"DoN. Nichols" wrote in message
...
On 2017-03-18, Jim Wilkins wrote:
"DoN. Nichols" wrote in message
...
On 2017-03-17, Jim Wilkins wrote:

[ ... ]

O.K. I was wondering whether it was the low yield at the board
level which accumulated such a high value. Toss in all of those
things,
and yes, 30K for a low production board is understandable.

I've built some fairly small custom instruments for which the customer
paid $50,000 or more.

...........
The "PADS" PCB design program I used was complex and disorganized
enough to need a week or two to learn. The instructors often had no
clue about the electrical issues I asked them about, like RF tuning
stubs and guard rings that their software saw as errors.
https://offlogic.wordpress.com/2009/...ery-very-much/

And the software is *always* right! Just ask it. :-)

Were their ways to *force* it to accept what you wanted?

Whoever wrote that web document did *not* like them. I won't
ask if it was you -- the writing styles seem different enough. :-)

The workaround was to draw free-form line items in copper and label
them the same as the net they touched so they didn't trigger spacing
errors (or ignore them).

The progam is powerful and difficult like Excel, with many tacked-on
features and non-intuitive menu paths. I use the free 2007 demo
version as my mechanical CAD program.

When engineers used my CAD workstations they stopped asking questions
after half a day on ViewLogic schematic capture, a week on PADS.

[ ... ]

Yes -- another difference between the 8080 and the 6800. (And
the 6809 took the relative jumps and branches to serious extremes,
with
the close ones all built into the opcode, and two layers of expanded
ones.

[ ... ]

Enjoy,
DoN.

I only went with the 8080 because the company gave me one and expected
me to build a computer with it. The analog test machine I helped
develop ran on a DEC LSI-11 and the memory tester used a TI TMS9900.
The market hadn't settled at that time.

The next places I worked used the MC68000 or the TMS320 DSP family,
for which I designed the custom DRAM controller.

The PIC seemed to be the popular choice for small tasks. It was fun to
play with so the engineers kept that part of the job for themselves
and gave me the boring parts like the backplane and calibration
modules.

The 8080 was good practice for designing small embedded systems
although it was too limited to be a general-purpose computer. I
shifted my focus to learning how to design add-ins for the PCs and
Macs that the lab inherited when the front office upgraded. You can do
a lot with the PC's parallel LPT port.

The Mac was difficult because plug-ins are supposed to have a driver
in ROM at the top of the slot's address block, written by an Apple
Certified Programmer. When I gave him the simple register model for my
16 bit A/D converter he quoted 3 months to write it. Instead I left
the card invisible and generated four lines of 68000 machine language
in LabVIEW to select a MUX channel and read the data when ready.

At that time Mitre allowed only MACs and SPARCs. We needed a note from
Jesus's mother to buy PCs for CAD workstations and then had to run
Novell NetWare instead of DOS on them.

-jsw