0005231: Hi Psygore, the ISS patch needs a few improvements, which I'll list here: -

View Issue Details [ Jump to Notes ]

[ Issue History ] [ Print ]

Project

Category

View Status

Date Submitted

Last Update

0005231

ISS

[All Projects] General

public

2021-05-24 23:14

2021-09-03 11:12

Reporter

StingRay

Assigned To

Psygore

Project Info

Incredible Shrinking Sphere (Electric Dreams)
http://www.whdload.de/games/ISS.html

Priority

normal

Severity

minor

Reproducibility

always

Status

closed

Resolution

fixed

Summary

0005231: Hi Psygore, the ISS patch needs a few improvements, which I'll list here: -

Description

GameVersion: english,pal,2 disks
SlaveVersion: 1.0 from 20.05.2000

Hi Psygore,
the ISS patch needs a few improvements, which I'll list here:
- 68000 quitkey support (game uses it's own level 2 interupt for keyboard handling hence the KickEmu support for that is rendered ineffective)
- default quitkey needs to be changed to something else than F10 as that key is used to pause the game
- the only OS routines used in the game are DoIO and WaitTOF, both are very easy to emulate so the patch can be made without any OS emulation at all.
I'll apply the needed code here so can copy/paste it.
The only other change needed to make the patch run without a Kickstart 1.3 ROM is adapting the level 3 interrupt code, this can be easily done as well.
Code follows.
Thanks and best regards,
Sting
    ; create exec and graphics library emulation
    lea $200.w,a0
    move.l a0,a6
    move.l a6,$4.w
    lea -456(a6),a1 ; DoIO()
    move.w #$4ef9,(a1)+
    pea DoIo(pc)
    move.l (a7)+,(a1)
    lea $300.w,a0
    move.l a0,$300-4.w
    lea -270(a0),a1 ; WaitTOF()
    move.w #$4ef9,(a1)+
    pea WaitTOF(pc)
    move.l (a7)+,(a1)
; ---------------------------------------------------------------------------
; Exec library emulation code
DoIo cmp.w #CMD_READ,IO_COMMAND(a1)
    bne.b .no_read
    movem.l d0-a6,-(a7)
    move.l IO_OFFSET(a1),d0
    move.l IO_LENGTH(a1),d1
    move.l IO_DATA(a1),a0
    moveq #1,d2
    move.l resload(pc),a2
    jsr resload_DiskLoad(a2)
    movem.l (a7)+,d0-a6
.no_read
    rts
; ---------------------------------------------------------------------------
; Graphics library emulation code
WaitTOF
    bra.w WaitRaster
.SetVBI pea .NewVBI(pc)
    move.l (a7)+,$6c.w
    rts
.NewVBI movem.l d0-a6,-(a7)
    btst #4,$dff01e+1
    beq.b .noCopInt
    cmp.w #0,$a400+$9DA4 ; 1: music enabled
    beq.w .lbC0078FA
    cmp.w #1,$a400+$9DA4
    bne.w .lbC0078F4
    jsr $a400+$790c
    bra.w .lbC0078FA
.lbC0078F4
    jsr $a400+$9df0
.lbC0078FA

.noCopInt
    movem.l (a7)+,d0-a6
.AckVBI move.w #1<<4|1<<5|1<<6,$dff09c
    move.w #1<<4|1<<5|1<<6,$dff09c
    rte

WaitRaster
.wait1 btst #0,$dff005
    beq.b .wait1
.wait2 btst #0,$dff005
    bne.b .wait2
    rts

Tags

No tags attached.

Machine

A4000

CPU

68060

CPUSpeed

ChipSet

AGA

GFXCard

Picasso IV

ChipMem

2 MB

FastMem

128 MB

Workbench

OS 3.1

KickROM

40 - Kick 3.1

KickSoft

None

WHDLoad

18.6

imported

yes

Attached Files

Relationships

Relationships

Notes
note ~0010382 Psygore (developer) 2021-05-28 15:54	Hi StingRay, Yep, if there are only DoIO and WaitTOF to patch, it will be easy to remove the kickemu (we have done some slaves with more OS stuff patched ;) I didn’t take a look at this slave since it was written in 2002. IIRC the kickemu hadn’t the quitkey yet back in the day, so it will have a working quitkey on 68000 now. I usually filled the jump table in library emulation with illegal instruction so it will quit if an os routine is not patched and you will know the function offset. Thanks for your ideas and suggestions, I really appreciate. I will rewrite the slave.

note ~0010385 StingRay (developer) 2021-05-29 16:42	Current KickEmu won't help with the 68000 quitkey support, the game bangs the level 2 interrupt vector ($68.w) directly and uses its own level 2 interrupt. If you're going to rewrite the slave, you may also add some trainers as the game is very hard. Lives are decreased at $a400+$e90, ammo is decreased at $A400+$49da.

note ~0010541 Psygore (developer) 2021-07-16 19:53	Install has been updated.

Notes

Date Modified	Username	Field	Change
Issue History
2021-05-24 23:14	administrator	New Issue
2021-05-24 23:14	administrator	Status	new => assigned
2021-05-24 23:14	administrator	Assigned To	=> Psygore
2021-05-28 15:54	Psygore	Note Added: 0010382
2021-05-29 16:42	StingRay	Note Added: 0010385
2021-07-16 19:53	Psygore	Status	assigned => resolved
2021-07-16 19:53	Psygore	Resolution	open => fixed
2021-07-16 19:53	Psygore	Note Added: 0010541
2021-09-03 11:12	Psygore	Status	resolved => closed

Issue History