Hitachi HM6116ZP-4 CMOS RAM Datasheet

[blueroomelectronics]

Nice work on the Z80.
Is the keyboard made of paper?

 

[kchriste]

Thanks, it was my final year project at BCIT. Yes, the part you see is a piece of tape covered paper. The actual keyboard was one scavenged from an old calculator; the kind with metal popples on a PCB. I drew my custom buttons on a piece of paper with colored pens, covered it with clear tape for durability, and glued it on top of the popple PCB. The display was robbed from the same calculator.

 

[Nigel Goodwin]

Nigel,
I checked my old Z80 project which I built in 1989. I think I have changed the batteries once or twice and the RAM data is still valid today! I'm powering two 6116's with a pair of AAA batteries:

As far as I remember, mine used a NICAD, and the life of those is VERY limited! - I'll try and dig it out and post a picture

 

[Krumlink]

So this is what I think:
1. Data input into the I/O lines.
2. Switch Addresses with the Address inputs with Binary, aka address line 1 in 000 0000 0001 and 37 in 000 0010 0101 correct?
3. All this will be configured with the Write enable and the Read enable stuff, which is easy. I believe I gotz it correct?

(Then to keep the chip alive I enable CS (Chip select) and GND, or so I think?

 

[kchriste]

Yes.
Set your address lines.
Put the data you want to load on the IO lines.
Make CS low. ( WR and OE are already high )
Make WR low and then high again.
The data is now stored at one address location.

To read the data back:
Set your address lines the same as above.
Make CS low. ( WR and OE are high )
Make OE low.
The data is now being outputted on the IO pins.
Make CS and OE high again and the chip is asleep with the data still valid inside it and the IO pins are disabled.
Note: The IO pins are typically connected to the data buss of a CPU. They are inputs when WR & CS are low and are outputs when OE & CS are low. They do nothing when CS is high and the RAM is asleep.