Fun? with ECS BASIC

[decle]

I thought it might be amusing to create a spoof Intellivision VIC-20 "emulator", showing the famous one-line maze program.  This is pretty easy to do in IntyBASIC:

 

 

ROM and BASIC source code: vic20.zip

 

However, I had hoped to implement this in ECS BASIC.  Surely this is doable?  Clearly I had forgotten quite how bad ECS BASIC is.  This is as near as I could get:

 

 

Implemented with the following "one-liner":

10 CLR
20 SET A$="///////////////////"
30 FOR A=1 TO 19
40 IF(RN(0)>49)A$(A)=60
50 NEXT A
60 PUT A$
70 GOTO 20

For a language implemented on a machine with reasonable graphics capabilities (for the day) ECS BASIC is poor.  The list of problems I encountered is as follows:

• As we know ECS BASIC is dog slow because of the synchronisation with VBLANK.  As it turns out this is the least on my concerns...
• You can't change the border colour!?
• It takes 18 seconds to set the background of the screen to a consistent colour (white in this case) using the following code:

10 FOR A=0 TO 239
20 BK(A) = 7
30 NEXT A

 

• All tiles can either have a printed character or a background colour, but not both - brings a whole new meaning to foreground / background mode

 

10 CLR
20 BK(0) = 1
30 PRIN "HELLO"
40 PRIN "HELLO"
50 BK(20) = 1
60 BK(40) = 1
70 GOTO 70

 

• All printed lines are terminated with a newline, so you can't print in the 20th column without generating an empty line

 

10 PRIN "12345678901234567890"
20 PRIN "12345678901234567890"
30 PRIN "1234567890123456789"
40 PRIN "1234567890123456789"

 

• This also means you can't build a line incrementally (so faking someone typing is impossible)

 

 

10 PRIN "H"
20 PRIN "HE"
30 PRIN "HEL"
40 SET A$="H"
50 PUT A$
60 SET A$="HE"
70 PUT A$

 

Oh well, back to the drawing board having learnt some things. ?

 

 

Cheers

 

decle

 

 

 

 

 

Edited November 26, 2019 by decle

[intvnut]

Hold up a tic:  Did you implement a Microsoft BASIC interpreter in IntyBASIC, or was that just scripted to look like you'd done so?  (I haven't downloaded the ROM itself yet.  Taking a lunch break at $DAYJOB.)

[+Gemintronic]

19 minutes ago, intvnut said:

Hold up a tic:  Did you implement a Microsoft BASIC interpreter in IntyBASIC, or was that just scripted to look like you'd done so?  (I haven't downloaded the ROM itself yet.  Taking a lunch break at $DAYJOB.)

Looks like it's scripted.  But, I like the idea of BASIC within BASIC

[Zendocon]

Ah, the bad old days!  There were so many games I wish I could have written in ECS BASIC in the late 80s, but I ran into all the problems you listed.

 

If you think that's bad, wait until you find out your programs can't exceed 2,000 characters!  All of a sudden, code lines are repainted all in grey, signalling an error.  My best workaround was to split the program in two: one to set up the environment with string assignments and all the (animated/linked) sprites, and another for the actual game loop.

 

Another annoyance is the length of time it takes to output a single 6-digit numeric value, even more so if you enable floating-point arithmetic.