I found a file containing the equation for the Apple IIe HAL.
it is in a language I dont understand
do you know if the same file exist in vhdl ?
or is there any information on how to read the file (this is a small extract)
Pin #
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
14M 7M CREF H0 VID7 SEGB GR' CASEN' 80COL' GND ENTMG' LDPS' VID7M PHASE_1 PHASE_0 Q3' CAS' AX RAS' VCC
/RAS':=Q3'
+7M*/RAS'*/PHASE_0
+/7M*/AX*PHASE_0
+7M*CREF*AX*H0*PHASE_0
+/7M*/CREF*AX*H0*PHASE_0
apparently it's just simple equation using just not, and, or...
there is this description
DESCRIPTION:
'=not (inverted)
+=or (# in CUPL)
*=and (& in CUPL)
/=low (! in CUPL)
but it's not so clear, for example the signal on pin 19 is ras' but the the part of the equation is /ras
apparently it is easy to deduce the and / or but with the /signal signal' signal
the not seems comfusing
any idea ?