waggoner@dtg.nsc.com (Mark Waggoner) (10/07/89)
QUESTION 1. Does anyone have experience with any printed circuit board layout programs for the Amiga. I am interested in something that would be capable of laying out a board for the 2000 using socketed fine pitch part(s). What is fine pitch you may ask: |< .075 >| ___ o o o ^ | .20 | v | ______ o o o | | |<>| .025 o o o Any comments on available software would be appreciated. Feel free to email. QUESTION 2. If you needed a chunk of memory and one of your constraints was that it had to be completely within a 64K boundary; In other words the upper 16 bits of the address of all of the memory in the block must be constant, how would you go about doing it. The only ways I can see are to either: 1. Allocate more than you need, maybe 2X, and then figure out whether to start at the beginning or start somewhere in the middle. 2. Allocate what you need and if it doesn't fall within a 64K page, allocate again and keep hoping you will get what you want eventually. 3. Look at and mess with the free memory list directly - Undoubtedly a no-no. None of these seem very good. Thanks, Mark -- ,------------------------------------------------------------------. | Mark Waggoner (408) 721-6306 waggoner@dtg.nsc.com | `------------------------------------------------------------------'
billsey@agora.UUCP (Bill Seymour) (10/24/89)
From article <119@dtg.nsc.com:, by waggoner@dtg.nsc.com (Mark Waggoner):
: QUESTION 1.
: Does anyone have experience with any printed circuit board layout
: programs for the Amiga. I am interested in something that would
: be capable of laying out a board for the 2000 using socketed fine
: pitch part(s). What is fine pitch you may ask:
:
: |< .075 :|
: ___ o o o
: ^ |
: .20 |
: v |
: ______ o o o
: | |
: |<:|
: .025
: o o o
:
:
: Any comments on available software would be appreciated. Feel free
: to email.
You can handle that fairly easily with Pro-Board. You won't be able
to route trace directly between the pads at .075 spacing, but there's plenty
of room for three or four traces between the .200 spacing pads. Pro-Board
allows you to create components on a .001 grid, so it's fairly simple to
handle what you need here. Note that the major limitation I've run into is
the .012 trace width minimum. That means that no matter what you do, you won't
be able to run two traces between pads on .100 centers. You're also limited
to .055 or larger pads and .050 vias. This makes for some interesting
topology problems when routing a complex board... :-) I've successfully
done six layer boards (the package only supports four, but I have two Amigas.)
And I supposed I could play with routing in 2X to get .006 traces... (Maybe
I'll give that a try later... I could edit the components to use .100 pads
to simulate .050. I'll let you know how it works.)
: Thanks,
: Mark
:
: --
: ,------------------------------------------------------------------.
: | Mark Waggoner (408) 721-6306 waggoner@dtg.nsc.com |
: `------------------------------------------------------------------'
--
-Bill Seymour ...tektronix!reed!percival!agora!billsey
...tektronix!sequent.UUCP!calvin!billsey
Bejed, Inc. NES, Inc. Northwest Amiga Group At Home Sometimes
(503) 691-2552 (503) 246-9311 (503) 656-7393 BBS (503) 640-0842