What's your threshold for "patch and pray" before you drop back and analyze the issue? Is it worth putting a scope on the setup with the desktop then compare the traces to what the laptop produces? A Google search on "serial protocol analyzer" turned up several with free/eval versions. Once you're sure the physical layer is wiggling properly you can look at the data to see if there's anything obvious. Of course getting a reliable connection to sniff the line adds another wrinkle. :-) On 7/22/2010 10:01 AM, Roger Weichert wrote: > Well, I had a go at a couple of the suggestions, but so far no joy. > > First I tried unchecking the FIFO buffer checkbox and several other > variations. Then I tried the USB to serial adaptor, but again, no go. > > The USB adaptor certainly works, because I've used it for another > communications job witth an RFID reader, and it worked at first attempt > which really surprised me. > > I got a reasonable number of my boards going, so I'll have another attempt > with the next batch. > > Next, I'll have to try booting into DOS via a floppy .. once I work out > how it's done. > > Thanks for all the help. > > Regards, Roger > > > > ----- Original Message ----- > From: "Roger Weichert" > To: "Microcontroller discussion list - Public." > Sent: Thursday, July 22, 2010 8:07 AM > Subject: Re: [EE] XP versus Win95 Serial ports > > > >> Carl Denk wrote >> >> >> >>> As I understand, some (many?) laptops and maybe desktops do not provide >>> the RS-232 voltage levels of +/- 12 VDC, but maybe TTL levels, and/or no >>> negative voltages. Also there may be an issue of providing enough power. >>> I assume the laptop has USB ports available. You might look at an >>> USB/RS-232 adapter, noting that some of those adapters may not provide >>> the necessary voltage/amperage. Might look at >>> http://www.scantool.net/accessories/usb-to-rs232-converter.html >>> I don't know if that will do the job, but seems like it might, and at >>> $13, that's hard to beat. I recently got a Nettop, with no RS-232, but >>> has 3 USB. Am considering getting one to talk to PIC embedded systems >>> and a PLC. >>> >> Thanks Carl, I actually woke up through the night and was thinking about >> it, >> and realised I have one of those type devices I bought off ebay a few >> weeks >> ago, and I didn't even think to try it. That's definitely something that's >> worth a try. >> >> >> Richard E. Teague wrote >> >> >>> I seem to remember something from my old ICD1 which used the serial port. >>> It would not work properly when FIFO buffer was enabled on the com port. >>> Try clicking start/control panel/system/hardware/device manager/ports >>> Then double click on your com port, then click port settings/advanced >>> Then uncheck "use FIFO buffers" checkbox. Click ok on all open windows >>> And give it a try. Don't know if that will fix it with your programmer >>> board, but it was necessary to make the ICD 1 work on the com port in XP. >>> >>> And ,yes, XP does do some very strange things with com and parallel ports. >>> >> >> Thanks Richard, >> >> I recall seeing that setting as I was checking everything, so I'll give >> that >> a shot. It's probably the easiest test to do out of all the suggestions >> >> >> John Hansen wrote >> >> >>> I think you have a couple of options here. If you can figure out what >>> this >>> old software is actually doing (could it be writing configuration values?) >>> you could acquire a modern PIC programmer and rewrite the chips using >>> MPLAB >>> (or the like). >>> >>> Or you could save the old clunker as you have been doing. >>> >>> One other possibility would be to boot into DOS using a floppy or a CD on >>> a >>> modern computer when you want to do this programming and boot into your >>> regular operating system off the hard drive at other times. >>> >> Thanks John, before I aquired a factory programmer, I actually tried using >> a >> couple of different pic programmers, but the beauty of the original is >> that >> there is a screen where you can set or change the variable parameters for >> the board and therefore rewrite the eprom easily. >> >> If I knew how to write higher level software maybe I could write my own >> version and use it with my own pic programmer. >> >> At least I've bought some time by getting the old clunker going. I have >> about 20 boards to finish fairly quickly. >> >> Your other suggestion of booting into DOS using a floppy sounds like a >> great >> idea to try if the earlier ones dont work. Thanks again. >> >> Carl Denk wrote >> >> >>> 2 questions: >>> 1: Could you duel boot DOS using GRUB or other loader? This would >>> eliminate the floppy. Or use a USB or SD flash card to boot DOS? >>> 2: Could you run the DOS under Linux with WINE? >>> >> Thanks Carl, yes it would be worth a try too. I'm not sure how all that >> works, so I will do some checking or may ask more questions if none of the >> earlier suggestions work out. My laptop still has a floppy drive, and I >> still have the original DOS disks. >> >> Thanks to everyone for all your input. Looks like my morning is taken care >> of trying out all the suggestions. It's great to fire off an email before >> I >> go to bed, and when I wake up find a heap of excellent ideas in my inbox. >> Thanks again. >> >> Regards, Roger >> >> >> >> >> >> -- >> http://www.piclist.com PIC/SX FAQ& list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > -------------------------------------------------------------------------------- > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.441 / Virus Database: 271.1.1/3018 - Release Date: 07/20/10 > 18:36:00 > > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist