RE: A85: Re: Tyrant ports

To: "'assembly-85@lists.ticalc.org'" <assembly-85@lists.ticalc.org>
Subject: RE: A85: Re: Tyrant ports
From: Erik Huizing <ehuizing@ucalgary.ca>
Date: Sat, 14 Nov 1998 11:59:21 -0700 (MST)
Delivered-To: assembly-85-outgoing@towerguard.unix.edu.sollentuna.se
In-Reply-To: <01BE0EFB.E04A52E0@RichardLewis>
Reply-To: assembly-85@lists.ticalc.org



Here you go:

reStart:
ld hl, jumpTab
ld bc, (PROGRAM_ADDR)
add hl, bc
ld de, TEXT_MEM2 ; TEXT_MEM2 can hold 168/3 rellocated addresses
ld a, 2 ; number of addresses to rellocate (in this case 2)
reloc_loop:
 push hl
 push af
 CALL LD_HL_MHL
 pop af
 add hl, bc ; calculate the real address
 ex de, hl
 ld (hl), 0xC3 ; opcode for JP
 inc hl
 ld (hl), e
 inc hl
 ld (hl), d ; these go in backwards coz the Z80 is little endian
 inc hl
 ex de, hl
 pop hl
 inc hl
 inc hl
 dec a
jr nz, reloc_loop 

; put your program here

ROUTINE1:
; stuff
ret

ROUTINE2:
; stuff
ret

jumpTab:
.dw routine1
.dw routine2

routine1 EQU TEXT_MEM2
routine2 EQU TEXT_MEM2 + 3
; ... etc for each of your routines

; now, if you want to call (or jump to ) ROUTINE1, just do this:

call routine1  ; make sure you're using the EQU from TEXT_MEM2

; what this does is calls what's at TEXT_MEM2 which is this:
; jp ROUTINE1
; except that ROUTINE1 has (PROGRAM_ADDR) added to is already


On Fri, 13 Nov 1998, Richard Owen Lewis wrote:

> 
> 
> I'm interested.  Can I see the code?  I could incorporate it in to Summit, and release it sooner.  =)
> 
> ----------
> From: 	Last Man Standing[SMTP:ehuizing@ucalgary.ca]
> Sent: 	Friday, November 13, 1998 2:42 AM
> To: 	assembly-85@lists.ticalc.org
> Subject: 	Re: A85: Re: Tyrant ports
> 
> 
> 
> I'll have to disagree there. There's still quite a few people I know who
> still use / write for ZShell (me for one). 
> 
> If anyone's interested, I've developed a way to rellocate ZShell programs.
> Its not as simple as Usgard, but still gets the job done. 
>

References:

RE: A85: Re: Tyrant ports

From: Richard Owen Lewis <richardlewis@cedarcity.net>