Nova-bb, rcross don't work (Concrete abstractions)

DrRacket Installation and Setup (umn.edu)

Hello, I am trying to follow the intructions, DrRacket Installation and Setup (umn.edu) but seems it doesn’t work anyway. Here is what I should see after installation. DrRacket Installation and Setup (umn.edu) :


This is what I can see after Update:

Then I do everything as described – I think:

  • Download the following file to your desktop: quilting.scm. (If it displays in your browser as Racket source code, use the browser's Save As option to save it.)
  • Confirm that the language setting is still Racket.
  • Click File in DrRacket's menu bar and select New Tab to create two "Untitled" tabs in DrRacket.
  • Click File and select Open....
  • Select the quilting.scm file you just downloaded and click Open. The file will be opened in one of the tabs in the definitions pane of the DrRacket window.
  • Click Run.


As I type nova-bb, this happens:

Do you know where is the mistake please?

Save your "untitled 2" file as something like "my-program.rkt" in the same folder you put "quilting.scm".

Then try:

#lang racket 
(require "quilting.scm")
nova-bb
1 Like

I was able to follow the instructions and here is a first attempt in developing a Spaceship:


I would like now to make e 2D videogame where the spaceship can move right and left. Is it possible to get a first help here?

The prologue of "How to Design Programs" ends in an animation of a rocket.

https://htdp.org/2023-8-14/Book/part_prologue.html