Amiga hardware info, help and support with a focus (but not limited to) North American NTSC experiences. Open to all.
User avatar
Seattle, WA, USA

by intric8 posted Sat Jan 06, 2018 8:05 pm

This is an update on the A1000 Phoenix motherboard replacement project.

This update is all about the internal floppy drive.

After the initial thrill of getting the Phoenix to work, I soon fell down a deep and dark rabbit hole for the floppy drive.

As I mentioned in the video, the Amiga 1000's original floppy drive was way too tall to fit above the Phoenix's Kickstart ROMs on the motherboard. The ROM chips pressed onto the bottom of the A1000 floppy drive's gigantically tall mechanical parts. This caused both the motherboard to go dark and not boot. It also prevented the floppy drive from even spinning.

After originally banging my head against this stomach-sinking problem, I eventually contacted the original owner in Australia to ask how he had gotten around it. That's when he told me he had managed to "fit an A500 drive in there no problem."

The internal drives from all other models fit the space using the A1000's original bracket just fine. With one exception - an original A500 drive wouldn't work. I know because I tried.

I actually took my stock A500 apart to look at that floppy drive first before doing anything.

First off... wow. What a complicated and interesting bracket it uses! I've never seen anything like it before. The issue is when you remove that drive from a machine, it doesn't have natural side-screws receptacles built into its case like virtually ever other internal floppy I've ever seen - at least mine doesn't (it's a pretty low S/N). The only way to put 4 screws into its sides to hold it in place is to use it's unusual bracket. But if you use really long screws (i.e. typical ones used on any other FDD or HDD drive) you run the risk of actually damaging the A500's drive as its mechanical parts are in the way! Total bust.

So, I wound up putting the 500 back together again and going with the replacement drive from Spain. What I got looked pretty great - at least in terms of size. Nice a vertically compact. The 3D printed button is hideous, but they did this because this is actually Sony drive that was manufactured in 2007 and the button had to be entirely custom made. I'll sand it down and paint it later. I'll also need to solder the FDD's LED to this new drive, which looks like it might be challenging as the connection points are set a bit inside the housing. But I think I can get to it.
New A500 for the Amiga 1000 Phoenix, flown all the way from Spain to Seattle, WA. The LED location is completely wrong, but I hope that won't be too big of a deal.

In order for this new drive to have its button in the proper location as well as not rub the motherboard, I had to drill 4 new holes into the bracket almost a perfect centimeter above the original holes.
To start, after carefully measuring where the new holes should go I had to use a punch before drilling.

I put it all together and it looked like I'd gotten the measurements perfectly!
New bracket hole locations (with the screws inserted). That tiny relocation is all it takes - and is 100% required for the floppy drive to eject disks properly.
Look at all of that clearance! The old drive's mechanicals actually would hang slightly below the bottom of the bracket shown.
I checked, and the new drive had PLENTY of clearance with the motherboard. Success! (Oh, I was a fool...) God that button is ugly! Looks like a folded up piece of chewing gum.
Houston, we have clearance.

After putting it all back together I put the A1000's front plastic case back on and... now the disk was getting stuck in the slot when I tried to eject it!

After looking very closely, when the new drive was put into place and a floppy inserted, somewhere around 1-1.5 mm (millimeters!) was protruding beyond the bracket. Even though I'd measured the holes perfectly, I needed to actually move them towards the back of the machine ever so slightly. All four.

I had to get a metal grinder for my drill, and adjust each hole by hand. It really didn't take much.
FDD re-installed into the bracket after adjusting the holes just a touch.

That right there took about 2 days for deciding what to do and ultimately going for it. I have to admit, I had sincere worries that this was going to get ugly.

After adjusting the holes, I could see that the floppy was not 100% level. So then I had to insert washers one one side of the bracket to make it absolutely 100% level. Talk about fine tuning a Swiss clock! Finicky sucker. . .

Anyhoo, after a lot of modding and drilling and sweating an cursing, the brand new FDD fits perfectly in its new home and ejects disks as it should - with no case contact whatsoever. Man! What a PITA but I'm glad it's working well now. I still need to solder the LED wire and ultimately sand and paint the button. But I'm going to put those nice-to-haves to the side and focus on getting the internal SCSI drive working. If I can get the HDD working... it's all good times after that! And actually using this freaking machine instead of jacking with it. <3
User avatar
Zippy Zapp

by Zippy Zapp posted Sat Jan 06, 2018 10:30 pm

Wow. Nice work on modding that floppy bracket. Sounds like a royal pain. But worth it in the end.

Sony drive that was manufactured in 2007

So I am guessing this is a modded 1.44MB PC drive?
User avatar
Seattle, WA, USA

by intric8 posted Sat Jan 06, 2018 11:34 pm

I honestly don't know. This is it.
User avatar
Zippy Zapp

by Zippy Zapp posted Sun Jan 07, 2018 12:05 am

Yeah I would say its a PC drive conversion. That's cool it should work great. I have at least two PC HD 1.44MB drives that have been converted to work with Amiga and they work fantastic.

Who is online

Users browsing this forum: No registered users and 1 guest