Decided do some tests with a LED hooked up to /XMEM (with a 330 ohm
resistor in series)
Whenever the /XMEM line gets active low the LED would ilLuminate.
Once bit 7 of HMPR port was set the LED would light up with any combination
with address line 15
high:
I/O ports &8000+
Refresh wi
It's fully encoded with A15 and MREQ, from what I remember.
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of [EMAIL PROTECTED]
Sent: Wednesday, March 24, 2004 3:34 AM
To: sam-users@nvg.ntnu.no
Subject: Antw: RE: /XMEM
Thanks for the braindump Simon
I've got the technical manual. If it's in there, I can do you a scan, no problem.
Andy
[EMAIL PROTECTED] wrote:
Thanks for the braindump SimonBut your talking about the decoded signals decoded by the interface.What i need to know is the ASICs implementation of the /XMEM signal.ie is
Thanks for the braindump Simon
But your talking about the decoded signals decoded by the interface.
What i need to know is the ASICs implementation of the /XMEM signal.
ie is it just a bit that can be turned on and off or if it is fully encoded with
A15 & /MREQ (//RFS?)
NVG is back online.
Well you did do a lot of fiddling around with it for the Ryan ;)Simon Cooke <[EMAIL PROTECTED]> wrote:
IIRC, the XMEM line goes low when the external memory area is addressed(upper 32k of the memory map, with external memory turned on in HMEM).The external memory addressing is controlled
IIRC, the XMEM line goes low when the external memory area is addressed
(upper 32k of the memory map, with external memory turned on in HMEM).
The external memory addressing is controlled by two latches at ports 128 and
129 (XMEML and XMEMH), which decide which 16k page of the external memory is
Thanks for trying. Nev,Geoff
I was looking for info about the /XMEM signal as the manal is not very
informative.
Does anybody know the implementation of it? or has a schematic of the 1Meg
expansion or original Soft Rom board in which this signal is also used ?
Edwin
