At 00:20 1/01/99 +1300, you wrote:
>Applies also to 16c74.

Oh, of course. For the same project I was actually using a mix of '64s,
'65s, '74s and I think even a 774 got in on the act accidentally. No need
to change any settings either.

If you want to know how to substitute JW parts have a look here for info:

http://www.pipeline.com.au/users/newfound/knowledg.htm

Regards

Jim


>Jim Robertson wrote:
>> Hi Folks,
>> Here is an interesting PIC lesson I just learned the hard way.
>> I am developing  new programmer firmware and using a 16C64 chip.
>>  Because the PCB  is only  single-sided, I only connected one of the
>> two VDDs to save headaches with the track layout.
>> Everything seemed ok  until I tried  to program 5x parts.
>> All of a sudden it would crash most times a "000" was to be programmed.
>> After stuffing around adding caps here and there, swapping chips,
>> regulators, and resorting to a fair array of unrepeatable verbal
>> incantations, I finally decided to connect the "other" VDD and voila! it
>> worked 100%
>> Ok, so I've learnt my lesson, don't cut corners with the PICs power rails.
>> So, if like me, you are tempted to only connect one VDD or GND, perhaps
>> this cautionary tale may help change your mind.
>>
>> Jim
>>
>> --------------------------------------------------------
>> Jim Robertson
>
>--
>Steam engines may be out of fashion, but when you consider that an
>internal combustion engine would require recovery of waste heat by
>transfer just before top dead centre then fashion becomes rather
>redundant, USE STRATIFIED HEAT EXCHANGERS ! and external combustion.
>
>You heard it first from: Graham Daniel, managing director of Electronic
>Product Enhancements.
>Phone NZ 04 387 4347, Fax NZ 04 3874348, Cellular NZ 021 954 196.
>
--------------------------------------------------------
Jim Robertson
Email: newfound@pipeline.com.au

http://www.pipeline.com.au/users/newfound
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