Search found 57 matches

by Tom
Fri Dec 27, 2019 3:14 pm
Forum: Emulation and Cross Development
Topic: The C64 Does have a Vic-20 Mode and it's great
Replies: 29
Views: 8381

Re: The C64 Does have a Vic-20 Mode and it's great

depending on platform, a modern piece of software isn't necessarily granted the right to open any old file it likes just because the user has done something to give it access to one, even if they're within the same folder. what kind of weird platform would that be? Any in-browser emulator, most obv...
by Tom
Thu Dec 26, 2019 10:12 pm
Forum: Emulation and Cross Development
Topic: The C64 Does have a Vic-20 Mode and it's great
Replies: 29
Views: 8381

Re: The C64 Does have a Vic-20 Mode and it's great

Extract from user guide: --------------------------------------------------------------------------------- Use of 'Flags' or Flags for loading games and / or programs ... Having learnt about these today, I've adopted all of the relevant ones in my Vic-20 emulator, Clock Signal . It otherwise tries ...
by Tom
Fri Apr 13, 2018 9:33 pm
Forum: Emulation and Cross Development
Topic: Clock Signal: a Vic-20 emulator for macOS and Linux
Replies: 64
Views: 34776

Re: Clock Signal: a Vic-20 emulator for macOS and Linux

A new release has been uploaded that corrects the timing of the raster count increment, under both NTSC and PAL. It's in the usual place . I've declined yet to correct the failure to delay palette changes because I'd like to adjust the whole VIC 6560 loop, but would prefer to be more certain in a wh...
by Tom
Mon Apr 09, 2018 8:06 am
Forum: Emulation and Cross Development
Topic: Clock Signal: a Vic-20 emulator for macOS and Linux
Replies: 64
Views: 34776

Re: Clock Signal: a Vic-20 emulator for macOS and Linux

Okay, I tried the most obvious fix: just repositioning when I increment the raster counter so as to match a corresponding test. That corrected the test, corrected Capture the Flag, and seemed to correct the NTSC colour demo but very obviously broke Atlantis. It started doing all of its colour change...
by Tom
Sun Apr 08, 2018 3:34 pm
Forum: Emulation and Cross Development
Topic: Clock Signal: a Vic-20 emulator for macOS and Linux
Replies: 64
Views: 34776

Re: Clock Signal: a Vic-20 emulator for macOS and Linux

Well, I found a first bug but it turns out to have been tangential: failure to wrap the raster count properly in NTSC mode. So it would allege itself to be on line 261 for the final half of the final line, before admitting it's on line 0 for the first half of the first line. That being fixed, my rep...
by Tom
Sun Apr 08, 2018 11:10 am
Forum: Emulation and Cross Development
Topic: Clock Signal: a Vic-20 emulator for macOS and Linux
Replies: 64
Views: 34776

Re: Clock Signal: a Vic-20 emulator for macOS and Linux

You should check the timing of the NTSC (and possibly also the PAL) version. In the first screenshot, the splits of the background register happen at the wrong place (after the first text column), whereas they're supposed to happen just after HSync, at the beginning of the raster. With non-interlac...
by Tom
Sat Apr 07, 2018 1:01 pm
Forum: Emulation and Cross Development
Topic: Clock Signal: a Vic-20 emulator for macOS and Linux
Replies: 64
Views: 34776

Re: Clock Signal: a Vic-20 emulator for macOS and Linux

Quick minor post: an updated version is available with fixes to the VIC colour palette as above, to the 1.6Khz low-pass audio filter (it was, unwittingly, ineffective), and other minor optimisations. Most obviously, the emulator now attempts to support S-Video output. So you're no longer stuck with ...
by Tom
Thu Apr 05, 2018 4:49 pm
Forum: Programming
Topic: Amen brother ~ 6 bit audio @ 16.3kHz
Replies: 34
Views: 6700

Re: Amen brother ~ 6 bit audio @ 16.3kHz

I used it to fix a bug in my emulator; my low-pass filter wasn't actually taking effect due to a two-line error. So this is how it'll sound in the next release, and I think it's probably accurate.

So: Youtube link.

It's very quiet though, as mentioned above. Turn your speakers up.
by Tom
Thu Mar 29, 2018 2:45 pm
Forum: Emulation and Cross Development
Topic: PRG Starter (v2.4.6)
Replies: 141
Views: 110273

Re: PRG Starter (v2.4.6)

I've sent a private message; I'll keep my fingers crossed but fair enough if that version has been withdrawn.

UPDATE: with immense gratitude to Robert Hurst for responding, the binary has long ago fallen off the internet but the source remains available. So that's even better!
by Tom
Wed Mar 28, 2018 11:39 am
Forum: Emulation and Cross Development
Topic: Clock Signal: a Vic-20 emulator for macOS and Linux
Replies: 64
Views: 34776

Re: A heavyweight Vic-20 emulator with twists

It looks like I stopped posting on this prematurely. The thing has actually been under continuous development in the 18 months I've been absent, but a lot of that work has been on emulating things that aren't the Vic-20. I actually let the Vic-20 go slightly to pasture, so shame on me. I mean, I kep...
by Tom
Tue Mar 27, 2018 1:48 pm
Forum: Emulation and Cross Development
Topic: PRG Starter (v2.4.6)
Replies: 141
Views: 110273

Re: PRG Starter (v2.4.6)

This is still the gold standard; askew query though: is the long-missing command-line version now gone forever? Nobody has found it elsewhere or kept a copy?
by Tom
Tue Mar 27, 2018 1:46 pm
Forum: Emulation and Cross Development
Topic: c++
Replies: 8
Views: 6387

Re: c++

Hi Why would one use C++ to generate 6502 code other than as a proof of concept? ANSI C allows object-oriented programming in a more efficient way (though, slightly less elegant), through: - composition + pointer to structs -> inheritance - pointer to functions -> virtual methods (sub-type polymorp...
by Tom
Mon Aug 22, 2016 7:06 pm
Forum: Emulation and Cross Development
Topic: Clock Signal: a Vic-20 emulator for macOS and Linux
Replies: 64
Views: 34776

Re: A heavyweight Vic-20 emulator with twists

If you can read my code it may help. I read CSM and TAP file format and covert to pulse widths. http://www.mdawson.net/vic20chrome/vic20/tapedrive.js Yep, that really helped, thanks! Most notable amongst my errors: outputting as header, data, repeat header, repeat data rather than header, repeat he...
by Tom
Wed Aug 17, 2016 5:03 pm
Forum: Emulation and Cross Development
Topic: Clock Signal: a Vic-20 emulator for macOS and Linux
Replies: 64
Views: 34776

Re: A heavyweight Vic-20 emulator with twists

Apologies for the conversation break; I've been working on PAL, memory expansion support and PRG->tape conversion, hoping to get to PRG Starter-type logic being all that's left. Attached is a PAL shot. I've yet to implement any of the findings of the recent thread on this so fetch-time noise is miss...