Started by revaldinho, 00:10, 25 April 18
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Quote from: revaldinho on 23:39, 18 May 18Just for future reference though, is there any well accepted board size or connector layout for expansion modules to aim for, to fit some easily available case ?
Quote from: revaldinho on 23:39, 18 May 18Here's a snap of the underside of the board (attached) where you can see that having the connector offset to be underneath the RAM IC has allowed the relatively large number of address and data signals to have short paths with few vias.
Quote from: revaldinho on 15:53, 20 May 18Aha ! OK, I didn't know that. I've been working only from the DK'T Technical Manual. That's definitely not going to happen with a handful of 74 series ICs.So, that's all good then. In that case the board seems to be fully DK'T compatible which was the original goal, and that's what the final 'old school' version will be.
Quote from: IanS on 20:37, 20 May 18The dktronics memory boards do nasty things with mreq to support more of the memory maps. See this thread for more details - http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/464-and-ram-extension/
Quote from: Duke on 23:40, 21 May 18Actually it is the only method to do an external RAM expansion on a 464(*1), afaik (thanks to Gerald). The write-through to main memory cannot be avoided unless MREQ is forced high during the write cycle (RAMDIS has no effect on write).Simple test, that should reveal the issue:poke &4000,&55out &7f00,&c4poke &4000,&AAout &7f00,&c0print peek(&4000)
C0 C1 C2 C3 C4 C5 C6 C7CPC464 PASS PASS PASS FAIL PASS PASS PASS PASS CPC6128 PASS PASS PASS PASS PASS PASS PASS PASS
Quote from: Duke on 18:22, 28 May 18128KB games (probably not many) and demos that use &4000 for screen RAM, would suffer from the shadow ram method aswell, even if just using C4-C7 banking and doing writes to those.
Quote from: revaldinho on 20:59, 28 May 18BTW have you got any demos or games in mind I could have a quick peek at ? Would be handy to have a test case I can look at just in case I might get around to looking for a motherboard mod later...
Quote from: kawickboy on 10:53, 10 July 18As far i know double dragon 1&2 floppy releases (Richard Aplin) aren't exactly the same. Double Dragon runs with a 128ko cpc (including 464 or 664+64ko) but Double Dragon seems to really need a true 6128. I evend bought a duchet computer FO.DOS (adding the 6128 rom) and the game ran, but wasn't stable.What about testing games like xyphoes fantasy, prehistorik 2, orion prime, targhan or zapt'balls AE ?
Quote from: GUNHED on 17:30, 12 July 18You can use the 'OS-Infos' Tool for FutureOS to check if RAM is properly detected too.
Quote from: GUNHED on 17:28, 14 July 18Well, if the mouse-pointer / arrow can not be seen in FutureOS then this is a indicator that RAM banking &C3 doesn't work properly.
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