On Tuesday, July 14, 2015 at 4:57:07 PM UTC-7, Jeff Albrecht wrote:
>
> On Tuesday, July 14, 2015 at 11:54:21 AM UTC-7, monahanz wrote:
>>
>> Those IDE boards are in fact a very simple boards. Essentially you are 
>> just talking to a 8255 three port chip.   If you cannot write,  you need to 
>> determine where the log jam is.  Using a simple logic probe determine if 
>> the chip CS* lines is going low with a write. If WR* is going low etc.  
>> Single step through a simple continuous write loop in RAM. Eg:-
>>
>
> These three screen captures are from my Owon DS7102V connected to pin 23 
> of GAL 1. The test computer is a IDE/CF v3 card in a CCS Z80 running it's 
> ROM monitor. Similar results were obtained from A CompuPro ZPU running DDT 
> under CP/M. I don't specifically remember seeing the ?glitches? when I ran 
> this simple test on an Altair when I began this theread.
>

I guess that ?glitch? is not to worry. I seem to have a clean CS on pin 6 
of the 8255 with the test loop running with IN or OUTs in the loop.

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