Search found 180 matches

by Richard Russell
Thu Feb 08, 2018 2:55 pm
Forum: off-topic
Topic: Why did CISC prevail?
Replies: 21
Views: 645

Re: Why did CISC prevail?

memory access is 200x slower than register accesses but you have lots of it so you don't need worry so much about instruction compactness. On-chip caches are relatively small however so 'instruction compactness' is still relevant, hence the Thumb instruction set (although it's noteworthy that there...
by Richard Russell
Thu Feb 08, 2018 11:47 am
Forum: off-topic
Topic: Why did CISC prevail?
Replies: 21
Views: 645

Re: Why did CISC prevail?

My understanding was that the branch prediction and speculative evaluation in 64-bit ARM CPUs effectively makes the conditional instruction execution redundant I suppose the challenge for ARM is how to maintain its edge in terms of power efficiency, which is presumably why it has captured most of t...
by Richard Russell
Thu Feb 08, 2018 9:54 am
Forum: off-topic
Topic: Why did CISC prevail?
Replies: 21
Views: 645

Re: Why did CISC prevail?

Something else I find interesting is that the 64-bit ARM architecture has ditched one of the key features of the original 32-bit instruction set: that every instruction can be conditional. There are just a few conditional instructions left in the 64-bit set, such as conditional jumps. This is much m...
by Richard Russell
Sun Jan 28, 2018 5:16 pm
Forum: off-topic
Topic: 40
Replies: 27
Views: 927

Re: 40

crj wrote:a BBC-style Bluetooth keyboard would be an awesome thing.

The keyboard is the one thing that virtually everybody agrees on, and making it Bluetooth keeps all the options open. It could be paired with a Raspberry Pi, or with custom hardware, or with a mobile device.

Richard.
by Richard Russell
Sat Jan 27, 2018 10:31 am
Forum: off-topic
Topic: 40
Replies: 27
Views: 927

Re: 40

The one thing I love about old computers is that you switch them on and the come on instantly! But then so do 'always on' smart devices such as mobile phones and tablets. I'm not too concerned about start-up time if you only very rarely need to reboot the device anyway. I use BBC BASIC on my phone ...
by Richard Russell
Wed Jan 03, 2018 5:50 pm
Forum: software & utilities for the pc, mac or unix
Topic: Help with translation to ARM code
Replies: 4
Views: 902

Re: Help with translation to ARM code

What about C? What is the rest of of SDL BBC BASIC written in? I'm not sure how relevant this is now, since it's no longer an issue. The release announcement of version 0.19a at the forum stated, back at the beginning of last November, that " The Raspberry Pi edition of SDLIDE now supports the...
by Richard Russell
Wed Dec 27, 2017 9:35 pm
Forum: off-topic
Topic: Sophie Wilson on TV
Replies: 4
Views: 516

Re: Sophie Wilson on TV

Didn't spot this elsewhere on the forum, but Sophie Wilson was on the Boxing Day edition of Christmas University Challenge, representing Selwyn College, Cambs. Indeed so. I found her potted biography a bit much; I can only assume they felt the 'general public' wouldn't otherwise have a clue who she...
by Richard Russell
Tue Dec 19, 2017 9:23 am
Forum: other vintage computer hardware, software and games
Topic: Microwriter MW4
Replies: 6
Views: 326

Re: Microwriter MW4

What I would really like is one of those BBC connectable versions, "Quinkey" was it called? I've still got mine somewhere; I was never proficient with it but could remember the patterns for the letters. I think I did interface it with a PC in the dim distant past, just for amusement. Rich...
by Richard Russell
Thu Dec 14, 2017 7:48 pm
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.19a released
Replies: 16
Views: 671

Re: BBC BASIC for SDL 2.0 v0.19a released

The MODE7 emulation works well but is slow and is only usable on a Pi 3. That's true of double-height characters; I don't think single-height MODE 7 is particularly slow. The reason double-height is slow is that the characters are 'stretched' at run time, rather than being pre-rendered that size. R...
by Richard Russell
Tue Dec 12, 2017 6:21 pm
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.19a released
Replies: 16
Views: 671

Re: BBC BASIC for SDL 2.0 v0.19a released

flaxcottage wrote:They accept Python, Java, Pascal-based languages, C-based languages and Visual Basic.

BBC BASIC's CASE statement is based on Pascal's syntax (CASE thing OF) so that makes it a 'Pascal-based language', right? :wink:

Richard.
by Richard Russell
Tue Dec 12, 2017 12:48 pm
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.19a released
Replies: 16
Views: 671

Re: BBC BASIC for SDL 2.0 v0.19a released

Why the language has not been accepted by the examination boards I cannot understand It has always been accepted - in fact recommended - by OCR (the Oxford, Cambridge and RSA Examining Board). Although it's no longer a current publication, the 'OCR Computing for GCSE' student's book has an entire c...
by Richard Russell
Tue Dec 12, 2017 9:11 am
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.19a released
Replies: 16
Views: 671

Re: BBC BASIC for SDL 2.0 v0.19a released

It looks like I shall have to have a go at 'bare metal' programming of the GPIO pins using the built-in assembler. You can if you want to, but it's not necessary (unless you want to do something for which BASIC is not fast enough). BBC BASIC for SDL 2.0 comes with the 'gpiolib.bbc' library, which a...
by Richard Russell
Mon Dec 11, 2017 10:28 am
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.19a released
Replies: 16
Views: 671

Re: BBC BASIC for SDL 2.0 v0.19a released

Tried installing this on my Pi but the installer reports that all files to do with libsdl2- are not found. Is this just me or is it a known problem? Nobody else has reported it. What model of RPi and what version of Raspbian are you running? Here I run it on an RPi 3 with Raspbian Stretch, and (so ...
by Richard Russell
Sat Nov 04, 2017 6:49 pm
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC side-scroller demo
Replies: 0
Views: 401

BBC BASIC side-scroller demo

To date there haven't been any really good examples of 'BBC BASIC for SDL 2.0' leveraging the power of hardware-accelerated 2D rendering. I have attempted to put that right by adapting some of the graphics from David Williams' recent 'Forces of Darkness' game to run in BBCSDL. The original BB4W game...
by Richard Russell
Fri Nov 03, 2017 9:34 am
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.19a released
Replies: 16
Views: 671

Re: BBC BASIC for SDL 2.0 v0.19a released

ouch! That's a serious performance regression, on the face of it. Indeed. Unfortunately nobody will accept responsibility for it: the Raspberry Pi people say it has arisen 'upstream' in Debian and therefore there is nothing they can do, but other Debian Stretch distributions don't seem to have suff...
by Richard Russell
Thu Nov 02, 2017 10:17 pm
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.19a released
Replies: 16
Views: 671

Re: BBC BASIC for SDL 2.0 v0.19a released

Sounds good! BBC Basic is a good fit for the Pi, I think. Yes, but Raspbian Stretch has a serious problem with its software OpenGL drivers (it runs much more slowly than the previous Raspbian Jessie) which is a great shame. BBCSDL is usable only if the 'experimental' (VC4) GL Driver is enabled, but...
by Richard Russell
Wed Nov 01, 2017 4:53 pm
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.19a released
Replies: 16
Views: 671

BBC BASIC for SDL 2.0 v0.19a released

I have updated BBCSDL, the cross-platform version of BBC BASIC for Windows, Linux, Mac-OS X, Raspberry Pi and Android. Full details of the new release may be found at the forum . Notable enhancements in this version are cross-platform support for network access, and that the Raspberry Pi edition now...
by Richard Russell
Tue Oct 03, 2017 8:00 pm
Forum: programming
Topic: Many DEFPROC, 1 ENDPROC?
Replies: 17
Views: 1277

Re: Many DEFPROC, 1 ENDPROC?

In your example though, doesn't the "LOCAL flag" get processed in exactly the same way as the procedure parameter? Well, not "exactly" because LOCALs don't have to be copied from the 'actual' parameters after saving. But that's not really the point, it's the 'real' parameters of...
by Richard Russell
Tue Oct 03, 2017 4:24 pm
Forum: programming
Topic: Many DEFPROC, 1 ENDPROC?
Replies: 17
Views: 1277

Re: Many DEFPROC, 1 ENDPROC?

The deeper call stack probably means it runs a bit slower It could be substantially slower, especially if there are multiple parameters (and even worse if some of them are RETURNed parameters). Interpreted BBC BASIC has a lot of work to do in making the formal parameters (especially strings) 'local...
by Richard Russell
Tue Oct 03, 2017 11:33 am
Forum: programming
Topic: Many DEFPROC, 1 ENDPROC?
Replies: 17
Views: 1277

Re: Many DEFPROC, 1 ENDPROC?

It's even possible in some versions of BBC Basic to do "overloading" As far as I'm aware the only 'overloading' you can do is of a function or procedure with no parameters and one of the same name with one or more parameters . This works - at least in my versions - because the opening par...
by Richard Russell
Sat Sep 30, 2017 8:57 pm
Forum: development tools
Topic: BASIC cruncher for PC
Replies: 22
Views: 1548

Re: BASIC cruncher for PC

Ah, the memories of trying to fix a crunched broken program with no access to the uncrunched version... For amusement, here's a snippet from 'lblib.bbcc', the crunched library used by LBB. It includes an example of one of the tricky cases: a space between '6' and 'E' being retained because otherwis...
by Richard Russell
Sat Sep 30, 2017 9:47 am
Forum: development tools
Topic: BASIC cruncher for PC
Replies: 22
Views: 1548

Re: BASIC cruncher for PC

I guess one big, huge, glaring question to ask in crunching BASIC programs is: does the EVAL token occur anywhere? If not, you've got a lot more latitude to shrink variable and function names. Leaving all variable/function names intact just because there's a single EVAL in the program is rather dra...
by Richard Russell
Sat Sep 30, 2017 9:38 am
Forum: development tools
Topic: BASIC cruncher for PC
Replies: 22
Views: 1548

Re: BASIC cruncher for PC

My *CRUNCH doesn't do this, and I haven't run through it mentally to check, but all spaces before and after arithmetic operators and brackets The rules for removing spaces are complicated, as I've found to my cost (it took years for the edge-cases to be discovered and fixed in BB4W; as far as I kno...
by Richard Russell
Fri Sep 29, 2017 8:34 pm
Forum: development tools
Topic: BASIC cruncher for PC
Replies: 22
Views: 1548

Re: BASIC cruncher for PC

I've tried BBC BASIC (bbcsdl) before and didn't like either of the ide's People's taste in IDEs differ, so it's impossible to please everybody. That's one of the main reasons why the BBCSDL IDEs are themselves written in BBC BASIC, making it relatively straightforward to customise them to suit indi...
by Richard Russell
Fri Sep 29, 2017 7:00 pm
Forum: development tools
Topic: BASIC cruncher for PC
Replies: 22
Views: 1548

Re: BASIC cruncher for PC

It's written in FreeBASIC so it should compile and work on any system FreeBASIC is available on which is linux,Windows,OSX and I think android. What a shame it's not written in BBC BASIC! I would have thought that was the 'obvious' choice, and of course it's also available on Windows, Linux (includ...
by Richard Russell
Fri Sep 29, 2017 5:45 pm
Forum: programming
Topic: Differences between BASIC1/2 and BASIC4 in handling an EVAL?
Replies: 20
Views: 1374

Re: Differences between BASIC1/2 and BASIC4 in handling an EVAL?

The following segfaults on BB4W 6.11a The reason is much simpler than you think! Remember that 'formal parameters' are automatically LOCAL, so the first thing that happens on calling a PROC/FN is that the existing value of each formal parameter is stored on the stack so that it can be restored on e...
by Richard Russell
Thu Sep 14, 2017 9:32 pm
Forum: other vintage computer hardware, software and games
Topic: Eastern Blok computers
Replies: 7
Views: 795

Eastern Block computers

Nice to see a mention of FOCAL, the first programming language I ever used (in 1970 or thereabouts).

Richard.
by Richard Russell
Wed Aug 16, 2017 10:23 pm
Forum: other vintage computer hardware, software and games
Topic: Tatung Einstien..
Replies: 58
Views: 6757

Re: Tatung Einstien..

Commie_User wrote:I'd be amazed if BBC BASIC on the Tatung was as good as it is on the real thing.

It was my BBC BASIC (Z80), so effectively identical to what was in Acorn's Z80 Second Processor.
by Richard Russell
Mon Aug 07, 2017 11:27 am
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.18a released
Replies: 10
Views: 1018

Re: BBC BASIC for SDL 2.0 v0.18a released

One of the new features of BBCSDL v0.18a is full support for 3D (OpenGL) graphics on the Raspberry Pi. Here's a video showing some of the supplied 3D example programs running on that platform.

Richard.
by Richard Russell
Thu Aug 03, 2017 9:02 am
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 v0.18a released
Replies: 10
Views: 1018

Re: BBC BASIC for SDL 2.0 v0.18a released

The idea of passing parameters in two places seems like a clever workaround. It quite literally came to me in the middle of the night. Persuading a C compiler to do it was challenging, and relies on a non-standard GCC extension (nested functions). I found it necessary to disable optimisation for th...