HP-65 goes on hold after reading a card

[albertofenini]

Thanks Tony
I think I only have the Display Section of that document
Can I have it all ?
I understand there is a lot of effort put in that document and I would truly understand if it's not coming for free
take care !

(11-16-2020 10:12 AM)teenix Wrote:  

(11-16-2020 09:46 AM)albertofenini Wrote:  but what is WE for ?

What documentation could we read (easy to understand) to better understand the functioning of this ?

WE is write enable. In the last image you can see that the signal went low to tell the sense chip that a write is required. That signal stays high for a read.

The low signal tells the sense chip that its internal buffers are going to be used to get data from the CRC chip and write it to the card.
The high signal tells the sense chip that its internal buffers are going to be used to get data from the card and send it to the CRC chip.

The image came from the Classic Notes PDF and there is some more info and oscilloscope traces for card read/writes.

cheers

Tony