On 09/17/2012 09:16 PM, firstname.lastname@example.org wrote: > > On September 17, 2012 at 2:26 PM email@example.com wrote: > > > > On 2012-09-17, at 19:50, Jim Brain wrote: > > > > > > BUt, what does JP301 do in the schematic? I don't think I accounted > for it, and I have just glanced at your schematic. > > > > As Gerrit already explained - it is there to select another 8K > segment of the 27C256 for a second KERNAL. One BASIC, two KERNALs and > two CHAROMs just fill up a 27C256 nicely. > > > Ah, well, the '148 option gives you 8 banks to choose from (I used only > 3, with a sub selection for CHARROM being only 4 kB). Adding more > options simply means routing the Select lines to another bank select. > So, with a 3 pin jumper, you can add 2 KERNALs to the design (middle is > KERNAL select, two ends are two inputs to the '148), but you can add > more KERNALs as well or BASICs with just more jumpers. Needs a larger EPROM though. 27C512 for example. Would give you 6 KERNALs, 1 BASIC and 2 Char-ROM. I'm looking forward to the finding out how you make the selections work. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2012-09-17 20:00:13
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