Subject: Re: [stella] Supercharger Bank Switching From: Eckhard_Stolberg@xxxxxxxxxxxxxxxxxxxxx (Eckhard Stolberg) Date: Sun, 22 Jun 1997 14:15:13 +0200 |
>What I don't get is which addresses trigger a which >bank switch? And which bank switches does the modification >disable. For example, I understand that I don't want to switch >the ROM back in once my program is loaded. However, >I might want to swap one 2K RAM for another from >my program, to use a total of 6K. Can this be done, >or am I stuck with the 4K that was selected when the >audio finished? Bob's hardware modification disables all bankswitches. It is meant to be used only with ROM dumps of actual carts. Some of those accidently access the address which triggers the bankswitching and therefore crash. It is limited to 2k and 4k games. For your own games you don't need the modification. Your program can switch banks and enable and disable the Supercharger ROM or writes to SC RAM everytime you want. Which RAM banks are currently accessable or if writing is enabled etc. is controled by the bits in the control byte at address $FFF8. You can't read it, but you can change it's content for example by LDX ControlByteValue CMP $F000,X CMP $FFF8 There is a very good text about the Supercharger by Christopher Salomon on http://www.primenet.com/~nickb/sctech.txt , where you can find more info on this. Ciao, Eckhard Stolberg -- Archives updated once/day at http://www.biglist.com/lists/stella/archives/ Unsubscribing and other info at http://www.biglist.com/lists/stella/stella.html
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
[stella] Supercharger Bank Switchin, Frank Palazzolo | Thread | [stella] Frame Timed Sound Effects, Eckhard Stolberg |
[stella] Supercharger Bank Switchin, Frank Palazzolo | Date | [stella] Frame Timed Sound Effects, Eckhard Stolberg |
Month |