Adventure games: written in assembler? What compression?

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occularis
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Adventure games: written in assembler? What compression?

Post by occularis » Thu Jan 11, 2018 10:26 pm

I have fond memories of playing adventure games like kingdom of hamil, philosophers quest etc.

Am I right to assume these were coded in assembler instead of basic? What sort of text compression algorithms were used, if any? What sort of hardware (plus any addons/peripherals) were used in coding them?

Also, did these adventures tend to be written from scratch each time, or were there adventure game engines used (I suppose particular software houses might have had a common engine)? I’m familiar with Quill.

crj
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Re: Adventure games: written in assembler? What compression?

Post by crj » Fri Jan 12, 2018 4:45 am

I definitely remember there being a significant BASIC component to Philosopher's Quest. I doubt there was any machine code at all, though they may well have tacked some binary data on the end of the program for the sake of compactness.

The Topologika games were in general developed on Cambridge University's Phoenix mainframe using a custom framework written in BCPL. I even played a few of the games in that environment directly from Jonathan Partington's "home directory" in the early nineties. To run on the BBC micro they were in effect compiled info BASIC.

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lurkio
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Re: Adventure games: written in assembler? What compression?

Post by lurkio » Fri Jan 12, 2018 12:26 pm

crj wrote:The Topologika games were in general developed on Cambridge University's Phoenix mainframe using a custom framework written in BCPL.
Interesting! I'm very ignorant about all this, so perhaps you can say something about how whatever it was they did with BCPL related to, and interacted with, whatever they did using "T/SAL"?:
crj wrote:I even played a few of the games in that environment directly from Jonathan Partington's "home directory" in the early nineties.
Wow!
crj wrote:To run on the BBC micro they were in effect compiled info BASIC.
Do you know anything more about the details of this?

:?:

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Re: Adventure games: written in assembler? What compression?

Post by crj » Fri Jan 12, 2018 4:03 pm

lurkio wrote:perhaps you can say something about how whatever it was they did with BCPL related to, and interacted with, whatever they did using "T/SAL"?
BCPL is the language they wrote T/SAL in. I'm afraid I never really investigated the innards of T/SAL.
crj wrote:To run on the BBC micro they were in effect compiled info BASIC.
Do you know anything more about the details of this?
Not much. If you load one of the games and type LIST it's pretty obvious the code wasn't written by a human, though. (-8

I seem to remember spotting some lines in Phliosopher's Quest that are too long to type in, which suggests either that T/SAL natively spat out BBC BASIC files rather than text files which got *EXECed, or that they ran some kind of compactor as a secondary step.

Now that I think about it, I suspect it was probably the latter. Working with ASCII on Phoenix was a complete pain because it was natively EBCDIC. If I was them I'd have had T/SAL spit out the BBC BASIC as an EBCDIC text file, then spool that into a BBC Micro text file via a terminal emulator.

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Rich Talbot-Watkins
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Re: Adventure games: written in assembler? What compression?

Post by Rich Talbot-Watkins » Fri Jan 12, 2018 4:14 pm

You might be interested in the articles in Acorn User August and September 1988 on the adventure "The Warlord". The September article goes into some details about the engine it used (TAG), including examples of its scripting language and text compression techniques.

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tautology
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Re: Adventure games: written in assembler? What compression?

Post by tautology » Fri Jan 12, 2018 7:46 pm

I've been extracting stuff from Text Adventures for decades. Some of my code is on my github page which includes Robico, Adventuresoft and the BBC Quill: I'm not very good at describing the file formats, although I started trying to when I was working through a disassembly of Island of Xaan: https://tautology.org.uk/blog/2017/11/0 ... d-of-xaan/

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Re: Adventure games: written in assembler? What compression?

Post by SteveF » Sun Jan 14, 2018 5:27 pm

Possibly a bit of a tangent, but FWIW there's some information on Phoenix, T/SAL etc in these articles:

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