OBJNAM CHGMEM.LIT ; Created 8-May-87, edited 8-May-87
; by Irv Bromberg, Medic/OS Consultants, Toronto, Canada
; Allows the size of any module in user's MEM: area to be changed relatively
; or absolutely.
RADIX 10
VMAJOR=1
VMINOR=1
VEDIT=2
SEARCH SYS
SEARCH SYSSYM
if eq,1
Syntax examples:
CHGMEM MODULE.DAT 10 ; increase size of MODULE.DAT by 10 bytes
CHGMEM MODULE.DAT +10 ; plus sign allowed, same effect
CHGMEM MODULE.DAT,10 ; comma separator allowed, same effect
CHGMEM MODULE.DAT +11 ; increase size of MODULE.DAT by 12 bytes (odd sizes
; are rounded up to even size)
CHGMEM MODULE.DAT 10K ; increase size of MODULE.DAT by 10 kilobytes
CHGMEM MODULE.DAT -10 ; decrease size of MODULE.DAT by 10 bytes
CHGMEM MODULE.DAT -11 ; decrease size of MODULE.DAT by 10 bytes (odd negative
; sizes are rounded down to even negative size)
CHGMEM MODULE.DAT=100 ; force MODULE.DAT to absolute size = 100 bytes
CHGMEM MODULE.DAT=101 ; force MODULE.DAT to absolute size = 102 bytes (odd
; sizes are rounded up to even size)
CHGMEM MODULE.DAT=0 ; make MODULE.DAT empty (warning will be issued)
CHGMEM MODULE.DAT -500K ; unless it was >500K MODULE.DAT is now empty
Of course any valid filename name may be substituted for MODULE.DAT (the
default extension for the module name is ".DAT").
When the specified change results in no change then there is no change
and no error message is displayed. Thus there is no harm in specifying
no change except for the computer's wasted effort in figuring out
that nothing should happen.
Be very careful when reducing the size of a module because crucial
information may be lost from the high end, depending on the module
contents. Also take care when there are additional modules at addresses
beyond the one being changed - these will be moved (either up or down,
depending on the relative change in size) and this may disturb software
contained within or operating upon those modules. In other words
the CHGMEM command is intended for advanced applications only, to be
used by programmers who know what they are doing!
Possible messages:
%Warning - MEM:filnam.ext is now empty
?Cannot find MEM:filnam.ext
?Memory allocation failed
?NULL relative size change
CHGMEM.LIT is re-entrant and re-useable.
endc
JCB=A0
Buffer=A2
Name=A3
Module=A5
Size=D0
Char=D1
Number=D1
Flags=D2
Minus=0 ; set if input number was preceeded by "-" (relative mode)
Abs=1 ; set if absolute size was specified (preceeded by "=")
PHDR -1,0,PH$REE!PH$REU
CLR Flags ; pre-clear all flags
MOV JOBCUR,JCB ; use JOBRBK as work area
LEA Name,JOBRBK(JCB)
CLR @Name ; pre-clear filename in case
CLR 4(Name) ; of invalid entry
FILNAM @Name,DAT
Search: SRCH @Name,Module,F.USR ; module already in MEM:?
BEQ GetSiz
TYPE <?Cannot find MEM:>
PRNAM @Name
CRLF
EXIT
GetSiz: BYP ; allow blank or tab separators
MOVB @Buffer,Char ; check for absolute specifier "="
CMPB Char,#'=
BNE ChkComma
BSET #Abs,Flags ; remember we got absolute signal
BR SkipIt ; no sign possible
ChkPlus:CMPB @Buffer,#'+ ; plus sign present?
BNE GetNum
SkipIt: INCW Buffer ; skip sign
BYP ; skip possibly more whitespace
GetNum: GTDEC
MOV Number,Size
BNE Kilo
BTST #Abs,Flags ; was it absolute size?
BNE Change ; OK, let him do it (hope he's right)
TYPECR <?NULL relative size change>
EXIT
Kilo: CMPB @Buffer,#'K ; kilobytes?
BNE FixSiz
MUL Size,#1024 ; yes, convert to KB
FixSiz: LSR Size ; check if odd
BCC 10$
INC Size ; yes, make it even
BTST #Minus,Flags ; but if it was negative
BEQ 10$
SUB #2,Size ; undo and make it less negative
10$: LSL Size ; restore value
BTST #Minus,Flags ; also if it was negative
BEQ Change
NEG Size ; convert to negative value
Change: BTST #Abs,Flags ; is it absolute size?
BNE DoIt
ADD -12(Module),Size ; add existing module size
SUB #12,Size ; deduct housekeeping words
BPL DoIt ; if now negative, convert to 0
CLR Size ; so empty module remains
