Search found 513 matches

by ThomasHarte
Tue Oct 20, 2020 12:25 am
Forum: 8-bit acorn emulators
Topic: 6502 cycle-level instruction detail
Replies: 19
Views: 624

Re: 6502 cycle-level instruction detail

So, I grabbed Dormann's repository and a copy of DOSBox in order to be able to run his preferred assembler, made appropriate edits, and the attached should be his 65C02 tests restricted to the appropriate subset for a 65816 — i.e. no Rockwell/WDC BBR, BBS, RMB & SMB, no testing that all the undefine...
by ThomasHarte
Mon Oct 19, 2020 4:24 pm
Forum: 8-bit acorn emulators
Topic: 6502 cycle-level instruction detail
Replies: 19
Views: 624

Re: 6502 cycle-level instruction detail

[*] Klaus Dormann's regular 6502 test works correctly, but his 65C02 test doesn't because it tests BBR, BBS, etc, which the 65816 doesn't implement; As supplied pre-assembled, yes, but testing of the Rockwell instructions is a conditional assembly option. You're completely right, and here is the pr...
by ThomasHarte
Mon Oct 19, 2020 2:16 pm
Forum: 8-bit acorn emulators
Topic: 6502 cycle-level instruction detail
Replies: 19
Views: 624

Re: 6502 cycle-level instruction detail

Yes, but it probably won't be useful because I wrote it as native code rather than emulated — specifically it's in Swift , e.g. func testDirectIndirectLong() { // "If the D register is $FF00 and the m flag is 0, then for LDA [$FE], the // address of the low byte of the pointer is $00FFFE, the addres...
by ThomasHarte
Mon Oct 19, 2020 12:34 pm
Forum: 8-bit acorn emulators
Topic: 6502 cycle-level instruction detail
Replies: 19
Views: 624

Re: 6502 cycle-level instruction detail

Having just implemented it myself, the full 65816 cycle-by-cycle steps are in its data sheet — check out Page 42 onwards. Also note that fhe “identical except for bug fixes caveat” is quite a caveat. Not only is JMP (xxxx) fixed so as not to be page-constrained, which they’d also fixed on the 65C02,...
by ThomasHarte
Sun Oct 04, 2020 3:50 pm
Forum: 8-bit acorn emulators
Topic: Floppy Image Formats
Replies: 23
Views: 1884

Re: Floppy Image Formats

I doubt it will inform much, but Clock Signal first stores tracks as regions of pulses, each region with its own window sizing; for many file formats it starts as one region per track but, regardless, the rate isn’t fixed or known in advance by the disk controllers. If a track is written to, it is q...
by ThomasHarte
Fri Aug 07, 2020 2:41 am
Forum: 8-bit acorn emulators
Topic: Clock Signal: now useable under Qt, too
Replies: 10
Views: 962

Re: Clock Signal: now useable under Qt, too

I have to admit to having insufficient experience to know how I would do anything more useful than gracefully report the problem there.

I'll have to do some more reading.
by ThomasHarte
Tue Aug 04, 2020 1:40 am
Forum: 8-bit acorn emulators
Topic: Index of links to 8-bit Acorn Emulators
Replies: 35
Views: 16407

Re: Index of links to 8-bit Acorn Emulators

Sorry, update on this: HTeMuLator now seems to work in Safari. Same version of Safari, same machine, same ad blockers, same everything.
by ThomasHarte
Thu Jul 30, 2020 3:37 pm
Forum: 8-bit acorn emulators
Topic: Index of links to 8-bit Acorn Emulators
Replies: 35
Views: 16407

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: 10
Views: 962

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: 35
Views: 16407

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: 35
Views: 16407

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: 35
Views: 16407

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: 10
Views: 962

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: 411

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: 2261

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: 2261

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: 411

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: 10
Views: 962

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: 535

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: 23
Views: 1884

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: 23
Views: 1884

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: 1594

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: 23
Views: 1884

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: 10
Views: 962

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: 10
Views: 962

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: 23
Views: 1884

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: 90
Views: 5563

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: 758

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: 90
Views: 5563

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: 90
Views: 5563

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...

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