Memory Address of BASIC RND Function?

Talk about your replica, what you have done and what you use it for

Memory Address of BASIC RND Function?

Postby castiglione » Jul Sat 09, 2011 12:47 am

Hi,

I've been looking around trying to find the memory address of the RND function in Apple I BASIC, mainly for the purpose of using it within assembly (I thought it'd be easier to just use a pre-existing RND function rather than write my own). Does anyone know where it is located? Barring that, any suggestions on how to go about writing a RND function from scratch?

Thanks in advance!

c
castiglione
 
Posts: 8
Joined: Jun Sun 05, 2011 1:33 am

Re: Memory Address of BASIC RND Function?

Postby jsissom » Jul Mon 11, 2011 10:20 am

will this help?

http://www.brouhaha.com/~eric/retrocomp ... le1/basic/

It doesn't give you the answer directly, but this would be much easier to read and figure it out than a hex dump.

Start looking at ef4e.
jsissom
 
Posts: 66
Joined: May Tue 04, 2010 10:52 pm

Re: Memory Address of BASIC RND Function?

Postby castiglione » Jul Mon 11, 2011 11:07 pm

Hi - thanks for responding.

I actually dug around a bit after my initial post and found this:

http://www.txbobsc.com/aal/1981/aal8108.html

which isolates the random number generator in Apple I BASIC - BTW - Apple I BASIC's RND function is actually quite good!

Back on topic - the disassembly is very useful but I can't for the light of me figure out what ".BS" means. ".EQ" is obviously that particular dissassembler's equivalent to ".=" but ".BS" has me scratching my head...
castiglione
 
Posts: 8
Joined: Jun Sun 05, 2011 1:33 am

Re: Memory Address of BASIC RND Function?

Postby jsissom » Jul Tue 12, 2011 9:45 am

I'm not sure what .BS stands for either, but it looks like the dis-assembler source code is available here:

http://www.txbobsc.com/index5.shtml

Maybe something in there can tell you what it means.

Jay
jsissom
 
Posts: 66
Joined: May Tue 04, 2010 10:52 pm

Re: Memory Address of BASIC RND Function?

Postby xprt » Jul Tue 12, 2011 6:52 pm

xprt
 
Posts: 23
Joined: Jun Sun 15, 2008 9:05 pm


Return to replica 1 General Discussion

Who is online

Users browsing this forum: No registered users and 3 guests

cron