Re: Results of Uthernet testing with Apple IIe and SN74LS245N

[mwillegal <mike@willegal.net>]

Hi,

PC suffix means plastic DIP package to Fairchild and Moto and perhaps others
N suffix means plastic DIP package to TI and many others.

So difference is more likely variation between manufacturers, which should not be very significant for LS series parts.  Note that differences between the data sheets can be due to variations in manufacturers qualification process.  The package type has little bearing on chip performance.  Another option to solve the problem may be to look at substituting a different technology pin compatible part, which has more margin for this application.

Regards,
Mike Willegal

On Saturday, April 14, 2012 7:26:28 PM UTC-4, D Finnigan wrote:
> Some people may remember back in November I was testing the Uthernet on my
> unenhanced IIe and II Plus to see if I could get it to work reliably with
> Contiki and ADTPro. I found that I had to remove almost every other card in
> order for it to work.
> 
> About a week ago, Glenn Jones told me that another Uthernet user was having
> a similar problem. He noticed that some cards had a 74LS245PC instead of a
> 74LS245N. It turns out that replacing the PC with the N solves the problem.
> 
> Complete notes in my blog: 
> 
> Part 1- http://www.macgui.com/blogs/?e=383
> 
> Part 2- http://www.macgui.com/blogs/?e=384
> 
> -- 
> ]DF$
> Mac GUI Vault - A source for retro Apple II and
> Macintosh computing.
> http://macgui.com/vault/