log in | register | forums
Show:
Go:
Forums
Username:

Password:

User accounts
Register new account
Forgot password
Forum stats
List of members
Search the forums

Advanced search
Recent discussions
- State of RISC OS software (Gen:1)
- Font Directory Pro moves to 3.23 (News:)
- CashBook and other goodies (News:)
- June News Round-up (News:)
- Getting started with Bash on RISC OS (News:1)
- !Organizer updated to 2.28a (News:)
- Geminus (Gen:8)
- A new monitor for my RISC OS and Mac systems (News:1)
- May news round-up (News:)
- How likely is it that... (PP:2)
Latest postings RSS Feeds
RSS 2.0 | 1.0 | 0.9
Atom 0.3
Misc RDF | CDF
Site Search
 
Article archives
The Icon Bar: Programming: Shadow registers for Latch A and Latch B on Aux I/O
 
  Shadow registers for Latch A and Latch B on Aux I/O
  PaulV (20:51 17/6/2012)
  PaulV (22:05 17/6/2012)
 
Paul Vernon Message #120628, posted by PaulV at 20:51, 17/6/2012
Member
Posts: 135
I've been trawling through the RISC OS 3 PRM's and various bits of source code for the last few hours and I'm getting nowhere.

I'm trying to figure out what the shadow register for Latch A is which is presented as Aux 2 on the Aux I/O header.

Referencing the PRM V1 p144, Latch A is mapped into memory at &3350040 and Latch B is mapped into memory at &3350018.

I've found in some code that Latch B is shadowed at &105 but I can't find any documentation or reference to the address at which Latch A is shadowed.

Is there any particular way I can determine this or does somebody know what the address is already and can share it with me.

Thanks

Paul
  ^[ Log in to reply ]
 
Paul Vernon Message #120629, posted by PaulV at 22:05, 17/6/2012, in reply to message #120628
Member
Posts: 135
Scratch that. I don't need it. I'd misinterpreted the mapping of Latch A and Latch B.

It turns out I only need Latch B to control both Aux1 and Aux 2 passing &20 to set Aux1 and &40 to set Aux2 as per the bit mapping in the Acorn TRM's for Latch B.

Happy days big grin

Paul
  ^[ Log in to reply ]
 

The Icon Bar: Programming: Shadow registers for Latch A and Latch B on Aux I/O