ISOMAX CHANGES FROM V0.5 TO V0.6
================================

INTERRUPT DRIVEN SCI PORTS
--------------------------
User-selectable polled or interrupt-driven serial communications, with
user-selectable buffer sizes.  Adds the new i/o objects SCI0 and SCI1
with methods RX, TX, RX?, TX?, BAUD, TXBUFFER, and RXBUFFER.

Note that terminal baud rate is now set with SCI0 BAUD instead of just
BAUD.  Also, the word TX? is now replaced with the phrase SCI0 TX?

Note also that on reset, the default for the terminal port is
unbuffered.  If buffered receive is needed (e.g. for downloading), a
buffer must be allocated and installed.

INTERRUPT DRIVEN SPI PORT
-------------------------
User-selectable polled or interrupt-driven SPI operation, with user-
selectable buffer sizes.  Now supports both Slave and Master modes.
Adds the new methods SLAVE, TX-SPI?, RX-SPI?, TXBUFFER, and RXBUFFER.

REVISED PROGRAM MEMORY MAP
--------------------------
Revised program memory map:
0000h to 15FFh. Run-time "core".
1600h to 3FFFh  Application program ROM (empty).
4000h to 7DFFh. IsoMax compiler and extensions.

AUTOSTART must now use addresses between 1600 and 3FFF, e.g., 3C00.

Compiler will not compile any words located higher than the address
   in the variable FENCE (default to $FFFF on coldstart).

REVISED DATA MEMORY MAP
-----------------------
Increased available RAM space by about 3/4 K.
SAVE-RAM image is now stored at the start of Data Flash ($1000-$17FF),
   instead of at the end.

MISCELLANEOUS NEW WORDS
-----------------------
Added HALFSPEEDCPU, FULLSPEEDCPU.
Added EXCHANGE.
Added ISOMAX (which returns the software version number).
Added CODE-INT.
Added ?KEY (a synonym for ?TERMINAL).

MISCELLANEOUS CHANGES
---------------------
Modified TIMERS ?ON and ?OFF to always return the pin state, even
   in output mode.
Added vectors to NEXT and ATO4 in low ROM.
Fixed problem of FLOG and FLN locking up with an infinite argument.
Fixed problem of EEWORD not handling CODE, CODE-SUB and CODE-INT words.
Fixed problem of SPI MBAUD not allowing values less than 20.
Fixed FATAN2 to return result in the range -pi..+p