BMOW title
Floppy Emu banner

DB-19 Substitute, Take Two

20160223_143257 copy

BMOW’s product Floppy Emu needs a male DB-19 connector to mate with vintage Apple computers, but these connectors haven’t been manufactured in decades. For two years I’ve been scraping by with “new old stock” DB-19’s from warehouses around the world, but that supply has almost completely dried up. I recently found a few hundred more, but it’s clear that the end will come sometime in 2016. To prepare for the worst, I’ve been working on a design for a DB-19 substitute. After more experiments, today I decided that this path has reached a dead end.

The current DB-19 adapter for Floppy Emu is shown at left, in the photo above. It consists of a small PCB with an edge-mounted male DB-19 at one end, and a 10×2 shrouded header connector at the other end. A ribbon cable plugs in to the 10×2 header, and the DB-19 plugs into the computer’s external disk port, and everything is great.

Designing a Substitute

The basic idea of a DB-19 substitute is to replace the male DB-19 with sections of 0.1 inch male header arranged in a DB-19 pattern, while keeping everything else more or less the same. I first explored this idea a year ago, and the prototype worked reasonably well, but had its share of problems. The 0.1 inch pin spacing didn’t quite match the 0.109 inch spacing of a D-SUB connector, and it put square pins into round holes. Without a surrounding shield, it was too easy to misalign the substitute connector while plugging it in, so I added two rectangular LEDs as structural elements to serve as mechanical guides. It sounds dodgy, but it passed some quick tests on several different Apple computers. Then I put the prototype away in a drawer, and didn’t think about it again.

This week I received a new PCB for what I hoped would be the final DB-19 substitute design. I shrunk the overall size of the PCB, and gave it a trapezoid shape with rounded edges to invoke the spirit of a real D-SUB. I split up the 0.1 inch headers into a larger number of smaller sections, so the average offset from the nominal 0.109 inch spacing was reduced. And taking a popular suggestion from the first prototype, I made the LEDs into more than mere mechanical guides – now they light up! It’s a pretty cool effect. A side-by-side comparison of this new DB-19 substitute with the current model DB-19 adapter is shown above, and a rear view of the same connectors is below:

20160223_143404 copy

Quality Control Failure

The new DB-19 substitute passed all my initial tests, and everything was looking good. But once I started testing more carefully, I realized that the connection wasn’t solidly reliable. It worked 100% of the time on my Mac Plus, Apple IIgs, and a borrowed Apple IIc+. But when plugged into the daisy chain connector of an Apple 3.5 Drive, it only worked about half the time. And when plugged into an Apple IIc, it never worked, unless I pushed on the connector with my finger during disk I/O. Ugh. At first I thought maybe this new DB-19 substitute had some new problem, but when I tested last year’s version more carefully, it had the same issues.

I think there are several things preventing this from working reliably. While putting square pins into round holes sounds crazy, I think that’s the least of the problems. What’s more significant is that the diagonal length of each pin’s cross section is probably slightly different than the diameter of the round pin that’s supposed to be there. Combined with the slight misalignment of some pins, I believe this leads to weak or no contact for those pins inside the female connector. I don’t know if the female’s interior has flat wipers, or a true round receptacle. Maybe different models of Apple computer have different receptacle designs. It doesn’t seem like a good idea to rely on that.

The other problem is the vertical height of the whole DB-19 substitute assembly. The current DB-19 adapter has only a male DB-19 at one end, with a height of about 3/8 of an inch. But the new, reduced size DB-19 substitute assembly has a PCB directly behind the pins, with a height of about 5/8 of an inch. For most Apple computers, the extra height is no problem. But for a few systems with recessed disk connectors, the extra bulk bumps into the plastic above the recessed connector, preventing it from being fully plugged in. On an Apple IIgs, it just barely fits. On the daisy chain connector of an Apple 3.5 Drive, it doesn’t fit.

Alternate Ideas

What to do? I’m probably going to abandon the idea of using 0.1 inch male header, as it just doesn’t seem reliable. Another option is to use 19 individual D-SUB crimp pins, soldered into the DB-19 substitute PCB. I built one of these last year, and it’s shown at left in the photo below, along with the first generation of the 0.1 inch male header substitute.


The version with the D-SUB crimp pins is definitely more reliable, but it’s a nightmare to assemble. Crimp pins aren’t designed to be soldered into a PCB like this, and to prevent solder bumps on the pin side from shortening the effective pin length, the pins need to be soldered from the “wrong” side of the board using an ugly technique. Individual pins won’t stay straight while soldering, so a female DB-19 must be used as a jig during assembly. And when it’s done, the crimp portion of each pin must be cut off with shears. The current DB-19 adapters are factory assembled with a mostly automated process. This crimp pins design would require a cumbersome manual process, driving up the cost, if the factory was even willing to do it. And the problem with the height of the assembly would still remain.

The other option is to find a D-SUB factory that could manufacture new male DB-19 connectors. I checked into this last year, and it looked like a tough road. Negotiating that kind of manufacturing deal is difficult for someone like me, with no industry contacts or big name credibility. Most places didn’t even respond to my emails. From those that did, it looked like setup costs would be around $10,000 before they could make even a single part. Given the small scale of my business, that’s not realistic. I’d have to buy a virtual lifetime supply of DB-19 connectors, and hope that Floppy Emu sales continued on pace through 2030 or so.

This just became my new #1 problem. I’m going to work on brainstorming other solutions involving D-SUB crimp pins or other round pins, and also make another set of inquiries for manufacturing new DB-19 connectors. The clock is ticking…

February 23 Addendum

After mulling this over for a while, I’m coming to the conclusion that I should get new DB-19 connectors manufactured, even if it costs $10,000. It’s the only solution I’m confident will work reliably. Everything else I can think of is a trade-off of quality for cost, and nobody’s going to be happy if I switch to a new style of DB-19 substitute that’s not always reliable or that has trouble fitting certain computers.

The cost of manufacturing new connectors is high, but the alternatives aren’t free either. I priced out one possible alternative involving an empty DB-19 male housing and 19 crimp pins, and it would cost about $5 per connector including the increased labor cost to assemble it. At the current sales rate, I’d be spending about $2000/year for a solution that’s inferior to a real DB-19. Compared to that, $10,000 doesn’t seem quite so unreasonable. The other alternatives I described earlier would be cheaper to build, but seem to have reliability problems, so they’re not really viable.

I’ve been using the number $10,000 as a rough figure, but it may be less than that. Assuming the best quote I received a year ago is still valid, it would be roughly $8000 to get 10,000 DB-19 connectors manufactured and delivered. That’s about one third of the total profit I made from all BMOW product sales last year. So it’s a big number, but not completely out of the question. I don’t need 10,000 DB-19 connectors, but I could probably resell some of those over the next few years and recoup $1000 or so of the manufacturing cost.

I’ve been talking with a person at IEC about splitting a new manufacturing run with them, which would help a lot if we can reach an agreement. Another possibility is to run a GoFundMe campaign and solicit donations to “save the DB-19”. If I could get enough vintage Apple enthusiasts to chip in $10 or so, it might make a significant dent in the manufacturing cost. Maybe I could put the names of the largest donors in the silkscreen of the adapter PCB.

At the end of it all, there’s just something cool about the idea of being the guy who resurrected the DB-19. Then the world can stop seeing sad pleas like this one. Maybe I’m insane, but that’s got to be worth something. 🙂

Read 24 comments and join the conversation 

24 Comments so far

  1. mdymond - February 23rd, 2016 11:53 pm

    Are the pin distances pretty much constant between the pins of the dual row DB connector series?

    My thought process is if the distances are the same between DB-19 and say, for example, a DB-25, it might be possible to take off the metal connector shell with a saw or Dremel and modify the more common connector to DB-19 size by using a Dremel tool to take off the excess pins. I don’t know what the labor cost would be, just brainstorming ideas for you.

    The biggest problem would be getting the shell off.

  2. Steve - February 24th, 2016 7:14 am

    Yes, that seems to be a somewhat common solution for people that need a one-off for personal use. There’s a photo of female DB-25 cut this way here: That can’t be automated though, and it creates a width clearance problem for computers with recessed connectors.

  3. rasz_pl - February 24th, 2016 7:56 am

    it can be semi automated, you make a jig to hold group of connectors, setup a steel cutting Chop Saw and do them in groups of 5 at a time
    but not like in the photo you linked, chop one end clean off
    $.4 + labour, lets say 1 minute per set of 5 connectors at $50 an hour = $2 per one modded connector

  4. Chris M. - February 24th, 2016 1:10 pm

    Another solution, come up with a group buy or sell to other vintage computing fans. There are several other Apple II disk adapters out there that could use DB-19s. The Atari ST uses the DB-19 for its ACSI port and a quick internet search shows the makers of the SATAN line of flash adapters was looking for a supply of DB-19s back in 2009.

  5. Chris M. - February 24th, 2016 2:29 pm

    Hmm… looks like the Atari folks had the same idea for a DB-19 substitute.

  6. Bob - February 26th, 2016 4:06 am

    Would it be possible to have a carrier for the crimp pins CNCed and a circuit board mounted on the back? It would be sturdier than a plain circuit board and align the pins for soldering.

  7. Steve - February 26th, 2016 7:46 am

    rasz_pl, any ideas who might be able to do work like that? Chris M, a group buy would be great, and I’ve talked to a couple of interested people. But they only need a small number, and no one really wants to commit until it’s a sure thing. So I would probably try to re-sell some of them after manufacturing, rather than trying to arrange a true group buy beforehand.

  8. rasz_pl - February 26th, 2016 9:43 am

    You could do it, or find someone at your local hackerspace maybe

  9. Josh - February 26th, 2016 9:24 pm

    I still have about 50 if it would help you nos db-19 if it would help you…

  10. Steve - February 27th, 2016 6:53 am

    Thanks, I may take you up on that, depending on what solution I find.

  11. David Kuder - February 27th, 2016 10:34 am

    not sure if they really have stock, but

  12. Josh - February 27th, 2016 10:14 pm

    I’ll also se what I can whip up with my 3D printer 🙂

  13. Rob Blessin - February 29th, 2016 11:25 pm

    Hello All: I’m interested in helping with this project as well. I maintain, support, rescue, refurbish and resell old NeXT Computers , Steve Jobs interim company between his stints at Apple I am currently in need of DB 19 connectors for our custom cable solutions to keep these up and running. I’m also one of the site admins at … the good old NeXT cubes and NeXT Mono Stations use db19 connections. I would be interested in purchasing new old stock. Josh, if you want to part with some of those after Steve, please let me know as I’ve scoured the world and found 9 in macedonia. I only have a few left myself ~ 20
    Steve, I would also be willing to contribute to buying in on a manufacturing run solution and that is how I came across your page. I’ve been researching manufacturing facilities in China and this is as good a place to start as any. Also we have had great success replacing scsi hard drives with this solution out of Australia , its brilliant uses a microsd card and may help some of you in the Apple Community as well! Best Regards Rob Blessin

  14. Steve - March 1st, 2016 9:23 am

    Hi Rob – sent you an email. Would love to collaborate with the NeXT community.

  15. Alex - March 5th, 2016 5:36 am

    Hey Steve, how about pins designed for individual installation on a PCB, with the proper female-threaded studs to hold everything in place?

    Take these for instance:

    My internet connection kinda sucks at the moment so I’m having trouble pulling up pdfs with dimensions, but I think that’s the right diameter and length. Anyway, that’s the style of pin I’m thinking of. They’re designed to be swaged in place, not soldered. So, have a local machinist drill a carrier for you (with appropriately spaced holes for all 19 pins to sit inside), then use a swage punch and arbor press to fix each one in place. See:

    For the nuts, you can do a similar thing:

    You’d have no shield of course, but I think the right pins and proper fasteners would go a long way. Maybe if you wanted a shield connection you could use contact fingers like the ones used for EMI suppression, or something, I dunno.

  16. reboots - March 5th, 2016 6:06 am

    Steve, just a quick note which may be redundant since you’ve obviously done a lot of brainstorming on this project.

    I’ve found that PC-mount dsub contacts are recoverable from certain types of sockets, with not much work. I have a write-up here (addressing female contacts):

    They’re naturally much better suited for PC mounting than crimp contacts. The labor involved in cutting apart sockets makes it a non-starter for production, but maybe you’re scaling to the point where you can approach a manufacturer and buy a bag of pins pre-assembly?

  17. Ryan Daum - March 5th, 2016 6:06 am

    In the Atari ST community we also need DB19 connectors. I’d suggest contacting Lotharek (, and posting on, to see if there’s any room for collaboration. If there’s new DB-19 connectors being made, I’d certainly pitch in to help out and I’m sure others would too

  18. seph - March 5th, 2016 7:25 am

    Brainstorming aloud, forgive me if you’ve been down this route. If you’re trying to mount d-sub pins in through holes, I wonder about using a thicker PCB (or a couple stacked). It might help with the alignment, and need to chop them. Potentially using some non-pcb, with cnced holes.

  19. Steve - March 5th, 2016 7:45 am

    Lots of people are finding their way here from Hacker News. Welcome!

    I’ve been chasing the DB-19 ghost for at least a year, and at this point I think I’ve come full circle on my views about building a substitute vs manufacturing new ones. For a few connectors, a substitute built from a PCB (like the one above) or a chopped DB-25 is an OK solution, but all the substitutes are kind of clunky and labor-intensive. Once you get to needing hundreds or thousands of DB-19 connectors, I think manufacturing new connectors is the way to go. I don’t have any good manufacturing contacts, and it’ll be expensive, but I’m reasonably confident I can figure out the details.

    So I’m about 90% sure I’ll get ~10,000 or so new DB-19s made. I will definitely share the bounty (and the cost) with others in the Apple, Atari, and NeXT communities, either by arranging a “group buy” before they’re manufactured, or selling 20-packs of excess connectors afterwards. I’ve already talked to a couple of other people who are interested in buying large lots of these, so at this point it’s a matter of nailing down the best manufacturing option and hammering out details on cost-sharing and shipping.

  20. rasz_pl - March 5th, 2016 8:31 am

    one more idea – Huaqiangbei, its totally possible one of the sellers at the seg market is literary sitting on a bag with thousands of connectors. Try contacting Ian from dangerousprototypes.

  21. chx - March 5th, 2016 9:03 am

    Perhaps talk to Andrew (bunnie) Huang perhaps to get connections (pun intended :P) into some Chinese manufacturers? This also looks quite relevant from him.

  22. David - March 5th, 2016 3:46 pm

    A little off-topic, but I’m investigating the possibility of getting a manufacturing run of the obsolete Apple Newton Interconnect (aka JAE RX04-26P-SF1) plugs. These were far less common than DB19s, of course, and there’s very few left in the excess inventory market (and at ridiculous prices).

    It’d be really useful to share information about potential manufacturers, etc.

  23. Rob Blessin - March 5th, 2016 5:30 pm

    Hello: I have a ton of quotes out waiting for responses as my email was bombed with rfq’s from over a dozen manufacturers local and distant, I included the technical drawing of the DB 19 Steve provided as well as actual photos of dsub 19 pin male connectors in sets of 10 I have been holding onto just trying to be proactive in locating a future source. Also included photos of the plastic shells and how they are used on the NeXT hardware via a NeXT Sony 17″ Monitor with NeXT Cube (Steve Jobs interim company between stints at Apple) showing the NeXT Monitor cable with DB 19 male connectors .
    I also just found this which seems real promising and I’ll contact them and find out the details as they take on minimum orders as little as 25 for custom connectors that are not a ridiculous amount of DB 19 connectors . It’ll be interesting to see the quote also I’m guessing that somewhere perhaps one of the original manufacturers has a cache of new old stock. At any rate we can continue to work in parallel and hopefully come up with a reasonable solution. Best Regards Rob Blessin

  24. Rob Blessin - March 5th, 2016 5:48 pm

    Also this should be useful in providing an accurate detailed description of what we need … …. any help appreciated here!

Leave a reply. For customer support issues, please use the Customer Support link instead of writing comments.