'wasting' 35 uSec ...

[Michael Cheponis]

Bill wrote:   "I see you are using dpy,

iohs the way they should be.. do some computing while the display is
wasting 35usec to draw a dot. Nice."

I just about fell over in my chair!

Having worked on the Type 30 in excruciating detail, knowing pretty much every wire in the standard 30G config (we removed the Type 33 cards so as not to make the debugging more complicated) --- and even simulating the deflection amp in MicroCap-12:  https://drive.google.com/file/d/1n-fXHXQdVv6vhb3Ku9TL19kr_8omnJpe/view?usp=sharing  well...

I'll bottom-line this: when Ben Gurley designed the Type 30, it was at the very cutting edge of what was possible for a mass market point-plot display.  The electrostatic display is clever by gum, and the precision of the electronics to achieve 10 bit x 10 bit display was, for the time, extraordinary.

The 'extra' time is required for the electronics to settle down.   Now, I know Bill is a "6-1" (as we called them), and so he knows what RLC is an how that works!

(I also know Bill was joking, so I'm ribbing him back.)

I have come to appreciate what an incredible design the Type 30 was for its time.  It's a testament to the guys (mostly) of that generation - they had the Right Stuff.

And yes, the only 'sane' way to maximize display performance is to dpy and then do other stuff and by the time you're ready to dpy again, enough usec have passed that you're good to go.   You get 20K points per second -- if you know what you're doing....  

-Mike

[Bill E]

It was quite remarkable for the time. I remember seeing a sentence in one of the hardware manuals about there being an airflow sensor to keep power being turned on to the deflection drivers unless there was airflow. The comment was something like 'overheating will destroy the power transistors which cost $600 to replace'. Wow, that was insanely expensive back then. But, they were silicon, not germanium. Must have been very early use of them. The precision resistor network for the D/As must also have been very expensive.

Bill