17 Aug
1998
17 Aug
'98
4:28 p.m.
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.