[Coco] OT: 63B09

[hhos at st-tel.net]

> I can across an NTE6809 processor and thought I would give it a try as a
> replacement for the 63b09.  It has an identical Pinot so I figured it may
> work.  I plug it in the socket, and I get nothing at all.  The external
> clock (4mhz) crystal does not even work, which on the one I am trying to
> replace does.  Is the IC bad, or is it a compatibility issue.

The datasheet I looked at
http://www.datasheetarchive.com/dl/Datasheets-23/DSA-444829.pdf
 for a NTE6809 indicated it was good to 4 MHz. This crystal frequency
would yield a 1 MHz operation clock on the E and Q outputs. The only
problem I can think of that would stop the crystal like that is if that
chip you have is actually a NTE6809E. Then the crystal inputs on the chip
would be connected to the TSC and LIC pins. Because there would be no
oscillator connected to the crystal there would be no clock, just as you
have reported.

You are probably better off to get a 63B09 or 63C09 for your replacement
part, though. The 68x09 has only a subset of the 63x09 family opcodes. If
the ROM uses any of the "undocumented" opcodes it could throw a pretty
good size wrench into the works for you.

>> On Thursday, October 20, 2011, Louis Ciotti <lciotti1 at gmail.com> wrote:
>> Off topic, but since the CoCo uses 6809s, figured someone on here might
>> know about this.
>>
>> I have a radio controller from circa late 80s that uses a 63B09 that I
>> think may be bad.  What can I use in its place and is there a source?
>>
>> The problem I am seeing is RN6(Pins 24-31) has some "noise" on the line
>> and the waveform is not exactly square like the rest of the data lines
>> when
>> observed with an oscilloscope.
>>