pcmhacking.net

Hi all,

I have just discovered this forum an am amazed with what can be done with the delco 808 and realtime these days. Was just wondering if there is a diy/homemade real time board available, looks like the nvram can be bought/made easily enough.

I am planing to use this on a Holden 202, with VK injection manifold, throttle body and associated sensors from VN.

Any advice would be appreciated.

Thanks

We have options in the for sale section, which include some extra features and jumpers to set cylinders. But if you want to convert a memcal to realtime yourself you will need to look at the pin diagram of the stock eprom and the ds1245y nvram and wire nvram IC up to it. You'll also need to connect the RW line from the processor to the RW line of the chip.

Those jumpers to set the ammount of cylinders. What is the reason for this? I thought that would be done through the programming.

Where would I find the pinouts?

Thanks

Check the FAQ area for information about the resistor pack. There is an analog component to the number of cylinders, including backup mode. Its set in hardware. Google a 32k eprom data sheet, and the dallas ds1245y datasheet, and plan to replace the eprom IC, and use a spare pin on the header to run the RW line from the nvram back to the processor.

I have just had a look at the data sheets for both chips and just have a few questions.

The ds1245y has 2 extra address inputs compared to the 32k eprom. Are A15 and A16 left unused?

The 32k eprom has a VPP pin (programming voltage), yet the ds1245y doesn't seem to have this. Is this now not required when using the ds1245y?

I assume the RW line on the nvram is WE (Write Enable) Where should this connect to on the delco ecm?

Thank you

The processor is 8 bit so has 64k of address space, so one of them is still connected. The other one is usually switched, giving you 2 banks switchable when the car is off. Or hard wire it one way or the other.
The VPP is not relevant to a ram chip, thats only used in a programmer.
WE is connected to the processor.

When you refer to the processor, where is this located on the delco 808 board and which pin does WE need to be connected to?