Search found 55 matches

by rv6502
Tue Dec 17, 2019 2:27 am
Forum: Off Topic
Topic: Intellivania: Castlevania for the Intellivision!
Replies: 11
Views: 2341

Re: Intellivania: Castlevania for the Intellivision!

Yes, that's also rather interesting, a quite unique CPU, in some regards it might do better than the 6510 due to being 16 bits. Otherwise it is not quite as fast by the clock counts in this Wiki, however it was clocked at almost twice the rate of the typical 6510 based machine (C64). The Wiki actua...
by rv6502
Fri Dec 13, 2019 3:42 am
Forum: Off Topic
Topic: Intellivania: Castlevania for the Intellivision!
Replies: 11
Views: 2341

Re: Intellivania: Castlevania for the Intellivision!

And it's a 16bits system!

But the ROMs were 12 bits wide to save cost which was possible thanks to the opcodes being only effectively 10bits long with 6 reserved bits.
by rv6502
Sun Nov 24, 2019 2:01 am
Forum: Uzebox Emulator
Topic: Emulation and sync behaviour of a CRT monitor
Replies: 3
Views: 1592

Re: Emulation and sync behaviour of a CRT monitor

Adding from the AD725.pdf data sheet: If no equalization or serration pulses are included in the HSYNC input there won’t be any in the outputs. Although sync signals without equalization and serration pulses do not technically meet the video standards’ specifications, many monitors do not require th...
by rv6502
Sat Nov 23, 2019 11:50 pm
Forum: Uzebox Emulator
Topic: Emulation and sync behaviour of a CRT monitor
Replies: 3
Views: 1592

Re: Emulation and sync behaviour of a CRT monitor

Writing emulators I find it easier to sync purely to the computer's audio using the cycle counters. So the audio becomes the speed governor. (if audio is disabled then I use a equivalent timer) The video is displayed using a small queue, regulated by computer's vsync or a timer, and doing a frame di...
by rv6502
Sat Nov 23, 2019 5:32 am
Forum: Programming & Software
Topic: 80 column text mode at quite high resolution
Replies: 23
Views: 3754

Re: 80 column text mode at quite high resolution

It is not totally un-readable one the 320x200 screen. It'd be more readable if shaken horizontally by half a pixel ( on a 320 scale ) every frame for a bit of temporal dithering. I tried with the capture card, it helped but I couldn't capture it (mpeg4 compression removed it. Thanks, motion compens...
by rv6502
Sat Nov 23, 2019 1:10 am
Forum: Programming & Software
Topic: 80 column text mode at quite high resolution
Replies: 23
Views: 3754

Re: 80 column text mode at quite high resolution

rv6502, What CPU tricks are you using to make the emulator not work? I'm being somewhat loose with the vsync signal and the emulator has a very narrow tolerance. Analogue hardware only cares if past a certain threshold of sync time with a simple capacitor charge/discharge and digital hardware only ...
by rv6502
Sat Nov 23, 2019 12:58 am
Forum: Programming & Software
Topic: 80 column text mode at quite high resolution
Replies: 23
Views: 3754

Re: 80 column text mode at quite high resolution

Emulator is happy with it once patched :D Screenshot_2019-11-22_19-47-04.png And I need to adjust my mid-frame audio generator call it's messing up the hblank by quite a few cycles even with the recursive interrupt. Funny enough the CRT doesn't care. I guess they used to try hard to keep the picture...
by rv6502
Sat Nov 23, 2019 12:42 am
Forum: Uzebox Emulator
Topic: CUzeBox - The new official Uzebox emulator
Replies: 243
Views: 78525

Re: CUzeBox - The new official Uzebox emulator

I got a patch that doesn't seem to break the Uzebox games and works with my somewhat-degenerate signal generator... I can submit a proper patch request on github but here it is in short: ~/builds/cuzebox-master.patched$ diff ../cuzebox-master/cu_avr.c cu_avr.c 596a597 > auint tdiff; 647,648c648,651 ...
by rv6502
Fri Nov 22, 2019 11:21 pm
Forum: Programming & Software
Topic: 80 column text mode at quite high resolution
Replies: 23
Views: 3754

Re: 80 column text mode at quite high resolution

I've also been working on an 8x8 80x25 mode for doing ports. Each row has to end with a null byte (memory is 81x25) to jump-table out of the sequence so I only got 127 characters usable. PA222684-small.JPG It's still a bit clunky and my cheap USB capture dongle doesn't line up the pixels right so ma...
by rv6502
Sun Nov 03, 2019 3:40 am
Forum: Off Topic
Topic: A bit of time off, but awesome stuff going on here
Replies: 6
Views: 1950

Re: A bit of time off, but awesome stuff going on here

Aw man, I know the feeling.

And It looks like things are ramping up at work so progress might slow down on the hobby side for a while.