Serial To USB Adapters

Ah, a feature I've not encountered.

I used a fax machine as a printer once, but then I just had to hit the start button when I heard the computer modem go off hook.

yeah, if it only needs to be used once something moderately complicated is fine.

A 16 bit PC Card to SD adapter, if it existed, which it doesn't, would require a driver. 32 bit PC Card to SD card adapters exist, but not 16 bit adapters. 32 bit PC Card to USB adapters exist, but not 16 bit adapters.

Serial to serial, like Laplink, would require software on both sides.

The best way to do this is to use a 16 bit PC Card (PCMCIA) Compact Flash adapter. It would require no drivers and no software has to be installed to get it to work. The Ethernet card drivers would be put onto the CF card from another machine using a USB to CF adapter. He would need a low capacity CF card.

Hardware Needed: Cardbus 16 bit CF Adapter: USB Card Reader with CF support: CF Card:

That laptop was meant to be used with PC Card peripherals. Floppy drives are available on eBay: . CD-ROM drives are also available. Win 98SE does have built in drivers for these devices so even the non-Toshiba versions of 16 bit PC Card floppy drive and CD-ROM drives would probably work. But the Compact Flash method is almost guaranteed to work since the PC Card bus is essentially the Compact Flash interface.

He could also buy a 16 bit PC Card memory card and skip the Compact Flash adapter and USB Compact Flash reader but he'd need another laptop with a PC Card slot to get the driver onto the card and almost no new laptops have PC Card/Cardbus slots.

Also, USB IrDA Infrared adapters are inexpensive. Could use one on another machine.

Reminds me of the days I spent in the IrDA booth at Comdex. "Your Mother Uses Wires."

I don't get why this is being rehashed over and over. Someone already pointed out that a CF interface is the same as PCMCIA and so would not require any extra drivers in this machine. It has also been pointed out that the really certain solution of moving the hard drive to another machine would allow copying of any drivers needed which would allow virtually any compatible interface to be installed.

I don't see where the OP has posted in a while. I guess he has given up or moved onto something else.

The Libretto uses a PC Card (PCMCIA) modem. If he has that modem then that would work.

I remember those Libretto machines. Very cool at the time. All external storage devices were PC Card based. The dock had another PC Card slot.

Getting the drivers for the network card into it is a pretty easy task but it appears as if the original poster was trolling since he doesn't want to take the advice given to him on how to do it.

We've been duped into answering by a clever troll who sounds serious at first.

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It's being rehashed because different people keep coming up with solution s, some different and some the same, but unfortunately none of them applica ble to my desire or situation (which I cheerfully admit I didn't lay out ve ry clearly).

I have budget and, um, external resource limitations. I can't afford to e Bay every shiny toy out there (especially if they're other-branded and only "might" work), and locally there just aren't the kind of hardware solution s suggested (PCMCIA-CF adapters, etc.) available.

I'm in a relatively small town. There's no local computer repair store wi th a goodie box full of the suggested solutions in a back room.

At the local indoor swap meet (read: collection of more or less permanent ly rented stalls under a common roof where people sell ancient crap and cal l it "antiques") there's a guy who specializes in older computer stuff but he came up empty on Libretto accessories (or even other-branded PCMCIA bits like CD or floppy drives or CF adapters) that would work as many have inde ed suggested.

If I had some ham, I could have some ham and eggs, if I had some eggs...

He does *think* he has an external drive bay (at home) that will allow th e dismounted Libretto drive to be installed into a relatively modern PC so that drivers can be loaded, but he won't sell it.

Well, I do have a life beyond getting the Libretto going.

Also, I wasn't and am not trolling. The reason I seemed, in some peoples' eyes at least, to be inappropriately focusing on a serial-USB connection i s that going in, I knew that adapters exist to permit serial-based peripher als to be used with USB-based computers, and could (naively) see no reason the converse wasn't possible. I had the vague idea in mind of assembling a standalone USB host in a box that communicated with the Libretto via serial rather than ISA as usual. Yes, severe layer mismatch, and slow, but it's a hobby challenge, not something I want to sell in the tens of thousands of units.

I didn't want to default to going out and buying a pre-made solution, I w anted to DESIGN and BUILD something, and hoped somebody here had some exper ience or other thoughts to contribute to that effort, or worst-case some de finite knowledge as to why it cannot work so I *could* move on. Maybe I sho uld have posted in sci.electronics.just.buy.it.off.ebay.

I guess wild-idea designing has gone out of fashion, and will have to jus t dig deeper into the Internet to see if it's doable.

I did have a small success, though.

I bought from the, uh, antique computer guy a working HP iPaq RZ1715 palm top because it has an IRDA 1.0 port (compatible with the Libretto's) and SD socket and was cheap and operational (otherwise it's a laughable POS). I m anaged to successfully transfer a small text file from the iPaq to the Libr etto but it choked on larger files, which may be due to my inability to kee p them properly aligned while balancing them on the arm of my recliner long enough to stay connected.

Anyway, thanks to all who responded, even the snarkers. I now know what w ill work thanks to them (if I can get my hands on it) and what not to waste money on.

I was just hoping I could, you know, fire up the soldering iron and build something instead of just plugging bits together.

Mark L. Fergerson

The first time I heard that was from a Kentucky couple who would also say, "Boy, I could sure use a nice, tall glass of hot gravy." lol

Now that, I am sure, can be had nearly anywhere. I have some myself... but I won't sell them to you.

PATA drives were the norm for a long, *long* time and you can still buy USB adapters all over the place.

Just to be clear, I never said you were trolling. I believe your need is real and I am trying to help. Maybe not effectively, but free help is worth the price... ;)

I'm not sure what you mean by the "converse". The USB part would plug into another computer, right? If you are thinking of a USB master emulation via serial port, then I think that would be a longer stretch than finding a CF-PCMCIA adapter. A much longer stretch. I've never even heard of one and I'm all about serial ports.

It would be possible to make, but you would need a driver for the Libretto which brings you back to the egg... or does it bring you back to the chicken?

I can't say this desire was ever fully articulated, possibly because it would have required an extra measure of explanation because it seems a bit unique. But you still have the problem of needing software on the Libretto to support it all and that software would not be entirely trivial. I would not need to know about the USB protocol, that could be done in the MCU in the box. But you still need a way for that MCU to access the Libretto file system via the serial port.

I just can't think of anything you could solder together that wouldn't need software on the Libretto.

one side only needs dos or something dos compatible, you issue a CTTY command and then the software is transferred over the serial cable.

another way:

win 9x has hyperterm which can do X-modem file transfers I think. but you'll need something compatible on the other end (like hyperterm or sz)

a serial laplink cable just needs DOS on the libretto.

Yeah, that has been indicated before. But that is not what he is asking about it seems. Getting software on the PC is not the end goal, the USB over a serial port thing seems to be the goal.

Way back when, before I was a Windows user (and I resisted a long time), I considered a serial-to-USB interface or possibly parallel-to-USB, so I could use a USB device on my antique pre-USB computer. I don't remember what device it was that I wanted to use, and it does not make sense now.

However, since that time I have built some USB devices using Microchip parts, but they were USB clients and not hosts, and they were primarily CDC USB to serial so that I was able to implement an isolated connection between my data collection section and the USB circuit. There is now a USB OTG (On The Go) protocol which can function as a host as well, so it should be possible to add a serial interface that connects to the computer RS232 port.

The specific design depends on what you need for it to do. To transfer data from the computer to, say, a USB thumb drive, you just need to have a buffer for the incoming data and transfer it to the mass storage device, which is one of many standard implementations that are recognized by Windows with generic drivers. The transfer should work both ways, but there may need to be some handshaking on the RS232 port.

Here is a presentation on Microchip USB OTG:

Here is an "Easy USB OTG" development board for about $30:

Here is something for about $20 with shipping that might be able to implement USB OTG with the PIC18F2550 which I have used in my devices:

It appears that the PIC18 USB library has hooks for OTG. It might be fun to try!

Paul

I've never heard of OTG on PIC18F2550 (and similar). Are you sure it is possible? Someone (Jan?) might know of the top of their head..