Image Map Image Map
Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: DEC 6502 Cross-assembly

  1. #1

    Default DEC 6502 Cross-assembly

    All --

    In a thread elsewhere in [DEC] (here: http://www.vcfed.org/forum/showthrea...still-relevant) dealing with historical uses for these machines, DougSnyder mentioned that Atari had used the PDP-11/20 to cross-assemble games. If you follow this trail, it indirectly leads to some stories here: http://www.jmargolin.com/vmail/vmail.htm

    The thread didn't dive into it, but I thought it might be an interesting topic. So, I did a little digging and found two interesting things. First, there was a 6502 cross assembler in the DECUS archive (ASM65, DECUS# 110520), but it doesn't seem to be archived anywhere. Then, I came across this book, "A Cross-assembler for the 6502 Microprocessor, with the PDP-11 as Host Computer and the SYM-1 as the Target Microcomputer" by Khin Nyan Chu. I can't find an ISBN, nor does it seem to be archived anywhere.

    I have an 11/23 in the basement and how cool would it be to re-compile an Atari 2600 game and run it on Stella...I think it would be a cool project.

    Rich

  2. #2
    Join Date
    Sep 2006
    Location
    Silicon Valley
    Posts
    1,813

    Default

    The Atari cross-assembler used by the arcade division is a set of MACRO-11 macros.

  3. #3

    Default

    That’s interesting. Does this code exist anywhere? I was intrigued how Gates & Allen used UUO on the PDP-10 for cross-compiling 8080 instructions, but I was never able to locate samples of how that would have been implemented. Different method, I know, but looking to learn something new

  4. #4
    Join Date
    Jan 2014
    Location
    Centero
    Posts
    6,874
    Blog Entries
    2

    Default

    Quote Originally Posted by RichCini View Post
    Going back to the cross-assembler, apparently there is a 6502 cross assembler on one of the DECUS tapes (#110520) called ASM65. I haven't been able to come up with it by Googling and the archive CD doesn't seem to have it. Any pointers?
    If I ever get proficient in PDP-11 (might just happen) I'll certainly write (port) my own. Of course, I'll probably write a cross-assembler for PDP-11 on 65xx first. And unless I suddenly find myself retired, (much less likely) don't expect anything to happen quickly.

  5. #5
    Join Date
    Jul 2014
    Location
    Rhode Island
    Posts
    1,116

    Default

    The RICM received an Intel 8008 cross assembler that runs on a PDP-8 with a recent donation.
    Member of the Rhode Island Computer Museum
    http://www.ricomputermuseum.org

  6. #6

    Default

    Quote Originally Posted by m_thompson View Post
    The RICM received an Intel 8008 cross assembler that runs on a PDP-8 with a recent donation.
    Ooh! Please share!

  7. #7
    Join Date
    Jul 2014
    Location
    Rhode Island
    Posts
    1,116

    Default

    Quote Originally Posted by antiquekid3 View Post
    Ooh! Please share!
    We haven't made an image of the paper tapes yet. We got two 8008 based systems too.
    Member of the Rhode Island Computer Museum
    http://www.ricomputermuseum.org

  8. #8
    Join Date
    Feb 2011
    Location
    NorthWest England (East Pondia)
    Posts
    2,082
    Blog Entries
    10

    Default

    Sadly much of the DECUS archive was thrown away. There are some items on Bitsavers, but this one appears lost. Cross Assemblers were pretty common place. for example, whilst it didn't have a 6502 the Mitchen Terminal System (MTS) which ran on an IBM mainframe contains cross assemblers for Intel 8080 and Motorola 6800 and 6809...
    Dave
    G4UGM

    Looking for Analog Computers, Drum Plotters, and Graphics Terminals

  9. #9

    Default

    Dave — that loss is partially what prompted this thread. I did look at several different versions of the DECUS archive on line (bitsavers is my usual first stop) and none had this program. I just didn’t know why it wouldn’t have been there. Sad to see that holes exist in the archive, though.

    Rich

  10. #10
    Join Date
    Feb 2011
    Location
    NorthWest England (East Pondia)
    Posts
    2,082
    Blog Entries
    10

    Default

    Rich,

    Well originally the DECUS library was a collection of physical media. From what I remember you paid DECUS for a copy of what you wanted which meant that no one other than DECUS had a complete library. The charges for a copy were not insignificant, so you only got a copy of what you needed, meaning not many copies exist. At some point DECUS discarded the whole caboodle and much was lost. I have no idea why they binned it, but that is why there isn't a complete on-line. Its very frustrating as a lot of interesting stuff appears lost.

    I know some of the missing stuff was mounted on one of the group servers, so it might be there...

    Dave
    Dave
    G4UGM

    Looking for Analog Computers, Drum Plotters, and Graphics Terminals

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •