Search found 8 matches

by Willymanilly
Sun Apr 22, 2018 6:02 pm
Forum: Hardware and Tech
Topic: VIA 1 CA2 behaviour when switching from output to input
Replies: 10
Views: 4833

Re: VIA 1 CA2 behaviour when switching from output to input

I guess that means the time that CA2 will be triggered when transistioning from an output to an input could vary between computers then? For now I will keep the constant time to discharge at around 400us in the emulator to match the reference data I have on hand from the shift register test suite. T...
by Willymanilly
Sat Apr 21, 2018 3:42 pm
Forum: Hardware and Tech
Topic: VIA 1 CA2 behaviour when switching from output to input
Replies: 10
Views: 4833

Re: VIA 1 CA2 behaviour when switching from output to input

i guess we really need 1541 versions of those tests :) (ie its not really a VIA emulation thing - its a VIC20 specific thing here) 1541 versions of the tests would be great in addition to the VIC 20 ones! I know it wasn't intended with your test programs but I think it's a good discovery that the C...
by Willymanilly
Sat Apr 21, 2018 3:31 pm
Forum: Hardware and Tech
Topic: VIA 1 CA2 behaviour when switching from output to input
Replies: 10
Views: 4833

Re: VIA 1 CA2 behaviour when switching from output to input

Thanks for looking into this and explaining the behaviour of that part of the circuit in more detail. My level of knowledge with electronics is only just enough for me to be able to read a schematic and get a basic understanding how the components interact with each other. ;) possibly whatever is at...
by Willymanilly
Fri Apr 20, 2018 5:12 pm
Forum: Hardware and Tech
Topic: VIA 1 CA2 behaviour when switching from output to input
Replies: 10
Views: 4833

VIA 1 CA2 behaviour when switching from output to input

I've started implementing VIA shift register behaviour for the emulators in Z64K ( http://www.z64k.com ) and am using the shift register test programs from the VICE repository ( https://sourceforge.net/p/vice-emu/code/HEAD/tree/testprogs/VIC20/via_sr/ ). What I don't fully understand is what is trig...
by Willymanilly
Sat Mar 24, 2018 5:22 am
Forum: Programming
Topic: Vic20 NTSC Graphics
Replies: 8
Views: 4871

Re: Vic20 NTSC Graphics

A new emulator... in java? Whyyyyyyyy?!? Why use Java... Why not? I've researched all the pros and cons of using multiple types of languages and have not experienced any issues with Java on the multiple systems I have tested my emulators on. The ease of distributing a single file that can run on mu...
by Willymanilly
Tue Dec 06, 2016 6:34 am
Forum: Emulation and Cross Development
Topic: Z64k - Java VIC 20 Emulator
Replies: 3
Views: 1700

Re: Z64k - Java VIC 20 Emulator

Default ratios have been changed to 5:3 PAL and 3:2 NTSC for the VIC 20 emulator. I will put customisable ratios via the emulators screen setting menu on my todo list. :)
by Willymanilly
Tue Dec 06, 2016 5:36 am
Forum: Emulation and Cross Development
Topic: Z64k - Java VIC 20 Emulator
Replies: 3
Views: 1700

Re: Z64k - Java VIC 20 Emulator

Thanks for the prompt feedback Mike! 8) It should be relatively easy for me to add customisable ratios to the emulators and I will change the default ratios for the VIC 20 emulator with your suggested values. I should have a new version available tomorrow with the ratios implemented. Cheers Will :)
by Willymanilly
Tue Dec 06, 2016 4:34 am
Forum: Emulation and Cross Development
Topic: Z64k - Java VIC 20 Emulator
Replies: 3
Views: 1700

Z64k - Java VIC 20 Emulator

I have updated my VIC 20 emulator available on http://www.z64k.com/ It is written in Java so will run on any platform that has JRE 7 or better installed. It is pixel perfect and new features include NTSC interlace support! It correctly runs all demos, games, and test programs I've tried. Make sure y...