Greaseweazle

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Revision as of 12:57, 5 February 2021 by Tingo (Talk | contribs) (Converting from .scp to .img (image) format: fixed formatting)

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Greaseweazle[1] is not an ND product. However, it allows you to connect a floppy drive to a modern computer and use it as a ND media reader for floppies. It is like the FluxEngine, but with cheaper hardware, and a different set of programs to use it.

Hardware setup

You will need a computer with a usb port. You will also need:

  • the Greaseweazle hardware
    • a STM32F103C8 "Blue Pill" development board (or alternative - see the Greaseweazle wiki)
    • a Blue Pill Adapter (files to order the pcb are available[2])
  • a usb to micro-usb cable for connecting the FluxEngine to the computer
  • a floppy cable, for connecting the FluxEngine to the floppy drive
  • a floppy drive capable of reading the floppies you want to read
  • a power supply for the floppy drive. Except for 3.5 inch drives, you can't power the drive from the usb port

You also need a bit of storage space for the images you capture.

Software setup

The Greaseweazle comes with the firmware, and the program to read data from the floppy drive. This program (gw.py - yes, it is written in Python) does only one thing: it reads data from the floppy drive, and stores it in a file, in .scp (SuperCard Pro) Flux image format[3]. You will need a program to convert the .scp files into something you can use, like a direct "image" format.

I have (briefly) tested keirf's Disk Utilities[4], and it appears to work, at least for ND format 17b floppies

Usage

Using the Greaseweazle consists of two steps: capture data from a floppy to a file (.scp file), and the converting this file into a more usable format.

Reading data

This is a simple operation. If you just type the command with no parameters, you get a help text

tingo@z30b:~/work/greaseweazle$ ./Greaseweazle-v0.11/gw.py 
Usage: ./Greaseweazle-v0.11/gw.py [action] ...
Actions: read, write, delays, update

you can add an action to get more info

tingo@z30b:~/work/greaseweazle$ ./Greaseweazle-v0.11/gw.py read
usage: gw.py read [-h] [--drive DRIVE] [--revs REVS] [--scyl SCYL]
                  [--ecyl ECYL] [--single-sided]
                  file [device]
gw.py read: error: the following arguments are required: file
tingo@z30b:~/work/greaseweazle$ ./Greaseweazle-v0.11/gw.py write
usage: gw.py write [-h] [--drive DRIVE] [--scyl SCYL] [--ecyl ECYL]
                   [--single-sided] [--adjust-speed]
                   file [device]
gw.py write: error: the following arguments are required: file
tingo@z30b:~/work/greaseweazle$ ./Greaseweazle-v0.11/gw.py delays
** Greaseweazle v0.11 [F1], Host Tools v0.11
Select Delay: 10us
Step Delay: 3000us
Settle Time: 15ms
Motor Delay: 750ms
Auto Off: 10000ms

To read a ND format 17b floppy, you would use

tingo@z30b:~/work/greaseweazle$ ./Greaseweazle-v0.11/gw.py read --ecyl 76 525_nd_f17b_211024-c01-xx-01d.scp
** Greaseweazle v0.11 [F1], Host Tools v0.11
Reading Track 76.1...

77 tracks means track 0 - 76.

For a ND format 0b floppy you would use

tingo@z30b:~/work/greaseweazle$ ./Greaseweazle-v0.11/gw.py read --ecyl 76 --single-sided 525_nd_f0b_nd-10005u_2.scp
** Greaseweazle v0.11 [F1], Host Tools v0.11
Reading Track 76.0...

This format also have 77 tracks, but is single-sided.

Converting from .scp to .img (image) format

This is the more complex operation, but it is where you can try many options until you get one that is perfect (assuming that the tools are able to decode the format that the floppies was written with). I'm testing keirf's Disk Utilities for this task.

Converting the .scp file from a ND format 17b into .img (image) format

tingo@z30b:~/work/greaseweazle$ LD_LIBRARY_PATH=Disk-Utilities/libdisk/ ./Disk-Utilities/disk-analyse/disk-analyse --config=./Disk-Utilities/disk-analyse/formats --format=ibm --end-cyl=76 525_nd_f17b_211024-c01-xx-01d.scp 525_nd_f17b_211024-c01-xx-01d_2.img
*** T0.0: Unexpected track length (seen 166573, expected 200300)
*** T0.1: Unexpected track length (seen 166559, expected 200300)
*** T1.0: Unexpected track length (seen 166569, expected 200300)
*** T1.1: Unexpected track length (seen 166566, expected 200300)
[..]
T0.0-76.1: IBM-MFM HD (8 1024-byte sectors, 8192 bytes)

It will report a lot of "unexpected track length" warnings - simply ignore those. The important part is the last line - it tells you if the program was able understand the data, and what format it thinks this is. Now you can use other tools (like ndfs) on the .img file.

To convert a .scp file from a ND format 0b floppy to .img you would use

tingo@z30b:~/work/greaseweazle$ LD_LIBRARY_PATH=Disk-Utilities/libdisk/ ./Disk-Utilities/disk-analyse/disk-analyse --config=./Disk-Utilities/disk-analyse/formats --format=ibm --ss=0 --end-cyl=76 525_nd_f0b_nd-10005u_2.scp 525_nd_f0b_nd-10005u_3.img
*** T0.0: Unexpected track length (seen 83293, expected 100150)
*** T1.0: Unexpected track length (seen 83406, expected 100150)
*** T2.0: Unexpected track length (seen 83407, expected 100150)
*** T3.0: Unexpected track length (seen 83404, expected 100150)
[..]
T0.0-38.0: IBM-FM DD (8 512-byte sectors, 4096 bytes)
T39.0-76.0: Unformatted*
** WARNING: 38 tracks are damaged or unidentified!

As usual, lots of "unexpected track length" warnings, but then a warning that some tracks are unformatted, and / or unformatted - never a good sign. But ndfs doesn't like the resulting image file

tingo@z30b:~/work/greaseweazle$ ~/bin/ndfs -t 525_nd_f0b_nd-10005u_3.img
Directory name            : ND-10005U
Object file index pointer : 150 SI: 0x1 (indexed)
User file index pointer   : 152 SI: 0x1 (indexed)
Bit file pointer          : 77 SI: 0x0 (contiguous)
No. of unreserved pages   : 1
Error reading page 152: Success

Too early to tell if the problem is with the conversion program or the floppy I used.

References

  1. Greaseweazle
  2. PCB-Projects - greaseweazle
  3. SuperCard Pro Flux Image format (.scp)
  4. Disk Utilities