Adding 527 or 520 board to C4PMF

[lowrybt1]

I have a C4PMF with 24K RAM installed on a 527 board. I have acquired 527 and 520 boards and want to install one in the C4PMF to increase available RAM. Does anyone know if I need to run power separately to either of these board and/or whether there are any jumpers that need to be set so the C4P will recognize the extra RAM?

Many thanks!

[dave]

The 2114L chips can draw up to 100 mA each, so a fully loaded 527 board may require 4-5A. I think the stock power supplies were 4.5A at 5V, so each 527 board may require its own supply. You could replace the stock supply with something beefier, and power all from the bus. However, I don't think the C4P was intended to have more than one 527 card. If you find lower power chips, you could try running one 527 together with the 505 card, and the second off a second supply.

If you do use two 527's, (assuming you have a 505 card), you'll want to jumper the second card to cover from 6000-BFFF.

Another option is to get one of the protyping boards Glitch has made, and wire in one or two higher density RAM chips, and not require any additional power supply at all.

http://osiweb.org/osiforum/viewtopic.php?f=3&t=270

Dave