!pr1
Apple //e ROM Revision.....................Bob Sander-Cederlof

Dated March 21, 1984, I received a pair of 2764 ROMs and 12-page writeup.  These are preliminary versions of a new set predicted to be in general distribution by early next year.

The new //e ROMs are substantially  better than the current ones.  Changes include:

Applesoft:  modified to work in 80-column mode, and with lower case.

Monitor:

*  modified to work with new Mouse ICON characters;

*  modified to accept lowercase input;

*  location $1F no longer used;

*  miniassembler is back;

*  search command added;

*  IRQ handling substantially modified.

Video Firmware (after PR#3):

*  fixed many bugs;

*  no more jagged scrolling, now smooth and 30% faster;

*  two new escape commands to enable/disable printing
   of control characters;

*  SETVID ($FE93) now turns off 80-column mode;

*  escape-R removed.

The new IRQ handler should finally make interrupts actually usable on the Apple.  The old problem with location $45 is fixed.  The settings of the various soft-switches which control memory mapping are saved and the machine is put into a cononical state.  The standard IRQ return sequence will restore the interrupted state of all those switches.

The total overhead from IRQ-event to your IRQ-subroutine will run from 250 to 300 microseconds, depending on the soft-switch settings.  If you are in a ProDOS environment, you will have to add all the overhead caused by ProDOS.

Of course, there will be new problems.  ProDOS bent over backwards in a very strange way to solve the $45 problem with interrupts.  Now that it is not necessary, ProDOS should be changed.  But it can't be changed for the new and still work in the old, so....  The new IRQ and BRK handler also clobbers locations $100 and $101, which is BAD!  Both those locations are used by Applesoft and many other programs!

If you think these changes will impact your work, or want to be involved in shaking out bugs, you might contact Developer Relations at Apple (408) 996-1010 and discuss the Certified Apple Developer program.  I think it is because I am one of those that I received this material.
