It’s a sad fact that, as technology marches forward, it affects even retro enthusiasts. For years, Commodore users have archived their personal disk collections using the ubiquitous “Star Commander” and some variant of the venerable “X-1541” adapter to connect IEC-based disk drives to the PC. As parallel ports have changed through the years, designers have adapted the X-1541 design to keep up. But, with the advent of the USB port, parallel ports have all but disappeared from the marketplace. The inherent design of the X1541-style cables cannot overcome the loss of a connection to the computer!
A few years ago, Till Harbaum created the XU1541 project, designed to connect via a USB port on newer machines. However, the project was eventually cancelled, with development efforts stalled.
ZoomFloppy Prototype (Courtesy Glenn Holmer)
Nate Lawson decided to do something about that. Taking a cue from the XU1541 design and identifying its shortcomings, Nate started working on a new implementation using a hardware USB-based Atmel AVR microcontroller via a Bumble B Mini USB Development Board. I got involved in March, when Nate asked if I would be interested in helping with the PCB design. Though initial ideas were to simply build a base for the Bumble-B, cost analysis led us to simply design the Bumble B functionality into a specific-use board.
Though my recent relocation hindered the timeline, I am excited to now announce the upcoming sales of the ZoomFloppy Commodore Drive USB Adapter. The schematic is finalized, board design is nearly complete. Nate presented details on the device at the recent Chicago ECCC show, outlining the many features of the new device on his web site, including his ECCC presentation.
It sounds like there is enough interest for a VIC-20 version of the X-Pander 3 expansion system. Thus, I’m sourcing the required parts for the units (the card edge connectors have the longest lead times and are the most expensive part of the design) and will work on the PCB design next week.
I thought I’d compose a quick note to let folks know that 64NIC+ Ethernet cartridges are in stock once again and the new X-Pander 3 3/4 slot cartridge port expander is finally in stock. I’m working to add 24/28 pin headers and cartridge cases to the store inventory.
Many apologies for the lack of postings, but I was preparing for the Cincinnati Commodore Computer Club EXPO (C4 EXPO), which happened over Memorial Day weekend, and I am just now getting caught up on postings.
Two weeks prior to the show, I shifted all focus to ensuring newly produced products would be available at the show. X-Pander3 expansion boards and 64NIC+ network cards were in production, but delivery had been delayed a week or so. This seems to always happen prior to a show, without fail. I spent evenings obtaining manufacturing and shipment statuses, making last minute parts purchases, and packing for the show.
The week prior to the show was spent traveling to Ohio, taking in some sights (Kings Island, for example), and spending time with the family. Since we were already on the road, I rescheduled last minute product shipments from China to arrive at the hotel before the show.
Though not the only reason, it is true I offer products for sale to finance these trips. I can enjoy catching up with old and online friends and relaxing and enjoying the hobby. This year was no different. I arrived mid afternoon on Friday, with the show room already open and a few folks setting up systems. Over the years, I’ve learned how to pack lighter, so my tables didn’t take too long to setup. Then, I spent time finishing some products for the show and chatting with the early arrivals.
I called it quits early Saturday morning (1AM or so Central), getting back to the room before 9:30AM. Traffic was lighter than usual, and seemed light all day. Sales were nominal, but steady. JiffyDOS sales were hampered by issues with my Willem programmer (after I returned home, I determined the configuration switches were faulty), preventing me from flashing some of the JiffyDOS versions.
Jim and Oliver working on project
Traffic stayed light all day, which is a bit disappointing because this is the second year traffic has been light. By afternoon, sales dissipated and I spent time fighting with the programmer. Oliver VieBrooks (Six of Style) came over late afternoon and we brainstormed on project ideas. Thus began the prototyping portion of the show. Given that sales had stopped, I decided to start on a project right then, and continued through the normal annual Saturday “C4 EXPO Golden Corral” dinner period (to be fair, I probably would have went, but we’d already enjoyed GC as a family earlier in the week).
Later in the evening, I worked on a project for Leif Bloomquist. Since the Fall ECCC ’09 show, Leif and I have been working to bring his VIC-20 MIDI cartridge to fruition. The main issue with the original design is the UART utilized, a MC6850 that is hard to source and pricey. I suggested rewriting the drivers to use the much more common 16X50-style PC UART ICs. I’d source a batch of them, but still needed to wire up one to Leif’s board so he could test.
By Sunday, I was out of energy, having worked on two prototypes the previous night. Thus, I packed up and left without much fanfare.
Seeing friends and talking hobby is always nice, but I feel the Memorial Day slot for this show hurts it quite a bit. Traffic was light, as previously noted, and sales were likewise light. Surprisingly, the Louisville crowd didn’t show, which hurt attendance more.
It appears I’m now the proud owner of 2600 custom manufactured IEC disk drive cables. Yes, you read correctly. 2600 IEC cables, with 26 AWG 6-conductor wire, shield, and DIN 6 connectors with molded covers. I know, it is insane, but it’s prohibitively expensive to order custom cables in smaller quantities, and it seemed like such cables were becoming a bit scarce. Well, no more! 🙂
1.2M (48") IEC Cables
The shipment of cables arrived this morning via eight 35 pound boxes. The cables are of 2 lengths: 48″ and 12″. Most of the cables were shipped here, but a box of 12″ cables is enroute to Gideon Zweijtzer for 1541U-II orders. Thus, if you’re a 1541U-II purchaser, hopefully this means an IEC cable will be included in your order.
The 48″ cable is already in the store, and I’ll add the 12″ option as soon as I can.
If you’re one of my friends in our neighboring country to the North and you’re interested in a 48″ cable, I’d recommend checking JPPBM‘s store out for a price check, as shipping from the US can be a bear. Currently, Joe’s not requesting 12″ cables, but I have plenty. Thus, if there is CA interest in 12″ cables, I’d recommend soliciting Joe to buy a batch for sale in his store.0.3M (12") IEC Cables
Powering CBM products can prove harder than initially thought. Many manufacturers choose the safe (and professional) route of including a power jack on the product and a plug-in power supply (wall wart). It’s a safe choice, but it carries a double cost. Power supplies tend to be $5.00 or so, and are often bulky and heavy, adding to shipping costs. On the consumer side, there’s a cost in finding another open outlet for the power supply and cable management.
For larger or more power hungry products, it’s a worthwhile tradeoff, but for smaller products, it is more efficient to power the product from the actual machine. Even today, USB devices can obtain power from the host computer, as long as they do not consume more than 100mA of power. Above that, and they require an external power source. Thus, for smaller CBM projects, it’s tempting to draw power from the console itself. On the Commodore VIC-20, C64, C64C, and C128, power can be sipped from the user port, cassette port, and/or expansion port, as well as from the joystick ports.
Over time, the cassette port has become the preferred port for power draw. Mainly, it’s rarely used. The joystick ports are smallest and probably cheapest to interface, but they are heavily used and can be prone to accidental disconnection. Still, the cassette port can prove challenging for interfacing in 2010. Most importantly, the .156″ 6 position connector is hard to source nowadays.
When I started offering products, I chose the cassette port because it offered a way to reduce prices for consumers, and the products used minimal power, making the port an ideal power source. With that decided, I simply needed to source the cassette port connectors and start selling products.
Oh, how I wish it were that easy! To understand the challenge, let me relate a bit of technical information. The standard PET/CBM cassette connector is a male 6/12 .156″ edge connector. For obvious reasons, Commodore created the male portion on the compute rmotherboard, as it was cheap (it requires no connector, just etching the connector conductive “fingers” onto the motherboard). To interface, one needs the female portion, which comes in 2 basic styles. One is designed for chassis (enclosure) mounting and contains 2 tabs on each end, each with a hole in them. They are called “mounting tabs”. The idea is to cut a hole in the case, mount the connector using the “tabs” and the holes, and then use the connector. The other foregoes the “tabs”. Since the “tabless” version is less useful (most use cases require a mounting option), it’s harder to source. Therefore, I initially obtained the more plentiful “tabbed” version of the cassette port connector for my power needs.
After I’d sold a number of units with the cassette port power connector, I noticed two things:
The installed connector was very hard to remove from the C64 or C128, as the cassette port on all CBM units is recessed into the case. Although I’d already know about the issue of removing the connector in general, that issue and this one didn’t concern me greatly because I surmised the connector would not often be removed.
The tabs prevented C128DCR usage. Commodore evidently reduced the width of the cassette port opening in the C128DCR case, making the tabbed connector too wide for entry. Although this was not a major issue (removing the tabs addresses the concern), it caught some folks off-guard and provided fodder for reviews and such.
Still, I had 150 of the tabbed connectors and no source for the non-tabbed connectors, so I pushed forward. Along the way, though, I both used up my stock of connectors and also managed to find a source for the more elusive non-tabbed connector.
With experience in hand, I decided to rework the power connection option for the product line. In addition to the previous issues, a few folks has lamented the lack of a cassette port “pass through”. Thus, I decided to fix all of the issues at once. The removal issues and the passthrough request could easily be solved by adding a small PCB to the connector (something to grab onto), and etching a cassette port male connector on the opposite end of the PCB. The C128DCR concerns required sourcing a non-tabbed connector. The resulting board would like similar to printer interface cassette port power adapters of the era. But it seemed a waste to create a PCB just to bring the signals out for passthrough usage.
Never one to ignore an opportunity, I decided to add some value to the power connector. In contemporary PCB design, it’s a fact that you’re paying for the area of PCB, rarely anything else. By creatively laying out the PCB, I managed to find space for a DIP-14 socket and a single pole switch. TO use the DIP socket, I mapped out the pin configuration for a small Atmel AVR microcontroller, the ATMEGA24/44/84. The cassette port signals all route to the AVR, as does the switch.
Mind you, I have no immediate plans to create a product using the uC onboard the connector. Thus, the uC is unpopulated, but one can easily add the socket and the controller. Nonetheless, I’m interested in idea for usage, and eager to see if hobbyists come up with independent ideas for usage.
In my continuing effort to sell more products for your Commodore computer, I determined users would buy more cartridge-based solutions if they could plug more into their machine at one time 🙂 Thus, given the lack of cartridge expansion options on the market at present, I am producing the X-Pander. Modeled off the CMD EX-3, CMD EX2+1, and the FB-3XP, X-Pander offers the following features and design aspects:
3 upright expansion slots
1 rear-facing slot for larger cartridge options (REU, etc.)
Each slot can be controlled via 8 DIP switches (GAME,EXROM,IO1,IO2,ROML,ROMH,POWER are selectable)
Slots #2 and #3 can swap IO lines (IO1->IO2, IO2->IO1)
Power LED indicators for each slot
Switches are located on right side for easy access
IO1/IO2 swap option located on right side for easy access
Long throw “piano” lever switches used for ease of configuration
Slot #3 can be accessed via top or rear port.
The prototype units have arrived and have been tested, production units are currently in manufacturing and should be in the store in a month. Current pricing estimates are $30.00.
The USB interface has become the ubiquitous interface for all kinds of peripherals, from file storage to cameras, wireless adapters to input devices. I wonder if there would be interest in a USB interface for Commodore machines, and how “intelligent” it would need to be. For example, I could easily design a “dumb” interface that simply maps the USB electrical interface into the C64/C128/VIC address space, but then each developer would be required to implement all USB protocol functionality. On the other hand, a more intelligent interface would help developers, but would cost more and some development would still be necessary, as many less common USB devices would require custom drivers to implement high level functionality.
Still, the idea seems a sound one. If the right balance is chosen, only software development would be required to use newer USB devices on the C64/C128. Software is much easier to develop and share, and if there are enough owners, it would be worth it to add support for USB devices in programs like GEOS, etc.
I’d appreciate any thoughts readers might have. Is this something you would find useful?
Finding economical 24 pin and 28 pin IC headers for adapter boards like ROM-el has been a significant challenge. DigiKey and Mouser stock on forked post headers, which are mainly designed for attachment of wires, not soldering to a PCB daughterboard. Aries Electronics offers the correct product, but they are almost $2.00 per piece, which is not sustainable.
Recently, I ventured into bulk purchasing of some components, like the 22/44 .100″ connector for C64/C128 cartridges, and the 6/12 .156″ connector for the C64/C128 cassette port. Given the success, I recently ordered 1000 each of some 24 and 28 pin IC headers, at much better prices. Of course, since I have no immediate need for so many units and I suspect others have the same issue sourcing these items, I’m soon placing them in the store.
Thus, if you’re in need of 24 or 28 pin IC headers, machine pin, low profile, check the store in a few days.
When the Cincinnati Commodore Computer Club approached me in late 2008 to design a low-cost ethernet cartridge for the C64/C128, I underestimated the interest. Not only has C4 sold out of their stock, but mine is gone as well.
I’m happy to report another order has been made, and should be available in a month or so. No changes, though I may take the lead time to see if I can source some cheap EPROMs for the ROM slot on the cartridge and see what I might be able to bundle in the ROM.
At some point, I’d prefer to improve on the design, but it may very well be that this design is “good enough” for what people want to do.
