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Posted By

SVS
on 2004-01-04
12:03:17
 ROMs setting.

Recently I learned that the number of selectable ROMs with Plus4 O.S. is 8 (instead of 4 as I thought).
If you also know this, what are the address of the moreother 4 ROMs?
Thank you, people

Posted By

Crown
on 2004-01-04
12:44:38
 Re: ROMs setting.

http://www.nic.funet.fi/pub/cbm/firmware/computers/plus4/index.html

There is 5 Kernel versions here 3 PAL and 2 NTSC revisions. There is one more in the 232 and in the 364 folder. If you find more versions let us now happy

Posted By

Gaia
on 2004-01-04
14:22:04
 Re: ROMs setting.

I guess SVS meant something else. Namely the ROM banks. There can be 2x4 of them 4 low and 4 high ones. They are banked in by writing their appropriate number to $FDDx. Theoretically it could be possible to bank in 2x8 as far as the addressing goes indeed...

Posted By

SVS
on 2004-01-06
07:17:11
 Re: ROMs setting.

Gaia: what do you mean with " There can be 2x4 of them 4 low and 4 high ones" ? What is the "2"?

I found in the new documentation I added to Ultimate +4 Rom Map, that only for autodetect needs, there can be 4 combinations ($0, $5, $A, $E) and really these masks are stored in the O.S.. On the contrary if you does not need autostart, you could have further 4 values.
My question is what are these different values?

Posted By

mike
on 2004-01-08
15:49:28
 Re: ROMs setting.

If you look in my old..old..........OLD! doc http://www.plus4.org/programming/hardware.htm you'll find how to control these ROM's

Its also documented in the ROM disassembly under the "Phoenix routine", also at label LFC1E


This isnt complete... but its fairly good.



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