== Fixed version (Gerald) ==
Original version from Porchy suffer from a bad handling of the RAMDIS signal. This cause screen artefact when accessing an external extension RAM like XMEM.
A14OUT = !( !A14
[[File:Amstrad6128.jed]] Original JED File posted on CPCWiki Forum
== See also PAL I/O port ==
*For RAM banking settings see Register 3 of the [[Gate Array]] (. Note that no settings are stored in the gate arrayGate Array, but the PAL and gate array Gate Array share an I/O port address).
*Bit 14 of the PAL selection address must be at 1 on CPCs equipped with CRTCs 0, 1, 2. It can be at 0 or 1 on CRTCs 3 and 4. For compatibility reasons, it is strongly advised to always set bit 14 to 1 to select PAL. See [https://www.cpcwiki.eu/forum/news-events/release-of-amstrad-cpc-crtc-compendium-and-amazing-demo-rev-2021/msg239536 Discussion on the forum] == PAL Type Detection ==<pre>10 OUT &7F00,&C0:POKE &4000,&C020 OUT &7F00,&C7:POKE &4000,&C7:OUT &7F00,&C030 IF PEEK(&4000)=&C7 THEN PRINT"PAL chip absent":END40 OUT &BC00,&F:OUT &3DFF,&C760 IF PEEK(&4000)=&C0 THEN PRINT"PAL I/O layout on CRTC 0/1/2":END70 IF PEEK(&4000)=&C7 THEN PRINT"PAL I/O layout on CRTC 3/4":END80 PRINT"Error!"</pre> == See also ==
*CPC 464/664 cannot deal with A14/A15 for bank 0 like the 6128 does. External So external RAM expansions differ in their behaviour regarding &C3 mode. See [https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/464-preasic-c3-ram-configuration-and-rom-7/ Discussion on the forum] and [https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/dk%27tronics-ram-c3-selection-464/ Another discussion]
*[[Gate Array and ASIC Pin-Outs]]
[[Category:Datasheet]]
