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Richard Russell

danielj wrote: ↑
Mon Nov 30, 2020 9:28 am
and only then after being explicitly warned to stop it.

I have been explicitly warned, as you know.

Richard Russell

BigEd wrote: ↑
Sun Nov 29, 2020 8:46 pm
You should have nothing to worry about on that front.

PM sent.

Richard Russell

I'm vaguely interested to know if your machine and the Beeb's machines used the 8271 for their disk controller. Yes. I posted a long and detailed account of my experiences with the 8271 in the thread discussing its reverse engineering. But I realised it was hopelessly off-topic (as it is here) and ...

Richard Russell

(Confirmed in jsbeeb for 6502 BBC Basic!) I think I'm pretty safe in saying that no version of BBC BASIC has ever got this wrong. In fact it's almost universal in the BASIC language more generally, but there are a couple of outliers: Liberty BASIC is one (its INT function truncates towards zero - o...

Richard Russell

there's a "real to int" function in BASIC which is used for INT() but when converting from real to int for procedure call parameters the module is called They should be different! BASIC's INT() truncates towards minus-infinity (i.e. it's the floor function) whereas coercing to an integer when calli...

Richard Russell

Splitting out Arithmetic probably seemed like a good idea at the time but with a bit of optimization it would probably have taken less space to keep the stuff in BASIC for faster calling and keep the module for ViewSheet. Roughly how big is the arithmetic module? The Z80 equivalent in the Z88 is ab...

Richard Russell

Nice, anything there I can emulate? Would need any ROMs, schematics, etc, anything you have on it really. The BBC's Zeus/Zelda or my homebrew system? Although the BBC's extensive documentation (including circuit schematics, parts lists, descriptions etc.) was carefully preserved for decades - survi...

Richard Russell

What was the OS on your machine Richard cp/m? Latterly mostly CP/M yes; earlier all the software would have been written in-house, for example the disk filing system was originally designed for the Presfax and Bennfax projects and later adapted for HF Automation. For those interested in such obscur...

Richard Russell

BigEd wrote: ↑
Sat Nov 28, 2020 6:05 pm
Oh, that's great! OK for me to reshare this information?

Of course. There's a lot more where that came from!

Richard Russell

Engraved front-panel label saved for posterity after they were junked, probably 30 years ago:

Richard Russell

Excellent! Should you be at all interested (probably not - and it is way off-topic) Zelda - Z 80 E ditor L inker D OS A ssembler - was a modular computer system developed by BBC Engineering Designs Department from their in-house Zeus range of 4U plug-in units, plus dual 8" floppy disk drives. Many ...

Richard Russell

Was that work at your own initiative, or at the request of the BBC Entirely at my own initiative (but given that I was a keen and experienced Z80 programmer it was a foregone conclusion that I would want to). And how did you test it? On my own homebrew ('CRF/RTR') computer when at home and/or one o...

Richard Russell

That sounds good - thanks for the explanation! I should probably add that the more generous availability of integer registers (16 on x86_64 compared with 8 on x86_32) and there being less register pressure generally (a 64-bit number requiring only one register on x86_64 and two on x86_32) means tha...

Richard Russell

I note that your 64bit build is faster than your 32bit build - not sure I would have expected that It's because my current BASICs all perform integer calculations internally as 64-bits. As I've mentioned before, even something like A% = A% + 1 requires the following steps: Sign-extend A% from 32-bi...

Richard Russell

Knowing that one interpreter is faster for some specific tasks than another is one thing, but being able to (or wanting to) choose the faster one is quite another. For example Brandy is typically much faster than my BASICs, but I don't see hordes of users deserting mine in favour of Brandy, typicall...

Richard Russell

To hit the 2Mhz spot on you have to disable many of them. You can't disable interrupts on any of the platforms I support, nor (I would expect) most others, so in the context of comparing different interpreters on different platforms (which is what my modified version is specifically intended for) l...

Richard Russell

Richard Russell wrote: ↑
Wed Nov 25, 2020 6:59 pm
If it's giving significantly different results in a real Beeb I'm afraid I have no idea why.

GOSUB being fractionally slower (even in BeebEm) could be because I've added a couple of lines, meaning it takes a little longer to 'find' the target line.

Richard Russell

I would've used the modified ClockSP with 'really real' tests in it, but I think some of the later tests need to be recalibrated. They don't add up to 2.00 MHz on a BBC B. Oh. I tested it in BeebEm and assumed that it would be representative of a Model B (the changes I made shouldn't have had any e...

Richard Russell

You would be perfectly in keeping with the license by changing the name of the binary (and either removing or changing the display string) I agree that removing the display string altogether would meet the terms of the licence, but that has not (until now) been proposed. My objection has only been ...

Richard Russell

What would you say would be enough, Richard? The phrase in the licence is "plainly marked" as being altered, but that's obviously subjective. I honestly never thought that anybody would want to modify the program after nearly 40 years; had I done so I wouldn't have released the source. My current v...

Richard Russell

am I missing something, the loops seem to time 1,000,000 iterations then take time as a time in nanoseconds but TIME is centiseconds not milliseconds so shouldn't it be 10,000,000 iterations? No. What you're "missing" is that in each iteration of the loop the statement or function being tested is e...

Richard Russell

Because I've got a fixed limit of 16384 bytes space is very tight! There's no problem with a long message in the CP/M version, but for the Spectrum I'm trying to squeeze as much as I can in 16K. I can understand that your priorities are different from mine, and I know that 'legal' restrictions can ...

Richard Russell

A more specific set of benchmarks would help me. I expect you're aware of timing.bbc supplied with all editions of BBC BASIC for SDL 2.0 but that's still heavily weighted towards timing mathematical operations rather than a more typical mix of statements. In fact I doubt that we would get much agre...

Richard Russell

can you let me know what you'd like it to say and I'll make the changes. I've got 64 bytes (2 rows of 32) due to space constraints (both screen and memory!). Why can't you add a third row? Surely an extra 32 bytes isn't going to break anything. :? I get the following results when comparing BBC BASI...

Richard Russell

Do you scan for them all at program start or cache them as they are used? Do they get stored in normal variables or have their own space. They share the same namespace as other variables (when machine-translated from Liberty BASIC I use a naming convention which avoids any collisions). I scan for t...

Richard Russell

it is my (humble) opinion that you should avoid buying through 123-reg.co.uk at all costs. They have an outage about once a month, which then stops domains from working, or users making changes to domain records. I buy domains through 123-reg but typically I then change the nameservers, so an outag...

Richard Russell

Is this mechanism available in any other versions of BASIC? All my 'modern' versions of BBC BASIC support labels, but they were added principally to aid machine translation from other BASIC dialects (particularly Liberty BASIC) rather than with the expectation that programs written from scratch in ...

Richard Russell

jms2 wrote: ↑
Fri Nov 20, 2020 4:30 pm
Robin is a pretty unusual name though isn't it.

Number 865 in the 2020 chart of boys' names but much more common in the past I would say; I have known several Robins and there have been plenty in the public eye. Quite commonly a girl's name in the US of course.

Richard Russell

Now i can start playing with a bbc if you get me! I have a master, but on the pi its so much easier, and fun, probably faster too. Note that switching to fullscreen won't (automatically) stretch the window contents to fit. So for example MODE 7 won't fill the screen. You can arrange to stretch it, ...

Richard Russell

avtovaz wrote: ↑
Fri Nov 20, 2020 10:32 pm
i am still struggling with this, i cant find the code i tried

Is this what you're looking for?

Code: Select all

      SYS "SDL_SetWindowFullscreen", @hwnd%, &1001
      VDU 26

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