Article View: comp.sys.atari.st
Article #37725electronics help sought
From: Barbara Hicks
Date: Wed, 05 Apr 1989 04:34
Date: Wed, 05 Apr 1989 04:34
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1803 bytes
Hello fellow netlanders, I have need of some electronic assistance. The
problem is as follows:
I need a board for an ST that will monitor the address lines and FC0-FC2 and
perform a range check for each User Data or User Instruction fetch. I would
like to have two separate ranges, one for Data and one for Instructions.
Ideally I would like to check all 24 address lines, but I would settle for
just the upper 16. If the address is out of range on either type of fetch,
a bus error will be generated. The bus error MUST occur fast enough to prevent
a data write from actually occurring. Also, I plan to grab the address lines
from the MMU and I would like to have the whole works fit under the shielding.
Oh, and last but not least, these ranges must of course be programmable via
software (like writing to $ffxxxx or some such thing). If anyone out there has
any thoughts on the matter or any thoughts as to where to find some help,
please Email me and I will summarize for the net if there is sufficient
interest.
I do not expect to find this device to be in existence and I am quite willing
to hack it all together, but I have not played around with electronics much
since high school. I don't know what wonderful chips are available these days
and I would welcome any suggestions.
Thanks much,
-- Barbara (bjhicks@trillium)
PS please don't hesitate to mail me if you have any advice as I only have this
account for another few weeks.
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!watmath!watdragon!trillium!bjhicks From: bjhicks@trillium.waterloo.edu (Barbara Hicks) Newsgroups: comp.sys.atari.st Subject: electronics help sought Message-ID: <13050@watdragon.waterloo.edu> Date: 5 Apr 89 04:34:34 GMT Sender: daemon@watdragon.waterloo.edu Distribution: comp Lines: 29