Considerations for making a Commodore 1581 Disk Drive 

Hey, thanks for featuring my board on your video. Nice build. To speak to your case wobbling, in my experience, this happens if the 3D printer that was used to print the case isn't perfectly square. The resulting print is then slightly out of square, and when assembled, it twists ever so slightly and causes it to rock. IF that is the case with your print, then you might want to mention to your friend to check their printer for square. On the topic of enhancements, I really like your suggestions, and in all honesty, some of those had been a passing thought subsequent to my last revision. I think I'll take those suggestions to heart and make a version 3. I do really like your thoughts on the double FD pin header to allow for either type of drive to be plugged in. I think removing the resistors will leave plenty of room for the circuit and IC. And lastly, on the thoughts on an FD-2000/4000 board... that's in the works!

Cool video! Happy Christmas (2023)!

Very interesting and thought provoking presentation, Steve. I'm currently collecting components for the DIY Chris board, but your mentioning the other PCBs has given me pause for thought. I particularly like the idea of a dual unit (although I wonder if there's a way to configure them as (say) Unit 8 drives 0 and 1 -- like the old PET drives. I'm sure I read that the code for it was still in the 1571 roms at least, so maybe it's in the 1581 too?)

Love how the Commodore community is "somewhat" discovering the DIY aspect of the hobby. Considerably later because they used to stick with "that can't be done" for way too long, but hey maybe the future might yield something making me return at some point, even tho I consider that very unlikely.

You might be able to fix the case "creaking", depending on what the problem is. The two longest screws that are used to hold the halves together go through a long plastic "tube". If you shorten the length of the tubes (filing) so the tubes don't physically touch the bottom (I'm assuming they're long enough to touch) you might be able to put a little extra force on the screws to force the case halves together. If there's too much force needed to squeeze it together, use small o-rings sandwiched between the plastic tubes and the bottom. The o-rings will squash like rubber and provide a flexible compliance between the attached halves. You might have trim the length of the plastic tubes as needed for a snug fit.

That is froogin' awesome dood. There is a replacement switching mini power supply out there for $18-$40. On Corei64's design you can replace the 7805 with a TSR-1 2450 and not have to buy the heat sink. Also takes up a lot less space.

"...And the through-hole component is what makes that possible." Not necessarily just possible, but reasonably easy in comparison. Surface-mount components _can_ be hand-soldered but they'd probably be a huge PitA to most people who would even try this!

A 1581 enhanced board that fits in a 1541 case would be nice too.

Very nice video, I have built many 1581 for friends and good known. The main problem are the floppies themselves you can only take DD 720KB floppies, but if you put a 1.44 MB HD floppy disk the drive does not work, even a masking of the HD hole is not a good idea for data retention. DD floppy disks are becoming less and less common but HD floppy disks are still enough, you would have to modify the drive that it can also safely write to HD floppy disks - test it.

Changing the ttl glue logic to surface mounts would save a lot of space.

Damn, an amiga fpga board on it... what a form factor!

I got the board with the regular on it. It looks like to me if you run a jumper wire from the regular to the the 12v line and you can power this with the DIN with just 12v. I agree with removing the resistors and use that room to have 2 headers.

If there is the STL that includes the top vent slits, then why did you not use that one? Also: Why black instead of beige filament?

500 USD nowadays for a working 1581? OMG. I used to have one in 1994, bought it with a defective disk drive, paid like 15 Deutsche Mark, and put an old Amiga Chinon drive in that I had laying around and boom it worked. Sold it in 2005 and by then the price already was like 50 Euros (100 Deutsche Mark, 55 USD). But 500? I should have kept it :( and several other vintage items I sold back then, too.

hey, i know which chips to use but what pieces need to go in there, like diy chris has a list to buy them but they are expensive like what resistors, what crystal oscilator, and that hole other stuff?

"When the case was first printed out..." How many times did you supposedly print it later?

Perhaps just add some rubber-feet where you can file away some of one to align it better and make it more flat in its contact surface?

Your PSU is so small, it could even fit within the case, wouldn't that be beautiful?

pi1541 baby!

Your friend doesn't know how much filament that print used and how much the filament cost per length unit?

"Other additional..." or just "additional"?

The 1581 is quite a powerful totem artifact in the 8 bit C= community. Good thing I have two of them. I'm not here to gloat, but I do have two 1581s. :) Nice project BTW.

"Predrill or drill a pilot hole"? What's the supposed "difference," according to you?

Based on a 1kg roll of PLA costing $20, the case would have cost approximately $7 in materials.

So are you saying that you might be saving a whole whopping $7 or so by when you build your power supply that you were going to build anyway, just including the cheaper switch in that? Why go out of your way to do all that workaround stuff just to save around $7 instead of just giving in and having a proper period-fit switch right in the external drive?

I assembled this whole thing, but all I'm getting in the red light blinking three times. I'm not sure what is going on here. I've tried everything I can think of. Different SRAM chips, different CPU, different EPROM's.

"Dual 1581..." * 1582, probably. Oh, wait, that would probably be if you're using drives 0 and 1. But it sounds like you're talking about a dual- *device* 1582 or something like that. But Commodore's standard would've had them as drives 0 and 1 in the _same device_ (8, 9, 10, or 11), used in this format: ' "0:"..." ' or ' "1:"... '. With the way most devs programmed for disk drives, either setup would normally be pretty useless, unfortunately. That sort of expansion was VERY underused for the 20 and forward, and that's too bad. It would be interesting, though!

"...Based off of this design..." If they're based _off_ of that design then what design are they based *ON?*

The 90s *and 80 (since it came out in the 80s).

This is an expensive project to be sure, and I really have to wonder about how things have changed in the year since you made this video both in terms of making this project perhaps way more expensive and in terms of making an analogue potentially a lot cheaper. What I mean is … 3.5" floppy mechanisms are still common enough, but I wonder if some of the chips you need for this kit are just no longer out there in quantity enough to make this viable. Something similar happened with the BYO VIC-20 kit. Made with all new parts … except the MOS 6560 of course. The VIC chip. At the time they were cheap and common enough on eBay for the intended use-replacement parts to bring a dead VIC-20 back to life. Not enough for a few hundred hobbyists to buy them all up hoping to build kits! If you were designing a kit like that with the scarcity of those chips now (they sell for > $100!) maybe you'd start by assuming those parts are unobtanium and try to get one of the more powerful microcontrollers to emulate it. The RA4M1 (Arduino Uno R4) can handle 5v logic, but it's SMT soldering so maybe you want to just have pins for the Arduino to plug in. You're gonna get people calling it "cheating", but it's literally emulating one chip, so they can stick it. Or if you're willing to do a little more to interface with the 6502 bus, the RP2040 or STM32 are even cheaper options. These are all SMT chips unless you get them with their common implementation boards, so that violates one of your rules of sticking to through-hole unless you make other more significant changes to the design. That said, if you're replacing a chip with a controller that can do more complex logic … can it also do some trivial glue functions without feeling like you're "cheating" too much? And is it worth "cheating" to bring the complexity and more importantly the cost down quite a bit without breaking backwards compatibility? It doesn't look like anyone's done this kind of thing yet, but … if prices for things continue to climb, I imagine it's only a matter of time. Maybe that will truly make it a 1581 for all? Maybe.

I bet there are no components on the back of the board even if we _don't_ look there.

Correction: These devices were NOT popular in the 90s. They were popular in the late 80s. The world have moved on from 8-bit C64s by the 90s.

Haha... "via a via"? 😛

50 CAD (40 USD)?! I paid at least $250 if not more when i bought mine, but it was around 1984-85. Hm, your was not new ...

"2 inches in length"? As opposed to 2 inches in diameter? Haha.