

                 Pascal 3.2 SRM/UX and MC68040 Supplement
               _____________________________________________


         I.) Introduction


Pascal 3.24 is a minor upgrade of the Pascal Workstation software for the
series 200 and series 300 systems. The primary objectives of this release
are to add support for the 25 Mhz 68040 based Series 300 Workstations, add
support for the HP-UX SRM/UX server, and resolve all critical and serious
defects.

The PWS 3.24 release will be supplied with the same media options
available on the 3.2 release: single-sided minifloppy, single-sided
microfloppy, and double-sided microfloppy.

The manual set for the standard product will not change.
This supplement enhances the existing manual set to explain changes
and enhancements resulting from the 3.24 release of PaWS.

Revision 3.24 will not require any new discs in either the single-sided 
or the double sided configurations. 





         II.) MC68040 Support

   Pascal 3.24 will provide support for MC68040 based series 300
   workstations for the first time. Key features of the MC68040
   include : 

 * Larger instruction and data caches (4096 vs 256 bytes) allowing
   for increased performance.

 * A copy-back cache mode is provided for the first time. This allows
   the data cache to be written into without the automatic updating
   of main memory.

   Copy-back cache mode will be the default mode of operation for
   the Pascal Workstation (except for supervisor mode and I/O space
   memory accesses). This could cause problems for programs with
   self-modifying code and as usual it is recommended that all such
   programs make a system call to the routine ASM_FLUSH_ICACHE to
   synchronize the caches and main memory before executing any
   such code.

   Also system programs that make DMA transfers directly will have
   to flush the caches (call system routine ASM_FLUSH_ICACHE) before
   outbound DMA to ensure that main memory contains correct data
   before the transfer.

   For programs that must run in write-through mode a sample routine
   is provided on the DOC: disc (COPY_OFF.TEXT) which when assembled
   and executed will put the processor in write-through mode. The
   routine COPY_ON shows how to put the processor back into copy-back
   mode.

   Copy-back mode allows for a substantial performance improvement
   over write-through mode.

 * Lack of support for a floating point co-processor. Instead, some of the
   previously supported floating point instructions are handled by a
   floating point unit built into the 68040 processor itself. The
   remaining floating point instructions will generate F-line exceptions
   where they will be emulated in software. Thus user programs running
   on pre-68040 workstations should run on 68040 workstations. 

   This floating point emulation package satisfies the requirements of
   the ANSI IEEE Standard for Binary Floating-Point Arithmetic 754,
   according to Motorola, and allows user code for the MC68881 or
   MC68882 to run without change. The performance of the transcendental
   function routines is equivalent or superior to that of a 33-Mhz
   MC68881/MC68882, and the error bound is equivalent to or superior
   than the MC68881/MC68882. 
   
   The Motorola supplied emulation software is provided in the module
   FP40 located on the LIB: disc for single-sided media or the SYSVOL:
   disc for double-sided media. This module may be included in one's
   INITLIB file or may be executed directly after booting (it P-loads
   itself). Note - this package is for 68040 based series 300 work-
   stations only.

   See the Motorola 68040 User's Manual and the Motorola Programmer's
   Reference Manual for more details on the floating point emulation
   package.





         IV.) Additions and Changes to Existing Features




         V.) System History


    Pascal 3.24
   ____________

This release adds support for the 25Mhz MC68040 Series 300 Workstations
as well the Hp-ux SRM/UX server.

    New Hardware
   ______________

 * SPU Model 380


   New Peripherals
   _______________

 * Plotter Model 7550B in HPGL compatibility mode only

   Object Code Compatibility
   _________________________

   Pascal 3.24 is generally upward code compatible with 3.2 systems.
   Programs compiled with 3.2, 3.21, 3.22, and 3.23 systems should run
   on 3.24 with no recompilation required. Note that this may not apply
   if the application contains linked in system modules.

   Applications which employ self-modifying code with an MC68040 based
   workstation are also potential trouble spots as the MC68040 allows
   copy-back cache mode for the first time in the 68k family history. 
   See the section on MC68040 support for more details.

   Software Changes
   ________________

   * A module FP40 is provided to emulate unimplimented 68881/68882
     co-processor floating point instructions. See the section on
     25 Mhz 68040 support for more details.

   * The module SRM has been enhanced to allow support of the Hp-ux
     SRM/UX server.

   * The Assembler has been enhanced to support new MC 68040 instructions.

   * The System reverse-assembly capabilities (Librarian and Debugger)
     have been enhanced to support new MC 68040 instructions.

   System Discs
   ____________

     The following changes were made:

    Single-sided discs:  FP40 was added to the LIB: disc.

    Double-sided discs:  FP40 was added to the SYSVOL: disc.
