Skip to content

BBC Micro - floppy drive #25

Open
Open
BBC Micro - floppy drive#25

Description

@patvdleer
patvdleer
opened on Nov 11, 2022

Any clue if this would work for a 5.1/4 floppy drive for the BBC Micro? I initially focused on getting the machine back up and running, since it now boots I want to backup/dump the floppies first. The floppy drive I have has a card edge style 34 pin connector with MOLEX (not MOLEX Berg) for power.

Activity

  1. RobSmithDev commented on Nov 12, 2022

    @RobSmithDev
    RobSmithDev
    on Nov 12, 2022
    Owner

    Hi, tbh I’m not sure, I suspect not directly. I suspect the code would need modifying for a different bit-rate

  2. patvdleer commented on Nov 13, 2022

    @patvdleer
    patvdleer
    on Nov 13, 2022
    Author

    I had some old Arduino Mini pro and a (possibly even older) FTDI in the closet, after flashing it with the ino I can't seem to be able to address it all. I've compiled the ArduinoFloppyReader drawbridge but it doesn't seem to be able to communicate with the Arduino. I'll order a new Arduino and FTDI tomorrow and see what happens.

  3. patvdleer commented on Nov 14, 2022

    @patvdleer
    patvdleer
    on Nov 14, 2022
    Author

    It works right away when I added sudo.... no clue why since I managed to flash without

  4. patvdleer commented on Nov 14, 2022

    @patvdleer
    patvdleer
    on Nov 14, 2022
    Author

    Is it ok to have the 1K ohm resistor between 5v of the arduino and pin 8 with separate power sources or should it be connected to the PSU of the floppy drive?

    http://amiga.robsmithdev.co.uk/images/promini_writer_plus.gif

    The first attempt is with the 5v not connected to the arduino, second is with it connected. I think the arduino is getting it's power over the IDC 34pin since the Arduino does turn on when only the floppy is hooked up and powered so without the FTDI connected.

    patrick@patrick-X470-AORUS-ULTRA-GAMING:~/git/ArduinoFloppyDiskReader/ArduinoFloppyReader/ArduinoFloppyReader$ sudo ./drawbridge /dev/ttyUSB0 OutputFilename.SCP READ
DrawBridge aka Arduino Floppy Disk Reader/Writer V2.8.8, Copyright (C) 2017-2022 Robert Smith
Full sourcecode and documentation at https://amiga.robsmithdev.co.uk
This is free software licenced under the GNU General Public Licence V3

Error opening COM port: Error reading response from the Arduino while running command EnableMotor.  

patrick@patrick-X470-AORUS-ULTRA-GAMING:~/git/ArduinoFloppyDiskReader/ArduinoFloppyReader/ArduinoFloppyReader$ sudo ./drawbridge /dev/ttyUSB0 OutputFilename.SCP READ
DrawBridge aka Arduino Floppy Disk Reader/Writer V2.8.8, Copyright (C) 2017-2022 Robert Smith
Full sourcecode and documentation at https://amiga.robsmithdev.co.uk
This is free software licenced under the GNU General Public Licence V3

Error opening COM port: Last command completed successfully.

  5. RobSmithDev commented on Nov 14, 2022

    @RobSmithDev
    RobSmithDev
    on Nov 14, 2022
    Owner

    Hi, first you always need to power up the Arduino first as (as you suspect) it will power up from the 34-pin connector, and not always in a good way.

    Re the resistor. It doesnt matter as long as its pulled to 5v. Probably the Arduino 5V is better.

  6. patvdleer commented on Nov 14, 2022

    @patvdleer
    patvdleer
    on Nov 14, 2022
    Author

    I butchered the wiring and hooked up the pin 8 resistor to an additional lead from the PSU but still the same result.

    As soon as I try to read from floppy the PSU shuts off, the PSU I'm using is an older ATX power supply with a short in the 20/24 pin header to keep it on

  7. RobSmithDev commented on Nov 14, 2022

    @RobSmithDev
    RobSmithDev
    on Nov 14, 2022
    Owner

    The issue after enable motor usually means the drive is pulling too much power, which has caused the 5V to drop too low and as a result the Arduino has probably performed a brown-out detected reset. I suggest for testing powert the Arduino from a seperate 5V power supply first

  8. patvdleer commented on Nov 14, 2022

    @patvdleer
    patvdleer
    on Nov 14, 2022
    Author

    I am, it's the ATX PSU that shuts off, both with and without the 5V from the FTDI hooked up to the Arduino.

  9. RobSmithDev commented on Nov 14, 2022

    @RobSmithDev
    RobSmithDev
    on Nov 14, 2022
    Owner

    The ATX power supply shuts off?

  10. patvdleer commented on Nov 14, 2022

    @patvdleer
    patvdleer
    on Nov 14, 2022
    Author

    yeah directly followed by Error opening COM port: Error reading response from the Arduino while running command EnableMotor.

  11. RobSmithDev commented on Nov 14, 2022

    @RobSmithDev
    RobSmithDev
    on Nov 14, 2022
    Owner

    IF the power supply shuts off it will mean overload or short circuit.

  12. RobSmithDev commented on Nov 14, 2022

    @RobSmithDev
    RobSmithDev
    on Nov 14, 2022
    Owner

    Looking around, and I don't know which model of BBC drive you have, but some of them can peek at 1.2 amps on the 12v

  13. patvdleer commented on Nov 14, 2022

    @patvdleer
    patvdleer
    on Nov 14, 2022
    Author

    Mitsubishi MF503B(-312M), the DC power requirements show:

    +5v   +-5% 0.5A typ 0.7A
+12v +-5% 0.6A typ 1.0A max

    https://www.minuszerodegrees.net/manuals/Mitsubishi/Mitsubishi%20-%20MF501B,%20MF503B,%20MF504B%20-%20Specifications%20and%20Application%20Notes.pdf

    page 2 near the bottom

  14. RobSmithDev commented on Nov 14, 2022

    @RobSmithDev
    RobSmithDev
    on Nov 14, 2022
    Owner

    I suggest you try to get the disk spinning without the arduino for the minute, sounds like theres a issue there somewhere. The Error you get from the software is because the arduino reset its self, probably because of the power issue

  15. patvdleer commented on Nov 14, 2022

    @patvdleer
    patvdleer
    on Nov 14, 2022
    Author

    Different ATX PSU, same issue, I still have a Teac 14733730, that one does spin up but results in: Error opening COM port: Last command completed successfully.

    I've been trying a bunch of stuff but everything seems to fail.

    Even the diagnostic,

    DrawBridge aka Arduino Floppy Disk Reader/Writer V2.8.8, Copyright (C) 2017-2022 Robert Smith
Full sourcecode and documentation at https://amiga.robsmithdev.co.uk
This is free software licenced under the GNU General Public Licence V3

Running diagnostics on COM port: /dev/ttyUSB0
Attempting to open and use /dev/ttyUSB0 without CTS
Testing CTS pin
CTS OK.  Reconnecting with CTS enabled
Board is running firmware version 1.9.25  (modded for DiskChange support)

Fetching latest firmware version...
Firmware is up-to-date
Features Set: 
      o Disk Change Pin Support
      o DrawBridge PLUS
      o HD/DD Detect Enabled
      o Accurate Flux Read Mode
Testing USB->Serial transfer speed (read)
The USB->Serial adapter in use is not suitable.
Arduino UNO: The on-board adapter is not able to sustain large data transfers
Arduino Pro mini: The USB-Serial board is not able to sustain large data transfers
Arduino Nano: The USB-Serial on this board is not fast enough to sustain large data transfers

If you are using any of the devices with a CH340 converter then swap it for an FTDI one.
If you still have problems after switching, connect the Arduino using a shorter cable
and if possible directly (ie: not via a USB hub)
DIAGNOSTICS FAILED: Diagnostics failed.

    [ ] DISKCHANGE 	Force DiskChange Detection Support (used if pin 12 is not connected to GND)
[X] PLUS 	Set DrawBridge Plus Mode (when Pin 4 and 8 are swapped for improved accuracy)
[ ] ALLDD 	Force All Disks to be Detected as Double Density (faster if you don't need HD support)
[ ] SLOW 	Use Slower Disk Seeking (for slow head-moving floppy drives - rare)
[ ] INDEX 	Always Index-Align Writing to Disks (not recommended unless you know what you are doing)

  16. RobSmithDev commented on Nov 16, 2022

    @RobSmithDev
    RobSmithDev
    on Nov 16, 2022
    Owner

    Not much I can help with if you are having power issues im afraid

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions