From: iking@killthewabbit.org (Ian King)
Subject: [pups] roll-your-own-unibus boards?
Date: Mon, 19 Jan 2004 23:03:35 -0800 [thread overview]
Message-ID: <007201c3df23$858c9c20$f10010ac@dawabbit> (raw)
In-Reply-To: <003801c3df20$2ad8baa0$eb8ca140@ca.sco.com>
BTW, there's a company called Douglas Electronics (http://www.douglas.com) that
sells DEC-style breadboards; I've purchased a couple of extenders from them, and
they were of good quality and promptly shipped. -- Ian
----- Original Message -----
From: "Michael Davidson" <michael_davidson@pacbell.net>
To: "Brad Parker" <brad at heeltoe.com>; <pups at minnie.tuhs.org>
Sent: Monday, January 19, 2004 10:39 PM
Subject: Re: [pups] roll-your-own-unibus boards?
----- Original Message -----
From: Brad Parker <brad@heeltoe.com>
>
> Does anyone have any thoughts on how hard it would be to make a unibus
> board which is an IDE controller?
It should be very simple.
Several people have built IDE controllers for the QBUS.
ftp://digital.dp.ua/DEC/ata/README.txt
http://www.chd.dyndns.org/qbus_ide/
A unibus controller will be very similar except for the obvious
differences in the bus interface.
> I've never looked at unibus controlleqr schematic, but plan to. I'm
> assuming much of the old ttl can be sucked into something like a Xilinx
> coolrunner CPLD...
Yes, but assuming that you are only implementing programmed i/o
there will be so little logic involved that you might as well just use
discrete TTL.
In fact, DEC used to make single height modules which did address
selection and interrupt control (M105 and M7821). If you could find
a pair of those, your work would be almost completely done for you.
> I also assume it's reasonably straightforward TTL, and at (by today's
> standards) slow speed... true?
Yes - very straightforward.
>
> Any hints, or gotcha's as far as fabrication or interface? Has anyone
> done this (in the modern day, that is :-)
Yes, make sure that you use appropriate bus transceivers, In particular,
make sure that your bus drivers conform to the unibus spec, can sink
sufficient current, and do not have rise times that faster than the spec
allows.
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next prev parent reply other threads:[~2004-01-20 7:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-01-19 23:38 Brad Parker
2004-01-20 0:35 ` Johnny Billquist
2004-01-20 6:39 ` Michael Davidson
2004-01-20 7:03 ` Ian King [this message]
2004-01-20 13:58 ` David Evans
2004-01-20 9:22 ` Jochen Kunz
2004-01-21 16:50 ` Brad Parker
[not found] <jkunz@unixag-kl.fh-kl.de>
2003-05-07 21:16 ` [pups] Tektronix 8560 with PDP-11/23 CPU running TNIX (UINX) Jochen Kunz
2003-05-07 21:32 ` Gregg C Levine
2003-05-08 21:03 ` David W. Talmage
2003-05-09 6:52 ` Jochen Kunz
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