Neolithic Tiny Basic

[barnacle]

It's been a bit quiet; I've been on holiday, was ill upon my return, and am now in the UK for a week visiting my ailing mother, but things have been happening.

BB8 has done some sterling work shrinking the code and adding new features, and I have a couple of new features to go it too - though I need to get rid of dead code and finish testing first... but to whet your appetites, TRON/TROFF, logic 'arithmetic', BREAK for FOR/NEXT and WHILE/WEND, looking at warm start after a reset... and still under 4kB. BB8 is a genius

When I've had a chance to review and test everything, there will be updates.

As a side note, might this 4k tiny basic be worthy of a formal place somewhere on here, or should I be waking up my html 'skills' and hosting it myself? I'm not overly fond of github and its friends.

Neil

[BigEd]

Yes there’s a source code section of the site
http://6502.org/source/
Where you’ll find VTL02 for example

[barnacle]

Cool, thanks. That looks like the place to put it, when it's done.

Neil

[barnacle]

With the famous Mandelbrot modified to take advantage of new instructions, this

Code: Select all

  10  print "Mandelbrot - Neo Tiny Basic"
  20  print "Start"
  30  let $ = ".,'~=+:;*%&$OXB#@ "
  40  F = 50
  50  for y = -12 to 12
  60    for x = -49 to 29
  70      c = x * 229 / 100
  80      d = y * 416 / 100
  90      a = c
 100      b = d
 110      i = 0
 120      while i <= 16
 130        q = b/f
 140        s = b - (q * f)
 150        t = ((a * a)-(b * b)) / f + c
 160        b = 2 * ((a * q) + (a * s / f)) + d
 170        a = t
 180        p = a / f
 190        q = b / f
 200        if ((p * p) + (q * q)) >= 5
 210          break
 220        endif
 230        i = i + 1
 240      wend
 260      print $[i];
 300    next
 310    print
 320  next
 330  print "finished"

completes in around four and a quarter minutes, on the '2MHz' Symon simulator.

Neil (still testing)

[BigEd]

That's a milestone!

[barnacle]

The code is derived from Gordon's code discussed upthread, but including the new 'break' feature and after removing a messy test/goto to print an indexed character or a space (I think that will work on Gordon's version directly; his code doesn't access the final space in the character string which I do if the loop doesn't break.)

Neil

[barnacle]

Also added: a warm start option if you've had to restart/reset the system. Saves a lot of typing if e.g. I've made changes to the basic source and reassembled and dropped a new 'rom' in the simulator, but not otherwise changed anything in memory.

The warm start happens if 'w' or 'W' is pressed at the message; anything else is a normal cold start.

I was amused last night to see a video from David Usagi in which he recovered a version of BASIC called BURP, for a Data General Nova, from what he said was the last digital tape holding it. He was impressed that it had automated indentation!

Neil