I recently bought a used NEC MobilePro H/PC, and I love it. Getting it to sync with my Macs has been a challenge, though. I’ve been able to do it so far by running Virtual PC on my PowerBook 3400, which has a high-density 15-pin serial port (needed for the sync cable) on the back of it… but it would be real handy to be able to perform the same feat with my G4 at work, since I don’t usually bring the PowerBook in to my office.
Therein lies the problem. The G4 has only USB ports, and I have not been able to locate any 15-pin serial adapters for USB ports. (9-pin and 25-pin serial adapters for USB ports are no problem, apparently.) In my wanderings through the web, I came across a post to another MB which said that such an interface was impossible, but didn’t say why. Can anyone explain this to me? Any remote possibility I can get around this by using a 9-pin serial adapter for USB, and then attaching a 9-pin to 15-pin serial adapter to that (cumbersome, but I don’t seem to have a choice)?
Thanks in advance for any enlightenment you can give me.
The problem is that USB is not RS-232 (the protocol that the 9/23 pin serial connectors use) and RS-232 is not USB, and never the twain shall meet. The protocols are completely different; yes, they’re both serial devices, this just means that the interface sends the data along the wire one bit at a time (as opposed to a parallel interface like IDE or SCSI that sends the data along parallel lines in 8 or 16 bit chunks). Other serial protocols are Ethernet, IEEE-1394 (Firewire) and Fiber channel. None of these interfaces are directly compatible with one another.
Actually, there might be some USB<=>RS-232 adapters, but if they do exist most likely they’re very expensive. Seems to me a better solution would be to get a PCMCIA (now called “PC Card”) network card and a crossover cable to connect your two machines together with Ethernet and use TCP/IP to communicate.
USB to RS-232 adapters are commonly available and they just got really cheap. They had been running in the $40-50 range, but I just got one for $16.95 at Best Buy. It is labeled as a USB to PDA interface adapter, but it is a full serial port adapter as it works fine with my V.90 RS-232 external modem.
I’m not quite following what’s going on here. Can you break down exactly what ports are on which machines? I can’t quite tell from your post and I haven’t worked on any hardware-based Macs since the Quadra series was state of the art. My subsequent exposre to Macs since then has been via Amiga-based emulation (I now have a 68060/603 based Mac! PowerPC or legacy at the click of an icon!).
It may be possible to use one of the Mac’s USB port, one of the aformentioned USB to RS-232 adapters, and the sync cable that came with the MobilePro for use with a PC, which in your case would be VirtualPC. If this is not possible, explain why and maybe we can help you find a solution.
The NEC comes with a sync cable that is meant to attach to a 15-pin serial port on a PC. Since my PowerBook has a 15-pin serial port, I’m able (with the help of a gender changer) to connect the sync cable directly to the serial port on the PowerBook, and sync the machine through VirtualPC.
My G4 has nothing but USB ports (legacy free!). I have found USB to RS-232 adapters for sale, but the RS-232 side is always 9-pin or 25-pin, never 15-pin, which is what I need for the sync cable. The message I saw posted to the other MB said that a USB to 15-pin RS 232 adapter would never be made, and frogstein has offered an explanation as to why not.
I have seen just a couple of 15-pin to 9-pin adapters, and I wondered in the OP whether a “sync cable to 15-pin/9-pin adapter to 9-pin RS-232/USB adapter” set-up would function properly… frogstein’s suggestion would be a simpler way to go. I hadn’t thought of getting a network card, mostly because I was hoping to find an inexpensive fix. If folks here think that the adapter daisy chain is unlikely to work, I’ll just have to fork over a little more $$$ for a PC card.
I have never, in 20 years of working on computer hardware, seen a 15 pin RS-232 compatible serial port on a PC, only 9 and 25. High-density 15 pin ports (i.e. the same shell size as a 9 pin serial port) are only used for video connections. The only common PC use for 15 pin D-Sub connections is MIDI/Joystick ports. Apple also uses it for the video connection on Macs. There are occasional other proprietary uses for these connectors, but I cannot possibly imagine NEC supplying a cable with this connector for use as a PC-PDA serial sync cable.
Are you sure you understand the correct way identify the various D-Sub connectors? DSub 9 has two rows of pins, 4 and 5, respectively. HDDSub-15 has three rows of 5. Both are the same size in terms of external dimensions. DSub 15 is two rows, 8 and 7.
HD15-9 pin adapters are for use with older multisync monitors that have 9 pin ports.
Please count the number of pins and verify what is going on here.
OK, you totally had me confounded, so I went to NEC’s site (this page) and looked at some of the information on MobilePro devices.
Note the section I bolded. You should have a sync cable that goes from the back of the MobilePro to a 9 pin PC serial port. Get the Belkin USB PDA adapter I mentioned from Best Buy (MacOS support is on the CD-ROM; I checked). Connect it to your sync cable and then to a USB port on the G4. Load the driver, fire up VirtualPC, load the WindowsCE services, and you should be in business.
I’m with sewalk. You wouldn’t be plugging a serial device into a port that looks like the picture you posted the link to. That’s a VGA-style connector. It’s not impossible that some manufacturer used that connector for a serial port, but it’s extremely unlikely and even if they did, your PDA definitely wouldn’t work out-of-the-box (you’d have to go find an adapter, and clerks at electronics stores the world over would stare at you and drool when you mentioned a serial port with three rows of 5 pins :))
Could it be that when you went to go looking for usb-serial adapters, you just looked at the VGA out port on the back of the laptop by mistake? That would make sense.
Oof! I’d seen references to 15-pin game ports (thought these were also serial, but perhaps not) and assumed that something on that order was what I needed to have in order to sync with my G4. Now I know better.
galt, you’re right about the clerks in electronic stores staring at me, but there was a distinct lack of drool - just incomprehension. That should’ve been my first clue that I was barking up the wrong tree, I guess.
Thanks for pointing me in the right direction, everyone.
As the others mentioned your description of what you have done with the Powerbook sounds impossible. According to Apples own specs the only 15 pin port on a PowerBook 3400 is the video port which is not used for serial IO.
You can easily obtain an Apple USB to 9 pin serial adapter which is what NEC’s own site indicates the phone has. The interesting part is if the Apple will properly emulate the NEC PC software, and in addition will simultaneously use the USB/serial adapter with the PC software. An interesting challenge.
Nope, the 15 pin game ports (which have two rows of pins and are noticable wider than the DB9/HDB15) are completely different. Some do support a special serial protocol for use with MIDI adapters, but that is a totally different matter. For their main use, they are analog and parallel. Each axis on the stick(s) has its own input line which is a variable analog signal created by applying a voltage across a potentiometer. The buttons are digital, though, but again, each one has its own input line. Some newer game ports are dual-mode and have a digital capability for use with some newer game controllers, but this is quickly losing popularity to USB.
