New batch of pdp8 OMNIBUS to USB interface! Please Read and react!

Philipp Hachtmann hachti at
Wed Feb 15 07:55:54 CST 2017

On 02/15/2017 12:45 AM, Alan Hightower wrote:
> Not sure if you are aware, but FYI - Malcolm MacLeod with some
> involvement from Kyle Owen, Jack Rubin, and others ported your code to a
> ATF1508 CPLD with a minimal test board.
Oh, ah! I looked into their github and the
There is a copy of the GPLv3 and as it looks no source code. And no hint 
that they used code from me.

That would NOT be ok!!!

Even if I have disclosed the source code, I have not licensed it under 
GPLv3 or put it into the public domain. It's a copyrighted work and I am 
the author. And the code is currently not licensed to anyone. And nobody 
but me has the right to license that code or parts of it to anyone.

That rant only to be clear... How something like that should happen:

1. Ask the author to license the stuff under a free license like GPL
    (I probably would do that!)

2. Start own project, copy and reuse as much or little as desired.
The new project's license *must* be compatible to the license of the 
used other code.
You have to mention the original author ("based on ... by...", "in parts 
based on ... by ...").

>  I believe the longer term plan
> was to make a full featured community project from it, but it's stalled
> a bit atm.

Why?!? To have a single board KL8E replacement? Which it actually is.

OmniUSB's strong points are the following:

- HIGH speed
- No baudrate setting
- Direct USB connection
- Special instructions to use really tight loops.
- USB FIFO solution implicitely double buffered AND locked on both 
sides: As long as you obey the teleprinter flag on the 8, you cannot 
create a buffer overrun and lose data. On the PC's side you access the 
device with usual blocking I/O. You can't write more data when the PDP8 
has not read from the FIFO. Therefore no single byte lost without 
thinking about it.
Example: PDP8 does a disk dump. PC program is stopped. The pdp8 waits.
Example: PC is sending a huge block of data to the pdp8. It just writes 
as fast as possible. The pdp8 is stopped for an our during the 
transmission. No byte is lost.

Using traditional RS232 somewhere in between is just stupid bullshit. It 
completely spoils the beauty of the idea.

Of course one could add an FTDI 240x FIFO (NOT!!! NOT!!! UART!!!!) to 
the design - then it would be equivalent to OmniUSB.

But why should one make another design? Through hole parts?!? We're 
living in the 21st century! The company where I want to bring the stuff 
for soldering just told me that they usually don't stock that old and 
clumsy 0805 components by default...

Soldering a 200 pin TQFP is easier than doing some wire wrap connections 
and takes 4 minutes if you are UNexperienced. SMT soldering is easier 
than THT if you have done it for more than one half hour! (Of course 
with SMT you're on the way to really difficult stuff, but that's not 
part of the discussion)

They just should have asked me about cooperation :-)

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