I agree, if this was strictly an S-100 board, the DB should never go there, it should be on the chassis with a ribbon back.
But I was thinking a little more universal, which is why I put 4 holes around the board for stand offs.
Someone could use the board as a stand alone product. But I'm looking at Murphy over there in the corner... he's talking to me. He says someone, someday is going to start mounting IC's from the bottom and when they get to this height, these misaligned holes are going to be a hassle. Dammit, he's right. If and when someone does want a DB, they will just have to hack the board with their dremmel like I've done in the past. Ok, the DB is out.
I'll look at the 80286 board. I don't think one little trace will get in the way... in fact, I might even use it for some chips? As you said, if it's a problem, it can be cut.
Now, what about the hole size? 42mil was the original size, I've reduced it to 38... but I think that's going to be a mistake, I want to return it to 42mil, thoughts?
Date: Sun, 2 Mar 2014 09:56:43 -0500
Subject: Re: [N8VEM-S100:2601] Re: Board Run: Unbuffered Prototyping
From: pbi...@gmail.com
To: n8vem...@googlegroups.com
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But I was thinking a little more universal, which is why I put 4 holes around the board for stand offs.
Someone could use the board as a stand alone product. But I'm looking at Murphy over there in the corner... he's talking to me. He says someone, someday is going to start mounting IC's from the bottom and when they get to this height, these misaligned holes are going to be a hassle. Dammit, he's right. If and when someone does want a DB, they will just have to hack the board with their dremmel like I've done in the past. Ok, the DB is out.
I'll look at the 80286 board. I don't think one little trace will get in the way... in fact, I might even use it for some chips? As you said, if it's a problem, it can be cut.
Now, what about the hole size? 42mil was the original size, I've reduced it to 38... but I think that's going to be a mistake, I want to return it to 42mil, thoughts?
Date: Sun, 2 Mar 2014 09:56:43 -0500
Subject: Re: [N8VEM-S100:2601] Re: Board Run: Unbuffered Prototyping
From: pbi...@gmail.com
To: n8vem...@googlegroups.com
I very much like what you'd done with the sea-flow.
Personally, I'd never put a DBxx directly on an S100 board. Instead use an IDC-type cable with a 2xN connector and ribbon . The DBxx belongs on the bulkhead. So I'm not enthusiastic about that change.
As for the LED, perhaps a placement consistent with what's used on the 80286 master/Slave CPU Board would avoid the (potential) card ejector handle. Or maybe just scrap it and let folks wire what they want, if they want anything at all? After all, they'll probably be bringing PWR/GND "around" for ICs anyway. So let them wire-where-they-will, rather than committing to that corner? (OTOH, they can always just cut the trace ...)
Personally, I'd never put a DBxx directly on an S100 board. Instead use an IDC-type cable with a 2xN connector and ribbon . The DBxx belongs on the bulkhead. So I'm not enthusiastic about that change.
As for the LED, perhaps a placement consistent with what's used on the 80286 master/Slave CPU Board would avoid the (potential) card ejector handle. Or maybe just scrap it and let folks wire what they want, if they want anything at all? After all, they'll probably be bringing PWR/GND "around" for ICs anyway. So let them wire-where-they-will, rather than committing to that corner? (OTOH, they can always just cut the trace ...)
On Sat, Mar 1, 2014 at 11:12 PM, Crusty OMO <crus...@hotmail.com> wrote:
Guys, Please find attached latest art work for this board.
I've done away with the 14 pin dips and let the "Sea of PTH" flow into that area.
Power runs through it.
I mixed in the terminations for S-100 bus to the lowest 2 rows of of the sea.
Look at top right, I added a DB connector, less the DB mounting holes.
I think it would be very handy to have this option, one can always put an IC over top the skewed pins if they don't want DB9. I'll keep the DB9 there unless it gets voted off the island (or sea).
It looks like it's ready to go... 2 questions still loom.
1. Position of LED,
2. Size of holes (I reduced to .038 from .042... I'm now thinking that was a mistake)
Cheers,
Josh
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