Do you have a Tektronix 4010? Want a screen capture for it?
legalize at xmission.com
Thu May 15 15:27:14 CDT 2008
In article <515507.71579.qm at web82706.mail.mud.yahoo.com>,
Bob Rosenbloom <bobalan at sbcglobal.net> writes:
> Mine gives a usable image. There's not much contrast, but
> it's better than nothing. Capturing the image and cleaning it
> up in photoshop would be worthwhile. I believe my paper is
> from 1981.
OK, since you're interested, I'll go into a little more detail of what
I was thinking...
In the 4010/4014 terminals (and probably more, but I've only read the
service manuals for those two) there is a little bit of additional
circuitry that is installed into the terminal to support the printer.
This is the "-1" designation, i.e. 4010 is just the terminal without
printer circuitry and 4010-1 is the terminal with the printer support
circuitry. This terminal circuitry was only available from the
factory and not as a user-installable option AFAIK.
As I understand it the 4631 hardcopy unit is entirely an analog
circuitry affair. It generates three input signals to the terminal
and the printer support circuitry in the terminal generates a response
signal. The hard copy unit generates a "slow ramp" that scans the
tube from top to bottom and a "fast ramp" that scans from left to
right many times within the slow ramp. This in effect runs a scanning
beam in a raster type pattern across the type. The third signal
generated by the hard copy unit is a sense signal that is sent to the
terminal to read out the tube at the location indicated by the current
values of the slow and fast ramps. The terminal sends a response to
the hard copy unit, which it uses to turn into an image on a drum with
My idea was to either a) cannibalize the ramp generation circuitry out
of the 4631 and interface that to a microcontroller that digitized the
response from the terminal, or b) use the ramp generation circuitry
diagrams for the 4631 to create an equivalent modern circuit driven by
the microcontroller which digitzed the return value from the terminal.
The microcontroller would probably use USB to attach to a host or
something like that. So you would press your hard copy switch on the
terminal and the microcontroller would scan through the tube by
generating the fast and slow ramps, digitize the responses and turn
this into a bitmap that would be available to the host.
Presto! Screen capture from your 4010-1/4014-1.
A followon idea would be to create the necessary printer support
circuitry in the terminal using the service manual schematics so that
people could "upgrade" their 4010 to a 4010-1.
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
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