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Posted By

Csabo
on 2003-01-06
 Oblido

Title:Oblido
Category:Game/Sokoban
Release Date:1986-06
Language:English
Size:16K
Machine:PAL & NTSC
Code Type:Machine code
Distribution:Commercial/TA
Oblido Screenshot


There was a topic on this quite a while ago here, but I didn't want to resurrect that thread. I've looked into this problem with the game (about crashing after level 4). I found the part that's called after a level is finished, but that part is well written. That is, it increases the current level variable, and checks whether its value is now 4. (Levels are numbered from 0-3.) If it is 4, then it resets that variable to zero, then continues. So that part shows that after level 4 we're supposed to get back to level 1. In this case, it even increases another variable (which can only go up to 4 as well). I'm not sure what that does, maybe increases the speed? Well anyway, the problem is not here.

While looking through this, I found a few interesting things though... First of all, you can shoot! I was shocked when I found that out. I've been playing this game for over a decade, and I never once shot... It's as simple as pressing space. Apparently it's not necessary to win the game (you can just crush the sinners instead of shooting them). Some of you probably knew this. However, there's yet another key that the game supports and this one is not even in the manual. By pressing Inst/Del you can restart the game from level 1.

In the previous thread I mentioned that maybe the game creator (we still don't know who wrote this!) didn't have enough memory. I realized that this is not the case, there's still lots of bytes left empty ($1C00-$1D00, or above $3DEC). So Lando's assumption must be right, that is the game is so difficult, that no-one sat down to fully test it. But from parts of the code it's clear that the game was intended to continue on level one after lever four.

I've also managed to create a new cheat for the game (playing without the sinners). I'll keep looking for the '4th level bug', and see what I can find.

Posted By

MIK
on 2003-01-06
 Csabo

Intresting stuff and a good read there buddy! happy

I knew about the fire wink Thing was, it was messy and very hard to shot the sinners because they flashed so you indeed did end up using the blocks to kill them which was much quicker happy

If you do get time could you take a peek at Molecule Man. The inlay card states joystick but it never worked wink

Posted By

Csabo
on 2003-01-16
 Oblido Bug Found

After all this time, the Oblido saga reached its final chapter... Well, anyway happy I finally found the bug in Oblido, and yes, it is a human error, a real bug. The game constantly checks whether the houses are full. To do that, it has to know the screen coordinates of each house, those are all correct. However, besides the coordinates, it also has to know the layout of the house. This is solved by using three separate routines. One routine ($2372) checks for a 3 by 3 house, the second ($2340) checks for a 4 by 3 house and the last one ($2363) checks a 3 by 4 house. (Like that blue house in question on the 4th level.)

That's where the bug is. The routine responsible for checking that blue house is at $26E5, and it is the 'last' house from the game's point of view. Well, it uses the JSR $2340 call... 4 by 3 layout, which is impossible on that screen (because of the wall). Yes, it should be JSR $2363. So to fix up the game (works in emus or on the real machine):

Reset, Monitor (return), then >26F6 63 (return), then G1068 to restart. That's it. One byte changed, and the game works fine, you can finish the 4th level and it does restart from level one.

One more thing: I have finally created a 'start from any level' cheat for this game. It was a bit difficult, because the game does some initializations only on level 1, but I figured out a way of doing it by changing only 5 consecutive bytes. Anyway:

Reset, Monitor, >131F 20 32 3D A9 00 (return), then >3F8 X where X is the starting level (0-3), then G1068 to restart. Happy crushing!

Posted By

George
on 2023-08-20
19:00:52
 Re: Oblido

Very underrated game. I really like the game

a) Any ideas who was the programmer?
b) I bought the game recently for a review and the instructions at the back are from POD (Proof Of Destruction). Manufacturing fault. See my latest video on my YT channel https://youtu.be/dNTkjhsHy2o?t=71.

Posted By

Csabo
on 2023-08-20
19:16:29
 Re: Oblido

I've said it several times that it's my favourite happy (It's also one of the very few games where I hold the top spot in the Hall of Fame.)

There's never been any definitive info on who programmed the game, but if I had to guess, I would say it was either Fergus McGovern or Vakis Paraskeva. They founded Probe Software, who produced this game (source: Retro Gamer 156).

I should sit down one of these days and play another round, but that's 2-hour-minimum affair happy

Posted By

George
on 2023-08-20
19:53:38
 Re: Oblido

Yes its a fantastic game. I actually ran into that bug in the 80's. Maybe i would have hold the record for the game...:)
I found Fergus McGovern is on facebook but he hasn't posted since 2012. (Edit: he died in 2016)

I found an article about Probe: https://segaretro.org/images/3/30/ProbeSoftware_AmstradUser1988-08_article.pdf



Posted By

MIK
on 2023-08-21
00:49:50
 Re: Oblido

Nice find George and good read!

So neither of them coded our games, they were just middle men. happy
Great to read they covered the C16/Plus4 side of things but for a company out to make a few bucks C16/Plus4 was a very strange choice to start with.
Those who lived in the UK all knew the game name Dirty Den was the nickname of a character from the BBC soap Eastenders, used hoping it was sell more copies... Maybe Dirty Den's loading screen is a clue to who coded it, One Man And His Droid uses a similar style just like Oblido does.

Not sure why or when but by the 1990's Probe were addressing them self as being based in Winchester, on my doorstep and I didn't realise for a long time.

and what a load of pony when the article was going on about OutRun on Atari ST lol, it's one of the most memorable games on both the Atari ST and Amiga for being utter crap! grin

Posted By

Csabo
on 2023-08-21
08:52:36
 Re: Oblido

Well... The Sega Retro article talks about later days. The Retro Gamer article says this on the other hand:

> Vakis programmed the company's early games, starting with Alcatraz on the C64, then Dirty Den and Defence 16 on the C16.

Since 1986 was "early days" for this company, and 2 of their 4 releases is confirmed to be coded by them... There's a chance that they wrote Oblido too.

It would be nice to find Vakis and get in touch with him!

Posted By

MIK
on 2023-08-21
11:13:10
 Re: Oblido

Probably best to stick with the original guys being credited then. happy

Posted By

Lavina
on 2023-08-21
18:56:04
 Re: Oblido

there is something about this game that captivated me a while back and I remember plaing a lot with this at some point. And thanks to Csabo for this new feature of the site that we can comment now for sw.

Posted By

Csabo
on 2023-08-21
20:03:19
 Re: Oblido

The thanks should go to @Murphy; he's the one who came up with the idea/request. It's definitely a good idea, so I implemented it. Seems to be popular happy



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