Den Tue, 13 Mar 2018 20:25:23 +0100 skrev Anders Carlsson <anders.carlsson@sfks.se>: > Ruud wrote: > > > Maybe interesting for some of you? > > > > http://www.a2heaven.com/webshop/index.php?rt=product/product&product_id=151 > > Availability: Out of Stock, but perhaps that is only temporarily? > > Suitable for a PET, VIC-20 or 1541, I presume, though the listing > mainly caters for Apple II. In other words it's probably not tested in anything else than an Apple II. Apple II afaik has a memory map where you really don't have much incent to rearrange stuff to gain more continous ram. Those Apple II that have more than 48k ram seem to be able to bank switch between ram and rom so only a 4k $Cxxx block is always occupied by I/O and I/O related ROMs. So a total of 60k ram can be accessed simultaneously by the CPU. (The reason for having 64k and also advertising it as 64k is probably the Z80 add-ons for running CP/M). http://www.kreativekorp.com/miscpages/a2info/memorymap.shtml On PET (except 8096/8296), VIC-20 and 1541, it's as we all know not that nice. Therefore IMHO a 65816 add-on for those computers should preferable also contain ram and a mechanism to bank switch between that ram and the computers built in stuff. Also ram on a 65816 board makes it possible to run code on the 65816 far faster. But all this stuff would of course add to cost. Btw has anyone tried what happens if you replace char rom (as seen from the CPU) with RAM? Will the KERNAL ram test/detect routines mess up with I/O? -- (\_/) Copy the bunny to your mails to help (O.o) him achieve world domination. (> <) Come join the dark side. /_|_\ We have cookies.Received on 2018-03-14 22:46:23
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