(This is part six of the chronicle of my Retrochallenge 2016/01 submission, which is to port some classic Star Trek text games to the Mattel Aquarius. To jump to the beginning, go here.)
STTR2
For the final week of this year’s Retrochallenge, I worked on creating STTR2. This is an embellished port of STTR1 taking some advantage of the modest capabilities of the Mattel/Radofin Aquarius.
To get to this point, I took the code for my “straight” port of STTR1 and completely re-factored the BASIC code to make it more structured. Next was to change any code that PRINTED to use relocatable, colored text and use the Aquarius’ graphic text characters to make grids, etc.
Sadly the project is incomplete for the purposes of challenge. There is no sound. It exceeds my target 16K RAM, and is slower than an ASR-33 teletype terminal. (The video above is running in an emulator with max speed enabled). But it was very fun to get this far.
Retrochallenge 2016/01 Epilogue
Well, I fell a little short for my challenge. I did not port Super Star Trek like I had originally planned and therefore ported STTR1 to the Aquarius instead of Super Star Trek. In retrospect I’m fine with it. I find STTR1 to be simple and enjoyable. The Trek games that followed added perhaps needless complexity.
What I was successful with was learning a ton about a game that I initially knew very little about. I have heard revering stories of the game from programmers who got an earlier start in computers than I did. I was also successful in learning more about the Aquarius and the great efforts of its enthusiasts.
(This is part five of the chronicle of my Retrochallenge 2016/01 submission, which is to port some classic Star Trek text games to the Mattel Aquarius. To jump to the beginning, go here.)
Thank Heavens for the Internet Archive
Today I came across Mike Mayfield’s personal account of the history of STTR1. This information was rescued from a defunct website by the fabulous efforts of the Internet Archive:
That page was part of a more general survey of the early Star Trek text games. I noticed a Palm Pilot version. I’ll be trying that on the Palm III I use for weekend To Do lists.
Work Begins on STTR2
I’ve begun working on (or at least mulling over) an enhanced version of STTR1 for the Aquarius that will take advantage of the system’s modest graphics and sound capabilities.
The set of goals is not solidified but at a minimum:
Use a fixed display (not scrolling). Left half is Short Range Scan, right half is output of all other commands except the Galactic Record.
(This is part four of the chronicle of my Retrochallenge 2016/01 submission, which is to port some classic Star Trek text games to the Mattel Aquarius. To jump to the beginning, go here.)
STTR1’s Gone Gold
STTR1 cassette case
The straight port of STTR1 for the Aquarius is nearing completion. These were the tasks on my TODO list:
Finalize the code
Create a Git repository for the files that will be publicly shared
Record STTR1 to a cassette tape
(Finally) run STTR1 on a real Aquarius
Create & print artwork for the cassette case
Finalize the Code
I’m trying to keep the target platform an Aquarius with a 16K RAM extension, even in emulation. One of the files I’ll be including in the distribution is a ROM (.bin file) image. This will allow easier loading on emulators or perhaps one day the file can be included with a multi-cart. To accomplish this, I used the modern hack Bootloader BASIC v2.1 (or BLBasic) found on the Atariage forums. This is an enhanced version of Aquarius Extended BASIC that, among other things, will create a ready-to-run binary version of a BASIC program. The clever trick exploits the fact that Virtual Aquarius emulator redirects printer output to a text file on the host computer. BLBasic re-purposes the LDUMP command to instead export a binary version of a BASIC program to the host computer via the emulated Aquarius printer port.
However I was seeing some strange behavior emanating from the .bin version of STTR1 while using MESS. It could be that MESS is not correctly emulating the Aquarius, or perhaps the STTR1 code along with whatever runtime is needed by BLBasic was hitting the upper bounds of the available memory.
So I’ve trimmed the memory footprint of the STTR1 code on the Aquarius by:
Consolidating multiple lines of HP Time-Shared BASIC to a single line using the “:” command separator. HP must’ve allowed strictly one command per line number in its Time-Shared BASIC because the original code never strays from that.
Trimming REM statements when HP added the program to their Contributed Program Library.
Consolidating commands introduced many new bugs because I inevitably removed a line number that was referenced somewhere else by a GOTO. I became very familiar with the “UL” error.
UL UNDEFINED LINE. Attemp-
ted branch to a line that is not in
memory, or deletion of a non-
existent line.
Create a Git Repository
Nothing too interesting . I’ve been using bitbucket.org for no particular reason. I know all the cool kids are hanging out at github, but I’m too lazy to migrate. So far, I’ve uploaded:
the text of the BASIC source
a .CAQ file (cassette file format for Virtual Aquarius)
Recording STTR1 WAV file to Cassette Tape using a GE 3-5015C Tape Recorder
In the Virtual Aquarius emulator, you can run the CSAVE command and it will export a .CAQ data file to your PC. Included in the tools sub-directory of the emulator is a program called CAQ2WAV.EXE. This Windows application will convert a .CAQ to a .WAV audio file.
I used Audacity to play the .WAV file to this gorgeous c.1986 General Electric 3-5015C tape recorder connected to the laptop’s audio output. Moved the tape over to the Aquarius’s Data Record and CLOAD’ed the muther in.
For all the stink eye that cassettes get, let me say that this all worked on the first try. Sure it takes 4m30s but that’s time to meditate – or run a very good mile.
Red DATA Light means life is good
(Finally) Play STTR1 on a Real Aquarius
STTR1 Instructions being printed to screen
The game plays well on the Aquarius. I even love the keyboard. The program includes an option to either print the instructions to screen or to the Aquarius’ thermal printer. I almost got weepy seeing that work on the first run.
Create & print artwork for the cassette case
I wanted a nice looking cassette case for STTR1. I looked at some examples of the third-party games sold in the eighties, for example “Chuckman“. And skimmed through episodes of Star Trek: The Only Series on Netflix to find some screen shots of space scenes to grab. After a long night of cutting, pasting, rotating, blurring, and undoing, I came up with something I like. Even has liner notes.
I’ll include this as a PDF or PNG in the repository.
Up Next
My original plan was to also port Super Star Trek. Alas that one may have to wait for a future Retrochallenge. Instead I want to add color, sound, and maybe even extremely crude graphics to STTR1, making it what? STTR2?
(This is part three of the chronicle of my Retrochallenge 2016/01 submission, which is to port some classic Star Trek text games to the Mattel Aquarius. To jump to the beginning, go here.)
Mind Melding
In porting the 1972 version of STTR1 from HP Time-Shared BASIC to the Mattel Aquarius, I had to learn more about the code than I originally thought would be required. I imagined merely dealing with syntax differences which I could search and replace with ignorant bliss. However, the implementation of string variables differ so much between the two systems, I inevitably had to time-travel, get into the head of the high school student who authored STTR1, understand the program’s logic to a sufficient degree, and re-code some critical sections.
Is it spaghetti code? Of course it is. This is early BASIC and therefore a design requirement. Even so, some very clever algorithms exist throughout. (I’m especially impressed by the code that calculates course and torpedo trajectory.) However, the 1 or 2 character limit for variable names makes for a dizzying experience.
So before I move on and allow the weeds to germinate, I’d like to at least catalog the more interesting variables found in the original STTR1 listing along with my understanding of each one’s purpose.
Noteworthy Variables Found in Original STTR1
In case you’re inclined to follow along, here is the original BASIC listing for STTR1.
Arrays/Matrices
230 REM ***** PROGRAM STARTS HERE *****
240 Z$=" "
250 GOSUB 5460
260 DIM G[8,8],C[9,2],K[3,3],N[3],Z[8,8]
...
420 C[2,1]=C[3,1]=C[4,1]=C[4,2]=C[5,2]=C[6,2]=-1
430 C[1,1]=C[3,2]=C[5,1]=C[7,2]=C[9,1]=0
440 C[1,2]=C[2,2]=C[6,1]=C[7,1]=C[8,1]=C[8,2]=C[9,2]=1
...
1885 C2=INT(C1)
1890 X1=C[C2,1]+(C[C2+1,1]-C[C2,1])*(C1-C2)
1900 X2=C[C2,2]+(C[C2+1,2]-C[C2,2])*(C1-C2)
...
2700 H=(X/K3/FND(0))*(2*RND(1))
2710 K[I,3]=K[I,3]-H
2720 PRINT USING 2730;H,K[I,1],K[I,2],K[I,3]
2730 IMAGE 4D," UNIT HIT ON KLINGON AT SECTOR ",D,",",D," (",3D," LEFT)"
...
3400 G[Q1,Q2]=K3*100+B3*10+S3
Variable Name
Data Type
Description
G
8×8 Matrix
Galaxy; Elements contain 3-digit values to store number of Klingons, Starbases, and Stars in each of the 64 Quadrants
C
2×9 Matrix
Lookup of Δrow, Δcol for a given course, where 1≤course<9
K
3×3 Matrix
Klingon attributes; row, col, and hit-points remaining for up to 3 enemies found in current Quadrant
Strings
270 DIM C$[6],D$[72],E$[24],A$[3],Q$[72],R$[72],S$[48]
280 DIM Z$[72]
...
460 D$="WARP ENGINESS.R. SENSORSL.R. SENSORSPHASER CNTRL"
470 D$[49]="PHOTON TUBESDAMAGE CNTRL"
480 E$="SHIELD CNTRLCOMPUTER"
...
950 Q$=Z$
960 R$=Z$
970 S$=Z$[1,48]
...
3790 IF C$ <> "DOCKED" THEN 3820
3800 PRINT "STAR BASE SHIELDS PROTECT THE ENTERPRISE"
3810 RETURN
Variable Name
Data Type
Description
C$
6 char String
Condition of the Enterprise – GREEN, RED, YELLOW, or DOCKED
D$
72 char String
First 6 labels for Damage Report – 72 char string treated as array of (6) 12-char strings
E$
24 char String
2 more labels for Damage Report – 24 char string treated as array of (2) 12-char strings
A$
3 char String
Symbol definition for Stars (‘ * ‘), Klingons (‘+++’), or the Enterprise (‘<*>’)
Q$, R$, S$
total 192 char String
Buffer used to display current Quadrant. 8×8 cells where each 3-char cell contains a copy of A$ or empty space
Z$
72 char String
Zeroed String – 72 spaces used to clear Q$, R$, and S$
(This is part two of the chronicle of my Retrochallenge 2016/01 submission, which is to port some classic Star Trek text games to the Mattel Aquarius. To jump to the beginning, go here.)
Work-in-Progress Port of STTR1 on the Aquarius
As with most of my Retrochallenge experiences, what I imagine I can accomplish in the first weekend requires the remainder of the month. So it has been with the no-frills port of the 1972 version of STTR1 to the Aquarius. My real goal is to extend a classic Star Trek text game to use Aquarius features such as color, sound, and hand controllers. But here we are halfway through January and I’m still just trying to get the original STTR1 game to run on the target platform.
As of the last several work sessions I have a foothold into the game and am able to play for a bit before encountering a mysterious syntax error at line number 1910. And torpedoes targeted towards Klingons instead say that I shouldn’t attack stars.
In this post I will enumerate the types of code changes I’ve had to make so far and provide some brief examples. At a high level there’s the trivial changes and, well, the non-trivial.
Trivial Changes
Printing Concatenated Strings
HP doesn’t require semicolons as concatenation operators.
HP Time-Shared BASIC
1580 PRINT "YOU HAVE"E" UNITS OF ENERGY"
Aquarius BASIC
1580 PRINT "YOU HAVE";E;" UNITS OF ENERGY"
Array Indexes
HP uses square brackets. Aquarius uses parentheses.
HP Time-Shared BASIC
1630 D[I]=D[I]+1
Aquarius BASIC
1630 D(I)=D(I)+1
Chained Variable Assignments
HP allows chained assignments, the Aquarius does not.
HP Time-Shared BASIC
320 E0=E=3000
330 P0=P=10
Aquarius BASIC
320 E0=3000:E=E0
330 P0=10:P=P0
Shortening Command Lines to 72 Characters
Aquarius BASIC has a maximum line length of 72 characters. The original STTR1 source for the HP contains many, many lines that exceed that limit. These are simple but somewhat tedious changes.
Aquarius Guide to Home Computing pp. 1-10
Reformatting Output for a 40 Character Display
The teletype terminals that would be connected to an HP2000C had generous line widths for displaying the program output. The 40 character display on a television set requires inserting line breaks into the original STTR1 text.
HP Time-Shared BASIC
3690 PRINT USING 3700;K[I,1],K[I,2]
3700 IMAGE "KLINGON AT SECTOR ",D,",",D," DESTROYED ****"
HP Time-Shared BASIC provides formatted printing akin to C’s printf() function. IMAGE statements define a mix of literal strings and placeholders with format codes. The PRINT USING statement points to the line containing the desired IMAGE statement and a list of variables to be substituted for the placeholders.
HP Time-Shared BASIC
2720 PRINT USING 2730;H,K[I,1],K[I,2],K[I,3]
2730 IMAGE 4D," UNIT HIT ON KLINGON AT SECTOR ",D,",",D," (",3D," LEFT)"
Aquarius BASIC
2720 PRINT H;" UNIT HIT ON KLINGON":PRINT " AT SECTOR ";
2730 PRINT K(I,1);",";K(I,2);" (";K(I,3);" LEFT)":PRINT
Zeroing an Array
The HP has strong matrix support and has the ability to operate on all elements in a matrix with one command.
HP Time-Shared BASIC
260 DIM G[8,8],C[9,2],K[3,3],N[3],Z[8,8]
...
910 MAT K=ZER
Aquarius BASIC
260 DIM G(8,8),C(9,2),K(3,3),N(3),Z(8,8)
...
910 FOR I=0 TO 3:FOR J=0 TO 3:K(I,J)=0:NEXT J:NEXT I
Jumped GOTO
HP Time-Shared BASIC provides a variation of the ON x GOTO line1 line2… seen in other BASICs on micros but not found on the Aquarius. And…Was GOTO originally intended to be GO TO (two words)!?
HP Time-Shared BASIC
1270 PRINT "COMMAND:";
1280 INPUT A
1290 GOTO A+1 OF 1410,1260,2330,2530,2800,3460,3560,4630
Aquarius BASIC
1270 PRINT "COMMAND:";
1280 INPUT A
1290 IF A=0 THEN 1410
1292 IF A=1 THEN 1260
1293 IF A=2 THEN 2330
1294 IF A=3 THEN 2530
1295 IF A=4 THEN 2800
1296 IF A=5 THEN 3460
1297 IF A=6 THEN 3560
1298 IF A=7 THEN 4630
Non-Trivial Changes
Fundamental Differences in String Variables
HP Time-Shared BASIC
HP BASIC strings are implemented as a one-dimensional array of bytes. The command DIM S$ [n] reserves n bytes for string S$.
Throughout the original STTR1 code, much of the game’s “graphical” representation is accomplished by injecting the symbols for the Enterprise (‘<*>’), stars (‘ * ‘), and Klingons (‘+++’) into large strings, exploiting HP’s treatment of Strings as special cases of matrices.
However, HP BASIC strings are limited to 72 characters. For this reason, the young Mr. Mayfield had to split the 192 (8 x 8 x 3) characters needed to represent the Short Range Scan view across 3 string variables Q$, R$, and S$. And then add code to cascade across the variables when trying to inspect a particular spot in a quadrant.
270 DIM C$[6],D$[72],E$[24],A$[3],Q$[72],R$[72],S$[48]
...
980 A$="<*>"
...
5510 REM ****** INSERTION IN STRING ARRAY FOR QUADRANT ******
5520 S8=Z1*24+Z2*3-26 (Note: Z1 and Z2 are values between 1 and 8)
5530 IF S8>72 THEN 5560
5540 Q$[S8,S8+2]=A$
5550 GOTO 5600
5560 IF S8>144 THEN 5590
5570 R$[S8-72,S8-70]=A$
5580 GOTO 5600
5590 S$[S8-144,S8-142]=A$
5600 RETURN
Aquarius BASIC
Strings do not need to be declared before use. The command DIM Q$ (64) creates an array of 64 (maybe 65) strings. For the Aquarius version of STTR1, strings will need to be used in a totally different way. Since the game’s “graphics” are stored as 3-character strings, I’ve opted to create an array of strings. In a 8×8 quadrant, Q$ will provide (64) 3-character strings.
270 DIM Q$(64)
...
980 A$="<*>"
...
5510 REM ****** INSERTION IN STRING ARRAY FOR QUADRANT ******
5520 S8=(Z1-1)*8+Z2 (Note: Z1 and Z2 are values between 1 and 8)
5540 Q$(S8)=A$
5600 RETURN
Memory
No-Frills STTR1 Consumes Most of the 16K on an Aquarius
The target platform is an Aquarius with 16K RAM. If I drop the STTR1 code into an Aquarius emulator, FRE(0) shows that 1K of RAM is remaining. If I want to add new features, then the existing program will need to be put on a diet. Otherwise OM (Out of Memory) errors will begin to appear.
Solutions include: moving the embedded instructions to a separate, stand-alone program, combining multiple BASIC commands onto a single line, and creating an array of resource strings to use in place of repeated literals, like “KLINGON”, “TORPEDO”, and “ENTERPRISE”.
Up Next
Documenting the important variables used in STTR1.
(This is part one of the chronicle of my Retrochallenge 2016/01 submission, which is to port some classic Star Trek text games to the Mattel Aquarius. To jump to the beginning, go here.)
Let’s Play the HP Time Shared BASIC Version of STTR1
I recorded a “Let’s Play” video of an abbreviated session of STTR1, enough to exercise all of the commands at least once. This was very, very late night recording – my mental acuteness was the opposite of acute.
How/Where to Run the Original STTR1
In preparation for my Retrochallenge, I spent some time in December trying to learn about STTR1 and how to play the original game. Well, I assume the “original” original game, which ran on an SDS Sigma 7 computer is lost to us and now resides in bit heaven. But the HP Time Shared BASIC port survived because of its inclusion in HP’s User-Contributed Library and the success of the HP2000 Family. In the end, I found at least three options for playing the HP version of STTR1:
Locate and restore (2) HP2000 Series computers. One unit is needed for multiplexing terminals and one to run Access/Time Shared BASIC. And don’t forget tape drives or paper tape readers. And the media (magnetic and/or paper tapes). So – this option is impossible.
Download, compile, configure, and run the SimH simulator. If you haven’t heard of SimH, it is to minicomputers what MESS is to microcomputers – only difficult. I did, in fact, have success with this route after several weeks of trying and would like to document my setup and perhaps share some configuration files. But that is a lower priority at the moment. If I fail to document this, I did find everything I needed, (though not in any single, tidy package) at the HP2000 Group but you’ll need to join the group to gain access to the necessary files.
Telnet to an already-running instance of a simh simulator. There are two such machines available at the time of this writing due to the generosity of the HP2000 Yahoo Group members :
mickey.publicvm.com
hp2000.brighton.ac.uk
The “Too Long, Didn’t Watch” Version
So, assuming these machines are still listening when you read this, the telnet option is the most straight-forward way to try out STTR1.
To Launch STTR1:
Launch a terminal, such as the classic ‘xterm‘, that won’t be confused by the HP’s strange End-of-Line characters.
Do this:
telnet mickey.publicvm.com or hp2000.brighton.ac.uk
CTRL+m,CTRL+j
HELLO-T001,HP2000,1
GROUPS
EXECUTE-*STTR1
For your convenience, the instructions for STTR1 have been pulled from the original source and reformatted in my previous post.
To Quit STTR1:
Use Command 7,2
Enter a long string at prompt for using the calculator. This causes a string overflow and breaks out of the program.
BYE
These machines have many other early text games including 1975 version of Oregon Trail. When looking at the list of programs in the output of GROUPS, the programs with a “C” attribute are semi-compiled and may need to be started using the command EXE-*progname, otherwise you should be able to use EXE-progname.
Up Next
Due to incompatibilities between HP’s BASIC and the version of MS BASIC found on the Aquarius, I’m forced to climb into the head of a teenage programmer from 1972.
Here are the instructions for the 1972 Star Trek text game as found(*) in STTR1’s BASIC listing.
(*) Modified from strictly upper case
SYMBOL
DESCRIPTION
<*>
Enterprise
+++
Klingon
>!<
Starbase
*
Star
Command 0 = Warp Engine Control
‘Course’ is a circular numerical vector arrangement as shown. Integer and real values may be used. Therefore course 1.5 is half way between 1 and 2.
4 3 2\ ^ / \ ^ /5 ------------- 1/ ^ \/ ^ \6 7 8
C O U R S E
A vector of 9 is undefined, but values may approach 9.
One ‘warp factor’ is the size of one quadrant. Therefore to get from quadrant 6,5 to 5,5 you would use course 3, warp factor 1.
Command 1 = Short Range Sensor Scan
Prints the quadrant you are currently in, including stars, Klingons, starbases, and the Enterprise; along with other pertinate information.
Command 2 = Long Range Sensor Scan
Shows conditions in space for one quadrant on each side of the Enterprise in the middle of the scan. The scan is coded in the form XXX, where the units digit is the number of stars, the tens digit is the number of starbases, and the hundreds digit is the number of Klingons.
Command 3 = Phaser Control
Allows you to destroy the Klingons by hitting him with suitably large numbers of energy units to deplete his shield power. Keep in mind that when you shoot at him, he gonna do it to you too.
Command 4 = Photon Torpedo Control
Course is the same as used in Warp Engine Control. If you hit the Klingon, he is destroyed and cannot fire back at you. If you miss, he will shoot his phasers at you.
Note: The Library Computer (Command 7) has an option to compute torpedo trajectory for you (Option 2).
Command 5 = Shield Control
Defines number of energy units to be assigned to shields. Energy is taken from the total ship’s energy.
Command 6 = Damage Control Report
Gives state of repairs of all devices. A state of repair less than zero shows that the device is temporarily damaged.
Command 7 = Library Computer
The library computer contains the three options:
Option 0 = Cumulative Galactic Record
Shows computer memory of the results of all previous long range sensor scans.
Option 1 = Status Report
Shows number of Klingons, stardates, and starbases left.
Option 2 = Photon Torpedo Data
Gives trajectory and distance between the Enterprise and all Klingons in your quadrant.
16kram 