On Fri, 13 Apr 101 g.baltissen@hccnet.nl wrote: > Hallo David, > > > The commodore REC (reu controller chip) is mainly a bunch of counters > > linked to a few registers. I've realized this, and have mapped most of > > these counters on paper. This is part of a project of mine to make a > > 16-meg REU, using the whole third byte (bank pointer) instead of just a > > few of its bits. > > I have done some paperwork as weel but haven't put it on the site yet. I'll > look for it tomorrow and mail it to you. Maybe it is of some help at least. I'll find my site's location for my REC. its on my starbase www site sompelace. hm. http://starbase.globalpc.net/%7ejbevren/rec.txt > > > DRAM side: > > CAS0-CAS3, RAS0-RAS3 8 lines > > I always wondered why AND CAS-lines AND RAS-lines were seppearted. I > expanded some C64 by piggybacking DRAM and only not connecting that line > which wasn't needed for refresh (CAS-line? I'm not sure right now). The CAS/RAS lines are separated so that a partial read can be performed by the host machine. This way you dobnt always have to read or write 32 bits. > > > Let this roll around in your head for a while and see what spills out. > > I always can help you with theoretical disputes and discussions :) Always appreciated. Sometimes discouraging, but still appreciated. - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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