Monday, 7 February 2022

"House Adventure" by Anonymous: A TRS-80 Model 100 Game

Similar to my last post about "Space Derelict" I recently converted another interesting and obscure text adventure program, but this time as a response to a request from someone who had wandered into my text adventure page:
Jim, I've got one more random game request that one of my cousins remembers playing. We believe we found the code here - It's under the first section on the page, and is called "House Adventure". Any chance it's an easy one to post for play on your emulator?

I converted this program to Micro Color BASIC from source from the Club 100 Library of text adventures link mentioned above.  As in my conversion of Space Derelict, I ended up making a lot of modifications to the program to make it more coherent. But for this one I also made changes to make it more forgiving/winnable/playable.  I think it had an excessively brutal level of expectation of a player's willingness to restart a game after losing or being put in an unwinnable position. This level was only justifiable in a time when programs were rare and hard to come by. It also simply had some bugs. Both of these reasons were possibly why my contact's cousin had been so frustrated/fascinated by the game to want to return to it all these years later.  But also, there was a swan of a game waiting to emerge, which I think must have also been a part of his captivation. So I don't feel bad about altering this old program from its original form.

It was only after a lot of bug fixing and conversion work and lots of frustrating hours trying to solve the game (using peeks at the code garnered from the conversion process) that I discovered via a comment by Strident on the CASA Adventure forum, that Gaming After 40 had done a walkthrough of the game: "Adventure of the Week: House Adventure (1983?)".  I had already fixed many of the oddities that he also had noticed, but his post put me on to a few more. Here's a list of the main changes that I made (and can remember):
  • I fixed the strange illogical wrap arounds in the map. They didn't seem to add anything to the game play, and if they were there as a way to create a surreal atmosphere it didn't work for me. It just made me feel like there were errors in the map info.
  • I also changed the game so that the player has 60 moves with the flashlight, not just 40, which would allow for a fairer exploration of the basement. Also, if you end up in the dark, you die less quickly, providing you with some possibility of making it out from memory after the lights go out.
  • Bugs relating to floating-point numbers being generated by the random number calls are also fixed.  This and the weird room wrapping makes me think this may have been a botched conversion.  Also, the messages seemed to be formatted for something like a 32 X 16 column screen and not the 40 by 8 screen of the Model 100, which makes me think it may have started life as a TRS-80 Coco program (or possibly for the C64 or Atari game). But I couldn't find anything like it in the 4 Rainbow Adventure books. One thing that speaks to it being a Coco or TRS-80 Model 1 conversion, is that the RND calls typically take the form of N=RND(1)*4-1 for floors (0-3) or magic words (0-3) and N=RND(1)*9-1 for one of the 10 rooms (0-9) on each floor.  On a Coco you'd get such numbers by doing RND(4)-1 and RND(10)-1. There is also one instance of RND(1)*10-1 for random room assignment.  I think the programmer didn't really understand the nuances of Microsoft's various random number generation conventions, which were different between the version of BASIC on the Model 100, and that of the Coco and Model 1. The programmer really shouldn't have kept the -1 in there, since, for example, RND(1)*4-1 would only result in integer values between 0 and 2, thus omitting the last magic word as a possibility. Instead, I changed these references to generate consistent 0-3 and 0-9 ranges where appropriate.  In certain instances, 0-8 was needed, such as to omit the possibility of  assigning monsters to the elevators (room 9 on each floor).
  • I corrected a few spelling errors.
  • Now when carrying the aluminum dime into a phone booth you are guaranteed to be transported to one of the other booths in the house, and therefore notice the magical effect. I think "phone nook" or "phone vestibule" might be a more accurate description of these rooms (old mansions have these), but I left it as "phone booth."
  • You now have a 5 item carrying limit, instead of 4, which means the game is no longer an endless slog of to-ing and fro-ing. You have to keep hold of the flashlight and its batteries (for the basement), which eats two items and later the dime (for using the phone booths to get to the 3rd floor), which only left 1 item space under the 4 item limit. Since you must usually also carry one item to complete a task, and there might be multiple tasks and sometimes multiple items in an area, you would have to make multiple tedious trips into an area just to bring items out after solving a puzzle to gain access to them. Seemed ridiculous, especially when some items (like the batteries) go inside another item.  Even the crazy map wrap arounds made little difference in regard to this problem. In terms of possible shortcuts they might save you one or 2 moves at best.
  • The awkward formatting of the final victory message is fixed.
  • The monsters can sometimes be relocated to the Foyer, which is where you can drop items before getting the key and transferring them outside for your points. Sometimes you can lose simply because a monster gets shifted to the Foyer and then it prevents you from picking up any of the items, including potentially the item that allows you to banish the monster if you didn't notice the monster before dropping that item; or if you carried it directly outside (where items disappear at random). It seems a real shaft that you can inadvertently take items outside and then lose access to them (are people stealing them?) and then realize you need them again because a monster got shifted into a room with another item in it and starts protecting everything there. This forces you to store things in the Foyer, just in case, and then once you do this and are hauling items there (all the to-ing and fro-ing) only to realize that a monster shifted in, and you are now stuck because you have just dropped an item needed to banish that monster.  Also, the fact that the items can create a list so long that they actually scroll the screen adds to this infuriating possibility.  So I added a scroll pause routine when the item list for a room gets long.  But I wonder whether it would be better to simply prevent monsters being shifted to the Foyer. The author certainly seems to have delighted in finding ways to foil the player's (tedious) efforts to collect treasures. 
  • Now the 3rd floor phone booth will always transfer you to another phone booth, even without having the dime, so you can't get trapped on the 3rd floor before getting the dime. This can happen if you get there by discovering and testing out the magical words, which can zap you to random rooms. Text adventures shouldn't just be about meticulously recreating movement patterns learned after continuous arbitrary failures. They should be about figuring out clues and solving puzzles while exploring.
I was tempted to correct the use of a garlic clove to scare the Werewolf away, but I did find a single reference online to Eastern European beliefs about garlic warding off all manner of evil creatures including werewolves. So perhaps this is a clue about the ethnic background of the programmer.  But as Gaming After 40 suggests, this is not "canon" in terms of broader popular culture.  Garlic and sunlight  (and flashlights?) are for vampires, wolfsbane or silver are for warding off werewolves.

I also did a bunch of alterations to the arrays to consolidate them into one single multidimensional array to make the game save feature work on an MC-10.  So if you want to use that feature you will have to use Tamer's VMC10 emulator rather than the online MC-10 emulator, which doesn't support file saving.  Here’s a link to the VMC10 repo:

It contains all the MC-10 programs including all the text adventures displayed on my rare text adventure page:

It also includes HOUSE.C10, in the JimG directory in the “Cassette” directory.  You can just launch vmc10.exe from the directory that you unzip the repo to and then can play any of the files in the Cassette directory.  Type RUN to launch the game after CLOADing it.

My version of House Adventure should be more coherent and forgiving than the original, but it is still a  tough adventure. I have played it to completion (see the video above--spoiler alert), so I know that it can be resolved. If you need help, then the Gaming After 40 walkthrough on his blog will get you through. He also outlines many of the bugs and weirdness that you need to remedy to get the original program to run on the TRS-80 Model 100.

I'd like to thank my informant for putting me on to the game. Strident and the other archivists over on the CASA text adventure site realized the the game wasn’t catalogued when I posted about it, so his suggestion was helpful for bringing it to their attention.

HOUSE can be tried online here, although you won't be able to use the helpful game save feature (saving is not supported by the online emulator):

Jim Menick's "Space Derelict"

Strident over on the CASA Text Adventure archive was doing a little research into Jim Menick, an author of a type-in how-to book "Basic Adventure and Strategy Game Design" from 1984. He mentioned that the book was published for the Apple II and TRS-80, but that there didn't appear to be any playable version of the game on the archive or anywhere out there on the Net. There was also supposed to be a version for the IBM PC Jr. but the demise of that machine apparently took that edition with it.

Strident posted a place to get a scan of the TRS-80  version of the book: ... lications/

Garry, another frequent contributor to the Classic forum on CASA and a typer-in and fixer of games, already had the game in progress.  He noted that there weren't any copies of the Apple version of the book available in scanned form online, but that he had started converting the TRS-80 listing into working code.  It was specifically programmed for the TRS-80 Model 4, which presented some problems, as that was a rather unique later version of the TRS-80 Model 1 line.  For example, it had an 80 rather than 64 column screen.

I decided to take a look at the TRS-80 scan, and realized it was pretty clear. Most of the source code listing could be easily copied from the PDF without too many errors, so I undertook to convert it into an MC-10 program. But first I had to get it back into a readable form for its original TRS-80 Model 4 form as printed in the book. For those interested a fairly bug free version can be found (DERELICT1.TXT) on my Github.

However, if you want a fully debugged version, it would be better to dig up Garry's conversion.  Also, my version had to condense some of the descriptions in order to get it all to fit in 20K.  I don't think anything critical has been omitted and in some cases the descriptions are perhaps even a little clearer and more elegant (a conceit on my part, I'm sure, but hey, it was a lot or work converting the program).  However, I did make one stylistic change that actually takes a little more space, which was to get rid of all contractions in the robot's responses.  Real robots and Androids, as commander Data teaches us, don't use contractions.

Garry notified me of a couple of bugs from his early notes. "In line 13130, '3180' should be '13160'. In line 6570, '5760' should be '6760'." I had already found the 6570 bug but not the other one. I also found an error in 5950, where it should print the A$(19) message instead of the one listed.  Garry also found another bug he notified me of later on, which  prevented you dropping anything: "In line 6570, '6950' should be '6590'."  I had already fixed this bug in the midst of my rationalization of the code to shrink its size to fit in 20K for the MC-10.

We both ended up tearing out our hair because we couldn't get past one of the first puzzles.  You get fried going into a room in the early stages that you clearly need to get into (you can see into it from a prior room).  Turns out that you have to be carrying a pentagon and a crystal, which together form a telepathic device for opening doors.  You have to "think open" in rooms with locked doors while carrying both items.  This includes the room you get fried going into.  But by using the telepathic pentagon and crystal doors will open (or in the case of that room, disengage whatever safety device that is frying anyone who enters.  In other cases you must "click" the pentagon.

I realized there was a walkthrough provided by Menick on pages 21-22 of his book that describe this, but it was not entirely clear. He also provides a map, with numbered rooms.  To get into room 5 (the frying room) you have to THINK OPEN or SAY OPEN in room 11 (the one where you can see into 5). You have to be carrying the pentagon and the crystal you can get from room 7 (by clicking the pentagon) for this to work. Menick admits in his walkthrough that this "mind trick" is a bit of a devious puzzle, although there are some clues.  For example, when you carry the crystal into the hologram you get a subliminal message saying "THINK HUMAN."  But I think there might be an error with the messaging in room 11. Menick's walkthrough description indicates that the player should be able to LOOK OBJECT and see that the burnt metal thing in room 5 is a fried robot. I think this is supposed to be your warning to stay back, but it didn't work on my version. But I can't be sure if that was a result of my conversion hacking or not.  In any case, I fixed it in my version so that you can LOOK OBJECT and see the fried robot.

Despite its relatively small size as an adventure there are lots of puzzles in this game and (as was typical) more than a few sudden deaths.  Menick tried to provide many synonyms (some of which I had to remove to save space) but there are still a few guess-the-verb situations.  There is a lack of abbreviation for things like INVENTORY and the non-standard directions like NORTHEAST. 

There were a few elements of descriptions that Menick mentions in his walkthrough but which don't appear in the actual game, such as the climbing ropes in the exercise room. They're not in the description, but if you CLIMB ROPE, you die (clumsy robot?).  CUT ROPE will allow you to get piece of rope if you have found the knife, but all this serves no purpose, as the rope element is a red herring.  I added the ropes to the gym description in my version.

It was like Menick was still tweaking the code when it went to press, or perhaps he only hurriedly converted it from Apple BASIC. Strident mentioned that he found biographical info on Menick that indicated that he was primarily an Apple user. This seems likely as the TRS-80 code is quite simplistic, and as a result, a little bloated. It was tough getting it down to under 20K.  I had to convert the room messages being loaded from disk, which relied on creating a special data file, and simply make them all into DATA statements.

But on the whole, I quite liked the creepy space derelict story and the robot-at-your-command idea that Menick uses to allow you to explore the ship at a distance. When the robot dies you just get a chilling repeated "END TRANSMISSION" message. The bugs were not of the game breaking type, just annoyances that somewhat spoil an otherwise neat little game. For example, you could press the green button to open the door into the ship without having pressed the black button to close the outer door without triggering explosive decompression. Menick sets a variable AL=1 for when the outer airlock door is closed, but he doesn't use again. I changed that. Now its black before green and you're keen, green before black you ain't coming back. I know the ship has air because there are footprints in dust on the floor and things aren't floating in a vacuum, etc.

The book is a little turgid, but having written some turgid pedantic books myself I'm not going to be overly critical.  And most of the how-to books of the time were like this. The code was very simple, which is perhaps justified for its pedantic purpose. Multiple repeated IFs for everything, including the handling of every movement. I've seen games with 3 times as many rooms and messages but about the same byte count because not all of it was eaten up by program commands (so many IFs!). Still, a neat premise that actually works out well for a little 8-bit BASIC adventure of the time period. However, I think Menick is a better fiction author than an elegant coder, although he gets the job done.  And he does suggest in the book that it is up to the reader to take the programing further.  I think I've fixed most of its annoyances in my version, so I took his advice.

Thanks to Strident for the original suggestion and to Garry for all the debugging tips.

Now I might take a crack at his five person poker game in the second half of the book, which is a demonstration of the "strategy" part of his title.  Converting "Space Derelict" was a fun little exercise in bringing an old program back to life from digital oblivion.  Perhaps his poker program might demonstrate some interesting elements of early AI programming.  He does mention that he tried to give all of the opponents playing styles from different people he actually knew.  I'll keep you posted.  In the meantime if you want to help bug test/try out DERELICT it can be played in Mike Tinnes online emulator here:

If I can get hold of Menick, I will hopefully be able to arrange permanent access to the program from my site.

Friday, 21 January 2022

Debugging Old BASIC Games with Neat AI Opponents

It started with an email from Greg Dionne that he had triggered an error in my ACHESS program with these moves:

Choose "0"
Then do the following moves:
E2 E4
B1 C3
G1 F3
D2 D3
C1 C2

It gave a ?BS ERROR IN 4200.

This got me looking at the program again. First thing I did was rename and move AChess to CChess, since this title had been bugging me a little. I had initially called the the program AChess because it was written in Apple Integer Basic, but the programmer had titled the program "Computer Chess" so I thought I should rename it and put in renamed directory reflecting its internal title:

I think the error Greg noticed was a problem in the original program. It didn’t clear some variables used in the input routine until after the branch taken by the “OO," which left those variables in states that couldn’t be handled by the 4200 routine, which was called after the return from the input routine after an "OO" is entered, but before the initiation of the "castling function," which would set those variables to some specific values.  Or so I think after having tried to chase down the assignments of all the variables involved that were causing the error and comparing them to the original code. Nothing would seem to account for them being miss-assigned. But by simply zeroing them before the check for the input of “OO”, since they were zeroed right after that branch anyway for processing the input of regular moves, the problem went away. As I said, those particular variables would eventually be set to specific values by the castling routine, but before that routine was reached after the return from the input routine, flow had to get past a call to 4200 (basically a routine subroutine needed to display pieces in their designated new locations).

I was a little surprised that such an error might have existed in the code, since after a little investigation I discovered that the programmer Mark Watson had made the program back in 1978, and it had been distributed on a sample disk by Apple. He apparently was programmer who made contributions to AI and computer game development.  Perhaps Integer BASIC is more tolerant of array variables going out of range or something like that, so it might never have triggered a catastrophic error.  It was neat to discover that the code was an interesting contribution to early chess AI coding in BASIC.  Hopefully, it is a program more people will try out now.  My impression is that getting an Apple emulator up and running to run the early Integer BASIC can be a bit of a challenge, so it might be helpful have it converted to Micro Color BASIC.

In the midst of conversing with Greg about this minor bug, he also pointed out another in another program I had converted from a while back:

Hi Jim!...noted a few funnies in OTHO36.TXT
* line 1350 when using MID$ .. an extra ')' in front of the ",2".
* line 1440. extra parenthesis.
There were definitely typos there. Not sure if they were fatal in Coco BASIC, but in the MC-10 they certainly triggered errors under certain somewhat rare circumstances. I also found another error in line 1430.  The assignment of the array variable had a 9 instead of a right bracket for the array variable.  That definitely caused an error.  So I looked back at the original source (from the Coco archive) and all the errors were there in the original source.  So I decided to look at the code more closely, since I now suspected that my conversion had involved too little checking.

I found a few more quirks.  Not major errors, but obvious oversights by the programmer, probably just because he didn’t have the luxury of a full screen editor view of the code.  The message to display “THE COMPUTER WINS” for example, didn’t work.  The IF checked an incorrect variable.  Stuff like that.  Also, in two player mode, there was no win check for the two human players.  They would have to both agree when someone had won and then break out of the program and type RUN to start a new game. So I added a quit option so that players could more neatly begin another match.  I also modified the “THINKING” flashing message as I found it too flickery. I added some speed-ups, such as converting IF AND constructs to IF THENIF constructs.

OTHO36 is by Alain Dussault from 1982. It's an Othello game that plays a very strong game, at least from my limited experience as player.  Like CCHESS it is another interesting example of an AI opponent programmed in BASIC in the early days of 8-bit computing.  I really hope people will give it a try and that my edits might help folks to have a less frustrating experience with it.  They mostly involve dummy proofing.  For example, I discovered an error that I think would only happen if you triggered two consecutive input errors (move onto an existing piece, move to an invalid location) on the first move of the game. Unlikely and rare, but nice to get ride of it.

I hope I have actually improved these two neat programs, and not actually damaged them in some way.  They can be played here under the "Classic 8-bit Games" and the "Other 8-Bit Basic Game Ports" menu selections after you choose "Play Game":

Thursday, 13 January 2022

Galactic Hitchhiker by A. Knight (1980)

I've made a recoding in Micro Color BASIC (for the TRS-80 MC-10) of the text adventure "Galactic Hitchhiker" (1980) for the Compukit UK101.

Gareth Pitchford (I'm assuming it's him based on his avatar pic from on CASA and Facebook) gave me the idea in a post over on the CASA Adventure archive forum.  He noted that it was an important landmark game; one of the very first original British authored "home computer" text adventures.  Unfortunately, it was for a very early 8-bit computer system, the Compukit UK101, which was a unique variation of the Compukit line from America. As a fairly rudimentary system, it was a little more difficult of operate than later home computers, and modern emulation can pose some difficulties for the uninitiated.  He suggested that if I was looking for adventures to convert or "fix up", this might be a good one to try.  He was right.

He set me on to a page he hosts "8bitAG" with a write-up about the game and a walkthrough and map by benkid77:

Benkid's walkthrough provided me with invaluable information, especially the video.  I used Gareth's page to find my way to the hex file of the original program. I was able to download it and then convert the hex listing to ASCII characters, which produced something like this:




This gave me all the messages and room descriptions. Then I just had to use my go-to BASIC text adventure engine, "Tower of Mystery," which was provided as an example in Compute's Guide to Text Adventures (1984). It has all the standard commands for handling all the functions of most BASIC 2-word text adventures.  I just stripped out the "Tower of Mystery" stuff, and put in the room descriptions from the hex dump converted to DATA strings.  Then I just had to figure out the directional relationship (N/S/E/W/U/D) between all the rooms working from the video walkthrough provided by benkid. From that and the printed walkthrough I was able to come up with a map like this:

Obviously, the maps have had a lot of erasing and editing from my original crappy versions. The room numbers are mine, from the reprogramming process, but because I didn't disturb the original order too much (except for the first few room descriptions), you can discern the mapping of the author. The rooms are arranged in a grid (roughly 5X4) of 4 "levels" corresponding roughly to 4 main episodes/locales in the game.  Another interesting structure I stumbled across involved the scoring (although this may not correspond to the original). There appear to be 10 main puzzles/milestones in the game, which boil down to this list:
  1. OPEN DOOR (to get to the escape craft)
  2. CHOP TREE (to get to Gerb City)
  3. CHOP GERBICOP (to get the scarf)
  4. CUT FENCE (to get to the Spacetran)
  5. PUSH BUTTON (to escape the Spacetran)
  6. WAVE SCARF (to get rescued and taken to Gomeril)
  7. FEED GHOULIBRUTE (to get blaster to shoot Ranger)
  8. SHOOT RANGER (to get into the Time Corp building)
  9. DON'T PANIC (to get into the Time Machine)
  10. PULL LEVER to return to the beginning where you must GET TICKET and then get to the Starliner in time (to win).
Not sure if this corresponds to the original, but I like its simplicity and the fact that if you give each step a weight of 10, you get a kind of percent meter to gauge your progress to completion.

My reconstruction of the directional information is made just from posted walkthrough's and analysis of my evolving maps. There might be some differences in the original in certain areas where the walkthroughs didn't go. I invite anyone with in depth knowledge to try it and then let me know if they can find any major differences. HITCHHIK can be played here: 

In particular, I have simply speculated about the wandering that might be present in the "Desert of Grey Ash" map, particularly around rooms 51 and 49.  It was also just from the apparent arrangement of room numbers that I have put the "Theatre" (Room 15) from the City of Gerb where it is.  

It is also speculation on my part that there is a count-down on the first map, and that the player has a limited number of moves before the planet blows up.  This is currently set to 30 moves.  I'm not sure if this is a fair amount for a first-time player.  When you return to the beginning by way of the time machine you get 20 moves to get to the Spaceliner to complete the game.  I tried this, and if you make a mistake like forgetting to pick up the ticket, you wont make it back to the Lounge and then back to the Liner to escape before the planet blows.  Again, I don't know if this is fair, or even like the original.

There is also some guess work on my part about the deaths. The video walkthrough provides some hints about these, as do the messages from the original code.  But there is still some speculation involved on my part.  Some deaths might be missing.

In any case, I don't think any of my speculations are weird. They make for a pretty standard game like any of that time period.  So my version might not be a perfect recreation, but then again maybe a slightly altered version might not be that bad, especially for those wanting to revisit the game. But I still would appreciate any comments that might allow me to improve fidelity. Then again, many of the commentaries I read about the game, such as Renga in Blue's (who also provided a useful partial map), note that the original (probably because of memory limitations or because the genre was still so young) had some annoying traits. There was no LOOK command. There was no INVENTORY command.  There were no shortcuts for the directions. These have all been fixed.  An EXAMINE command has also been added, along with other niceties curtesy of the Tower of Mystery engine.

I hope some folks who wouldn't have had an opportunity to play this quirky game now will be able to try it. It's a wonderful parody/homage to the Hitchhiker 's Guide to the Galaxy franchise by Douglas Adams, with a little reference to Dr. Who thrown in for good measure.  Spike is Ford Prefect. Maurice is Arthur Dent. Marina is Trillian. You can get a taste for the sense of Knight's humorous take on these characters from the intro screen:

Enjoy.  And please comment.


I realized after watching my own video walkthrough that the Tower game engine was using the phrase "You see" as part of its description.  However, in the original game the references to the main character are always in the form of "I" references coming from Maurice, with the player being the "You" who is recommending actions to him as a helper per Spike's initial request to "help him" get home (or controlling him a la Scott Adams' "puppet" metaphor for the dynamic between player and character in text adventures). So, for example, Maurice refers in several places to "You" such as in the desert, where he asks "Have you got me lost?"  So I cleaned up all the references to "you" coming from the parser that were referring to the player, and switched them to "I" references, such as "I see" "I'm carrying" and "I can't", which refer to Maurice the character and what he is experiencing.  This convention is an indication that this text adventure is a very early one (for Britain) and that such conventions were still fluid.

I also added the ability to get an INVENTORY by typing "OPEN RUCKSACK" to be like the original and fixed a misplaced comment from Spike.  He says "Cool baby" when you are ejected into open space, rather than when you get to the final elevator, which had been a complete speculation on my part.  It's much funnier as a comment when Maurice is floating in open space.  I also fixed it so you die if you don't wave your scarf in open space, rather than simply being left in a room with no exits.


With the help of Gareth's page I finally got the Compukit emulator up-and-running and played through to the Desert region.  I was able to figure out the rooms in the 49-51 grouping.  I realized that I had left out and combined a number of room descriptions.  I was able to restore the original map, but I had to add 3 new rooms.  In the course of making that change, I was able to consolidate the repeating Desert description, so it used a single string for the initial part of all the desert room descriptions. This saved a bunch of memory, so I was able to go back and fix up some things and make some minor additions to the program.  I had been somewhat constrained because I was reaching the max of memory.  I noticed a misspelling of "corridoor," which I changed to "corridor."  I added a description to the EXAMINE function that notes that the axe is for chopping trees, since Renga in Blue had complained that there was no specific reference to TREE as an object in the game. I also made it deadly to try to kill the Jolly Gerb Giant or the Ghoulibrute, since there are plenty of warnings about Ghoulibrutes (and who attacks a giant!). I also made the Ghouilbrute disappear after you feed him, since I noticed that happened while playing the original. And I made Maurice's complaint that "the whole place is blowing up..." disappear after your reach the lift to the Starliner the first time. Seemed a bit excessive to have it repeated ever time you enter the room, and the original game removed it.  Anyway here's the new desert map:

Saturday, 8 January 2022

Simple 5-Heuristic Chess by Mark Watson

An idea I had for some simple chess pieces using SG6 mode got me looking for more chess source code on the Net that I might be able to use to implement them.  Here is a rough mock-up of what I had in mind.

Pawn Rook Knight Bishop Queen King

I came across a neat little program:


Ported to Micro Color BASIC for the TRS-80 MC-10. It's a fairly tough little program, at least for an extremely casual player like me, although I do get it in the end. There is no wrong move detection, so I could have cheated without knowing it. Let me know if you spot anything fishy. See here for info about the original:

Here's me playing the game:

Here's me winning:

I might try converting the code to use my SG6 chess pieces if I'm really bored.  Or perhaps pitting this game against one of my other chess programs.

Here's a mock-up of what my SG6 chess board might look like:

Wednesday, 5 January 2022

The "Four" Colours of SG6 Mode

On Cocotalk last week L. Curtis Boyle mentioned my "Tank Capture" port (from a TRS-80 Model 1/3 game) and noted the "stripy" green characters left as trails behind the tanks.  I made a short video about these green characters.  Not all the “undefined” characters (0-127) from the MC6847 SG6 character set appear as “stripy” characters.  Two characters (ASCII characters 0 and 85) appear as solid dark green and solid light green characters on real hardware, probably due to some NTSC artifact effect. You can see them in the video (the dark green block on the last few seconds is one of the target blocks).  In many of my SG6 games I use these two characters to provide some visual variety to the otherwise limited RED/BLUE semi-graphic block characters.

Flywheel with light green sky and dark green wheels

XRally with dark green fuel bar and light walls.

From what I have been told, the 0-128 characters of the character set in SG6 mode are a result of the fact that the lines for the MC6847 VDG chip are not wired up fully for that mode.  Other computers like the NEC PC6001 do wire up the VDG to exploit all its abilities.  You can see that demonstrated here:

The NEC PC6001 really pushes the VDG to its max.

You can see that there are actually 4 semigraphic block colors available and text mixed in, so how the VDG is wired up can be much more complex. It's interesting to think about what the possibilities would have been for games if some extra wiring had been added to the MC-10 to exploit those modes to their maximum.

Monday, 3 January 2022

Greg Hassett and Other Text Adventure Games

I generally only upload games to my Retrogame site that I have confirmed the distribution status with the owner of the copyright.  However, one of the people it has been difficult to find extensive biographical information about in order to try to make contact with is Greg Hassett. Many commentator's note that Mr. Hassett started programming at the age of 12 and that he was very prolific [1][2]. But it is unclear what happened to him after his contribution to the early age of home computing. But I've noticed that some people might already have been using one of my early games distributions to examine one of his games, such as:

I've also been contacted by a number of people wanting to play this game from my faculty site, so I have decided to upload his games so these people can access them, at least for a month or so.  If anyone out there knows anything about the copyright status of these games, please contact me.

I have already ported the following games by Hassett:

  • The House of Seven Gables
  • Journey to the Center of the Earth
  • Sorcerer's Castle Adventure
  • King Tut's Tomb
  • Voyage to Atlantis
  • Enchanted Island

I am now in the process of considering converting some of Hassett's games to Micro Color Basic, so that people will have easy online access to the works of this important contributor:

  • Mystery Mansion
  • World’s Edge
  • Curse of the Sasquatch
  • Devil's Palace

I have listed them in order of my priority for porting. When I have finished any of these conversions I'll also make them available. I'll take them back down by April 2022.  Let me know if you have any thoughts on the priority.

I've also stumbled across a neat publication: Captain 80 BASIC Adventures. It has a huge list of classic text adventure games, many I have already converted to Micro Color BASIC (See the ones with *s).

Chapter 1 Atlantean Odyssey Teri Li 37
Chapter 2 Dog Star Lance Micklus 87 *
Chapter 3 Thunder Road Don & Freda Boner 97
Chapter 4 Deadly Dungeon Don & Freda Boner 107
Chapter 5 Revenge of Balrog Don & Freda Boner 117
Chapter 6 The Fortress at Times-End Don & Freda Boner 125
Chapter 7 Temple of the Sun Jack Powers 134
Chapter 8 Lost Ship Charles Forsythe 148
Chapter 9 Spider Mountain Teri Li 157
Chapter 10 Lost Dutchman's Gold Teri Li 167 *
Chapter 11 Journey to the Center of the Earth Greg Hassett 177 *
Chapter 12 King Tut's Tomb Greg Hassett 187 *
Chapter 13 Voyage to Atlantis Greg Hassett 197 *
Chapter 14 House of Seven Gables Greg Hassett 206 *
Chapter 15 Sorcerer's Castle Greg Hassett 216 *
Chapter 16 CIA Adventure Hugh Lampert 225 *
Chapter 17 Arctic Adventure Harry McCracken 234
Chapter 18 Adventureland Scott Adams 241 *

I will be converting some of these that I haven't done yet over the next few months.  But first I must investigate which one's are already easily available in repositories.  If I find any that are not I'll come back to this list and mark them with a + sign to indicate that they are on my radar screen for porting.  If anyone has any suggestions for any that I should prioritize for porting please post a comment.

One final "Text Adventure" project I am thinking of undertaking is converting my re-code of Planet of Death by Artic Soft.  I have read many reviews of this game, and they all praise its innovative features.  But there are also a number of specific complaints that reviewers make about its puzzles that they agree spoil the game, especially for modern players. It might be nice, since I have converted it to BASIC, to make my recode a new version of the game that addresses these complaints. That way it might serve a useful function of providing an opportunity for modern players to give it a try and not be overly frustrated.  Any comments on this project would be much appreciated.