Re: Apple IIGS bank latching

[mressl@macgui.com (Marc S Ressl)]

Daniel Kruszyna wrote:
> Marc S Ressl <mressl@macgui.com> wrote:
>> Now, the problem is experiment #7 I posted earlier (omg, I sound like a
>> craZy scientist!!)... here is a snippet:
>> 
>> C029:01
>> 2000:12 34
>> C029:41
>> 2000.2001
>> 
>> This returns "12 34", but I would have expected something different (as
>> the
>> memory map is changed). Is it possible that the monitor is messing with
>> C029? What do you guys think is going on?
> 
> It's very likely that the monitor is changing this register. When I did my
> experiments, I used a program that first clears all of $2000..$9fff. It
> then
> sets one byte with linearization disabled, and searches the entire range
> with
> linearization enabled for that byte (or bytes). Repeat for all bytes.
> 
> Here it is:
> http://krue.net/junque/linear.po
> 
> (To Antoine, who will probably disassemble this -- I know that the code is
> terrible, but it does get the job done. :)
>

It's probably the monitor.

Anyway, I have taken the liberty to grab your experiment, and re-post it
here in all hex-glory!

2000:4C 78 20 00 00 DA C2 20 8A EB 38 FB 20 41 F9 A9
2010:A0 20 ED FD 18 FB C2 10 FA 60 DA 38 FB 20 8E FD
2020:18 FB C2 10 FA 60 A2 00 20 A9 00 9F 00 00 E1 E8
2030:E0 00 A0 D0 F6 60 A9 40 1C 29 C0 AE 03 20 A9 FF
2040:9F 00 00 E1 20 1A 20 20 05 20 A9 40 0C 29 C0 A2
2050:00 20 BF 00 00 E1 F0 09 A9 00 9F 00 00 E1 20 05
2060:20 E8 E0 00 A0 D0 EB 60 20 36 20 AE 03 20 E8 8E
2070:03 20 E0 00 A0 D0 F1 60 18 FB E2 20 C2 10 A2 00
2080:20 8E 03 20 A9 40 1C 29 C0 20 26 20 20 68 20 4C
2090:8F 20

I do think that's was very clever thing to do :-). So that answers
experiment #7!

Thanks a lot,
and with the best wishes,

Marc.-