MOTM

a) the new connector board MOTM-995 is at wave solder (along with 25 
MOTM-960s!). This *replaces* the
'stand-alone' MOTM-900PCB board (it is still integral to the MOTM-900). The '995 
has 4-pin, 6-pin and 3 of the
.com MTA-100 connectors. The function is to convert MOTM<>.com without fancy 
harnesses.

In order to power .com modules (cough), you *must* use a MOTM-950 (NOT a '900). 
Many
.com modules use +5V.

I will add this to the existing order form on Sunday. I will be able to ship 
beginning Sept. 26th.

b) I am starting the pc board layout of the CPU/DAC board for the '650 today. 
This is a 4-layer SMT board.

There is a change in how 2 MOTM-650s can daisy-chain to form an 8-voice system. 
Originally I was going to
use Ethernet patch cords. But I don't have the room. So I am using 14-conductor 
ribbon cable. In order
to use 2 MOTM-650s in 'sync', all you do is connect the 2 together. I will have 
cables available.

There was a scheme in place (but not yet coded) to allow up to 4 to be connected 
(16-voices!) but the
limit is now 2 (8-voices). Of course, you can have *multiple sets* of 2 
MOTM-650s.

If you haven't placed an order for one, now is a good. time. I won't charge your 
credit card until it's ready
to ship. This allows me to plan ahead in terms of the # of units going out the 
first 2 weeks.

c) For newbies: just to let you know the schedule for the upcoming months.

Last day to "cash in" module points: Nov. 15th (see the PDF catalog)
Last day to place kit orders for 2005 delivery: Dec. 1
Last MOTM work day: Dec. 15th
Return from holiday: Jan. 15th

MOTM modules make the ideal holiday gift :) Just don't wait until Dec. 10th to 
order!

Paul S.

> b) I am starting the pc board layout of the CPU/DAC board for the '650
> today.
> This is a 4-layer SMT board.

It must not be all SMT if it has 4 layers...   :-)

--Adam

> It must not be all SMT if it has 4 layers...   :-)

I'll disagree. Just because there are multiple layers doesn't mean there are
through-hole parts.
--
john

(So... does X or O get the square? ;-)


----- Original Message ----- 

From: "Adam Schabtach" <adam@...>
To: "'MOTM litserv'" <motm@yahoogroups.com>
Sent: Saturday, September 17, 2005 6:38 PM
Subject: RE: [motm] Update/MOTM-650/MOTM-995


>
> > b) I am starting the pc board layout of the CPU/DAC board for the '650
> > today.
> > This is a 4-layer SMT board.
>
> It must not be all SMT if it has 4 layers...   :-)
>
> --Adam

> > It must not be all SMT if it has 4 layers...   :-)
> 
> I'll disagree. Just because there are multiple layers doesn't mean there
> are
> through-hole parts.

[drifting off topic here]

I suppose I should have clarified, although I thought a smiley would
indicate that I wasn't 100% serious.

I'm currently starting to consider using SMT for my own DIY projects, and
hence am curious about such things as a 4-layer board that uses SMT
components finding its way into a MOTM module. I understand that the
connectors must be through-hole, and that the remaining components can all
be SMT (as Paul described). What I'm puzzled by is why four layers are
necessary, and how they are utilized. I assume that vias are used to make
transitions from one layer to another, but it still surprises me that four
layers are necessary for a CPU, the DACs, and associated support devices. I
imagine that it is because of the density of the board, given its small
size.

The other thing I'd like to find, and have googled for without success, is
something which tells me what SOP, SSOP, SOIC, TQFP, etc. mean in terms of
actual size, lead spacing, etc. I'm beginning to think I'll have to order
one of each from Digi-Key just to have a frame of reference.

--Adam

I believe the two inner layers are for power and ground.  Am I right, Paul?

-Richard Brewster

Adam Schabtach wrote:

>I'm currently starting to consider using SMT for my own DIY projects, and
>hence am curious about such things as a 4-layer board that uses SMT
>components finding its way into a MOTM module. I understand that the
>connectors must be through-hole, and that the remaining components can all
>be SMT (as Paul described). What I'm puzzled by is why four layers are
>necessary, and how they are utilized. I assume that vias are used to make
>transitions from one layer to another, but it still surprises me that four
>layers are necessary for a CPU, the DACs, and associated support devices. I
>imagine that it is because of the density of the board, given its small
>size.
>
>The other thing I'd like to find, and have googled for without success, is
>something which tells me what SOP, SSOP, SOIC, TQFP, etc. mean in terms of
>actual size, lead spacing, etc. I'm beginning to think I'll have to order
>one of each from Digi-Key just to have a frame of reference.
>
>--Adam
>
>  
>

*shameless-off-topic-self-promotion*

If you're in the bay area please come to the next San Francisco Dorkbots 
meeting (http://dorkbot.org/dorkbotsf/)  I will be (really, finally got my 
shit together) doing a live demonstration of assembling a surface mount 
board, as well as discussing various issues a DIYer might have trying to 
do so at home. I would love to meet some fellow MOTMers at the next 
meeting!

--mikes

On Sun, 18 Sep 2005, Adam Schabtach wrote:
> [drifting off topic here]