Short:    patcher for compatibility with relocated sys vars
Author:   Mark J Swift
Version:  1.09
Uploader: msw@blackpool.ac.uk


This program takes a QL exectable, scans for $28XXX and
patches it appropriately.


ARCHIVE CONTENTS

SYS_REF_README_txt - this file
SYS_REF_bas        - BASIC source
SYS_REF_task       - TURBO compiled code

D68K_README_txt
D68K_rext          - a disassembly toolkit

PDTK_README_txt
PDTK_rext          - a toolkit with many TK2-like commands
PDTK_asm           - the assembly source to the toolkit


PROGRAM FEATURES

* TURBO COMPILED for speed
* BASIC source is provided
* CACHE friendly - your code will still work on 68030, '40 and '60
  processors - will even work with COPYBACK enabled
* FREEWARE


PURPOSE

A lot of QL programs won't run when the system variables are
not located in the usual place ($28000 hex - 163840 decimal).
This can happen in Minerva with the second screen enabled or
in Amiga-QDOS with extended memory.


PATCHING TURBO

If patching CODEGEN_task of the TURBO compiler, patch ALL
references EXCEPT the two that refer to $28010. These are not
part of the CODEGEN code, but are included in all TURBO
compiled programs. Patched versions of TURBO produce code
identical to unpatched versions, i.e. newly compiled tasks still
require patching.  If patching PARSER_task, or any other TURBO
program replace ALL references.


32 BIT FRIENDLY

SYS_REF makes all TURBO'ed programs 32-bit clean. This means you
can run them from high in memory. This is especially useful in
Amiga-QDOS, where if you have 16 meg of memory, the memory map
could be from $07000000 - $08000000 with the system variables
relocated to $07000000.


CACHE FRIENDLY

On a QL with a big processor (68030/'040/'060) the caches are
flushed/disabled/enabled at the appropriate time.


PROBLEMS?

Turbo and Turbo patched programs work fine on my 16 meg 68040 Amiga
running Amiga-QDOS with intruction, data and copy back caches enabled.
You should have no problems with the code on a bog standard QL.


REQUIRES

Requires the D68K toolkit (D68K_rext included) and some TK2 commands.
If you don't have TK2 use PDTK instead (PDTK_rext included).


SYS_REF, D68K and PDTK are freeware - distribute freely