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Richard Russell

I don't think BASIC 2 supports comma. If you try it then BASIC will only emit one byte. beebasm I think does support commas. I don't know about BASIC 3 and BASIC 4. JGH or someone else will know. I don't know about those BASICs either, but none of mine (Z80, 8086, x86-32, x86-64, ARM) supports a co...

Richard Russell

Hadn't seen that syntax before As far as I know it was in ARM BBC BASIC (BASIC V) from the very start, 35 years ago or thereabouts. Just one of the many 'whole array' operations supported by BBC BASIC. I remember wanting to implement a 'shift register' in an array (whereby each element is shifted a...

Richard Russell

So whereas we might print what day it is using something like: DIM Day$(7) FOR A=1TO7 READ Day$(A) NEXT ... DATA Monday,Tuesday,Wednesday,Thursday,Friday,Saturday,Sunday In BBC BASIC V and later I would be more inclined to do this rather than use READ/DATA: DIM Day$(7) Day$() = "","Monday","Tuesday...

Richard Russell

Depending on the library... I'm so glad that I work only with Operating Systems (Windows, Linux, MacOS, Android, iOS) in which BBC BASIC's SYS statement calls exactly the same API functions, in the same libraries, and with the same ABI, as a C program would. It makes life easier for a BASIC program...

Richard Russell

I don't know if RISC OS SWIs generally returned any kind of meaningful output in the flags, but one special case is of "X" SWIs, e.g. "XOS_File", which used the V flag to denote an error condition instead of actually generating an error. I know nothing about RISC OS, but I would have expected that ...

Richard Russell

Supress the absence of a question mark in INPUT. Simply an alternative to a comma, I think; not sure why semicolon is accepted here at all. Collect flags from SYS call: SYS call[,in[,in...]] [TO [out[,out...]] [; flags]] That's a new one on me. I assume it's a RISC OS feature and if so it must have...

Richard Russell

I'm posting this for no other reason than that it interests me. I'm strange like that. :wink: BBC BASIC uses the semicolon character (;) in several different ways, but they all* come under the general category of 'suppress forthcoming action'. Here are the ones that I know about: Suppress right-just...

Richard Russell

unless it's impossible to use the LIST token in a program line; as a command it's limited to immediate mode only and thus likely removed from BBCSDL. As you surmise, LIST has been removed as a keyword from BBCSDL (and its original 8-bit token of &C9 reallocated to WHEN). From time to time somebody ...

Richard Russell

There's no need to introduce any new reserved words if you just extend the parser to accept constructs such as: FOR J% = 2, 3, 5, 7 To be pedantic BBC BASIC is interpreted and doesn't have a "parser", but I take your point. You'd have to ask the person who originally proposed the syntax what his th...

Richard Russell

BBC BASIC may not use IN as a reserved word... I’m sure I have seen ‘AS’ used (as a reserved word) in a BASIC somewhere... I was of course referring to BBC BASIC (more specifically BBC BASIC for Windows , BBC BASIC for SDL 2.0 and Matrix Brandy BASIC which are the only ones to which the proposed la...

Richard Russell

My initial preference would be to use "IN" instead of "OF"... Or maybe "FROM". They suffer from the same objection as 'AS', namely that they involve the introduction of a new keyword and hence risk breaking compatibility with existing programs. Admittedly I have added new keywords myself (EXIT and ...

Richard Russell

Someone more used to PHP or Perl might expect it to look a bit more like 10 FOR ("HELLO", "BBC", "FANS") AS WORD$ To me that feels a less comfortable 'fit' with existing BBC BASIC syntax than what the OP proposed; why should the affected variable come first in the case of the conventional FOR state...

Richard Russell

Would you also support 1d array and string variables? FOR I% OF A%() NEXT FOR I% OF A$ NEXT I think my current feeling is that they can be so readily and elegantly implemented with a conventional FOR loop that the benefit wouldn't justify the complication: FOR P% = 0 TO DIM(A%(),1) I% = A%(P%) NEXT...

Richard Russell

The following has appeared at the BBC BASIC forum : Would something like the following be hard to implement in BBCSDL? FOR I% OF 3, 22, -9 NEXT FOR Day$ OF "Mon", "Fri", "Sun" NEXT Just wondering as it would be so powerful to an already extremely powerful programming language. My immediate reaction ...

Richard Russell

BigEd wrote: ↑
Sun Oct 27, 2019 7:26 pm
one day we'll run 64 bit OS on our Pi 3 and Pi 4, at which point perhaps long double becomes quad precision (probably in software.)

Wikipedia implies that, but when compiling BBC BASIC for 64-bit iOS (using Clang) I've seen no evidence that 'long double' is any different from 'double'.

Richard Russell

Running these in BBC Basic SDL version, we can get more digits: So long as it's an x86 edition; sadly when running on ARM (e.g. on the Raspberry Pi) BBC BASIC for SDL 2.0 has only 16 or so decimal digits of precision compared with the 19 you listed. Although the old, software emulated, ARM floating...

Richard Russell

if the I/O is important, It’s a fair and valid thing to do. I would say it depends on the kind of I/O. If it's output to the screen, for the sole benefit of a human observer, I might argue that increasing the speed above that at which somebody can read it is of no value, and should not be counted a...

Richard Russell

Here are some screenshots of the SkyBaby 'planetarium' application featured in this release:

Richard Russell

Version 1.07a of BBC BASIC for SDL 2.0 - the cross-platform programming language for Windows, MacOS, Linux, Raspbian, Android and iOS - has been released. The changes in this version are as follows: BASIC Interpreter / Run Time Engine User-defined characters may be used even if *FONT is active (impr...

Richard Russell

dhg2 wrote: ↑
Wed Oct 16, 2019 12:17 pm
Tested with this code:

If you want to make the choice of GCOL style automatic, Jonathan Harston's recommended test for 'my' BASICs is this:

Code: Select all

DEFPROCgcol(R%,G%,B%)
IF (INKEY-256 AND &D0)=&50 THEN
  COLOUR 2, R%,G%,B%: GCOL 2
ELSE
  GCOL R%,G%,B%
ENDIF
ENDPROC

Richard Russell

dhg2 wrote: ↑
Tue Oct 15, 2019 4:10 pm
I notice that if you try to draw text at the location of the graphics cursor (with VDU 5 and then PRINT), and if the current graphics colour is black, no text is drawn.

How very strange. Here's what BBC BASIC for SDL 2.0 produces:

Richard Russell

geraldholdsworth wrote: ↑
Mon Oct 14, 2019 12:39 pm
I noticed that the first digit always seems to '0', and the decimal point is missing.

The subject line does say 'Calculating digits of Pi', not 'Calculating Pi', so omitting the decimal point and adding any number of leading zeroes is entirely consistent with that.

Richard Russell

BTW, my switch to indirection rather than array mightn't have helped at all As I am increasingly wanting my BBC BASIC programs to run on 64-bit platforms I am trying to change my mind-set away from thinking of indirection as a way of saving time and space to being unhelpful from a compatibility sta...

Richard Russell

the only variables available to hold addresses/pointers are signed integers. Sorry, that was a silly thing to say because of course BBC BASIC's floating point variables can hold positive 32-bit integers over the entire &00000000 to &FFFFFFFF range. But it isn't usual to use floating-point variables...

Richard Russell

Conversely, if addresses are signed at 32-bits then you can end up with the odd situation where HIMEM < PAGE. That can't be right either. But that's always been true in BBC BASIC, in principle, since the only variables available to hold addresses/pointers are signed integers. Theoretically even Aco...

Richard Russell

BigEd wrote: ↑
Mon Oct 14, 2019 8:30 am
But wait: the OS supports a printer, and control-B enables it, so how about capturing that output into a text area?

Can't you currently 'print' to a PDF and copy-and-paste the text from that?

Richard Russell

scruss wrote: ↑
Mon Oct 14, 2019 12:52 am
Couldn't get it to run at all in Matrix Brandy on the same machine.

It runs fine in BBC BASIC for Windows and in BBC BASIC for SDL 2.0 (in the latter case on a 32-bit platform; the modification to use indirection rather than an array has of course broken 64-bit compatibility).

Richard Russell

Elminster wrote: ↑
Sun Oct 13, 2019 5:41 pm
I am not sure there was a huge consensus though.

The only other name they came up with was David Allen, but they (rightly, I think) concluded that he would have been unlikely to attend such a 'technical' meeting.

Richard Russell

"Micro Men - 10th Anniversary - With Chris Curry, Steve Furber and Hermann Hauser". https://www.youtube.com/watch?v=yaonVYOTSsk So the historical record doesn't become even more muddled, can I confirm that I wasn't one of the representatives from the BBC who visited Acorn for that original demo (th...

Richard Russell

Is it tokenised, so is it Acorn format or Russell format? It arrived with me as 'Russell' format but they had already tried running it in, and may have saved it from, BB4W. The program *LOADs some machine code (apparently) to access a serial port, which would help with CPU identification, but they ...

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Re: Proposal for BBC BASIC 'FOR lists'

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Uses of the semicolon in BBC BASIC

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