Is rapid swapping of ROM pages OK or a problem?

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By NYYRIKKI

Enlighted (5875)

NYYRIKKI's picture

08-01-2021, 01:47

Manuel wrote:

By the way, why did you make this i SymbOS? Just because you can?

It was mostly to see how far we can push the disk I/O without problems... In 3.5MHz this was the point I started to get some glitches, but on R800 it was still piece of cake. The major problem is that in SymbOS you really can't control the interrupts on your own or install new ones, so you can only try to play with priorities and just hope you get the interrupt about when you wished.

Quote:

You directly accessed MSX hardware to go beyond the standard SymbOS capabilities?

Yes, I was a bit bad in that sense, but I wanted to feel at least a bit home... Smile I used the routine loaned from screensaver to make SymbOS leave the screen alone and then I just copy/pasted typical MSX code from Grauw examples. Palette needs to be stored/restored using SymbOS routines, but SymbOS can restore the screen and rebuild VRAM from scratch if you just ask it to change screen mode back to original. I cheated also with music by sending just remote control commands from my program to SymAmp...

It was mostly just testing how things work and I must say I kind of love the internal beauty of the OS as well as very developer friendly documentation in constant style. It is easy to see the OS is made with love... As exercise I also made little SC* picture viewer out of this. Later I ported also MSX-DOS debug.com to SymbOS and wrote small BrainFuck JIT-compiler. These were already real SymbOS applications and not just MSX hacks. Smile

By thegeps

Paladin (863)

thegeps's picture

08-01-2021, 02:00

No need to wait for something to be load. The slowdown occourred was just a while. A quarter of sec musiv stop then all went bsck to normal speed. Only on the SD device+real hardware. Never on OpenMSX. And I was able to fix it just by moving the bank switch and/or the stuff to be loaded after the switch itself. So, really, don't worry! Wink

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