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The End of Things


After predicting the end of the DB-19 connector supply for over a year, it’s finally happened. I recently sent my last stockpile of new-old-stock DB-19s to the board shop for assembly of more Floppy Emus. I have two left that I’m keeping as souvenirs, and that’s it. I’m sure there are still a few left somewhere in the world, hiding out in some obscure surplus warehouse, but they’ve become so difficult to find that they may as well not exist.

This also means the end of the Universal Adapter for Floppy Emu Model A, because building one requires a DB-19. I think I have two or three left, and when they’re gone that will be the end.

My stock of Floppy Emu Model B boards is nearly exhausted as well. I still have enough of the older Model A for the time being, but I expect the Model B will be sold out within a week. If all goes as expected, it will hopefully only be a short sell-out, since I’m expecting a new batch of Model B’s from the board shop in a few weeks. But later this year when those are all gone too, things will get interesting.

I’m working with a group of other vintage computer collectors and parts dealers to manufacture a large run of new DB-19 connectors. As far as I’m aware, these will be the first new DB-19s made anywhere in the world in the past couple of decades! More details on this soon.

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Floppy Emu Firmware Update: Mac HD Menu


I’ve added a new feature to the Macintosh/Lisa firmware for the Floppy Emu disk emulator: a menu for selecting disk images while running in Mac hard disk emulation mode. This is the mode that enables Floppy Emu to function as an HD20-type hard disk with compatible Macintosh models, with disk sizes up to 2 GB. Previously the hard disk image was always taken from a file named “HD20.dsk” on your SD card. If you had a few different hard disk image files, and wanted to select the right one for a given situation, you had to put the SD card into your Windows/OSX computer and rename the desired file to HD20.dsk. While this wasn’t a common need, it was not especially user-friendly.

Get the new firmware here: hd20-0.7F-F14.5

With the new firmware, the first time you run it you’ll see a hard disk image selection menu. The name of the chosen disk image file is saved in EEPROM memory, and will be used for all future sessions. If you later want to choose a different disk image file, the NEXT button will return you to the selection menu.

After choosing a new disk image for hard disk emulation mode, the Mac needs to be turned off and on (Floppy Emu will prompt you to do this), or you need to press the Mac’s hardware reset switch. That’s because the Mac doesn’t expect HD20-type drives to be removable media, and doesn’t recognize when the disk has changed. Without a reboot, it will blindly continue as if the original disk were still present, leading to unpleasant results.

I welcome your feedback on this change. Let me know if you run into any trouble.

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DB-19 Group Buy


Holy cow, this is actually happening! After over a year of searching what seems like every warehouse and basement on the planet to scrounge for DB-19 connectors, I’m finally moving forward with the manufacture of new ones. As far as I’m aware, these will be the first new DB-19s made anywhere in two decades, since the days of the Macintosh II, Atari ST, and NeXT.

To make this work, we need to place a BIG order. Right now that looks like 10,000 pieces. If anyone else in the vintage Apple, Atari, or NeXT communities might be interested in joining this group buy for a minimum of 500 pieces or more, please contact me by Monday, March 21. For a male DB-19 with solder cups as pictured above, the price will be about USD $1.41 each, plus or minus a few percent depending on the final tally for shipping and other fees. If you’re interested in a smaller number of connectors, or just one, stay tuned. Other participants in the group buy will be selling individual connectors at retail once the manufacturing is done. More details soon…

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Floppy Emu Firmware Update: Disk Automount


By popular demand, I’ve added a new feature to the Apple II firmware for the Floppy Emu disk emulator: auto-mounting of the previous floppy disk image. If you turn off the computer while a disk image is inserted in the emulated floppy drive, the next time you turn the computer on, Floppy Emu will skip the menus and immediately load that same floppy disk image. This is a nice time saver if you tend to use the same disk image every time, but it’s buried in a sub-sub-directory on your SD card. It also makes it possible for an Apple IIc, IIc+, or IIgs to cold boot directly from a floppy disk image. Previously it was necessary to select the desired disk image from the Floppy Emu menu, then soft-reset the computer by pressing control-apple-reset.

apple-II-0.1P-F8Apple II, for Model B
apple-II-0.1P-F6Apple II, for Model A

I welcome your feedback on this change. While the convenience is undeniable, I’m not completely sure I like the new behavior. After the power is turned on, if the Floppy Emu is going to auto-mount a disk image, there’s a very short window of time during which it can be done. In order to auto-mount the floppy image quickly enough for the computer to boot from it, the Floppy Emu must skip the normal self test (smiley face logo) and version info screen (diagnostic info, and emulation mode selection). This may be a little confusing for people who are looking to verify their current firmware settings, or change the emulation mode. They can eject the auto-mounted disk to restore the normal startup screen flow. What do you think?

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New Demo Video

I put together a new demo video for the Floppy Emu Model B, since the old videos had become hopelessly out of date. Enjoy!

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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:

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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. 🙂

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