Jump to content
Sign in to follow this  
TGB1718

Ultimate 1M Upgrade Question

Recommended Posts

Now that I have one installed and working, I'm trying to find out how to access the extra memory banks, I assume it still

uses bank switching through $4000-$7fff as in the 130XE, but obviously there are not enough bits available in the PIA chips

to access 1Mb.

 

Does anyone have a link to the technical documantation for this upgrade, I've Googled, searched this forum etc. but all I can

find is installation instructions and a fine document 'Firmware Manual' which although extensive doesn't give this information.

 

Any help would be much appreciated.

Share this post


Link to post
Share on other sites

Look in the U1MB section:

 

http://www.virtualdub.org/downloads/Altirra%20Hardware%20Reference%20Manual.pdf

 

All extended memory models and PORTB bit usage are described.

 

NOTE: Ultimate 1MB simply implements three common extended memory schemes, using identical bank selection techniques.

Edited by flashjazzcat

Share this post


Link to post
Share on other sites

Many thanks, I already had that manual but didn't realise it had that information in it, looks like I should read it next time  :grin:

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...