BBC Micro

[javierglez]

I tried to type some listings from the Microbot twitter account (the Model B one, not the Archi) into Beeb'Em emulator.
I got working some easy ones but one I liked quite a lot didn't.
It is an animation similar to the Windows 10 waiting one, a circle made up of smaller circles changing colors to simulate a spinning effect.

Code: Select all

0 DATA 6155, 6948, 13351, 14136, 26683, 27540, 50327, 51144, 55499, 56292, 62695, 63480, 43259, 43860, 1111 
1 MODE 2:
   VDU32797;2;2,5:   GCOL 16,0:
   FOR R=0 TO 6 STEP RAD24:
      READ C:      VDU 535;C;C;C;C;:      MOVE -448*SINR,448*COSR:      PLOT &99,0,64:
   NEXT:
   B%=4:
   REPEAT B%=B%MOD15+1:
      C%=C%MOD15-INKEY3:      *FX19 2V.19,B%,4;0;19,C%;0;0:
   UNTIL 0

I wonder where's the mistake. Beeb people mock a lot about Commodore's Pokes but their VDUs are equally cryptic.

I got a Master from UK but right now it's stored. It's my favourite 8 bit computer after Commodore's.

Here's the link
https://twitter.com/rheolism/status/1294377785461374976

[Kweepa]

That tweet relies on the Acorn Graphics Extension Rom (GXR) being plugged in (or setting BeebEm to Master emulation).
You can tell by the "PLOT &99" which is a circle drawing routine that doesn't exist on a stock machine.
Also the data at the top defines fill patterns that are used by the plot. These fill patterns are also unique to the GXR.

Although the VDUs are rather obscure, generally a BBC BASIC program isn't as opaque as this - rheolism is a master of writing obfuscated code!

(It does look like you have at least one mistake in the listing - after *FX19 there should be a carriage return for line 2.)

[vicist]

Code: Select all

0 D.6155,6948,13351,14136,26683,27540,50327,51144,55499,56292,62695,63480,43259,43860,1111
1 MO.2:VDU32797;2;2,5:GC.16,0:F.R=0TO6S.RAD24:READC:V.535;C;C;C;C;:MOV.-448*SINR,448*COSR:PL.&99,0,64:N.:B%=4:REP.B%=B%MOD15+1:C%=C%MOD15-INKEY3:*FX19
2 V.19,B%,4;0;19,C%;0;0:U.0

Just need to get the formatting right. Copy and paste into BeebEm with hardware set to master and it works fine.

[javierglez]

It's interesting that the Master has some commands that are not default on the Model B. This was unexpected, needed both of you repeating the same to acknowledge and retry.
Also, didn't know you could paste each line directly into Beeb Em. If I'm not wrong we can't do that on VICE, we have to use a crossdevenv such as CBMPRG. I didn't enter the typo, I retiped the line, it's just that I posted a copy & paste from an edit of the original tweet.
Today I was more successful with Kweepa's raytracing snippet which was even nicer. I guess rewriting it for C16 or C128 basic is feasible.

[vicist]

This is also possible in VICE.
You could write an entire program in notepad if you wish, copy the whole thing and paste it into a running emulator. The entire program is rendered on screen and you just have to press return to enter the last line. Type run and watch it go. Simple.

[orion70]

Maybe I'm wrong, but in vice you can't copy and paste special characters like cursor up/down/left/right, reverse on/off, etc.

[16KVIC20]

It's a great machine. I picked one up a few years ago complete with a nicely populated Turbo MMC.
I do, of course remember them from school. I see them as being the ultimate development/expansion /educational computer available at the time, at least in the UK. I suppose in the US you had the Apple II, which probably filled the educational area, as well as many others.
I think of there being a bit of a hierarchy:

At the bottom you had Sinclair, who produced what is really an unfinished product with any add on having to be connected direct to the motherboard via the dreadful Edge connector and an interface.

Then you had Commodore, who did provide some decent options for expansion, and even included proper Joystick sockets, all built in.

Then the BBC just had seemingly endless expansion options, and users were almost encouraged to pop the lid and add extra chips even. It is a beautifully made machine.

A BBC also ran, that actually got lost in the race due to many problems with it was the Dragon 32/64 range of computers. It had a similar case to the BBC and decent expansion sockets. The size of the case also meant that it was well suited to user development. The unfortunate thing is that it had no lower case ability, and the colour palette and graphics resolution were pretty bad. For instance, to get Jet Set Willy at a decent resolution, it had to be in black and white. Other programs were in really nasty colour combinations, with bright green and muddy green, or white and red fetauring heavily. It's a shame, with a bit more thought, it could have been a really nice machine.

Nothing beats the mighty VIC, of course. Did we ever get Graphical Adventure CReator on the VIC 20?

[English Invader]

Another game I forgot to mention in the other thread is Chip Buster (also on the MMC):
https://www.youtube.com/watch?v=qOJM7em0cuU

[Noizer]

(...) It's a shame, with a bit more thought, it could have been a really nice machine.(...)

If you look at the history of the 8 or 16 bit machines of the 80s, they are all fraught with design flaws and, consequently, a sense of shame ours who survived to look closely at them.
There were many brilliant minds, but most of them just made it easy to make a profit. Why the hell did they have to worry about it, the world goes to the dogs today thanks to these creatures.
Discoveries belong to enthusiasts.
To be continued