MEDIA CHANGE FIXS
Posted: Mon Dec 18, 2017 11:40 am
As there is no easy tested solution for this I just created this solution which seems to work. It is basically the same mod as I use in my V6 floppy upgrade kit. But in this case the mod is done internally in the GAL.
This mod could likely be done with the logic level MOSFET in which case it would not need the resistor. But I do not have any these at the time of typing and well.. Life is too short
In any case I use a simple PNP BC558 transistor. Any generic low-power PNP transistor will likely work.
PNP transistor...
connect:
C to 0v (WD pin 14)
B via 1K to MON (pin 20)
E to WP (pin 25)
When MON is high, transistor is off.. When MON is low, transistor turns on, connects WP to 0v. In this case TOS should always assume that disc has changed and should always re-read the FAT.
The program to use is here..
http://www.exxosforum.co.uk/atari/last/floppy/MEDIAC.TOS
This program was just a very fast knock up in STOS a few years ago.. But does the job.
If run on a unmodded ST the message will say "Disc has definitely not been changed" constantly.
On a modded ST. After loading and the floppy drive light turns off, the 558 will set WP LO and the message will say "Disc may have changed!". The message shows up regardless of if you actually change the floppy or not.
I have only done some quick tests with this is to work okay obviously others need to try this as well..
This mod could likely be done with the logic level MOSFET in which case it would not need the resistor. But I do not have any these at the time of typing and well.. Life is too short
In any case I use a simple PNP BC558 transistor. Any generic low-power PNP transistor will likely work.
PNP transistor...
connect:
C to 0v (WD pin 14)
B via 1K to MON (pin 20)
E to WP (pin 25)
When MON is high, transistor is off.. When MON is low, transistor turns on, connects WP to 0v. In this case TOS should always assume that disc has changed and should always re-read the FAT.
The program to use is here..
http://www.exxosforum.co.uk/atari/last/floppy/MEDIAC.TOS
This program was just a very fast knock up in STOS a few years ago.. But does the job.
If run on a unmodded ST the message will say "Disc has definitely not been changed" constantly.
On a modded ST. After loading and the floppy drive light turns off, the 558 will set WP LO and the message will say "Disc may have changed!". The message shows up regardless of if you actually change the floppy or not.
I have only done some quick tests with this is to work okay obviously others need to try this as well..