Search found 506 matches

by ThomasHarte
Thu Jul 30, 2020 3:37 pm
Forum: 8-bit acorn emulators
Topic: Index of links to 8-bit Acorn Emulators
Replies: 32
Views: 14136

Re: Index of links to 8-bit Acorn Emulators

Tested in [desktop] Safari 13.1.2 (an up-to-date version), the following worked:
  • jsatom;
  • Tiny Emulators;
  • virtualkc;
  • Elk JS; and
  • JSBeeb.
So, assuming I didn't miss any, only HTeMuLator failed. It worked in Firefox so I'm pretty sure Safari is the relevant factor.
by ThomasHarte
Tue Jul 28, 2020 3:19 am
Forum: 8-bit acorn emulators
Topic: Clock Signal: now useable under Qt, too
Replies: 7
Views: 459

Re: Clock Signal: now useable under Qt, too

Update again: the first round of Qt and Snap bug reports has thrown light on some extreme flaws but I'm hoping that everything severe is now fixed. So if you've tried to use the Qt build before via either route to availability, it's definitely worth updating. Binaries via Snap ; tagged source from G...
by ThomasHarte
Tue Jul 28, 2020 3:12 am
Forum: 8-bit acorn emulators
Topic: Index of links to 8-bit Acorn Emulators
Replies: 32
Views: 14136

Re: Index of links to 8-bit Acorn Emulators

Suggested updates for the lead post: b2 is available as a prebuilt Linux binary via Snap ; as is Clock Signal ; also, given that Clock Signal emulates only the Electron from Acorn's lot, could it please just be listed as an Electron emulator?; alternatively, Tiny Emus is much, much broader in scope ...
by ThomasHarte
Sun Jul 26, 2020 5:06 pm
Forum: 8-bit acorn emulators
Topic: Index of links to 8-bit Acorn Emulators
Replies: 32
Views: 14136

Re: Emulator information

Regarding SDL using outdated APIs, b2 is using an outdated version of SDL - I have my own fork, because of a long story , which is now rather out of date. I aim to do something about this at some point(tm), arranging things so that b2 can use unmodifed latest SDL on all platforms, and hopefully thi...
by ThomasHarte
Sat Jul 25, 2020 11:22 pm
Forum: 8-bit acorn emulators
Topic: Index of links to 8-bit Acorn Emulators
Replies: 32
Views: 14136

Re: Emulator information

After going through Apple's "control + click, cancel, control + click, oh look, you now get the option to run the program, run program" rigmarole, b2 starts up and runs as expected. OK, I don't know enough to test everything, but it runs the program I'm developing so that's enough for me at this st...
by ThomasHarte
Sat Jul 25, 2020 7:00 pm
Forum: 8-bit acorn emulators
Topic: Clock Signal: now useable under Qt, too
Replies: 7
Views: 459

Re: Clock Signal: now useable under Qt, too

Minor update: Clock Signal's Snap listing now possibly works.

Snaps are not Ubuntu-specific but this also means that if you're a Ubuntu user then Clock Signal should now be listed in the 'Ubuntu Software' storefront. Hopefully. I'm not good at this stuff.
by ThomasHarte
Fri Jul 24, 2020 2:45 pm
Forum: 8-bit acorn emulators
Topic: Horizon on MacOS 10.15 "Catalina"
Replies: 4
Views: 224

Re: Horizon on MacOS 10.15 "Catalina"

I think security professionals will agree that you don’t need quote marks. But like any software security there are ways around them, either through bugs or human ingenuity, which Apple fix as quickly as they can. Right — heightened is correct, resolved unambiguously wouldn't be. Sandboxing moves y...
by ThomasHarte
Thu Jul 23, 2020 11:04 pm
Forum: programming
Topic: Drawing lines - BASIC vs machine code
Replies: 48
Views: 1201

Re: Drawing lines - BASIC vs machine code

If people are writing machine code and handling floats, do they write their own routines for e.g. multiplication from scratch, or do they call built-in routines that are already as fast as can be? I'd be interested to hear of anyone who is using floats from machine code. I thought it was more usual...
by ThomasHarte
Thu Jul 23, 2020 9:35 pm
Forum: programming
Topic: Drawing lines - BASIC vs machine code
Replies: 48
Views: 1201

Re: Drawing lines - BASIC vs machine code

As an aside, supposing it ever becomes a bottleneck, I once checked out the MOS routines versus completely hand-crafted line drawing on an Electron. On that machine the processor accesses ROM more quickly than RAM so if you wanted to reproduce the full swathe of MOS functionality then you'd be at qu...
by ThomasHarte
Thu Jul 23, 2020 4:47 pm
Forum: 8-bit acorn emulators
Topic: Horizon on MacOS 10.15 "Catalina"
Replies: 4
Views: 224

Re: Horizon on MacOS 10.15 "Catalina"

I don't know what the quotation marks are meant to imply, but to confirm Apple's model with respect to file access: Apps which have opted in for neither the sandbox nor the hardened runtime still act exactly as they always did, other than that the user has to jump through more hoops to be permitted ...
by ThomasHarte
Mon Jul 20, 2020 3:46 pm
Forum: 8-bit acorn emulators
Topic: Clock Signal: now useable under Qt, too
Replies: 7
Views: 459

Re: Clock Signal: now useable under Qt, too

I've got it working in VMware/Ubuntu! I'm running the Electron emulator part and noticed that the screen is quite wobbly. It doesn't matter if I select RGB, CompositeColour or CompositeMonochrome. Is that a feature of the interlaced PAL signal? Almost certainly; there's no explicit deinterlacing st...
by ThomasHarte
Fri Jul 17, 2020 10:07 pm
Forum: 8-bit acorn software: other
Topic: Name of the CRC from the Advanced User Guide?
Replies: 6
Views: 350

Re: Name of the CRC from the Advanced User Guide?

It is on the wikipedia list... it is the 16 bit CRC with normal polynomial 0x1021. Thanks. AIUI, it's initialised with &0000 not &FFFF, so it's not the CCITT CRC-16. Closer to the XMODEM CRC16, though perhaps with a permutation of the byte/bit ordering. To expand on this, from browsing the definiti...
by ThomasHarte
Fri Jul 17, 2020 9:51 pm
Forum: 8-bit acorn emulators
Topic: Floppy Image Formats
Replies: 18
Views: 956

Re: Floppy Image Formats

beebjit and MAME do. I'd be surprised if there were not others. Yeah, Clock Signal too — the sector image + FDC response-style formats are sometimes a real hassle to support as a result. Thankfully mid-level stream formats are pretty popular on a bunch of platforms; off the top of my head there's G...
by ThomasHarte
Fri Jul 17, 2020 5:11 am
Forum: 8-bit acorn emulators
Topic: Floppy Image Formats
Replies: 18
Views: 956

Re: Floppy Image Formats

Anyway the real adoption problem with stream or cells based formats (SCP, KF RAW, HFE...) are not the formats documentations or whatever but the fact that most emulators don't really emulate the FDC. beebjit and MAME do. I'd be surprised if there were not others. Yeah, Clock Signal too — the sector...
by ThomasHarte
Tue Jul 14, 2020 7:55 pm
Forum: 8-bit acorn emulators
Topic: Supporting FSD in MAME
Replies: 5
Views: 1373

Re: Supporting FSD in MAME

Picking up on this late, but John Morris created the WOZ disk image file format for Apple IIs; in order properly to advocate on how support should be implemented he's written a bit on the MC3470 here, in the 'Freaking Out Like a MC3470' section . Specifically: The MC3470 chip is the heart of the App...
by ThomasHarte
Tue Jul 14, 2020 3:51 am
Forum: 8-bit acorn emulators
Topic: Floppy Image Formats
Replies: 18
Views: 956

Re: Floppy Image Formats

Coeus wrote:
Tue Jun 30, 2020 11:46 am
Anyway, that says it is revision 1.1. Is that the latest, other than 3, i.e. was there no revision 2?
Nothing after v1.1 is documented, and the only there thing I've heard of people using is v3. So my guess would be that there's no revision 2.
by ThomasHarte
Mon Jul 13, 2020 3:46 pm
Forum: 8-bit acorn emulators
Topic: Clock Signal: now useable under Qt, too
Replies: 7
Views: 459

Re: Clock Signal: now useable under Qt, too

Hi Thomas, thanks again for your great talk! I really, really want to experiment with CLK but I can't figure out if it is possible (and easy) to build a Windows version? Alas, I don't have a good answer for that question. I haven't used Windows at home for 17 years, or at work for 12. That said, I'...
by ThomasHarte
Mon Jul 13, 2020 3:28 pm
Forum: 8-bit acorn emulators
Topic: Clock Signal: now useable under Qt, too
Replies: 7
Views: 459

Clock Signal: now useable under Qt, too

Clock Signal is: an emulator of multiple systems, including the Acorn Electron; that tries to be a little more rigorous than the average in audio and video output — raw audio is sampled at the machine's native rate then lowpass filtered and resampled to whatever your machine supports, composite vid...
by ThomasHarte
Mon Jun 29, 2020 2:35 pm
Forum: 8-bit acorn emulators
Topic: Floppy Image Formats
Replies: 18
Views: 956

Re: Floppy Image Formats

Also, HFEv1 has been supported by Clock Signal, an Electron emulator, for a few years now. I intend to look at HFEv3 soon, due to its momentum around here.
by ThomasHarte
Fri Jun 19, 2020 9:51 pm
Forum: archive submissions
Topic: Starting an archive of HFE protected disc files
Replies: 71
Views: 3579

Re: Starting an archive of HFE protected disc files

Yeah, my argument was: original author of file format advocates against HFE as an emulator file format; the format has already changed substantially since the only time it was documented; the author makes no promises whatsoever about future stability; and the only code offered locks out three-quart...
by ThomasHarte
Fri Jun 19, 2020 4:44 pm
Forum: 8-bit acorn software: classic games
Topic: Electron ELITE Cheat
Replies: 7
Views: 573

Re: Electron ELITE Cheat

I find ElectrEM a bit buggy. ElectrEM hasn’t been updated for a number of years and doesn’t work well with Windows 10. Elkulator works better on Windows 10. It also can be configured for either DFS or ADFS file systems. With ElectrEm you can just import the text file directly as BASIC — the emulato...
by ThomasHarte
Fri Jun 19, 2020 3:54 pm
Forum: archive submissions
Topic: Starting an archive of HFE protected disc files
Replies: 71
Views: 3579

Re: Starting an archive of HFE protected disc files

Where can I read an overview / specification of stream HFE? Is it supported by Gotek + FF? I'm not against a change of tack here but I've been studying all of the particularly advanced BBC on-disc copy protections and HFEv3 is continuing to hold up as a really robust match. I'd have to defer to the...
by ThomasHarte
Fri Jun 19, 2020 12:37 am
Forum: archive submissions
Topic: Starting an archive of HFE protected disc files
Replies: 71
Views: 3579

Re: Starting an archive of HFE protected disc files

Hi, Working with @billcarr2005, I'm starting to convert his large library of FSD protected beeb disc files to HFE files. Why HFE? 1) HFEv3 files are capable of accurately representing all currently-known copy protection methods used on the beeb. I have designed the HFE (v1/v2/v3) for the H xC F lop...
by ThomasHarte
Fri Jun 12, 2020 10:15 pm
Forum: new projects and releases: demoscene
Topic: BBC Micro and Acorn Electron demo effects
Replies: 86
Views: 8500

Re: BBC Micro and Acorn Electron demo effects

I dispute this claim. :shock: :shock: :shock: Could you try this one as well? https://stardot.org.uk/forums/viewtopic.php?f=64&t=18431 Alas something seems to be off with that; I guess I don't quite have one of my interrupts properly placed horizontally. The ball bounces up and down properly, and t...
by ThomasHarte
Fri Jun 12, 2020 2:59 pm
Forum: new projects and releases: demoscene
Topic: BBC Micro and Acorn Electron demo effects
Replies: 86
Views: 8500

Re: BBC Micro and Acorn Electron demo effects

tricky wrote:
Fri Jun 12, 2020 7:46 am
Do you get any CPU in MODE 0-2 while the beam is off-screen per scanline?
Yes — on lines with pixels you get 1Mhz access to RAM in the border region, i.e. 24 cycles/line.
by ThomasHarte
Thu Jun 11, 2020 9:43 pm
Forum: new projects in development: games
Topic: Zezito and Ambrosia's Potions - Acorn Electron 32K
Replies: 35
Views: 1533

Re: Zezito and Ambrosia's Potions - Acorn Electron 32K

That looks really cool. I'm not on Twitter, but will subscribe to this thread. Re: memory footprint, I've heard other modern retro coders raving about LZ4 compression; e.g. here's an Apple II implementation that claims to be able to decompress full Apple II frames at 4.3 fps. So that's a 1Mhz 6502 d...
by ThomasHarte
Thu Jun 11, 2020 3:53 pm
Forum: 8-bit acorn emulators
Topic: Threads and emulators
Replies: 38
Views: 1389

Re: Threads and emulators

part of the FIR filtering will utilise Apple's Accelerate framework for vector operations Sorry for the plug, but if you're into FIR filters (particularly polyphase filters for scaling or phase-shifting) you might be interested in another of my BBC BASIC programs (it's the only language I know well...
by ThomasHarte
Thu Jun 11, 2020 3:20 pm
Forum: 8-bit acorn emulators
Topic: Threads and emulators
Replies: 38
Views: 1389

Re: Threads and emulators

Thanks Thomas, for your information about CLK, I'd not come across your emulator before - there are a lot around. I will have to try it out it looks to have an interesting approach! I'll try and get a look next week at it - when the child is back at school and I get some thinking time. Did you use ...
by ThomasHarte
Thu Jun 11, 2020 2:42 pm
Forum: new projects and releases: demoscene
Topic: BBC Micro and Acorn Electron demo effects
Replies: 86
Views: 8500

Re: BBC Micro and Acorn Electron demo effects

It will NOT work 100% correctly on any existing Electron emulator; only on the real machine! I dispute this claim. Screenshot 2020-06-11 at 09.41.39.png ... and since I haven't changed anything in the timing on the Electron part of my emulator in a few years, I backdate that to 2019. All I did was ...
by ThomasHarte
Thu Jun 11, 2020 2:36 pm
Forum: 8-bit acorn emulators
Topic: Threads and emulators
Replies: 38
Views: 1389

Re: Threads and emulators

15 or so years later it became possible to achieve the same functionality purely in software on a (fast) PC, which made it much easier to manufacture and more flexible. The challenge was to get as close as possible to the timing predictability that the hardware implementation had achieved. Locking ...

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