I've been up to:
(101 things to do with a dead ISA network
Despite the often debilitating pain I suffer,
I've manged to get a few things done. These pictures are here mainly
so a few friends can see this stuff but if you're curious here's
This is a real rough and ready page because
I'm suffering badly right now but I wanted to get these up so take
them as you find them.
THE ELECTRIC CHAIR. At the end of last year
Jaycar had all their stocks of interactors going out for 10 bux
a pop. An aura interactor is essentially a mini sensoround driver
and amp. It was designed primarily for games heads and to work with
computers and games consoles. I belive they cost a lot of money
when they were first out but no-one wanted them. They had bought
up huge stocks of them and couldn't off-load them. Eventually, some
years later they ended up almost giving them away.
There are two models. A back pack model which
you strap on and a cusion model which is designed to go on the back
of your chair. The one you see here is actually the back-pack model
bolted to the back of my "Comfie Chair." tm. I have another
cussion one as well but it turns out that it was less than comfortable
to use. So what I decided to do was bolt the back-pack version (Minus
it's straps) to the back of my chair and then arrange for the cabling
to come down from the ceiling.
What I needed was some kind of flexible goose-neck
or conduit and a way of guiding it so that it didn't become tangled
or get in the way. Enter one Paul Perry. Paul cleaned out his lab
one day and found all this junk. Knowing that I find junk better
than sex (Well better than any sex I've ever had. Including with
myself.) he sent it to me. In amongst that pile of junk was this
hose thing. We still don't know if it was of medical origin or perhaps
part of an old hand-held shower. But it was perfect. So that's what
this is all about. Showing Paul how it got used.
The chair it self is a severely modified
office chair. I bolted the head rest on myself and used industrial
strength brackets so I could lean right back and listen to music
etc. Or I could sit up and work at the computer. The amplifier/driver/filter
thing can be seen bolted to the head rest. I can reach round and
adjust it if need be. The cable and it's snake go through a piece
of engineered conduit which is also bolted to the back of the chair
as a guide. I intend to make a housing so you can't see the cable
hanging in the back like that at some point and also a spring mechanism
that encourages it to retract.
The interactor is literally kick-ass. Subwoofers
are nice but this thing can give you a massage. Before I built this
it took me about a month of experimentation on placement. Bolting
it to the back of the chair seemed about right although I did consider
bolting another under the seat as well. No need really. And it leaves
the cussion to go freelance for that special friend.
All this got me thinking of those sex machine
things. How to build something a bit better than a dildo driven
by various old mix-master parts. Although I did look into it, there's
no point really since there's a severe shortage of volunteers to
beta test such a thing round here. But trust me, If I could put
into practice what I have in mind, it would be the ultimate in tele-dildonics.
But I digress.
Moving right along we come to the many can
varied uses of an old ISA network card. Actually 28 brand new perfectly
working old ISA network cards.
As many of you already know I've been researching
my S/PDIF problem. This saga has been going on for 2 years and has
enough intrigue, and back stabbing to make a politician feel right
at home. I'll save that story for some other time. Perhaps when
I've got a fuck of a lot of other time. But needless to say I've
discovered a few interesting things. And I have to thank Steve Ridley
and and Roman Sowa in particular for their help in this research.
Simply put. it turns out that you can use
the same transformers that you'd find on a 10base network card as
S/PDIF or AES/EBU transformers. There's quite a lot of choice too.
Because of the complexity of the problem, I knew I'd need quite
a few of them so when I saw someone selling a box of brand new SMC
ISA 10baseT/2 NICs on eBaY I jumped. There's far more than I need
here and taking up far too much room. So I sold some of them back
on eBaY in pairs. Mainly at a loss per unit but it did offset the
cost of the original purpose a little bit.
One of the cards is shown in the photo below.
There are 3 transformers on these cards. One is for the 10baseT
side. Another is entirely for the 10base2. But a third is used as
a DC to DC converter to produce an isolated negative 9 volts. This
is used as some kind of VEE supply for the 10baseT collision chip.
Which actually lives outside of the isolating transformers on the
physical network side.
This transformer is particularly interesting
since it's essentially just another pulse transformer but it has
2 secondary windings. (Or two primaries depending on how you look
at it) There is a bit of weirdness here with a pair of chokes thrown
in series for good measure but in this particular case, they are
bipassable. What that means is that this can be usedto
take 1 S/PDIF or AES/EBU line and split it into two.
The 10BaseT transformers themselves are a
little tiny SMD affair. Single block with three transformers in
it. Each having a 1:1 ratio. So you have 3 for the price of one.
Finally there's a dual 1:1 transformer for
the 10Base2 (RJ45) But the fun doesn't stop there. There's also
a small serial EEPROM. A 20 meg crystal. CMOS static RAM. Numourous
SMD components to raid of need be. Not to mention these kinky RJ45
sockets with a pair of LEDS built in.
So for starters, I've used the triple 1:1
SMD transformer for an I/O for one device and a feed from another
computer. It just so happens that 3 is exactly what's required for
this run. To mount the SMD I used a piece of my custom matrix board.
The pads are standard 10th inch spacing so I ground off the pads
between the two end ones. Then I could solder the 4 end pins of
the SMD down SMD style. And using Kynar wire I wired the pins to
The Posts are there to make it easier to
solder some rather dificult to work with, 75ohm cable to. The other
side of the transformer has a bit of ribbon (IDC) cable with some
internal RCA connectors on it. These go into the back of the digital
audio patch bay. A fancy name for an RCA patch panel but distinct
because it's designed for handling digital audio and not analogu
A small word about that. I find it difficult
to refer to it as S/PDIF at this point. Nor is it really AES/EBU.
It's kind of a mixture of the two. The reason for all this trouble
is that S/PDIF from most devices is not floating. That is to say
that the ground of the RCA is at chassis ground potential. Since
in most cases, the analog audio is running paralell to the digial
audio, this could have potentially noisy consequences should a ground
loop develop between the two. So whilst it may be one or the other,
I want to isolate it with pulse transformers in order to prevent
that from happening.
The other reason is that it's just too hard
to patch AES/EBU easily. Even if I could afford 16 SLR sockets and
their associated patch cables. the thing would be fucking huge!
And to do all this electronically at this point would be a total
head fuck. Having said that, an electronic patcher is on the cards
but is not an immediate problem. When I do get to that, I'll make
it all balanced and isolated and it should kick much ass.
But for now though, I just want to see if
I can get this network up and running.
There is one other major consideration. And
this whole thing could be in vain. But this isn't entirely of my
making. I was supposed to get a system that would allow me to conect
all this stuff together asynchronously. It took Yamaha ages to get
back to us on whether this AES/EBU podule for their digital mixer
would do the job. They assured us it would. Unfortunately it doesn't.
In fact it's pretty lame. Through circumstances beyond my control,
there's fuck all I can do about that.
In order to make this work I really need
to build an external 5 channel sample rate converter. Easier said
than done but I'm still looking into it. In the mean time, the only
way I'm going to be able to get anything working is to hope that
the mixer can pump out word-clock and that all devices in the chain
can lock to it. Unfortunately the AWE32 has no input so the real
fun part starts right there. In that the AWE has to provide the
master clock for the rest of the system. And that in it self is
a scary as fuck thought.
But to that end I've built a proper isolated
and cleaned up digital output for it. I'll further clock that through
a TBS card and finally out to the desk. It's probably not well appreciated
that although this introduces word delays through each system, it
also cleans up any jitter in the clock. So with a bit of luck I
might get away with it. Because if I don't I'm pretty much shit
out of luck.
The board you see in these very fuzzy pictures
will obviously need to be cut to size yet. It'll be mounted somewhere
in the back of the patch bay and that will hopefully take care of
For another sync problem, I'll use that rather
special transformer mentioned first above. Because I'll need to
split S/PDIF output in two in order to distribute sync. Many of
these systems don't actually need a digital audio input feed other
than this. So the complexity of all this shit has been blown right
out of all propotions thanks to a dud product.
Finally in the midst of all this, I found
a little mount thing and I was sick of losing my various rotary
tools. So I've now got the first one clipped to the side of my bench
lamp. I'll try and find something to bolt to the other side to hold
the other such tools and keep the wiring neat and off-the-bench.
Where I don't have to seach through all the clutter all the time.
And that's it for now.