SPACE 2/SPACE - Library 2 - Volume 1.iso/demos/11/general/onedrv.doc

Text File | 1986-04-17 | 5.6 KB | 103 lines

USING PERSONAL PASCAL WITH A SINGLE DISK DRIVE ST SYSTEM
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If you have only one single-sided disk drive, using Personal Pascal to
write  programs  of any practical size requires some planning and disk
organization.    More  specifically,  the  Pascal  disk,  as  shipped,
contains enough free space to compile perhaps two or three of the very
small  demo  programs  included  on  it.   In following paragraphs, we
describe suggested steps to take (in order of their effectiveness)  in
order to be able to compile larger programs.   Owners of 1040ST's will
find  some  information  of  value here, though simply copying all the
Personal Pascal files to a double sided diskette  will  probably  give
you all the space you need for most projects.

[  1.  ]    Buy  a  second  drive.   You weren't looking for expensive
advice like this?   Sorry, keep reading:  we get  cheaper  as  we  go.
(But  we  still think that this is the only viable long-range solution
for not only Pascal but  several  other  existing  or  anticipated  ST
products.)

[  2.  ]    Remove  all  files  in the DEMO and INFO folders from your
working copy of the disk.   Remove the folders, also.   You should now
be able to write 200 to 300 line programs.

[ 3. ]   If you have not yet purchased and installed the TOS ROMs,  do
so!!!   Then obtain a RamDisk program (there are a couple of free ones
on  CompuServe  and various bulletin boards) and allocate no more than
200K bytes to the RamDisk (160K may be a better compromise).   You may
use the RamDisk to hold your source code,  work  files  (see  "Compile
Options" menu item), and/or the library files (as described in section
3,  below).    This  is  not only a relatively easy option, it is also
fairly  effective:   compiles  and/or  links  will   be   speeded   up
considerably.    PLEASE,  PLEASE,  PLEASE, though, BEFORE you run your
compiled program, go back to the desktop and  copy  your  source  code
from the RamDisk to a physical diskette!   Thanks.

SPECIAL NOTE:   At 200K bytes, though, the RamDisk is not large enough
to  hold  the  compiler  and its associated files (and if you make the
RamDisk larger, you won't have  room  in  normal  memory  to  run  the
compiler...catch  22).    However,  if you own a 1040ST (or are one of
those brave souls who has upgraded your 520ST to a megabyte  of  RAM),
you  can  create a 600K or 700K RamDisk, which is large enough to hold
all the Personal Pascal files (compiler, linker, libraries,  etc.)  as
well as all the temporary files produced during a compile.

[  4. ]   Copy the files PASLIB and PASGEM to another diskette.   Then
remove both of them from your working disk.   Then  edit  and  compile
(do NOT link) the following program:
     (*$M+,E-,D-*) (* a module, but no external access, no debug *)
     PROGRAM JUNK();
       BEGIN
       END.
From  the  GEM  desktop,  rename  the object file you just produced to
"PASLIB" (no extension).   Then compile  the  program  again  (without
linking!) and rename the object file "PASGEM" (no extension).

Back  in  the Personal Pascal manager, specify "additional link files"
as follows:
    B:PASGEM,B:PASLIB
(if linking for GEM) or just
    B:PASLIB
(if linking for TOS).   It's a good idea to then  save  these  options
(using the menu item "Save Options").

The  effect of all this is strange and wonderful:   when it comes time
to link your program, the  manager  AUTOMATICALLY  requests  that  the
files "PASGEM" and/or "PASLIB" be linked with your file ("PASGEM" only
if  you  chose  the  "link  for  GEM"  option).   But now "PASGEM" and
"PASLIB" are junk files, containing only  a  single  dummy  procedure.
However,  since  you  asked  for  the  "additional" link file(s) to be
included from drive B, the linker obligingly asks the operating system
for them.   Here is one place where TOS really shines:   when you  ask
for  a  file from drive B and drive B doesn't exist, TOS automatically
prompts you to remove the "A:" diskette and insert the "B:" diskette!!
And, when it is time to go back and read or write files from/to  drive
A, TOS prompts you again.

So  simply  follow  the  TOS  prompts.   When it asks you for the "B:"
diskette, insert the one on which you placed the copies of PASLIB  and
PASGEM.   Then, when it asks you to insert the "A:" diskette, reinsert
your  working disk.   Voila!   You just gained about 80K bytes on your
working disk.

COMMENTARY:   Although TOS allows you to specify "B:" for any file and
will keep careful track of all swaps needed, we chose to move only the
library files to the second disk in order to minimize  the  number  of
disk  swaps necessary.   When the linker is reading in a library file,
no other files are open, so a swap is necessary only at the  beginning
and  end  of  the file read.   If we were to put your source file (for
example) on diskette "B:," you would have to swap several times as the
various "INCLUDE" files were encountered and/or as the object file was
written.   However, if you are desparate, you  might  try  moving  ALL
source  files  (including  GEMSUBS.PAS, GEMTYPE.PAS, etc.) to disk B:.
What we are doing this way is turning the situation  around:    almost
all  files  will come from diskette "B:," and the only time the system
will need to swap to "A:" is when it needs to load one of the Personal
Pascal ".PRG" programs (the editor, compiler, or  linker).    CAUTION:
we have not tried this procedure as of this writing.   Use at your own
risk.


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