Login
Back to forumReply to this topicGo to last reply

Posted By

SVS
on 2014-07-06
09:45:27
 $FC00 RAM/ROM

As known the memory segment $FC00 is reserved for Banking routines and is present in all Configurations of ROM/RAM.
I've just discovered that the RAM under it is indeed used sometimes by DOS. Could you give me a confirmation?

Posted By

siz
on 2014-07-06
12:59:01
 Re: $FC00 RAM/ROM

$FC00 is in use by the ROM but it does not get copied to RAM. If you look at the BASIC memory top variable at $0533-$0534 after a reset on a machine with 64k RAM you can see that it's $fd00 meaning you can freely use that area (and in fact BASIC is using it).

Posted By

JamesC
on 2014-07-06
18:32:45
 Re: $FC00 RAM/ROM

$FCFF (the byte below $FD00) = 64767.
64767 - 4096 (start of BASIC) = 60671, the "bytes free" reported on power-up.
Does this confirm, SVS? happy

Posted By

SVS
on 2014-07-11
15:15:46
 Re: $FC00 RAM/ROM

Thanx for answers.
I'm more specific: is the RAM below used by Basic strings or by DOS? Because in the case I've seen it was used by OS during a DOS operation.

Posted By

siz
on 2014-07-11
15:22:40
 Re: $FC00 RAM/ROM

It is used by BASIC strings. But I can imagine that for example DS$ value is stored there as a normal string.



Back to topReply to this topic


Copyright © Plus/4 World Team, 2001-2024. Support Plus/4 World on Patreon