ftp.whtech.com/ftp.whtech.com.tar/ftp.whtech.com/Geneve/mdos/80column_funnelweb/rept.txt

Text File | 2006-10-19 | 14KB | 461 lines

.LM 8;RM 72;CE 3
FUNNELWEB Vn 4.40 BUGS & PROBLEMS
---------------------------------
.FI


(1) Bugs and Mods
~~~ ~~~~~~~~~~~~~

The bug report is being zeroed out at
the time of first issue of Vn 4.40 of
FUNNELWEB, but new bugs are being
created all the while.  That's the
price of progress! Fixes and changes
since that release are listed in
chronological order below.  Minor
changes in associated document files
may well be made without explicit
mention, or other non-functional
changes.

.LM +3;RM -3

Bug ..... After use of Myart file View
from DR80, the XB RUN from DR80 engages
XB but then locks.  <Quit> is still
there though.  The cause is not yet
obvious.

System bug ..... Anomalous error
recovery behavior may occur with SD and
the DRs in systems with 80-track Myarc
FDCs.  See FWDOC/DR41 or /DR81 for
details.

May/30/91 ...  First issue of Vn 4.40.

Jul/26/91 ...  Fixes for LOAD's XB user
list program loading, and for ED80
<P>Dir function from SD. FILENT routine
in FW/LOAD now clears the last char in
the window with <fn-3>. ML40 repaired.

Oct/30/91 ...  Back to programming with
renewed vision !! Read/Write failure
indicators added for DR file copies.
DSKU notes handling revised and
corrected.  FWDOC files /DR40,1,
/DR80,2, /PSRV updated.  Dual 80/40
Editor, files ED80 & ED81, now windows
correctly in 40 col mode. Cause of
error recovery bug in DR narrowed to
Myarc 80-Tk FDCs.


.LM -3;RM +3

If you come across a later version of
FUNNELWEB, use it, but it is a good
idea to update ALL files.  Significant
changes are indicated in the update
notices.  Use CF/CG and your SYSCON
file to re-customize the LOAD and FW
files if these have been updated.


(2) Programmers' reference
~~~ ~~~~~~~~~~~~~~~~~~~~~~

The FUNNELWEB program has to interact
with a number of external programs
which (to TI's eternal shame) were
never intended to work together, so its
internal structure is an ad hoc
response to many independent pressures.
As the scope of FUNNELWEB grew it
became necessary to define an interface
so that other parts of the program
could call on routines or data in the
main body of the program.  This has
grown somewhat haphazardly, but at this
stage in the history of the 99/4a (and
level of fairware support) it is
unlikely to be reorganized.  Details
which may be relied on by external
programmers are given in the
supplemaentary file FWDOC/PSRV.  A set
of articles "Living with Spiders"
appeared in the HV99 Newsletter and on
some BBSs, which goes into coding
details, and is still relevant.

The FUNNELWEB LOAD program is composed
of 4 parts, the Extended Basic code,
the XB user list data, and 2 pieces of
machine code tucked between the XB code
and the top of memory.  DSRLNK
(TI-Forth form - you handle the errors)
and GPLLNK are in a >FA byte block
immediately above the XB program code.
These are shifted to follow the normal
XB Utilities and the memory pointer
updated, and are available for use by
XB programs loaded from the XB User
List (BLWP at >24F4 and >24F8
respectively) provided CALL INIT or
CALL ILR are not invoked.  This is
followed by code and data used only
while XB is still preserved.  This same
area is used later by UL, ML, FSAVE,
and the ScriptLoad error handler.  When
FW/UTIL1 is prepared the C2 character
set and FW/UTIL1's entry code are
tucked between the entry point (>E006)
and the actual FUNNELWEB code to speed
up loading.

The end of the program is kept fixed at
>FFD7 so the interface block items are
at known addresses.  The >FFD7 limit is
compatible with E/A and XOP 1 which is
not used by FUNNELWEB (but it does make
transient use of the area above >FFD8,
without altering the Load Interrupt
vector at >FFFC).


(3) GPLLNKs with FUNNELWEB
~~~ ~~~~~~~~~~~~~~~~~~~~~~

From Vn 4.40 onwards GROM address
setting from within the program and
DiskReview calls a reference block
routine which uses GPL workspace R13 as
base value (see FWDOC/PSRV).  Whenever
the central menu screen is displayed
the following conditions have been
established.

.LM +3;RM -3
(a) The GROM address is left pointing
to an XML instruction in cartridge
GROM, else in console GROM 0, and this
address is also saved in the program.

(b) The GPL stack is dropped to just
one entry which is this value copied to
>8380.

(c) The table address pointed to by the
XML instruction is loaded with the
FUNNELWEB re-entry address.  For
maximal compatibility with existing
software the XB return is at >2000 and
the E/A return is at >2002.  All others
use PAD (>8300).

.LM -3;RM +3
With these preparations it was possible
to write a GPLLNK to fit invisibly in
the E/A utilities without altering the
FFALM pointer.  In any event the E/A
GPLLNK cannot be used because it
branches to E/A module GROM code.
Programs run other than from E/A or XB
under FUNNELWEB may give trouble if not
written to preserve the contents of
location >8300.


(4) Returns
~~~ ~~~~~~~

The easiest returns to FUNNELWEB are
when FUNNELWEB is still all there
unmolested, from >EBC8 to >FFD7.
FUNNELWEB always hands over with R11
loaded with the return address.  Any of
the standard returns to GPL will return
to FUNNELWEB provided that the XML
table entry is preserved for B at >70
returns.

If FUNNELWEB is overwritten the
simplest return is to the Title Screen.
If your program doesn't make extensive
use of VDP memory, it may be possible
to stash FUNNELWEB (from >E9B0 to cover
UL or else from >EBC8 to >FFD7) there
below the disk DSR buffers and to
restore it to CPU RAM after an
irrevocable decision to exit has been
made, and then a normal exit as if to
GPL may be used.

If memory usage is too complete to
allow this, FUNNELWEB may be reloaded
from disk as the program file FW or
UTIL1.  Only a very simple loader is
needed as there is only a single file
and the memory location and start
address, (>E006) and the length
(through >FFD7) are prior knowledge.
Strictly, only Atrax Robustus can get
away with not deriving the start
address and length from the file
header, but given the present level of
fairware support and future of the
99/4a system, it is unlikely there will
ever be enough new developments to
change this.  It is recommended that
the loader first try to load the file
under name FW and if this is not found
then to try it as UTIL1 before taking
error action.  If the application
program is such that disks may have
been swapped around, prompts should be
issued for the primary and secondary
disk numbers or the original drive or
pathname assumed, as appropriate.  The
flag to turn on boot disk tracking in
FW is at BTFLAG EQU >FF1A.  A null word
here disables the tracking, in which
case primary and secondary system drive
numbers in ASCII form must be provided
in the bytes at RDISK EQU >FF18 and
>FF19.  Rewrite the drive numbers after
loading but before handing over if
these have been changed.  It is always
necessary to suppress boot disk
tracking when split T-W and E/A access
is needed.

The flag for a hard pathname is at
HDFLAG EQU >FF02 and the pathname is at
the address pointed to by the value at
>FF58.  The length byte includes the
standard 2-character system filename
length as well.  This flag should be
checked first and used by program
reloaders before checking the other
paths.  The DM-1000 supplied in earlier
issues followed this prescription.

Programs intended to work only with
FUNNELWEB may re-enter it at the
Central Menu Screen by LWPI of the FWB
main workspace at FWREGS EQU >FF7C,
SETO of R13, and CLR or SETO of R4,
followed by a branch to the address
contained in location CMSRET EQU >FF5C.
Do not alter R8 and R9 of this
workspace.  A program (Opt 1-3) can
tell that it was loaded from FUNNELWEB
by comparing R11 at entry with the word
at LDR11 EQU >FF9C.


(5) Filename transfers
~~~ ~~~~~~~~~~~~~~~~~~

FUNNELWEB has a standard way of
transferring the DV/80 workfile name
from one utility to another.  The file
name is stored on final exit from a
component program at MLBOX EQU >A000
without any length byte, and padded
with spaces out to >A050.  This is the
"mailbox".  A file name so stored will
survive OLD or RUN of an XB program or
passage through the Title Screen.  The
utility entry routines inspect this
location for the 2 ASCII characters
"DS" or "RD" or "WD" or "HD" and if
found the block as far as the first
space is written to the appropriate
buffer in the utility program, and the
rest of the block is filled with
blanks.

If utility programs are not to destroy
the resident file-name then they should
not overwrite this area, or else should
restore it before exit, or load the
file name to be passed back.  Test with
Formatter and Editor to see if this has
been done properly.  Modification of
existing programs not available as
source code may require a little
ingenuity, and is not always possible.


(6) Standard Utility Loading
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In contrast to versions of FUNNELWEB
earlier than 4.30, the loads of the
Editor, Assembler, and Formatter files
are now just normal program loads,
Option 1 for the Editors and Option 2
for Formatter and Assembler.  This
means that other files may be
substituted for these if desired, as
long as the same leading name is used,
eg FO for Formatter.  Test and/or
correct for proper returns (see (4))
using one of the configurable menu
slots first.


(7) Problems
~~~ ~~~~~~~~

Various problems have been observed by
users of FUNNELWEB.  Many of these are
intrinsic to the programs being loaded,
and these we can't do anything about.
If you have commercial programs which
you would like to use with FUNNELWEB
but can't for one reason or another,
particularly because of protection
schemes, you should contact the sellers
or originators of these programs to
make your problem known.  Good luck
Charlie Brown! Other problems are
associated directly with use of
FUNNELWEB.

.LM +3;RM -3
(a)  Loading difficulties

Lockup during file loads occurs because
some part of FUNNELWEB has been
overwritten.  The code for program file
loads is located close to the top of
high memory and will be destroyed if
overwritten by a file that is not the
last one to be loaded in normal E/A
sequence with the last byte incremented
for each successor file.  Altering the
file sequence to put the overwriting
file last in a multiple load will
usually solve the problem.  Use
DiskReview to correct the load flag in
the first word of the files being
interchanged (>0000 for the last file,
>FFFF for all others) and DiskReview or
other DM program to interchange file
names.  File lengths of >2000 in 33
sector files, such as produced
incorrectly by E/A SAVE, may need to be
corrected to >1FFA if the changed order
would result in overwriting of
previously loaded code.

Load/Run of object files is handled by
the Loader in the E/A utilities.
Autostarting of files is by a direct
branch from the Loader to the program
code, so that a autostarting object
file may overwrite FUNNELWEB.  Files
that are too long may refuse to load.
Unsuitable absolute file addresses may
destroy the code for DEF table entry.


(b) Running difficulties

The program file loader gives a fair
approximation to GPL or E/A module
environment.  If problems are observed
they are usually associated with key
unit choice and key response in the
program loaded, particularly with
programs that set a key-unit of 0
instead of choosing the one they really
want.  The cartridge loaders now reset
the GPL stack pointer at >8373 to >7E
which seems to help.

Programs that sense which module they
are running with and adjust their
action accordingly can cause problems.
Since the point of FUNNELWEB is to make
all sorts of programs work with modules
they weren't intended for or even no
module at all, it has already taken the
necessary actions and must not be
second-guessed by programs it has
loaded.  The only solution is to modify
the programs or else not use FUNNELWEB.
Running from the E/A module gives the
easiest way to switch back and forth
between FUNNELWEB and a standard
environment.

Some programs in E/A program format
contain code to unload the standard
utilities from the E/A GROM because the
E/A module does not do this for Run
Program File.  The c99 memory image
files prepared with the original
unmodified C99PFI use this method to
force the utility load.  Running or
return from such programs may not be
graceful if FUNNELWEB was loaded from
E/A.  c99 is smart enough not to try
getting code from non-E/A GROMs, but
other programs may need revision.

FUNNELWEB has also adjusted the E/A XML
object file loader path for its own
purposes.  If an assembly program needs
to load an object file it should use a
direct BLWP at LOADER to the E/A
routine.  Error returns may need
special attention.


(c) Exit difficulties

Read (4) above on returns.  Opt. 2
loads will be necessary for program
files that overwrite the E/A utility
area in low-mem but still use a GPL
return via the contents of R11 as would
be acceptable for a Opt. 2 (or E/A 5)
program file load.

Some programs which do not appear from
their load size to overwrite FUNNELWEB
may in fact corrupt it while running.
Some particular cases of pre-existing
programs may be helped with minor
changes, as a return to the title
screen is usually preferable to a
lockup.

An example of this kind is the
Dragonslayer Spellchecker.  An early
version inspected of this commercial
program runs normally under FUNNELWEB
with load parameter 2, but crashes the
machine on exit.  This is improved by
changing the words 0460 0070 to 0420
0000 to return to the title screen.
Use HEX string search in DiskReview
to find this exit.

Another example needing modifications
to exit code is DSKU which leaves
interrupts on, the interrupt hook
loaded and pointing to an address
overwritten by the incoming FW.

.LM -3;RM +3

ÇåÇ¡ïÉòƒ╒╒╒╒╒╒╒╒╒╒╒╒Çåáááááááááááááááááááááá