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6 MHz CPC

29 bytes added, 22 April
/* Disadvantages */
* RAM should to be at least 160ns fast. Many CPCs only have 200ns RAM built-in. Replacing RAM requires to desolder the old RAM ICs.
* Z80 might need being replaced by a 6MHz capable version. Pay attention to get a NMOS version of the Z80 as the CMOS version has different behavior for some undocumented but (rarely) used opcodes
* Sound must be reprogrammed / patched. No patches are publicly available.
* The horizontal timing of the CRTC is affected. In order to get a stable image, you need to program register 0 at 95 (96 characters line) and Register 2 at 61 (centering for 40 characters default)
* Pixels are no longer square. Their pitch is 66.7% of their original pitch.Theses pictures show this fact (320×200 mode 1 pixels with black border)
<gallery>
Image:12062011055.JPG|Original CPC @16Mhz
Image:12062011054.JPG|Overclocked CPC @24Mhz
</gallery>
* Sound must be reprogrammed / patched. No patches are publicly available.
== Software ==
164
edits