My plan to ship uIEC/SD units by end of June was evidently overly optimistic. It took longer than expected to modify the uIEC/SD PCB design, and the design had to be checked more thoroughly since I will not have time to assemble and test a sample before ordering the SMT stencil (a metal “mask” laid over the PCB that is used to force solder paste to only deposit on the exposed PCB pads) and a production PCB run. Thus, I am crossing my fingers that the redesign is correct. The new design looks very similar to the older, though I have designed the PCB to fit a small Hammond 1551 enclosure (the 2 half-present holes on the corners of the board).
At this point, I’ve moved the expected ship date to July 12, and alerted customers about the delay.
Thanks to the hard work of Thomas Winkler, ZoomFloppy now supports Commodore IEEE-488 devices. Many thanks also to Nate Lawson for incorporating Thomas’ changes into the ZoomFloppy base firmware image.
Existing units require a firmware update and the population of the IEEE-488 connector fr operation. As there is not a simple firmware update utility at present, users may wish to wait until an official upgrade solution is available. However, users who wish to download some programming SW and follow a step by step tutorial can upgrade immediately (disclaimer: RETRO Innovations takes no responsibility for upgrade issues, though there is no way to completely brick the unit. At worst, RETRO Innovations can reprogram the unit and ship back to the customer). All newly ordered units will contain the updated firmware.
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 just finished the order for 1000 22/44 .156″ card edge connectors. These will be used to create the 3+1 cartridge “slots” on the VIC version of the X-Pander 3 cartridge expansion system. Now, so secure more switches for the signal configurations.
As some may know, IEEE-488 is no longer a preferred global interface standard. I would even go so far as to state it was niche even in its heyday. HP used it as the “Hewlett Packard Interface Bus”, and it was also known as the “General Purpose Interface Bus” (GPIB), as I recall. Still, more names do not increase a standard’s usage.
Now, 30+ years later, it’s becoming quite difficult to find economical sources for IEEE-488 parts. I surmised cables would be expensive, given the number of wires in IEEE-488 cables and the pass through connectors present on many of them. However, I was surprised at the expense for the Centronics 24 pin connector used in the standard. Though 36 pin Centronics (parallel port) connectors are nominal in price, I initially found but a single source offering the 24 pin connectors. Of course, that source offers them for $9.00 a piece.
Recently, I’ve found a more economical source, one that can supply not only the connector, but also the special studs that the standard requires. Though the minimum order is 1000 units, I feel there’s enough demand to justify a bulk purchase. The ZoomFloppy hardware supports the connector already, and future devices should support IEEE-488 as well. Thus, I’ve ordered 1000 connectors, and will add them to the store at the reduced price one they arrive.
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.
Often times, classic computer peripheral designs can easily utilize contemporary electronics components without compromise. However, two areas require special care:
As electronics components move to LVTTL (3.3 volt) and below, designs require more buffering to maintain electrical compatibility. Thankfully, such buffering solutions are common and relatively inexpensive. Connectors, on the other hand, bring additional issues.
However, with contemporary connectors moving to serial-based solutions and miniature sizes, larger classic connectors become harder to source and more expensive. This, in turn, greatly drives up product costs and can often price a product out of manufacturing viability. Thus, a while ago, I started dipping my toe into the bulk purchasing pool. With success in hand, I’ve expanded the effort, just recently purchasing 24 and 40 pin headers (for PCB designs that plug into DIP sockets, IEEE-488 jacks (for ZoomFloppy usage), 22/44 .156″ edge connectors (for VIC-20 expansion port usage), and DIN6 jacks (for most IEC-based applications).
While there is inherent risk in such purchases, I feel it’s required to ensure designs can be viably produced and sold.
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.
During a discussion on the Lemon64 forum, someone suggested a version of ZoomFloppy that would fit inside the CBM drive. After some tweaks to the idea, I hereby present “Micro ZoomFloppy”. This unit will sit in the 6522 IC socket and provides complete ZoomFloppy functionality. The only external connection is a USB jack
Though the board looks finished, it’s just a rough draft. Some pin changes would help with layout, and I still have one wire to route. Still, it is coming along nicely.
In case you’re wondering, the 2×8 connector on the bottom is the parallel port header. The PCB serves double duty. When fully populated, it’s a complete ZoomFloppy unit. But, if not populated, it can still be used to add parallel port capabilities to a 1541 device.