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5675Re: creating a cosmacelf simulator in C

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  • Andrew Wasson
    Oct 4, 2008
    • 0 Attachment
      I haven't played with the Arduino myself but I'm impressed with the
      following it has generated. Some really neat things have been created
      with them. Other than that, I'm a fan of the Ubicom SX Chips...

      They can be run in Pic mode if need be or they can run in their native
      turbo mode which is several times faster. I've only used them with ASM
      code but I believe you can program them in a variant of C.

      Andrew

      --- In cosmacelf@yahoogroups.com, "J.C. Wren" <jcwren@...> wrote:
      >
      > Color me confused, but I can't understand the appeal of the Arduino.
      Other
      > than some canned libraries, and some pre-made PCBs, what exactly do they
      > have to offer that I can't do with some simple C code anyway? And
      this bit
      > about "sketches" and "shields"... We've been calling them
      "programs" and
      > "daughter cards" for the last 40+ years. Why do we need some new
      words for
      > this?
      > --jc
      >
      > On Sat, Oct 4, 2008 at 1:15 PM, Bill Rowe <bill_rowe@...> wrote:
      >
      > > That's it and there's a wonderful picture of it with switches and
      lights.
      > > http://www.compendiumarcana.com/CDP1802/CC1802.PNG
      > >
      > > I've fallen in love with the arduino which uses the AVR microcomputers
      > > instead of the PICs but they offer the same kind of wonderful
      compactness.
      > > ----- Original Message -----
      > > From: J.C. Wren
      > > To: cosmacelf@yahoogroups.com
      > > Sent: Saturday, October 04, 2008 12:01 PM
      > > Subject: Re: [cosmacelf] Re: creating a cosmacelf simulator in C
      > >
      > >
      > > http://www.compendiumarcana.com/CDP1802/PIC1802.asm
      > > Not sure of the currency of it, but Google found it.
      > >
      > > --jc
      > >
      > > On Sat, Oct 4, 2008 at 11:57 AM, Andrew Wasson <andrew@...
      > > >wrote:
      > >
      > > > That's right Bill.
      > > > If I remember correctly it was Kevin Timmerman who created the Pic
      > > > 1802. I used to have the ASM listing for it. I thought it was a
      really
      > > > neat idea.
      > > >
      > > > Andrew
      > > >
      > > >
      > > >
      > > >
      > > >
      > > > --- In cosmacelf@yahoogroups.com, "Bill Rowe" <bill_rowe@> wrote:
      > > > >
      > > > > re the PIC version, if you look way back in the message
      archives to
      > > > where we were talking about a "Membership Card" single board
      system,
      > > > someone had built a tiny replica with 1802 emulation on a chip - I
      > > > forget the builder and the chip type but I thought it was
      wonderfully
      > > > cute.
      > > > > ----- Original Message -----
      > > > > From: akshay parelkar
      > > > > To: cosmacelf@yahoogroups.com
      > > > > Sent: Friday, October 03, 2008 5:05 PM
      > > > > Subject: Re: [cosmacelf] Re: creating a cosmacelf simulator in C
      > > > >
      > > > >
      > > > > Thanks a lot for all the tip, suggestions and articles.
      > > > >
      > > > > I will now proceed with the project.
      > > > >
      > > > > Thanks again
      > > > >
      > > > > --- On Fri, 10/3/08, ted_rossin <ted_rossin@> wrote:
      > > > > From: ted_rossin <ted_rossin@>
      > > > > Subject: [cosmacelf] Re: creating a cosmacelf simulator in C
      > > > > To: cosmacelf@yahoogroups.com
      > > > > Date: Friday, October 3, 2008, 11:30 AM
      > > > >
      > > > > I just uploaded the source code to my Elf emulator in the
      > > > >
      > > > > Files/Simulators folder (TedsElf.zip) . It is in C++ but
      should give
      > > > >
      > > > > you some hints on how to proceed. The source is for a Visual
      Studio
      > > > >
      > > > > project. The real meat is in 1802.cpp and 1802.h. You can find
      > > > >
      > > > > programs that will run and instuctions on my web site:
      > > > >
      > > > > http://www.geocitie s.com/ted_ rossin/Electroni cs/RCA/RCA. html
      > > > >
      > > > > One problem with many of the 1802 emulators that I tried is that
      > > > >
      > > > > they are not coded up for real-time operation. They tend to
      run as
      > > > >
      > > > > fast as they can which tends to be much faster than the real
      machine
      > > > >
      > > > > and varies based on processor speed. I use Windows timers to step
      > > > >
      > > > > my emulator at a periodic rate (I think every 50ms) for a tunable
      > > > >
      > > > > number of steps. This keeps the simulator speed constant across
      > > > >
      > > > > multiple machines. I don't have it perfectly tuned up but it does
      > > > >
      > > > > run within 10% of my real Elf system.
      > > > >
      > > > > The point I'm trying to make is to not make your emulator a giant
      > > > >
      > > > > while loop but instead write it such that it is a subroutine that
      > > > >
      > > > > maintains the state of the machine so that it can be called
      once per
      > > > >
      > > > > unit of activity. For example, you could model all the machine
      > > > >
      > > > > states and call the subroutine once per clock cycle. I choose
      to do
      > > > >
      > > > > it once per instruction but I maintain state as to the number of
      > > > >
      > > > > machine cycles executed (2 or 3 per instruction) . Machine cycles
      > > > >
      > > > > are 8 clock cycles.
      > > > >
      > > > > This also allows you to hook up devices to your emulator such as
      > > > >
      > > > > LEDs, keyboards or 1861 video chips.
      > > > >
      > > > > Good luck and have fun. I enjoyed the process and am now able to
      > > > >
      > > > > develope code for my 1.6 MHz Elf on a 3.0 GHz PC.
      > > > >
      > > > > --- In cosmacelf@yahoogrou ps.com, akshay parelkar <va7aax@>
      wrote:
      > > > >
      > > > > >
      > > > >
      > > > > > Hi Fans of Cosmac Elfs,
      > > > >
      > > > > >
      > > > >
      > > > > > I recently discovered this fancy little computer while
      searchig on
      > > > >
      > > > > the web. I dont have a Real Cosmac Elf yet(Have digital ones
      > > > >
      > > > > though).
      > > > >
      > > > > >
      > > > >
      > > > > > Lately, I have been thinking about writing up my own code
      (in C)
      > > > >
      > > > > to simulate the Cosmac elf. I dont expect this project to compete
      > > > >
      > > > > with the ones already available, just something with which I can
      > > > >
      > > > > undertand more about the 1802 itself and improve and exercise
      my own
      > > > >
      > > > > (rather limited) knowledge of C.
      > > > >
      > > > > >
      > > > >
      > > > > > Can somebody give some suggestions as to how and where I
      > > > >
      > > > > can/should start?
      > > > >
      > > > > >
      > > > >
      > > > > > Also, another idea rolling in my mind is, Would it be
      possible to
      > > > >
      > > > > build a replica Cosmac Elf based on a PIC or has anyone
      already done
      > > > >
      > > > > this?
      > > > >
      > > > > >
      > > > >
      > > > > > Thanks,
      > > > >
      > > > > >
      > > > >
      > > > > > Long live cosmac elfs!
      > > > >
      > > > > >
      > > > >
      > > > > >
      > > > >
      > > > > >
      > > > >
      > > > > >
      > > > >
      > > > > > [Non-text portions of this message have been removed]
      > > > >
      > > > > >
      > > > >
      > > > >
      > > > >
      > > > >
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      > > > >
      > > > >
      > > > >
      > > > >
      > > > >
      > > > >
      > > > > [Non-text portions of this message have been removed]
      > > > >
      > > > >
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      > > > >
      > > > >
      > > > >
      > > > >
      > > >
      > > > ----------------------------------------------------------
      > > > >
      > > > >
      > > > > No virus found in this incoming message.
      > > > > Checked by AVG.
      > > > > Version: 7.5.524 / Virus Database: 270.7.5/1705 - Release Date:
      > > > 03/10/2008 8:18 AM
      > > > >
      > > > >
      > > > > [Non-text portions of this message have been removed]
      > > > >
      > > >
      > > >
      > > >
      > > > ------------------------------------
      > > >
      > > > ========================================================
      > > > Visit the COSMAC ELF website at http://www.cosmacelf.comYahoo!
      Groups
      > > > Links
      > > >
      > > >
      > > >
      > >
      > > [Non-text portions of this message have been removed]
      > >
      > >
      > >
      > >
      > >
      > >
      > >
      > >
      ------------------------------------------------------------------------------
      > >
      > >
      > > No virus found in this incoming message.
      > > Checked by AVG.
      > > Version: 7.5.524 / Virus Database: 270.7.5/1706 - Release Date:
      > > 03/10/2008 6:17 PM
      > >
      > >
      > > [Non-text portions of this message have been removed]
      > >
      > >
      > > ------------------------------------
      > >
      > > ========================================================
      > > Visit the COSMAC ELF website at http://www.cosmacelf.comYahoo! Groups
      > > Links
      > >
      > >
      > >
      >
      >
      > [Non-text portions of this message have been removed]
      >
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