Disciple / Plus D with Gotek 'Check Disc in drive'
Posted: Mon Mar 25, 2024 10:23 pm
Posting this here as a FYI as I couldn't find any information on the internet on this issue.
TLDR; Plus D will throw a 'CHECK DISC in drive' error when formatting a disk (image) using a Gotek; needs config item in flash floppy to fix.
I'm guessing lots of people use Plus D with Gotek, but mostly for reading images and not writing / formatting disk images.
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12.2 Using the Plus D / Disciple with a Gotek (Flash Floppy)
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CABLING: There are various ways of doing this, but by far the easiest method is to use a straight floppy cable with no twists and close the Gotek S0 jumper (Gotek drive id0; Shugart standard). If a second drive is to be connected, it should be jumpered as drive B (most drives are by default) and again connected to the same cable with no twists. As straight floppy cables are harder to get in 2024, I found it easier to buy a small box of IDC 34 way connectors and clamp them to an existing cable before the twists. The Gotek will also work with a twisted cable, but will need drives jumpered appropriately which can be difficult as some drives are missing the drive select jumpers altogether now.
FLASH FLOPPY CONFIGURATION: You will need to create a flash floppy FF.CFG file on the USB stick with the following config directive:
Both interfaces look for index pulses in their firmware, which the Gotek suppresses in certain conditions; the Plus D in particular will fail to format disks and sometimes write files if this isn’t done. This can be seen at Plus D ROM address 0x06C5 (TRACK_0 routine) https://www.biehold.nl/rudy/plusd/disk. ... 20TRACK_0 in the V2 ROM (G+DOS 2a). The ‘CHECK DISC in drive’ message will be frequently displayed without this configuration.
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I spent quite some hours staring at Disciple and Plus D disassemblies to figure this out. The Plus D is more sensitive than the Disciple, because the firmware does a Forced Interrupt towards the WD1772 in a different order during TRACK_0, the Plus D triggering the issue, the Disciple not.
Some useful background here:
https://forum.vcfed.org/index.php?threa ... ek.69852/
https://github.com/keirf/flashfloppy/wi ... tion-File
I hope this helps someone, I've also added the information to my Disciple Pals unveiled latest document.
https://spectrumcomputing.co.uk/entry/1 ... _Interface
TLDR; Plus D will throw a 'CHECK DISC in drive' error when formatting a disk (image) using a Gotek; needs config item in flash floppy to fix.
I'm guessing lots of people use Plus D with Gotek, but mostly for reading images and not writing / formatting disk images.
-->
12.2 Using the Plus D / Disciple with a Gotek (Flash Floppy)
=======================================================
CABLING: There are various ways of doing this, but by far the easiest method is to use a straight floppy cable with no twists and close the Gotek S0 jumper (Gotek drive id0; Shugart standard). If a second drive is to be connected, it should be jumpered as drive B (most drives are by default) and again connected to the same cable with no twists. As straight floppy cables are harder to get in 2024, I found it easier to buy a small box of IDC 34 way connectors and clamp them to an existing cable before the twists. The Gotek will also work with a twisted cable, but will need drives jumpered appropriately which can be difficult as some drives are missing the drive select jumpers altogether now.
FLASH FLOPPY CONFIGURATION: You will need to create a flash floppy FF.CFG file on the USB stick with the following config directive:
Code: Select all
# Index pulses suppressed when RDATA and WDATA inactive?
# Values: yes | no
index-suppression = no-->
I spent quite some hours staring at Disciple and Plus D disassemblies to figure this out. The Plus D is more sensitive than the Disciple, because the firmware does a Forced Interrupt towards the WD1772 in a different order during TRACK_0, the Plus D triggering the issue, the Disciple not.
Some useful background here:
https://forum.vcfed.org/index.php?threa ... ek.69852/
https://github.com/keirf/flashfloppy/wi ... tion-File
I hope this helps someone, I've also added the information to my Disciple Pals unveiled latest document.
https://spectrumcomputing.co.uk/entry/1 ... _Interface