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USB connection for the old PC

Cimonvg

Experienced Member
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Apr 4, 2009
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scandinavia
Hello
I dream of making the old pc more useable.. to have a xt pc with USB interface.
I was think of , something like a SCSI controler and a CARD reader , and a SD-card/USB (in one). But it was not a complete solution, and not that cheap either.
Yesterday I did stumbled on a device , that could do the job ??
I firm that makes rs232 til usb converteres:
http://www.sureelectronics.net/category.php?id=36

Any comments on this idea ?? :confused1:
I know some sort of programming is nessesary .. (not that I know that much programming..) ...but perhaps worth the effort.
/cimonvg
 
Given that most PC USB host adapters (I'm assuming that this is what you're asking about) are PCI-oriented, you may have to concoct your own solution. The FTDI Vinculum is a very simple device that supports some USB devices and has a very simple interface. There are also mid-level MCUs such as ARM and PIC32 that have no problem supporting USB Host mode or even USB OTG.

Getting the result to look anything like a standard USB stack on an ISA legacy PC would entail quite a bit of coding, however.
 
I think you'll find that device adds a serial port to a computer with a USB port.
Their bad english confuses things in the detailed description, but I'm 99% certain it's USB -> serial.
Explains the "Virtual COM Port Driver" :)

I'm just using an Iomega ZIP100 parallel drive - 100Mb disks that works on DOS through Windows 7 via parallel port. Can also get them in IDE to throw in a newer server/desktop. Cheap and work well. On an 8088 using PalmZIP, just gotta be careful and try to get the oldest working one you can find.

Another option is the XT-IDE controllers being developed with the CompactFlash slot.
 
Well I am only missing the USB-stick (USB-flash) opportunity. The quick access to files from a modern PC to the old pc!
/cimonvg
 
Hello
the model DB-DP11118 looks to me like rs232->usb ..
And yes some day going to try out ZIP's , but USB are in every modern PC , so..
/cimonvg
I think you'll find that device adds a serial port to a computer with a USB port.
Their bad english confuses things in the detailed description, but I'm 99% certain it's USB -> serial.
Explains the "Virtual COM Port Driver" :)

I'm just using an Iomega ZIP100 parallel drive - 100Mb disks that works on DOS through Windows 7 via parallel port. Can also get them in IDE to throw in a newer server/desktop. Cheap and work well. On an 8088 using PalmZIP, just gotta be careful and try to get the oldest working one you can find.

Another option is the XT-IDE controllers being developed with the CompactFlash slot.
 
Sorry I thought you meant the one at the top of that page you linked.

Yes the DB-DP11118 - http://www.sureelectronics.net/goods.php?id=1135 sounds like it is what you're after.
Not a bad price too. It uses a PIC24 chip, so will be easy to reprogram if necessary or fetch the source code to enable driver writing.

Good luck, definately doable with that model, just need someone with DOS driver experience I'd imagine.
 
Well I am only missing the USB-stick (USB-flash) opportunity. The quick access to files from a modern PC to the old pc!
/cimonvg

I guess it's whatever you're comfortable with. I find that the instant access provided by networking is the best solution when using DOS on a machine that will take a network card. There's lots of simple solutions to connection to "modern" machines from DOS, but perhaps you're running some other OS.

I don't normally access a memory stick from DOS but the proof is in the pudding, so I just tried it and it works like any other directory. Stick a network card in you XT and save the shoe leather. :)
 
Software they have has 8.3 limitation and it really doesn't like directories much by the looks.
But it's a start.

What OS are you running on an XT that doesn't like 8.3 names? They're not normally a problem. I either rename on the modern computer or us mget with a wildcard and they will automatically be truncated in the transfer. It simply doesn't get any simpler, but I understand that you may have your own preferences. :)
 
thank you for your comments - I will think it through again, and then decide which projekt I am going to follow.
/cimonvg
 
Hi Andrew!

A USB device is easy to implement; it can even be done with a low-end ATTiny using V-USB software. Real, full-function host controllers are a different matter, since they need not only to figure out the serial bus topology, but also conduct negotiation with each device as well as manage power. Medium-scale MCUs are powerful enough to do this and vendors offer software to assist the implementer. I don't know if the Vinculum can deal with hubs, etc. or if it supports just a small number of specific devices (I suspect the latter).

Given the memory limitations of an XT, I suspect that the driver stack and software would represent a major obstacle to a general-purpose host interface, much less how one would incorporate such drivers into an OS like DOS that essentially needs to know about all of its devices at system boot time.
 
It's far easier to interface to an SD card or even a CF card than it is a USB flash drive. SD cards are basically SPI (serial) interface; CF is basically IDE. Drivers for that are pretty simple.
 
I believe “deviceside” still offers a card so you can get a USB port on an older computer so you can use that device for reading some old 5.25” disks in various formats.

Check them out – just do a Google search.

Also check my many posts on this site about “deviceside.”

I used it a lot for my voluminous Kaypro disks.

BTW – I am not involved financially in any way with “deviceside.” I value my independence too much and they know that.

But I am enthusiastic about it since I just found that it really helped me a lot in converting thousands of Kaypro disks via a USB port for my decades of science, technology and society [STS] research dating from the 1980’s..

All the best !

Frank
 
The title "USB connection for the old PC" is a red herring. What the OP said was:
I dream of making the old pc more useable.. to have a xt pc with USB interface.
Which is a perfectly legitimate dream. :) However note the use of the word useable. I think useabiltiy has a lot to do with ones technique, and as it turns out:
Well I am only missing the USB-stick (USB-flash) opportunity. The quick access to files from a modern PC to the old pc!
/cimonvg

So the idea is to use sneakernet with a USB-stick. The OP is not really looking for USB as such, but rather the ability to transfer files from a modern PC. Sneakernet (moving files by transferring physical media) is not mandatory for that.

As Chuck(G) pointed out, USB is not that simple in the software department. You need a fully USB aware OS to be able to plug and play. I'm not a coder but reenumeration does not sound like a small task to me, nor one that will result in code that you could put on a floppy.

Indeed all that is needed to accomplish the task at hand is to have a network card or a serial card. Add a couple of utilities and a configuration file and you're all set - even running off a floppy. One does not need to re-engineer a historical situation to accomplish the task at hand, but rather to learn the techniques which are already in place.
 
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