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RE: [cosmacelf] Re: PC Parallel port to Cosmac

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  • Chuck Bigham
    Thanks Steve. I need to create a package that I can upload to the files section with the Picaxe code, a schematic, and if I can figure out how to do it, an
    Message 1 of 40 , Feb 3 8:12 PM
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      Thanks Steve.

      I need to create a package that I can upload to the files section with the Picaxe code, a schematic, and if I can figure out how to do it, an installer for the Windows application. I'm not sure about a PC card, but I'll give it a shot.

      I picked Intel HEX for a rather prosaic reason -- the two assemblers that I have for 1802 assembly code create hex file output. It's only the Windows program that will send hex files, and it's an incredibly brain-dead implementation. The section of code that sends the hex file reads in a line, checks that the first character is a colon (:) and the eighth character is a 0, then sends the ninth character to the end of the line (less 2, for the checksum) out the serial port. Brute force -- no subtlety, but it works well enough for me.

      I'm not too worried about code space. The converter controls the Membership Card exactly the same way the front panel does, so there is no bootstrap program on the Membership Card. Lee sent me an 8K RAM chip, so I have the full 8K to play in. I'm pretty sure that will last me a long time. If it doesn't, I have a 32K RAM in the parts box that I can plug in.

      On the Picaxe side, I'm using 316 bytes of the 4,096 that I have available. There's a lot of space there if I decide to make the converter "smarter." The 20X2 is overkill for this simple application, but it does provide all the I/O ports that I need. Once again I've gone for brute force over subtlety.

      Chuck




      To: cosmacelf@yahoogroups.com
      From: steve@...
      Date: Thu, 3 Feb 2011 23:57:20 +0000
      Subject: [cosmacelf] Re: PC Parallel port to Cosmac






      Chuck,

      Love the write up, espically the tone and bleary eyed realizations.

      I hope you will post schematics and Pic code. Have you considered laying out a small PC card with the implimentation?

      I'm particularly interested in your choice of Intel HEX since its a rather universal format.

      Also, since Lee has provided so much code space do you see any file size issues?

      Nicely done,

      Steve

      --- In cosmacelf@yahoogroups.com, Chuck Bigham <chuck@...> wrote:
      >
      >
      > (Darn it. I got interrupted and then pressed send too soon.)
      >
      > I build a serial-to-parallel port converter with a Picaxe 20X2 so I can talk to my Membership Card using a USB-to-Serial-to-Picaxe-to-Membership-Card converter. It enables you to control the Membership card using a very simple protocol -- simple enought that you can control and load programs on the Membership card using a terminal program.
      >
      > I've got code for the Picaxe, a Windows PC program to control the Membership Card and to load Intel hex files from the PC to the Membership Card. I wrote up a brief description on my blog (http://www.bramblyhill.com/post/Killer-Serial.aspx). There's a picture of the Membership card connected to the Picaxe, and a screen shot of the Windows program and a screen shot of a session using TerraTerm.
      >
      > I've been meaning to write it up for the group -- now that I've mentioned it in public I'll probably have to.
      >
      > Chuck
      >
      >
      >
      >
      > To: cosmacelf@yahoogroups.com
      > From: leeahart@...
      > Date: Tue, 1 Feb 2011 22:58:47 -0600
      > Subject: Re: [cosmacelf] PC Parallel port to Cosmac
      >
      >
      >
      >
      >
      >
      > On 2/1/2011 10:53 PM, latheid wrote:
      > > Has anyone written a utility to load bytes into memory of a Cosmac Elf from a PC parallel port? If so has it been posted for download anywhere?
      >
      > My Membership Card ELF does it. It's described in the files section. At
      > least one customer has a working PC loader program. Basically, the PC
      > manipulates the ELF's front panel switches with bits from the parallel port.
      >
      > --
      > Lee A. Hart | Ring the bells that still can ring
      > 814 8th Ave N | Forget the perfect offering
      > Sartell MN 56377 | There is a crack in everything
      > leeahart earthlink.net | That's how the light gets in -- Leonard Cohen
      >
      >
      >
      >
      > [Non-text portions of this message have been removed]
      >





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    • bill_rowe@rogers.com
      ok, I went thru the avr code and made it more similar to the picaxe and it seems stable now. now i just need a simple serial app that i can bootstrap in with
      Message 40 of 40 , Mar 9, 2011
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        ok, I went thru the avr code and made it more similar to the picaxe and it seems stable now.

        now i just need a simple serial app that i can bootstrap in with it. off to the filepile!

        --- On Tue, 3/8/11, Chuck Bigham <chuck@...> wrote:

        From: Chuck Bigham <chuck@...>
        Subject: RE: [cosmacelf] PC Parallel port to Cosmac
        To: cosmacelf@yahoogroups.com
        Date: Tuesday, March 8, 2011, 8:55 PM


        I'm not sure why the application would stop working after you press a key. The application runs two threads, one that manages the UI and sends data to the serial port, and one that listens to the serial port and signals that data is available to the UI thread. The listener expects that the incoming data is formatted as lines, i.e., that they end with a CR-LF pair. If your application isn't sending a CR-LF the receive buffer will eventually fill up and throw an exception. I'm not sure what else would cause it. It sounds like I need to put in an application level exception handler that will catch all the exceptions and write a message with the details.

        An installer is not actually necessary for this version of the package, but it does provide a convenient automated method of packaging up the required files for distribution, and to remove the files that I put on your hard drive when it's time for them to go away. I hold out the hope that I will eventually have a "real" application package -- one that creates a Start menu group, and even has a configuration file in a standard location. Small steps. Small steps.



        To: cosmacelf@yahoogroups.com
        From: bill_rowe@...
        Date: Sun, 6 Mar 2011 22:12:53 -0800
        Subject: RE: [cosmacelf] PC Parallel port to Cosmac


         



        ok found it thanks.  I've started the control panel by double clicking on the program inside the C:\Program Files\BramblyHill\MCControlPad directory - right?  I don't see any shortcuts anywhere.  Is the installer really needed by the way if all the files are in that directory?

        Windows says "ControlPad has stopped working" after I (say) press the I key.  Now - this is my own serial app it's talking to - not the picaxe. will it end badly if it doesn't get the responses it expects?

        --- On Sun, 3/6/11, Chuck Bigham <chuck@...> wrote:

        From: Chuck Bigham <chuck@...>
        Subject: RE: [cosmacelf] PC Parallel port to Cosmac
        To: cosmacelf@yahoogroups.com
        Date: Sunday, March 6, 2011, 3:49 AM

        Hi Bill,

        The schematic for the converter is a PDF file inside the installation archive, http://bramblyhill.com/downloads/Converter.zip. I didn't use current limiting resistors on the outputs, but I probably should.  When I was testing I did have the outputs connecting straight to ground until I figured out what position the switches needed to be in -- which means I was running a dead short to ground for those lines.

        The PIC is a tough little chip. Probably shouldn't abuse them as much as I do, but so far I've been lucky.

        That's a good idea, I'll update the schematic the next time I update the program archive.

        Chuck

        To: cosmacelf@yahoogroups.com
        From: bill_rowe@...
        Date: Sat, 5 Mar 2011 14:18:06 -0800
        Subject: RE: [cosmacelf] PC Parallel port to Cosmac

         

           
             
             
              Chuck: did you post the schematic somewhere? I didn't see it.

        Did you put resistors between your picaxe output pins and the MC?  If the switches are grounded and you try to drive them you could wound your picaxe couldn't you?

        --- On Thu, 2/3/11, Chuck Bigham <chuck@...> wrote:

        From: Chuck Bigham <chuck@...>

        Subject: RE: [cosmacelf] PC Parallel port to Cosmac

        To: cosmacelf@yahoogroups.com

        Date: Thursday, February 3, 2011, 11:00 PM

        I build a serial-to-parallel port converter with a Picaxe 20M so I can talk to my Membership Card using a USB-to-Serial-to-Picaxe-to-Membership-Card converter. It enables you to control the Membership card using a very simple protocol -- I've

        I've got code for the Picaxe, a Windows PC program to control the Membership Card and to load Intel hex files from the PC to the Membership Card. I wrote up a brief description on my blog (http://www.bramblyhill.com/post/Killer-Serial.aspx). I've been meaning to write it up for the group -- now that I've mentioned it in public I'll probably have to.

        Chuck

        To: cosmacelf@yahoogroups.com

        From: leeahart@...

        Date: Tue, 1 Feb 2011 22:58:47 -0600

        Subject: Re: [cosmacelf] PC Parallel port to Cosmac

         

        On 2/1/2011 10:53 PM, latheid wrote:

        > Has anyone written a utility to load bytes into memory of a Cosmac Elf from a PC parallel port? If so has it been posted for download anywhere?

        My Membership Card ELF does it. It's described in the files section. At

        least one customer has a working PC loader program. Basically, the PC

        manipulates the ELF's front panel switches with bits from the parallel port...

        --

        Lee A. Hart | Ring the bells that still can ring

        814 8th Ave N | Forget the perfect offering

        Sartell MN 56377 | There is a crack in everything

        leeahart earthlink.net | That's how the light gets in -- Leonard Cohen

                                 

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