Re: [CAD_CAM_EDM_DRO] Troubleshooting a BTR

Roy J. Tellason wrote:

>On Saturday 07 August 2004 04:48 pm, Harvey White wrote:
>
>
>>On Sat, 7 Aug 2004 15:13:35 -0400, you wrote:
>>
>>
>>>On Saturday 07 August 2004 02:57 pm, Alan Marconett wrote:
>>>
>>>
>>>>Hi Steve, list,
>>>>
>>>>Might be older then 8250. How about the old AY5-1013? What was the
>>>>year of the controller?
>>>>
>>>>
>>>This would make sense if there was no CPU, as an 8250, etc. has
>>>registers that need to be set up while that one you mention is settable
>>>by way of DIP switches, if I'm remembering right...
>>>
>>>
>>that's correct, the 8250 needs to be programmed, the 1013 can be
>>programmed by switches, that's what all the extra pins are for.
>>
>>IIRC, there's going to be a baudrate generator on that, say a motorola
>>14411, for example. Look for a 1.8432 Mhz crystal, or a multiple of
>>that frequency, common baudrate use.
>>
>>
>I don't remember 14411, but I do remember a Motorola part with a number
>somewhere close that that did indeed use one of those frequency crystals.
>Looking in my card file I do indeed find one listing "MC14411P" and showing
>me that I salvaged one back in 1985. :-)
>

Ahhh - before my time, I'm afraid. :)
It's hard to find (free) documentation for these old chips online.

- Steve