Commodore Amiga A500 Technical Reference Manual page 156

#define jio-RamBaseAddr 0x1 fff
l*
r/w, sets extra ram base
address
*/
l*
now the magic bits in each register (and boy, are there a lot of
them!)
*/
l* bits for PclntReq, PclntGen registers
*/
#define JPCINTB-IRQ1 (0)
l*
active high
*l
#define JPCINTB-IRQ3 (1
)
l* active low */
#define JPCINTB-IRQ4 (2)
l*
active low
*/
#define JPCINTB-IRQ7 (3) l* active low
*/
l* pc side interrupts
*/
#define JPCKEYINT ( O x v l* keycode available */
#define JPCSENDINT (Oxfc)
l*
system request
*/
#define JPCLPTl INT (Oxf6) l*
parallel port acknowledge
*/
l*
bits for RamSize
*/
#define JRAMB-EXISTS (0) l*
set if there is any ram a t
all */
#define JRAMBZMEG (1)
l*
set if 2 meg, clear if 112
meg
* l
#define JRAMF-EXISTS
(1 <<0)
#defineJRAMFZMEG (1<<1)
l* bits for control register
*/
#define JCNTRLB-ENABLEINT (0)
l*
enable amiga interrupts */
#define JCNTRLB-DISABLEINT (1)
l*
disable amiga interrupts
*/
#define JCNTRLB-RESETPC (2)
l*
reset the pc. remember t o
strobe
*/
l*
ReleasePcReset afterwards
*/
#define JCNTRLECLRPCINT (3) l* turn off all amiga->pc ints
*/
l* constants for sizes of various janus regions */
#define JANUSTOTALSIZE
(5 1 2* 1 024)
/*
112 megabyte */
#define JANUSBANKSIZE
(1 28* 1024)
l* 128K per memory
bank
*/
#define JANUSNUMBANKS (4)
/*
four memory
banks */
#define JANUSBANKMASK (0x60000)
/*
mask bits for bank
region
*/