A bizarre interface: I learned some things about the MSX and soon realized that its video chip was not as coupled as the video chip in other machines, like the Amstrad, the C64 and of course, the Spectrum. In fact, the video chip of the MSX (TMS9929 for PAL machines) could be operated by any processor (I even saw a project in which it was operated from the parallel port of a IBM PC compatible).This was possible because the TMS doesn't need the CPU to map RAM for the TMS to use, and the TMS doesn't allow th CPU to access RAM directly. To communicate with the video chip and its VRAM, you can only do it through I/O ports.So, what if I turn this TMS 9929 into a device which I can IN and OUT from the ZX Spectrum. And what if I use the same ports ($98 and $99) that MSX uses?The result is this: one of my very first projects, built only for amusement: a ZX Spectrum with "dual screen" support smile emoticon Its normal ULA output, and the TMS 9929 output. Having the same ports as the MSX implementation, it is somewhat easier to port existing MSX games onto "this". I didn't try any serious game, but I found some minigames/demos with full source code, which was easier to port not only video, but input and sound. Output is YPrPb which I turned into a VGA signal with a VGA converter.
Mazzalo che brutto salamander su MSX... Vuoi mettere quello per Commie (che compari originale all'uscita)?https://www.youtube.com/watch?v=dnww_FoopV4
Citazione da: lucommodore - 10 Febbraio 2015, 23:47:13Mazzalo che brutto salamander su MSX... Vuoi mettere quello per Commie (che compari originale all'uscita)?https://www.youtube.com/watch?v=dnww_FoopV4 Quello lo ho gia' sperimentato quando era nuovo nel 1988 anzi mi inca22ai dimolto con la Ocean perche' non fece il port sotto Amiga - e si che sarebbe facilmente stato un port 1:1!
Citazione da: saimon69 - 11 Febbraio 2015, 00:04:26Citazione da: lucommodore - 10 Febbraio 2015, 23:47:13Mazzalo che brutto salamander su MSX... Vuoi mettere quello per Commie (che compari originale all'uscita)?https://www.youtube.com/watch?v=dnww_FoopV4 Quello lo ho gia' sperimentato quando era nuovo nel 1988 anzi mi inca22ai dimolto con la Ocean perche' non fece il port sotto Amiga - e si che sarebbe facilmente stato un port 1:1!eggià perché i port per Amiga sono storicamente una meraviglia... Tipo questo che quando l'ho giocato per la prima volta volevo togliermi la vita:https://www.youtube.com/watch?v=O9qzm5Bt_kE