[Coco] [!! SPAM] Re: Anyone still play text adventure games?

[Aaron Wolfe]

When I first started pulling apart the Bedlam ASM code, I thought it
used something similar to encode the strings, as I couldn't find any
text. After running in MESS with the single step debugger and
following along closely, I found that what Bedlam did was actually
much simpler, but it was effective at reducing size and making things
unreadable.  They basically just reduced characters to 5 bits wide and
packed them into ram.  A lookup table is used to turn the 5 bit values
into ascii for screen display.  Since the coco was upper case only at
that time, having only 32 possible characters wasn't too limiting.
Bedlam can display A-Z, a period, comma, and I think only 1,2 and 9 or
something like that.  I do recall at least one character in the lookup
table that doesn't occur in the text strings.

On Wed, May 25, 2011 at 6:16 AM, John Kent <jekent at optusnet.com.au> wrote:
> Hi Steve,
>
> My brother & I bought a copy of Black Sanctum too for Flex. The problem with
> a lot of the games was that people would cheat by dumping the binary. We
> bought the Colossal Cave adventure for the 6800 running Flex2. Because of
> the memory map of Flex2 and the size of the adventure game it actually
> overwrote sections of operating system so you had to reboot Flex2 after
> playing the game. The Flex9 version didn't have that problem because there
> was more continuous memory.
>
> My bother started to write adventure compilers. I wrote a Huffman (Huff?)
> coding algorithm for the text strings. That involved do a character count of
> all the text and generating a coding table that was unique to the adventure
> game. The length of the character code was inversely proportional to
> frequency of the character. English text though I think is pretty standard
> in the frequency of characters. We used a serial bit stream reader to read
> the text strings and convert them back to ASCII codes. Not only did this
> optimize the use of memory, it also made it difficult for people to cheat
> and look at the text strings embedded in the program. Huffman (Huff?) or
> entropy encoding is used in MPEG video streams I believe.
>
> We started off with the Scott Adams adventure interpreter but ended up with
> a language syntax  that was almost like written English. The code was moved
> to the IBM PC and the working compiler got lost I think. We were told that
> most of the game developers at the time were writing their games in C. There
> was something at the time called Quill for writing adventure games. I think
> it might have been cassette based.
>
> John.
>
> On 25/05/2011 1:33 PM, Steve Ostrom wrote:
>>
>> A group of us at work bought one of the first Cocos available in the
>> Minneapolis area.  We also purchased the Black Sanctum text adventure when
>> that was available, and played the adventure during every lunch break for
>> weeks.  I so fell in love with Black Sanctum that I decided to write my own
>> adventure.  Our small work group then played my adventure and everyone
>> seemed to like it, and suggested I try to sell it.  I sent it away to Tom
>> Mix and to Dennis Lewandowski of DSL Computer Products, and both took it and
>> sold it for about a year.  Graphic adventures were just then beginning to be
>> popular, so my text adventure never really earned a lot of royalty money.
>> Tom Mix actually scolded me for getting rid of a few areas in the adventure
>> by making it fit into a 16K Coco, but I thought that would increase it's
>> selling market.   Oh, well.  I'll never make money in Marketing.  The
>> adventure is called Shipwrek, and was eventually sold to T&D for one of
>> their issues.
>>
>> That relationship with Tom Mix enabled me to start some assembly
>> programming.  I was playing the game Qix in the arcades, and asked Tom if he
>> was developing a similar game for the Coco.  He said no, but would love to
>> have it.  He asked if I could write it.  I knew nothing of assembly language
>> programming at that time, and I learned a lot about 6809 assembly during
>> that exercise.  Tom kept encouraging me, and I kept sending him my updates
>> on a weekly basis.  He was telling me that the author of his Donkey Kong
>> game was pulling down huge royalties every month.  Then my first child was
>> born and the development slowed.  I finally told Tom that I couldn't meet
>> his deadlines.  He asked if it would be OK to give my code to another
>> developer who wanted to try that same game, and I said of course.  Needless
>> to say, about 3 months later, Tom was selling a very good version of Qix.
>> Somewhere, the author did credit me with having helped, but his final
>> product was so much better than mine that I had little to do with it.  I was
>> able to make a good spinning Qix, and developed the game play and the
>> scoring.  I never did finish any sound effects or sparks.
>>
>> After that attempt, I just did assembly language programming on some fun
>> stuff.  Mark and Boisy have a BASIC program that wll back up a full 256
>> drive hard drive, and I wrote that same program in machine language, which
>> runs about twice as fast.  That was disappointing to me, but I think the
>> speed of the drives is the limiting factor, not the programming.  My ML
>> version of that program was actually written and hand assembled on paper
>> only while at my family's lake cabin one summer.  Hand coding and hand
>> assembly is really cool if you really want to learn exactly what your code
>> is doing.  I never did use an assembler on that code, but just dumped the ML
>> code into DATA statements.  I still use that ML code to back up all my
>> software from one HD to another.
>>
>> -- Steve --
>>
>
> --
> http://www.johnkent.com.au
> http://members.optusnet.com.au/jekent
>
>
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