Minor Tektronix success story.

From: Joe <rigdonj_at_intellistar.net>
Date: Mon Aug 17 15:55:07 1998

  I just picked up a Tektronix 4041 computer. I think it's a general
purpose HP-IB instrument controller similar to a HP 9915. How close is it
to your 4052? I HAD a Tektronix 4046 disk drive unit for the 4041 a few
months ago but I traded it off (A_ S___!) Does anyone know anything about
the keybaords for the 4041? It uses a strange 4 pin connector. I've heard
that you can operate them from a terminal. Does anyone know anything about
this?

   Joe

At 07:14 PM 8/17/98 GMT, you wrote:
>A minor success story compared with some I read here, but I wanted to
>share it with you...
>
>This weekend I finally got my Tektronix 4052 graphics computer loading
>and saving on a Commodore 8050 disk drive. The problems:
>
>Commodore's weird handling of IEEE-488 protocol, especially with OPEN
>and CLOSE. This requires bit 7 (the 128s bit) to be set when sending a
>secondary address; bit 4 - usually the 16s bit of the address - tells
>the drive whether it's an open or a close.
>
>This was easily solved - the Tektronix WBYTE statement gives full
>control over such things.
>
>But the Tek is designed as a tape based machine. You FIND a file on the
>tape and type OLD to load it. The machine then resets and loads the
>program.
>
>On a disk, you WBYTE _at_40,240: some bytes to specify the file name. But
>if you type OLD _at_8,0: it asserts IFC during the reset, thus causing the
>drive to have forgotten all about your program by the time it comes to
>load it...
>
>So I toyed with the idea of cutting the IFC line in a suitable cable.
>But then I came across the APPEND statement. "APPEND _at_I/O address:line
>number" loads a program without resetting, renumbering it to start at
>the specified line. Neat.
>
>So I now have a program to display the directory of the disk, prompt you
>for a filename and APPEND the file on the end of itself. It then
>performs an INIT (initialise variables, IFC and things) and drops into
>the program.
>
>Saving is easier, so less automated. You type something like
>WBYTE _at_40,241:48,58,80,82,79,71,82,65,77,32,78,65,77,69,-13
>WBYTE _at_63:
>SAVE _at_8,1
>WBYTE _at_40,225,63:
>
>Not perfect, but it works. If anyone has an 8050 at the VCF, I'll
>happily demonstrate!
>
>Now, has anyone got a PET hard drive? And, for that matter, has anyone
>got a MUPET system for sale?
>
>Philip.
>
>
Received on Mon Aug 17 1998 - 15:55:07 BST