Minor Tektronix success story. - test-drb@ccmp.vtda.org

17 Aug 1998

Hmmm... Is the 4046 the SCSI Floppy Disk/Hard Disk rack mountable unit?

Tony

...
  -----Original Message-----
 From: Joe [mailto:rigdonj@intellistar.net]
 Sent: Monday, August 17, 1998 11:55 AM
 To: Discussion re-collecting of classic computers
 Subject: Re: Minor Tektronix success story.

   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 @40,240: some bytes to specify the file   name.  But 
 if you type OLD @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 @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 @40,241:48,58,80,82,79,71,82,65,77,32,78,65,77,69,-13
WBYTE @63:
SAVE @8,1
WBYTE @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.