cable or with the twist? how does power work?

 

Had good results reading 1.44 disks, but no 800k's have worked so far in fluxengine or gw - though I've only spent a few minutes on it so far.

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4 hours ago, Andrew said:

Sorry I meant a Mac floppy drive operating in an actual Mac!

Ahh! makes more sense :) what command do you use to read 800k disks? Also I have a bunch of notes i'll post here later as setup is not "simple" - just a lot of things to setup

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On 2/18/2021 at 1:16 PM, erichelgeson said:

Ahh! makes more sense :) what command do you use to read 800k disks? Also I have a bunch of notes i'll post here later as setup is not "simple" - just a lot of things to setup

 

It is the same command as 1.44MB disks. I think it reads the right format from the diskcopy header.

 

The command is 

fluxengine write mac -i mac.diskcopy

and relevant information can be found here http://cowlark.com/fluxengine/doc/disk-macintosh.html

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I have a good 800k disk I formatted on my real mac and put a file or two on to test. I just get a bunch of failures to read tracks - same disk works fine in a real mac. Reading 1.44 disks are fine - recovered a few things already. Someone on the forum mentioned this model had issues with 800k disks too. The Sony & Samsung seem to be validated working.

 

https://cdn.discordapp.com/attachments/812357379004956672/812410313168519188/unknown.png

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  • 3 weeks later...

Hi,

After purchasing a Plus some weeks back, and realising I had no OS disks to boot from, I did look at the SD options. Deemed too expensive for me I stumbled across the FluxEngine project online too but couldn't get the Bluepill I had laying around to work. 

 

I did however get the FluxEngine board to work first time. A simple 20pin header soldered as per the instruction to the controller,  a ground wire connected to the floppy drive(an old 1.44mb pulled from my pc) and it works.

 

I have finally been able to get my Plus to boot, albeit it from an External drive into 6.0.8. First time since I purchased it. I

 

Next is to fix the internal drive, create some more floppies, and sus out what memory I actually have in the Plus.

 

Edited by GBrigden
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  • 2 months later...

This is slightly necro, but only by a few months... I only just noticed this thread!

 

So, some PC drives won't work with Mac formats at all --- Mac formats in a PC drive require the interval between flux pulses on the disk to be 2.6us, which is significantly lower than the 4us for a PC 720kB disk. It seems that some drives can't cope with pulses closer together than about 3.5us. I have one drive which works, and one which doesn't. Given that the sector map quoted by erichelgeson above shows bad sectors at _both_ ends of the disk, but a perfect read in the middle, this could well be the issue. There's a relatively new tool which will actually measure this. See http://cowlark.com/fluxengine/doc/driveresponse.html. Sadly there's no cure other than to use a different drive.

 

(If you still have this set up and could try the command at the top of that page and attach the graph, I'd be really grateful --- I'm still sorting this out.)

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