Image Map Image Map
Results 1 to 5 of 5

Thread: Tektronix 4051 Tape Emulator

  1. #1

    Default Tektronix 4051 Tape Emulator

    I've read with interest the recent 4051 discussions here and have noticed that a tape emulator has been mentioned. I too have recently repaired a 4051 and since the tape drive is not functional, I am looking for alternatives. I thought it would be nice to just throw a bunch of images on an SD card and access via the GPIB. I was working on a similar project for the HP series 80 machines so already have a microcontroller wired to an SD card and HPIB drivers. I was planning to work on this over the holiday break when I have some spare time. Is anyone else actively pursuing this? Does this sound useful or is there a better way? I'd prefer not to have to connect to another computer to load programs.
    Thanks,
    Bill

  2. #2
    Join Date
    Jun 2012
    Location
    UK - Worcester
    Posts
    2,152

    Default

    First of all, welcome to VCFED.

    Congratulations on restoring yet another 4051!

    I think it may have been Monty who mentioned about the tape emulator?

    It might be worth a www search for GPIB emulators before you make a start - as it is just possible that a unit for a Commodore PET either may work as-is or with a few modifications...

    I think this would be useful. I could use it on my NASCOM for example...

    Where are you based?

    Dave

  3. #3

    Default

    Dave,

    Thanks. I was glad to get it up and running.

    I used one 35 years ago while in college and always remembered what a cool machine it was.

    I am in the US.

    I'm not sure a general purpose emulator would work with the 4051.

    I've looked at the documents for the 4924 external tape drive and it has a very particular command set.

    The commands are identical to the internal tape drive commands - just directed at the GPIB via the @n: syntax.

    I'm thinking it would make sense to emulate the 4924.

    Bill

  4. #4

    Default

    Quote Originally Posted by oldmicros View Post
    I've read with interest the recent 4051 discussions here and have noticed that a tape emulator has been mentioned. I too have recently repaired a 4051 and since the tape drive is not functional, I am looking for alternatives. I thought it would be nice to just throw a bunch of images on an SD card and access via the GPIB. I was working on a similar project for the HP series 80 machines so already have a microcontroller wired to an SD card and HPIB drivers. I was planning to work on this over the holiday break when I have some spare time. Is anyone else actively pursuing this? Does this sound useful or is there a better way? I'd prefer not to have to connect to another computer to load programs.
    Thanks,
    Bill
    oldmicros,

    I started a thread on a Tektronix 405x GPIB flash device:
    http://www.vcfed.org/forum/showthrea...793#post518793
    and wired an Arduino NANO board to a GPIB cable and added a microSD flash card.

    Arduino code that I found for GPIB was all as GPIB master - so they could connect to GPIB devices.

    What we need is a GPIB device - and the 4051/4052/4054 BASIC instructions for GPIB work with primary and secondary address bytes to define the operation. Later GPIB equipment used text commands.

    I did some research in Tektronix GPIB documentation I had and that posted on bitsavers, and began a document specifying primary and secondary addresses we needed to support.

    Then I got sidetracked looking at how Tektronix supported the hierarchical file system in their floppy drive - imagining that we needed to support at least one level of directories so we can put the entire repository of files I have recovered from tapes and posted on my github repository for Tektronix 4050 programs:

    https://github.com/mmcgraw74/Tektron...-Program-Files

    Right now - I'm trying to write an Arduino program to stabilize my Star Wars BB-8, so I can have it ready to drive at the Star Wars Celebration in Chicago next April, so I have not made any further progress on my GPIB flash drive project.

    Monty

  5. #5

    Default

    Dave,

    Thanks. I was very happy when it was alive again! I used one back in college and always remembered how cool it was.

    Monty,

    Thanks for the link to your previous thread. Sounds like you were making good progress with this..

    I have looked at the 4924 docs and my first thought was to emulate that. It doesn't look like tape image files exist so these would need to be created from the separate program files.

    I wasn't aware that there was a GPIB floppy drive available. Your plan of emulating that may be a better way to go.

    Think I'll connect my existing circuit just to see what the bus traffic looks like. It's already got a monitor function programmed in.

    Thanks,
    Bill

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
  •