Search found 194 matches

by litwr
Sat Aug 11, 2018 6:02 pm
Forum: software
Topic: Unix for Archimedes
Replies: 21
Views: 495

Re: Unix for Archimedes

Thanks! :) Archimedes has been among my favorite computers since 1991. However it was very difficult to buy one that time outside the UK. :(
by litwr
Tue Aug 07, 2018 6:55 pm
Forum: software
Topic: Unix for Archimedes
Replies: 21
Views: 495

Re: Unix for Archimedes

A Google search has given that SWP appered with ARMv2a and deprecated with ARMv6. However it is not easy to find the exact years. BTW it is possible to implement a mutex without atomic operation, for example, https://en.wikipedia.org/wiki/Peterson%27s_algorithm . There is something odd around Unix f...
by litwr
Tue Aug 07, 2018 4:36 pm
Forum: software
Topic: Unix for Archimedes
Replies: 21
Views: 495

Re: Notes on ARX, not a Unix

I was aware of this reason for implementing the SWP instruction in hardware, but something else I once read was that LDM or STM instructions had previously been used as a mechanism for implementing mutexes in an atomic way. Anyone got any idea how that would've worked (or even where I read it)? SWP...
by litwr
Sun Aug 05, 2018 7:21 pm
Forum: software
Topic: Unix for Archimedes
Replies: 21
Views: 495

Re: Unix for Archimedes

Thank you very much! :) It is a shame for me that I completely missed this information. R140 has even a MMU. However Wikipedia said that it was a Unix-like system not just Unix... It is also interesting to get some statistics like in an Byte's article https://archive.org/stream/byte-magazine-1984-08...
by litwr
Sun Aug 05, 2018 5:09 pm
Forum: software
Topic: Unix for Archimedes
Replies: 21
Views: 495

Unix for Archimedes

It is quite possible that somebody could ask this question earlier. However after some browsing I couldn't find any answer. I have found a related subject https://stardot.org.uk/forums/viewtopic.php?f=3&t=13991&hilit=unix only. So I am very curious why did Unix miss Archimedes in the 80s? It looks l...
by litwr
Thu Jun 14, 2018 9:42 am
Forum: programming
Topic: 12-second Mandelbrot rendering on the BBC Master!
Replies: 107
Views: 3018

Re: 12-second Mandelbrot rendering on the BBC Master!

If we assume that z80 is about 2.5 slower than 6502 at the same СPU frequency then we get that BBC Micro is about 60% faster than Amstad CPC which true CPU frequency is close to 3.2 MHz
So 30 seconds for CPC are roughly equal to 18-20 secs for BBC Micro.
by litwr
Wed Jun 13, 2018 8:21 pm
Forum: programming
Topic: 12-second Mandelbrot rendering on the BBC Master!
Replies: 107
Views: 3018

Re: 12-second Mandelbrot rendering on the BBC Master!

Ok, so seeing this is for an Amstrad CPC, and as Thomas Harte's ClockSignal emulates a CPC I thought I'd give it a go but never having owned a real one I am stuck as to how one runs the programs from the disk. Any ideas? 1. unzip and get mavdelbrot.dsk ; 2. attach the disk image to your emulator; 3...
by litwr
Wed Jun 13, 2018 2:27 am
Forum: software: other
Topic: Border tracing Mandelbrot generator for the Beeb
Replies: 83
Views: 6450

Re: Border tracing Mandelbrot generator for the Beeb

Coeus wrote:
Wed May 30, 2018 6:05 pm
Interestingly I tried that in Brandy BASIC and it complains that the NEXT s% on line 28 isn't incrementing the current loop control variable.
Basic interpreters allow to have several NEXT for one FOR. This feature is too difficult to support in the modern world of fast compilers...
by litwr
Tue Jun 12, 2018 1:12 pm
Forum: programming
Topic: 12-second Mandelbrot rendering on the BBC Master!
Replies: 107
Views: 3018

Re: 12-second Mandelbrot rendering on the BBC Master!

Yet another very fast Mandelbrot from z80 world - https://www.octoate.de/wp/?s=mavdelbrot - it uses 16 colors.
by litwr
Tue Jun 12, 2018 10:35 am
Forum: software: other
Topic: Border tracing Mandelbrot generator for the Beeb
Replies: 83
Views: 6450

Re: Border tracing Mandelbrot generator for the Beeb

I am curious what is the frequency of the 2nd CPU that gets us only 45 sec?
BTW Raspberry Pi @700 MHz under RiscOS does BBC Basic Mandelbrot program in less than 5 sec.
by litwr
Mon May 01, 2017 7:04 pm
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Re: Have Acorn Archimedes? Please run it for me!

steve3000 wrote:Results from my A440/1 with ARM2 (8MHz) and MEMC1a running RISC OS 3.11, in MODE 0.
Thank you for these results - the tables are updated. :D
by litwr
Sun Apr 30, 2017 11:33 am
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Re: Have Acorn Archimedes? Please run it for me!

It's 24% faster per CPU clock , I think. You can see from the posts upthread that the timings are approx 13 seconds and 31 seconds. Thanks, it is my point. At 1st between ARM3 and ARM250 (24%) and then between the eval system and an ARM 250 where it's 7% and not 24 % ? Where is the logic in this wa...
by litwr
Sun Apr 30, 2017 9:24 am
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Re: Have Acorn Archimedes? Please run it for me!

[SNIP] It is interesting that ARM3 in A4 shows appreciably better (≈24%) performance than ARM250 at A3020. It is too much, I have no idea how to explain this. I continue to wait for ARM2 results. ;) ARM3 has cache and runs at 24 Mhz ... I'm surprised it runs ONLY 24% faster. No, A4 is 31.05/12.73 ≈...
by litwr
Sun Apr 30, 2017 6:43 am
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Re: Have Acorn Archimedes? Please run it for me!

We can't run `pi1' and `pi' - these codes are called from Basic programs `pi-bas' and `pi1-bas' respectively. Basic programs are called from obey scripts but may be used directly.
EDIT. The obey scripts assure more the correctness of the current directory.
by litwr
Sun Apr 30, 2017 6:35 am
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Re: Have Acorn Archimedes? Please run it for me!

A lot of thanks for the help. :) The tables are updated. However I doubt in the results for A3020. I can't believe that `pi' and `pi1' have the same speed. The archive contains two obey scripts `pi-mla' and `pi-no-mla'. Are they tried? The type for `pi-bas' and `pi1-bas' is set to `ffb' - it looks c...
by litwr
Fri Apr 28, 2017 7:27 pm
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Re: Have Acorn Archimedes? Please run it for me!

So I was in error. Maybe ARM2 is even more rare... I met the genuine Acorn Archimedes only once in 1991. I was shocked, it was too good to be reality. :)
by litwr
Fri Apr 28, 2017 7:02 pm
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Re: Have Acorn Archimedes? Please run it for me!

danielj wrote:I shall try it on ARM250 later this evening! :)

d.
Wow! IMHO ARM250 is a rare species. Thanks! :)
by litwr
Fri Apr 28, 2017 6:42 pm
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Re: Have Acorn Archimedes? Please run it for me!

Bump! The request is still actual. Maybe someone could help a bit? Please... BTW I continue to test my Raspberry Pi under RiscOS with BBC Micro software. I have run ClockSP and got combined average 7914.89 MHz - it is more than 11 times bigger than the actual frequency of Pi. :o I ran also Mandelbro...
by litwr
Sun Mar 19, 2017 5:14 pm
Forum: hardware
Topic: Have Acorn Archimedes? Please run it for me!
Replies: 33
Views: 2366

Have Acorn Archimedes? Please run it for me!

I continue to gather data for my pi-spigot project . I have just made two programs for Acorn Archimedes. Two programs instead of one are caused by the intrigue question. What is faster a single MLA instruction or four general data processing instructions? Please help with genuine ARM2 or ARM250 base...
by litwr
Sun Mar 19, 2017 9:57 am
Forum: software
Topic: Several lamer's questions
Replies: 6
Views: 762

Re: Several lamer's questions

Thanks. :) However I can think that I have found a bit shorter way.
Obey script:

Code: Select all

<obey$dir>.prog
I had to add <obey$dir> prefix. A script doesn't work with GUI without it for me.
Basic line:

Code: Select all

OSCLI "LOAD <obey$dir>.PROGNAME "+STR$~ADDR
by litwr
Sun Mar 19, 2017 8:08 am
Forum: software
Topic: Several lamer's questions
Replies: 6
Views: 762

Re: Several lamer's questions

I have another question for Basic. I want to load a ML program. I use

Code: Select all

OSCLI "LOAD PROGNAME "+STR$~ADDR
.
This doesn't work with GUI. I should add a path (folder) of PROGNAME before PROGNAME. How to get this path? Are there other ways?
by litwr
Sun Mar 19, 2017 5:59 am
Forum: software
Topic: Several lamer's questions
Replies: 6
Views: 762

Re: Several lamer's questions

More thanks for the detailed help. :) However the purpose of *DEBUG still misses me. I called it from BASIC and got DEBUG* prompt. I can't catch the difference between it and the standard *-prompt.
by litwr
Sat Mar 18, 2017 8:40 pm
Forum: software
Topic: Several lamer's questions
Replies: 6
Views: 762

Several lamer's questions

1. Is there ways to make Archimedes of the 80s faster? To stop video or something else? Some magic Basic commands?
2. What does DEBUG-command make? I tried it with command line and got a prompt changed from * to DEBUG*. Any details or links?
A lot of thanks in advance. :)
by litwr
Sat Mar 18, 2017 8:28 pm
Forum: emulators
Topic: Arculator on Linux?
Replies: 100
Views: 8193

Re: Arculator on Linux?

I am using version 3.11. 3.00 doesn't work with Arc-em for me, it gives the blank screen. Is there a way to set up a proper configuration for floppies?
by litwr
Sat Mar 18, 2017 4:21 pm
Forum: emulators
Topic: Arculator on Linux?
Replies: 100
Views: 8193

Re: Arculator on Linux?

Thanks for support. :) It looks like I had made something wrong with sources. I downloaded them again, compiled, and things began to work! :) HostFS works too but I still fail with floppy images. They didn't show themselves at GUI panel. :( It is the only HostFS and mysterious :4 drive.
by litwr
Sat Mar 18, 2017 8:23 am
Forum: emulators
Topic: Arculator on Linux?
Replies: 100
Views: 8193

Re: Arculator on Linux?

Thank you very much for the link to documentation. It would be good to have it with the sources. I made my ROM-file by cat IC24.ROM IC25.ROM IC26.rom IC27.ROM >ROM I placed it into a directory with `arcem' file. Then I used micro@my2:~/arcem-src$ ./arcem --memory 4M --processor ARM2 and got the same...
by litwr
Fri Mar 17, 2017 5:45 pm
Forum: emulators
Topic: Arculator on Linux?
Replies: 100
Views: 8193

Re: Arculator on Linux?

The ArcEm works great for me with RISCOS 3.1 and run games about 90% of original speed, so is very playable. Thank you very much for this information. :) So what is wrong with my ArcEm? Is it working with 64-bit Linux? It works with problems with ArthurOS, it can't work with discs. :( I use the nex...
by litwr
Wed Mar 15, 2017 6:38 am
Forum: emulators
Topic: Arculator on Linux?
Replies: 100
Views: 8193

Re: Arculator on Linux?

Is it possible to make the emulation 4-5 times slower? It is too fast now, impossible to use. BTW is there any working Archimedes emulator for Linux? I tried arcem but I could run only ArthurOS with it. :(
by litwr
Fri Mar 10, 2017 12:41 pm
Forum: software: other
Topic: A mathematical demo and the request for help from the hardware owners
Replies: 69
Views: 7413

Re: A mathematical demo and the request for help from the hardware owners

I have just added VAX-11/785 to the list. It is interesting that this very expensive computer (several hundreds thousand bucks?) is slower that 8 MHz PC AT and doesn't have proper hardware division for integers.
by litwr
Sun Mar 05, 2017 7:27 pm
Forum: emulators
Topic: Arculator on Linux?
Replies: 100
Views: 8193

Re: Arculator on Linux?

Thank you. However there are so many clones... The clone for Debian has a bigger 'arm.c' file... I tried Arculator-pending and a Linux branch. It works but with problems. I have made `discs' sub-directory and placed several ADF there. I have also added a line disc_name_0 = discs/Lemmings-1991.adf to...