Floppy write protected (when its not) fix.

Post by **exxos** » 06 Dec 2018 18:10

IMG_3667.JPG

This is a shortened version of this thread..https://www.exxosforum.co.uk/forum/viewt ... =23&t=1410

The issue was with a STE machine, which was continuously or intermittently reporting the floppy was write protected when it was not.

The assumptions are the drive has been tested and working fine in another machine. It is also assumed that the WP pin on the 1772 is always high (for write enabled operations).

The fix for this issue to solder a 10K bussed resistor array to the 1772 databus pins as illustrated below.

The white wire connects the common pin on the resistor array to 5V.

ste_fix.jpg

Video below demonstrating one error without DMA pullups.

Post by **terriblefire** » 31 Dec 2018 17:56

Just made this mod to my STFM

Hasn’t helped my issue but was easy to do

C8242480-1053-4E8D-8CB4-9FB.jpg

BAC020C4-60EB-4C31-9A95-5C7.jpg

Post by **PhilC** » 20 Jan 2019 13:09

Just checking, as I dont have any 10k, do you think it will work with 4.7k?

Post by **exxos** » 20 Jan 2019 13:16

Forgottenmyname wrote: 20 Jan 2019 13:09 Just checking, as I dont have any 10k, do you think it will work with 4.7k?

Assume would be ok..

DoG · Post by **DoG** » 06 Apr 2019 14:28

Did this on a STfm (070789-001 RevD) since I fitted 2.2 booster on it and having problem reading disks. Works perfectly now.

EDIT: v2.3 booster

Post by **exxos** » 06 Apr 2019 14:30

DoG wrote: 06 Apr 2019 14:28 Did this on a STfm (070789-001 RevD) since I fitted 2.2 booster on it and having problem reading disks. Works perfectly now.

Thanks for letting us know :thumbup:

tzok · Post by **tzok** » 31 Jul 2020 10:10

This fix solved my issue with ACSI CF adapter in 1040 STfm. Before, it was writing complete garbage on the CF card, after applying this fix - works like a charm!

pixelk · Post by **pixelk** » 13 Aug 2021 10:28

Thank you !

As I didn't have the right resistor network, I built my own.

IMG_2021-08-13_10-21-42.jpg

Seems to do the trick.

Post by **exxos** » 13 Aug 2021 11:04

pixelk wrote: 13 Aug 2021 10:28 As I didn't have the right resistor network, I built my own.

Wow today's geek award goes to...

FujiMan · Post by **FujiMan** » 18 Aug 2022 20:54

I'd remove the chip, put a precision socket in and place the resistor array on the bottom of pcb. ;)

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Floppy write protected (when its not) fix.

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