Msg: 2900 *Conference*

07-24-92 01:05:58

From: RICHARD HANSON

To : JERRY DORICH

Subj: REPLY TO MSG #2895 (XR4)

Jerry: Hold on... you're thinking "physical" not "logical" but that's one of
the problems we're having with ROM image swapping.  Let me run through a
scenearo as if you had a rampac, an XR4 and the three ROMs you mentioned.
 
1) Insert the rampac and call the software.
 
2) Take each of your three ROMs and place them into the ROM socket--one at a
time, of course--and run the program called N2X.CO -- it comes with the rampac,
the XR4 and the extRAM products.
 
3) The N2X.CO program will read the ROM in the option ROM socket and write its
contents to a file on the rampac.  This file is the exact image of the contents
of the ROM; called a ROM image.
 
4) Once you have run the N2X.CO on each of the three ROM, writing three
different ROM image files onto the rampac, put your ROM's away and install the
XR4 into the option ROM socket.
 
5) The XR4 is a 128K RAM, divided (logically) into 4, 32K areas called banks.
In other words, the XR4 is a complete unit that fits into the option ROM
socket.  It IS NOT something you physically stick ROM's into.
 
6) Now, you're ready to fill the XR4 with either 4 ROM images, or use as 4 RAM
banks, or mix and match, i.e., 3 ROMs and 1 RAM, or 2 ROMs and 2 RAMs, or 1 ROM
and 3 RAMs... get it!!!
 
Does this make more sense, now?  Again, this is the biggest problem we're
having... understanding of how it works by folks who have never see ROM
swapping before.  I've mentioned to Tracy that perhaps a video would be a good
idea.
 
Anyway, that's the way that works.  Thanks for asking... -Rick-