========================================================================== WARNING: This text describes a hardware hack that involves voiding the warranty of your computer and doing some solders inside it. If you do it and something goes wrong, I have no responsibility at all about it. >>>>>>>>>>>>>>>>>>>>>>>>>>>>DO IT AT YOUR OWN RISK<<<<<<<<<<<<<<<<<<<<<<<< ========================================================================== There seem to be a problem with the new Amiga 1200 manufactured by Amiga Technologies, at least with some of them distributed in Spain. The problem is that the AmigaOS can use df0: without problems, but a lot of NDOS disks (demos and games) just doesn't work at all. Usually these games/demos just 'freeze' the computer, waiting for somethig that never comes.... ...and this is the problem. The READY signal of df0: has dissappeared in the new Amigas (yuck! it's a nasty PeeCee drive!! aarrgghhhhh!!!!!). While the 3.1 ROMs simply ignore this signal (I think that Amiga Technologies modified it so they can use cheaper, and nastier, PeeCee drives) , and so it has no problem at all when using df0:, the NDOS games/demos access directly to the floppy hardware, so this missing signal affects directly to them. In the old Amiga floppies this signal remains inactive while the drive motor is off, and it switches to active when the motor is on and there is a floppy inside the drive, indicating that the floppy has spined up to the correct rotation speed, an so it is READY for reading/writing. A lot of games/demos (but not all of them) wait for this signal to be activated to begin reading, but as this signal is missed, the computer remains waiting forever for a signal that will NEVER be activated. The only solution is to create a READY signal for the games/demos that need it, so I decided to do a signal that always appear active when the software accesses to the drive. This is not the best solution (maybe, the BEST solution would be to put 3.0 ROMs and a REAL Amiga floppy, but I think that AT has modified something about the DiskChange signal too, so maybe even with 3.0+Amiga floppy df0: will not work... :-\) but worked really well when done in a friend's computer (my A1200 is an old Commodore one, so I haven't this problem), and it's REALLY EASY to do (and cheap too ;-) The signal can be created simply by joining, with a diode, the SELECT0 signal (this signal indicates that the computer wants to access to drive 0, and it's in pin 10 of the _internal drive_ data cable) and the READY signal (pin 1 of the _external drive_ connector, as in the internal connector this signal is missed), so when the computer activates the drive (with the SELECT 0 signal) the READY signal will be activated too, appearing always active. The anode of the diode have to be connected to the pin 1 of external connector, and cathode have to be connected to pin 10 of internal connector. This diode doesn't need to be a specific type, but I used a 1N4148 as it is small, cheap and easy to find. In the diode, the cathode is the side marked with a line. Take a look at the included picture for more detail. From the OS point of view, this doesn't affect it as this signal is ignored by the 3.1 ROMs, and the behaviour of the system will not change with this hack. From the NDOS point of view...well, a lot of programs work now, so there is no problem, I think... ;-) The ONLY problem that can appear is when program that uses df0: by hardware wants to write to the floppy right after starting the drive's motor. If instead of doing a pause by itself (some soft do it, like the 3.1 ROMs) it waits for the READY signal to be active, with this hack it could begin to write when the floppy still doesn't rotates to the right speed, so the track will be trashed......if this is bad, think about it without the hack....the program would wait forever for the READY signal..... A better READY signal could be done by taking the MOTOR0 signal (pin 16 of the internal floppy connector, I think...) and passing it (ORed with the SELECT0 signal) to the READY signal (pin 1 of external floppy connector) with some kind of delay (with a condenser, for example), but as I don't know if this is really needed (the AmigaOS doesn't need it, and NDOS programs usually doesn't write to floppies) I preferred to do it by the simplest way :-) NOTE: I couldn't test thoroughly this hack, but what I tested worked perfectly. If you find something that works on an old A1200 but not in the newer A1200 with this hack, please report it to me. Well, enjoy your Amiga, and sorry for the nasty english ;-) Toni Pomar (tpomar@ibm.net) P.D.: This hack is in the Public Domain, but if you intend to earn money by doing it.....well, just remember who made you rich ;-)