ABelliqueux/psx-spx.github.io
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Merge pull request #1 from asmblur/patch-1

Browse Source 
Update expansionportpio.md
This commit is contained in:
Nicolas Noble 2020-07-23 15:14:35 -07:00 committed by GitHub
commit d7e968acf1
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
expansionportpio.md
View File

@ -4,7 +4,7 @@ bytes would contain the expansion ROM header.<br/>
For region 1, the CPU outputs a chip select signal (CPU Pin 98, /EXP).<br/> For region 1, the CPU outputs a chip select signal (CPU Pin 98, /EXP).<br/>
For region 2, the CPU doesn't produce a chip select signal (the region is For region 2, the CPU doesn't produce a chip select signal (the region is
intended to contain multiple I/O ports, which do require an address decoder intended to contain multiple I/O ports, which require an address decoder
anyways, that address decoder could treat any /RD or /WR with A13=Hi and A23=Hi anyways, that address decoder could treat any /RD or /WR with A13=Hi and A23=Hi
and A22=Lo as access to expansion region 2 (for /WR, A22 may be ignored; and A22=Lo as access to expansion region 2 (for /WR, A22 may be ignored;
assuming that the BIOS is read-only).<br/> assuming that the BIOS is read-only).<br/>