Hypothetical Kickstart ideas

[amigaksi]

>by Piru on 2009/5/11 0:53:51

>@save2600
>Quote:

>    I was just thinking emulation would/could have been more practical had it been written on and for more of a hardware level than software.


>Putting something to KS ROM doesn't make it any more "hardware level" than having it as a separate program to run. ROM is just read only memory to store software to.

For Atari ST, it would make it more hardware level since the TOS would be residing at same memory location as original TOS on Atari ST ($FC0000) so software accessing OS functions wouldn't require any address translation.  They should be able to run full-throttle (7.16Mhz instead of 8Mhz).  And if they re-compile the ST executables and filter out the direct I/O calls like $FFFF9201 to vector to Amiga software equivalents, they should also be able to run stuff that directly accesses hardware ports.  However, that would be a more challenging program to write.

[amigaksi]

>by freqmax on 2009/5/12 9:02:42

>There's an alternative to filter direct I/O calls inside software. Scan the memory location residing at the same location as the I/O port and update any hardware with it.

But then you have to determine the maximum frequency, freqmax, for updating those i/o ports.  For example, joystick ports and paddles can be read at any time; others may not require an update that frequently, for which your algorithm is good.

I was thinking scanning the graphics memory area to fix up the image.  I.e., map the graphics memory to the same area as STs so ST writes full throttle to the graphics memory and then update/fix the image during VBI before making it visible.

[amigaksi]

>by freqmax on 2009/5/12 13:53:41

>amigaksi, I know my update-I/O suggestion have serious drawbacks. But so has other approaches to. The only really clean path is FPGA

FPGA, you mean "Forget Programming to Get an Atari"?   I thought it was "Forget Programming to Get an Amiga" since Atari ST was more emulatable.

>VBI is however a suitable opportunity to update at.

For joystick i/o, Atari st uses 7812.5bps instead of 50/60hz.

[amigaksi]

>by Ratte on 2009/5/13 6:39:23

>details about kickwork

>the crunched 256kb are loaded to the wom
decrunching a 512kb (executable) rom-image to fastmem
same as twinkick, but without kick1.3

Another useful item for A1000 users would be to compress the 256K kickstart into the bootstrap ROM space and decompress that into the WOM upon power-up.  Using a pair of 27512 EPROMs to replace the bootstrap ROMs would give you 128KB so compress the 256K Kickstart into less than 128KB (and decompressor also would have to fit into that space).

Perhaps, someone who has the copyrights to those bootstrap ROMs and Kickstarts could do it.