fastVBR/fastVBR 					      fastVBR/fastVBR

fastVBR.DOC		  fastVBR version v1.03
			    January 12, 1992

fastVBR, (c)1992, Mark C. Barnes.  All Rights Reserved.

    Author: Mark C. Barnes
    E-Mail: Aurelius@cup.portal.com

    DISCLAIMER:

    This software is FreeWare.
    The author accepts no responsibility for any damages or loss of data that
    may be attributed to the use of this program. Please contact the author,
    at the above E-Mail address, with any comments or questions. Enjoy!


---------------------------------------------------------------------------

0   Installation
I   Overview
II  Workbench Support
III Revision Summary
IV  Compiling


				    0
			       INSTALLATION

FastVBR should be placed in the C: directory, or a similar place. Add FastVBR
to you startup-sequence, after SetPatch and any AddMem commands. Any commands
that alter the Exception Vector Table directly, like DECIGEL, should be
placed before fastVBR, unless you are *sure* that it checks the 68010 VBR
register (DECIGEL does not).


				    I
				 OVERVIEW

fastVBR is designed to move the 68010 Exception Vector Table from low memory
to *true* FAST RAM. The purpose of this is twofold. First, for 68010/20/30/40
processors, which have the VBR register, moving the Exception Vector Table
to FAST RAM allows the Amiga to respond to interrupts without being held
off by AGNUS (as much). Second, to add the 1016 bytes of low memory back
to the system for extra CHIP RAM.

NOTE: Although AmigaOS has entries for low memory checksum in EXECBASE, it
      does not GURU when this memory is used as CHIP RAM. A personal thank
      you to Rick Younie at MindLink for some AmigaOS v2.04 BETA testing.

After the copy is completed fastVBR will add the old memory to EXEC's free
memory list as CHIP RAM.

The 254 longwords from $00000008 are added to EXEC's MEMLIST as PUBLIC
CHIP RAM. A new MEMCHUNK is created at $00000008, the start of the new
region. A new MEMHEADER containing the particulars for this region is
created in FAST RAM. The MEMHEADER is initialized with:

	   LN_TYPE	   :   NT_MEMORY
	   LN_PRI	   :   -10
	   LN_NAME	   :   "EVT Chip RAM"
	   MH_ATTRIBUTES   :   MEMF_PUBLIC | MEMF_CHIP
	   MH_FIRST	   :   $00000008
	   MH_LOWER	   :   $00000008
	   MH_UPPER	   :   $000003FF
	   MH_FREE	   :   1016


The MEMHEADER is then ENQUEUE'd into EXEC's free memory list. Under normal
configuration it will be the last CHIP memory allocated by the system.

Once this is done, the new CHIP RAM will be available to the system.


				    II
			      WORKBENCH SUPPORT

fastVBR v1.03 does not support the WorkBench. It is intended to be run only
from the CLI, specifically from within startup-sequence.


				    III
				ASSEMBLING

fastVBR is written in Assembler. The source is included along with the
distribution. It can be built using A68K and Blink, as follows:

    A68K  -iINC: fastVBR.asm
    Blink VERBOSE FROM INC:startup1.3/Astartup.obj,fastVBR.o
	  TO fastVBR
	  LIBRARY LIB:amiga.lib WIDTH 80
	  MAP fastVBR.map,H,S,X,F,O
	  XREF fastVBR.xref


				    IV
			      REVISION SUMMARY


24-jan-92   Mark C. Barnes  allow for SLOW FAST RAM, since these Amigas
	    v1.03	    need the extra CHIP RAM the most.

14-jan-92   Mark C. Barnes  added memory from $00000008 to $000003FF to
	    v1.02	    EXEC's free memory list. This results in an
			    additional 1016 bytes of CHIP RAM.

14-jan-92   Mark C. Barnes  Changed from 68000 TRAP to Exec's Supervisor
	    v1.01	    function, to get into supervisor mode, simpler.

10-jun-91   Mark C. Barnes  Original Version.