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software_library:compatibility [2020/08/13 22:32]
muaddib [Tips]
software_library:compatibility [2020/09/01 07:39] (current)
muaddib [Discussion]
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     * ✅ If you have Core version >= GOLD3 (as in the Vampire Standalone):​ The Apollo 68080'​s smart data cache snoops data writes done by the chipset (in Chip RAM), and updates itself accordingly.     * ✅ If you have Core version >= GOLD3 (as in the Vampire Standalone):​ The Apollo 68080'​s smart data cache snoops data writes done by the chipset (in Chip RAM), and updates itself accordingly.
   - A Blitter operation consumes most memory cycles of the Chip RAM.  So, in Amigas with no Fast RAM and having an older 68k CPU without an instruction cache, the CPU can't make much progress while a Blitter operation is running. ​ As a result, the subsequent Blitter operation is almost guaranteed to be delayed until the current Blitter operation has completed. ​ But with the available memory cycles on Fast RAM, and due to the instruction cache and higher speed of newer 68k CPUs, the CPU can make much more progress while a Blitter operation is running. ​ If a program is relying on the CPU being delayed during a Blitter operation, it fails on Amigas with Fast RAM and having a newer CPU, if the unimpeded CPU reaches the subsequent Blitter operation and re-programs the Blitter mid-operation,​ for example.   - A Blitter operation consumes most memory cycles of the Chip RAM.  So, in Amigas with no Fast RAM and having an older 68k CPU without an instruction cache, the CPU can't make much progress while a Blitter operation is running. ​ As a result, the subsequent Blitter operation is almost guaranteed to be delayed until the current Blitter operation has completed. ​ But with the available memory cycles on Fast RAM, and due to the instruction cache and higher speed of newer 68k CPUs, the CPU can make much more progress while a Blitter operation is running. ​ If a program is relying on the CPU being delayed during a Blitter operation, it fails on Amigas with Fast RAM and having a newer CPU, if the unimpeded CPU reaches the subsequent Blitter operation and re-programs the Blitter mid-operation,​ for example.
-    * ✅ If you have Core version < GOLD3: ​If the Apollo 68080 tries to re-program the Blitter, the Vampire checks if a Blitter operation is already running. ​ If so, then the 68080 is delayed until the current ​Blitter operation is complete. +    * ✅ If the Apollo 68080 tries to re-program the Blitter, the Vampire checks if a Blitter operation is already running. ​ If so, then the 68080 is delayed until the current Blitter operation is complete.
-    * ✅ If you have Core version >= GOLD3 (as in the Vampire Standalone):​ If the Apollo 68080 starts a Blitter operation, the 68080 is delayed until that Blitter operation is complete.+
   - Newer 68k CPUs simply run "too fast"​. ​ If a program is relying on the exact timing of CPU instructions,​ it fails on newer CPUs.   - Newer 68k CPUs simply run "too fast"​. ​ If a program is relying on the exact timing of CPU instructions,​ it fails on newer CPUs.
     * ✅ Most programs that rely on the legacy CPU behavior store their code in Chip RAM.  If the Apollo 68080 starts executing program code from Chip RAM, then it puts itself into "​turtle mode" automatically. ​ (You can also trigger turtle mode manually.) ​ In turtle mode, the CPU does not run too fast.     * ✅ Most programs that rely on the legacy CPU behavior store their code in Chip RAM.  If the Apollo 68080 starts executing program code from Chip RAM, then it puts itself into "​turtle mode" automatically. ​ (You can also trigger turtle mode manually.) ​ In turtle mode, the CPU does not run too fast.
   - Amiga models other than the CD32 do not have the Akiko chip.  If a program is using Akiko C2P routines, it fails on Amigas other than the CD32.   - Amiga models other than the CD32 do not have the Akiko chip.  If a program is using Akiko C2P routines, it fails on Amigas other than the CD32.
-    * ✅ The Vampire ​supports ​all Akiko C2P routines.+    * ✅ The Vampire ​1200 V2 and the Vampire Standalone support ​all Akiko C2P routines. ​ ​(Akiko C2P is only useful for AGA-compatible Amigas.)
   - Newer AmigaOS versions have different internal (undocumented) behavior than older AmigaOS versions. ​ If a program is relying on the exact internal behavior of a particular OS version, it fails on newer OS versions.   - Newer AmigaOS versions have different internal (undocumented) behavior than older AmigaOS versions. ​ If a program is relying on the exact internal behavior of a particular OS version, it fails on newer OS versions.
     * ✅ The Vampire is compatible with all AmigaOS versions, and provides a variety of convenient ways to use older Kickstart versions.     * ✅ The Vampire is compatible with all AmigaOS versions, and provides a variety of convenient ways to use older Kickstart versions.
Last modified: le 2020/08/13 22:32