Re: A86: Recalling string variables into programs with asm
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Re: A86: Recalling string variables into programs with asm
On Thu, 31 Jul 1997 MTNBIKE560@aol.com wrote:
> Does anyone know of a way to write an asm program that would recall a string
> variable into a program? i.e. if l had a program A that had 15 bytes of
> random letters inside it and had a string B that was also 15 chars. (but
> different), that the asm program would overwrite the contents of prog A with
> the contents of string B. yeah. that's it.
Fortunately for you, I've been working on a shell that does something very
similar. Try the following:
Step 1: Create the variable search structures:
AStruct: .db $12,1,"A" ; $12 is type PRGM, 1 is name length
BStruct: .db $0C,1,"B" ; $0C is type STRNG, 1 is name length
Step 2: Use rst 20h and rst 10h to find the variables.
Point HL at AStruct
rst 20h copies AStruct into OP1
rst 10h finds "A" and returns its 24-bit address in BDE
the carry flag is set on failure (I think)
Step 3: Use various functions to do what you need
$462F translates a 24-bit address in AHL to a 16-bit address
in HL and sets the proper RAM page.
$4633 translates a 24-bit address in AHL to a 16-bit address
in HL and puts the RAM page number into A
the RAM page is unchanged
$4637 INC AHL
$463B DEC AHL
These should be good for getting started. I take no responsibility for
any demons you summon into your calculator. It is a good idea not to
release programs using unofficial information. In fact, people who
distribute such information ought to be... hold on, my doorbell's
ringing... brb
--------
Dan Eble (mailto:eble@cis.ohio-state.edu)
(http://www.cis.ohio-state.edu/~eble)
References: