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 with I Register &80+ Memory &8000 So /XMEM is just the XMEM bit nanded with A15. Just thought I share it and waste your precious brain space for yummy recipies :-) BTW Scans of schematics are still welcome ! Edwin
