Research on Micronik HD 1.76 MB Power M-disk

[salteadorneo]

This one is a bit simpler, you don't have to use the diode and you only have to change the value of a resistor. It only works for sony floppy drives and some models of these drives have serious problems with the trackdisk.device of amigaos 3.2.

I have one working perfectly.

[chrisfi]

Originally Posted by DigDug

I just got some GALs and ask myself: how does the @chrisfi project compare to AriseHD from https://eab.abime.net/showpost.php?p...34&postcount=7? Which one is easier to solder, and which one is more compatible?
I would be happy to get a beta release, so I could compare myself.

Thanks for the link. Good find!

I had heard of Arise, but I’ve not tried it because I couldn’t find the jed for it. Something to try when I get some spare time…..

I can’t say which is more compatible, but looking at the notes on the schematic there is an option to pull up one of the pins to improve compatibility with some NDOS games. I’ve not carried out much testing of my mod with NDOS games so it will be interesting to get feedback from others when I release my mod.

There is a bit more soldering with the Arise and it requires a resistor and diode. I can’t work out why a diode is needed. It looks like its there to simulate an Open Collector output for the RDY signal, but the GAL outputs can be configured for Hi-Z which is what I’ve done so the modded drive will work nicely in a two drive system.

I would think both my and the Arise mod will work with both the Sony and Panasonic drives. The principle is the same - when a HD floppy is inserted, generate the HD ID signal and half the oscillator signal.

I’m finishing off the instructions for my mod right now. It should be ready to release within the next week or so.

[salteadorneo]

I have quite a lot of samsung floppy drives, but none panasonic.

[salteadorneo]

I have been testing with an A3000 KS2.04 and ndos games. In principle they start, although the games that I have tried do not finish working. I have tried NO SECOND PRIZE, Starquake, I have never been able to get it to boot on any system, with the Sony I have been very close to making it work, at least the presentation screens load them, and some other game with similar results.

[Yulquen74]

Have you placed a decoupling cap onto the GAL chip? I did not see it mentioned in the description.

[chrisfi]

Originally Posted by salteadorneo

I have been testing with an A3000 KS2.04 and ndos games. In principle they start, although the games that I have tried do not finish working. I have tried NO SECOND PRIZE, Starquake, I have never been able to get it to boot on any system, with the Sony I have been very close to making it work, at least the presentation screens load them, and some other game with similar results.

Thanks for the feedback.

Are these single disk games? If not, did the problem occur at disk change?

If we can post here which games do not work, I will check what protection they use to see if it helps work out why they don't work with the mod.

[chrisfi]

Originally Posted by Yulquen74

Have you placed a decoupling cap onto the GAL chip? I did not see it mentioned in the description.

I did test with a decoupling capacitior and inline resistors, but it did not improve anything and takes up more space in the drive.

[salteadorneo]

I don't think it's a problem with the modified floppy drive. For example, with starquake I have never been able to get it to work on any machine. In fact, with this floppy drive I have come close to getting it to work at all. With other games, I'm not sure they will work on the A3000. He had no more two sets at hand. Let's see if I can find more and do more tests.

[salteadorneo]

I have tested several ndos games with the modified Sony floppy drive on an A500 with Kickstar 3.1 and on an A3000 with Kickstar 2.04.

Superfrog: works fine on both machines.

Pang: Only worked with the original Chinon floppy drive. It doesn't work with the sony or other modified floppy drives. It may be a copy thing. On the A3000 it doesn't work with any floppy drive.

Fire and Ice: Works correctly on the A500. It does not finish booting in the A3000.

Sword of Sodan: Works correctly in the A500. It does not do it in the A3000.

Brian of Lion: Works correctly in the A500. Hangs on the title screen on the A3000.

Universe. Works on the A500, but it shows the disc change warning very fast and you can hardly see it. On the A3000 it works correctly and does not show the disc change warning.

Walker. Works correctly on A500 and A3000.

Agony. Loads correctly in both computers, but slows down in the A3000. It happens with all the floppy drives I have tried, so it must be a matter of the computer configuration.

SuperStardust. It works correctly on the A500. On the A3000 it crashes at the splash screen, it happens with all the floppy drives on the A3000.

No second Price. It works correctly on the A500, nor does it work on the A3000. It will be an equipment thing once again.

Elfmania: Works correctly on both machines.

Lionheart. It works correctly on both computers, but on the A500 it gives the same problem as the universe when displaying the disk change. It shows it once and then it doesn't do it anymore. On the A3000 it does it correctly.

[chrisfi]

Thanks for this. Very interesting.

I think some games will not work on the A3000 because its a slightly different architecture to the A500/A2000/A600.

As for the games failing on disk swap, this may be down to the way the modified drive identifies the density of the disk. In my implementation it generates a HD ID when there is no floppy inserted which may be causing the game to crash when you eject the DD disk.

If I’m correct, a possible fix to this would be using the disk present signal to generate the density ID only when a disk is inserted. An extra wire from the PCB to the GAL would be required and a minor modification of the logic.

It may be some time before I can test this because I’m working on other projects right now.

[salteadorneo]

A clarification, the games do not hang when changing the disk, the message is simply displayed very quickly or is only displayed once. The floppy drive works great as it is now. The only issue to solve the problem of SONY floppy drives incompatible with AmigaOS 3.2.
If you want, I can test the same games on an A4000. Unfortunately I don't have an A1200... :-(

[chrisfi]

Originally Posted by salteadorneo

A clarification, the games do not hang when changing the disk, the message is simply displayed very quickly or is only displayed once. The floppy drive works great as it is now. The only issue to solve the problem of SONY floppy drives incompatible with AmigaOS 3.2.
If you want, I can test the same games on an A4000. Unfortunately I don't have an A1200... :-(

Hey, thanks for clearing that up. I’ll correct the notes on the release thread.

The issue with some Sony drives not working with OS 3.2 (and 3.1.4 from my experience) is strange. However, this is the same if the drive is modified as DD or HD so I suspect it has nothing to do with my mod.

[chrisfi]

To all following this thread - just in case you've missed it I have released the JED and instructions for the modification in Hardware mods. Please feedback your experience, good or bad.