From: groepaz (groepaz_at_gmx.net)
Date: 2002-05-28 19:31:41
Hello Ullrich, Tuesday, May 28, 2002, 7:15:06 PM, you wrote: UvB> Hi! UvB> On Tue, May 28, 2002 at 04:38:01PM +0200, groepaz wrote: >> - same for memory under ROM (a000-bfff and e000-ffff) and memory under >> i/o (d000-dfff) ... the VIC always reads from the respective ram, no >> matter what the current banking is. UvB> One (maybe stupid) question: Is it possible to place the high res color map UvB> under the i/o area, and if so, how is this done? The current grlib allows for UvB> two graphics pages: UvB> 1. High res screen at $E000 with color RAM at $CC00 UvB> 2. High res screen at $A000 with color RAM at $8C00 UvB> Two pages are nice but they eat way too much RAM, so I'm thinking of removing UvB> the support for the second page. If it would be possible to place the high res UvB> color RAM below the i/o area, having full high res graphics would need no UvB> additional RAM at all! UvB> Or are there any serious objections against removing the second video page? there are certain problems with that approach 1) when you place both bitmaps in one bank, where do you put the videoram ? :o) 2) working with the ram under i/o (specifically the VIC i/o) is troublesome.... you cant really use it together with interupts for example. (try it :=)) eg when an irq occurs while the ram under the vic is banked in => crash (regardless of correct vectors at both $ffff/fe and $0314/15 and regardless where the interupt-service-routine lies in memory) there were certain other little obscure things i think.... thats why most ppl dont use the ram under vic for any gfx stuff -- Best regards, groepaz mailto:groepaz_at_gmx.net ---------------------------------------------------------------------- To unsubscribe from the list send mail to majordomo_at_musoftware.de with the string "unsubscribe cc65" in the body(!) of the mail.
This archive was generated by hypermail 2.1.3 : 2002-05-28 19:29:48 CEST