Denial

Hopefully I could help. Testing a CPU emulator is not an easy task, ie just an opcode is wrong and a program (or ROM) does not work, and sometimes it's hard to tell what's going on (easy not to be able to spot a little typo or something like that) ... Honestly, though I could spot some problems &quo...

By the way, have anybody here some kind of VIC20 program on a tape but in digitalized form? :) I mean WAV (!!) actually (not TAP file). Unfortunately I have no tape at all, but it would be interesting to see if I can "feed" my emulator somehow with the actual data recorded from playing a t...

Holy crap thats pretty sweet - nice stuff man! :) EDIT - played Qbert pretty nice too.. :) Nice to hear :) As I am new for VIC20, and just write an emulator to get to know it better, I am kinda bad to know VIC20 softwares, so no idea about Qbert - but it's a global tendency of mine, that I never pl...

Your emulator runs 'vector.prg' (see attached) successfully with the commandline xvic20.win32 @8 @16 @24 vector.prg , so it can't be too far off. ;) Nicely done! Thanks. Honestly, I don't know if my emulator makes any sense, as there are much more accurate emulators for the VIC-20, even with sound ...

It seems I like to write unfinished and inaccurate emulators :) Maybe someone is interested anyway. Don't let the project name confuse you :-) https://github.com/lgblgblgb/xclcd The emulation is not so much accurate, no need to mention. The CPU is 65C02, which for sure is incorrect for a VIC20, but ...

Well, back to the original topic, VIC-I addressing :) While writing my emulator I met with problems I don't know how VIC-I solves. Especially with modifying screen/chargen/colour addresses. What happens if you modify these (or just one of them, etc) at a given place? As far as I can imagine, VIC-I s...

Well, since I am too much in my own solutions, multitask OS, etc, I was not so about the compatibility with anything, but indeed you're right, it would be a better thing in general. Moreover, I also thought that SD2IEC with some kind of parallel connection "hack" can be useful, and it even...

... VIAs - in theory - can be also replaced to modern parts, and the "new CPU" is free to access them in "fast mode" too ... anyway they are fed with the original clock in VIC20 mode, so it wouldn't introduce an incompatibility because of the different timer meanings etc then). ...

[...]more modern storage solutions (like SD card, but not as with sd2iec but *also* a more direct and faster connection)[...] ... if you think about a RAM-link like method (i.e. pumping data to/from SD card with some kind of DMA, circumventing the slow serial bus), you're running into open doors wi...

Mike, thanks for the information and links. Surely, I could think I am not the first (it would be a naive thought!) who thought about these. Just because I am new here (and also for the VIC20) I am not so familiar with the topics already mentioned/discussed etc. I've already read some topics on the ...

First of all, thanks for you message! The main issue the developers of the VIC-20 originally faced, when putting 6502 and VIC-I into one machine was the 6502 could not tri-state its address bus. The VIC-I, on the other hand, plays nice. Yes, as far as I know, 6510 basically more than 6502 with this ...

Put the question the other way round: what exactly did you have in mind with the (extra?) RAM for VIC-I? ;) Honestly? I don't know :) I just got to know VIC20 since some days (well, of course I knew even before that VIC20 exists, just I didn't know more about it than the fact about its existence, o...

I'm curious what would happen if I replace the lower 32K to a single SRAM chip [...] ... that could give some interesting effects with cartridges that map ROM into BLK1, BLK2 or BLK3. Well, yes, I can imagine that, however I haven't got a single cartridge for VIC20 :) Still there should be some con...

Interesting. I'm curious what would happen if I replace the lower 32K to a single SRAM chip, but *internally* (removing the original SRAM(s?) first). Then, RAM expansion is solved, cartridge port is not used, and *maybe* we can get some extra space at least (in the first 8K, if I see things well?) f...

Thanks for the information. Maybe I was not careful enough to read all messages of the corresponding threads on this topic ... but ... I'd like to also know, what is the hardware reason that VIC-I is not able to use expansion RAM if it's in the "right" place otherwise (ie, inside the addre...