Though I tried for weeks to source a few more of the connectors used on the current uIEC/SD design, the effort proved fruitless. In parallel, I started asking suppliers for other options. As the hope for more old stock dwindled, I decided to source a new connector. I selected a connector that is both less expensive than the older option and can be sourced from multiple companies. This should alleviate my dependence on a single supplier for such a critical component.
I also purchased a stock of Micro SD sockets. The price was right, and I think it’s time I designed something using uSD.
Of course, this decision implies I have to finish the new uIEC/SD board design, spin a new board, and create a new surface mount stencil. Still, the total cost compares favorably to buying old stock SD connectors, even if they were available.
I guess I should feel lucky I have been immune to the issue until now, but I have just received word that the newest batch of uIEC/SD units is stalled. The SD connector has been discontinued from 3M, and though I successfully ordered a final reel of them for this production run, the supplier evidently over-committed the remaining units. I’ve spent the last few days attempting to source a comparable option, to no avail. Seeing no other options, I will have to redesign the board to accommodate another SD connector, which means the 200 existing PCBs are now official useless, I’ll need to order a new surface mount stencil (used to apply the solder paste to the PCB before parts are laid onto the board), and the pre-ordered units will be delayed beyond May 31.
It does cause me to wonder why 3M decided to discontinue the offering. It was a economical and very robust connector, so I can’t imagine it was little-used. In any case, it’s no longer available, and I’m left to find a suitable replacement and notify customers of the additional delay.
After I’ve worked on a project for a suitable amount of time, it’s important to let it sit for a few days to allow the design to “mature”, so to speak. Sometimes, nothing changes, but other times, you come up with a great idea that solves lingering concerns with the existing design.
With the uIEC/SD daughtercard design “n the shelf”, an email exchange with customer Ken Page caused me to rethink parts placement. I was unsatisfied with the vertical arrangement of the uIEC/SD main board in the v2 design, but could find no other way to mount the board. However, during the conversation, I came upon the idea of moving the IEC connectors to the bottom of the board. That solved two problems. One, the board needs “standoffs” when plugged into the VIC/64/128 cassette port, or else the board will flex when buttons are pushed or SD cards are inserted. Bottom mounted IEC connectors provide the required height positioning. With them mounted under the unit, I can now offer a horizontal mounting option. In addition, I was able to add 2 more connection pinouts. This means that one can use the daughtercard as a miniature “backplane”, attaching up to 3 uIEC/SD units to a single daughtercard.
I also took the opportunity to put a 7805 voltage regulator pinout on the board and a “barrel plug” wall power adapter option. I do not intend to populate those items, but customers can easily add them.
I realized that no amount of restructuring this design will appeal to everyone. Some people want the smaller board with the single IEC connector. So, I decided to offer both options. The older design is harder the manufacture, so I will price accordingly.
Due to some changes in the PCB houses my assembler uses, and cost issues with the DIN6 connector for the uIEC/SD daughtercard, it’s actually cheaper to create a new PCB design than to use the old one. To that end, I have slightly modified the design to include a power supply connector and a switch to disable the RESET line (in case you wanted the device to stay in a subdirectory across reboots of the computer). To stay on delivery targets, I need to send this off to the assembly house this week, but I am interested in comments on the changes and any others that might be possible. Before people ask, I attempted to add a second IEC connector, but then the IEC connectors must be positions to face the side, and the board ends up larger than the uIEC/SD itself.
Ingo Korb has released a minor update to sd2iec (used in uIEC, among other solutions). Users are encouraged to update to this release. Fixes/Features include:
U1/2, B-R/W commands now work without a trailing CR character (reported by Draco)
UI now always reports the dos version no matter what characters are following unless it’s a + or -. Previously anything but ±/nothing would result in a SYNTAX ERROR which doesn’t match what a 1541 would do. (reported by skoe)
JiffyDOS timing optimized, now loads a massive 1.8% faster!
One of the most often requested features for uIEC is GEOS support. Given that uIEC emulates a Commodore Disk Drive at the protocol level, not at the hardware level, such support is harder than it sounds. Like many applications of the day, GEOS uses a custom disk drive transfer routine (commonly called a “speeder” or “fastloader”) called diskTurbo to make drive access times more manageable. Since the normal protocol is discarded in favor of a faster variant, successful emulation requires emulating the custom protocol. uIEC uses the sd2iec firmware, which has supported a handful of custom protocols for some time (including JiffyDOS), but does not currently support the GEOS custom protocol.
That may soon change, though. RedumLOA has created a site called “Commodore Bounty” that will allow interested individuals to fund project activities. The first bounty is for sd2iec GEOS support, which has been funded to over $750.00 at the time of this posting. If you are interested in seeing GEOS support on sd2iec and uIEC, please consider a donation.
