logic analyser for capture

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artag
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Joined: Mon Jan 30, 2023 1:54 pm

logic analyser for capture

Post by artag »

I saw an announcement on twitter that it's now possible to dump a raw floppy using a logic analyser.
Where can I find details of this ?

I have a 31/2" 1.44M PC floppy that can no longer be read using DOS and I hope to extract its contents using this method.

Jeff
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Re: logic analyser for capture

Post by Jeff »

artag wrote:
Wed Feb 01, 2023 6:45 pm
I saw an announcement on twitter that it's now possible to dump a raw floppy using a logic analyser.
Where can I find details of this ?

I have a 31/2" 1.44M PC floppy that can no longer be read using DOS and I hope to extract its contents using this method.
Hello,

The last release notes (v2.14.4.1) contains the explanations :

https://hxc2001.com/download/floppy_dri ... r_soft.zip

https://hxc2001.com/download/floppy_dri ... _notes.txt
-> Logic analyzer capture loader :

Can now load tracks captured with a simple logic analyzer. (Saleae logic analyzer or similar).

The current state/limitations are :

Need only 2 jumper wires : data (floppy pin 30) & index (floppy pin 8).
Load only a track at a time.
The sample rate is set by default at 16MHz. This can be changed through the "LOGICANALYZER_SAMPLERATE" variable.
The floppy data signal is mapped by default to the bit 0. This can be changed through the "LOGICANALYZER_DATA_BIT" variable.
The floppy index signal is mapped by default to the bit 3. This can be changed through the "LOGICANALYZER_INDEX_BIT" variable.
The supported input file format is a raw 8bits binary format (change the file extension to ".logicbin8bits").
Each byte in the file is a sample.

How to use it ? :

Connect the ground, data and index wires : machine ground to vss/gnd wire, floppy pin 30 to wire 0, floppy pin 8 to wire 3.
Start the machine, start the logic analyzer software. Start the capture and on the machine use any software/way to read a particular track.
The track should be read during at least to 2 revolutions ( 3 index pulses ). Save the dump in raw binary mode.
Change the binary dump file extension to ".logicbin8bits".
Before loading the file into the hxc software you may need to set the LOGICANALYZER_IMPORT_START_OFFSET and LOGICANALYZER_IMPORT_END_OFFSET
variables to define the region of interest in the file. You can use PulseView or similar software to roughly get the values to use.

TODO / Work in progress :

- Add the xx.y file naming convention to load multiple track files (xx=track number, y=side number)
- Add the dir,step,side, track 0 signals support to load a whole disk from one single file.

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