X-Git-Url: https://git.libre-soc.org/?p=crowdsupply.git;a=blobdiff_plain;f=updates%2F009_register_overwrites.mdwn;h=e89e0c5ae6a9d1c71faa6d70b4b028b5e81414c6;hp=396e4c0a5b5dc0551078f8b6c5f445749ea66b42;hb=095eff7b470c055c5b3d0bb6726169ce5d7936c3;hpb=66bc5cb6ac3c6fbe71ca77e672cbb94bf61490f0 diff --git a/updates/009_register_overwrites.mdwn b/updates/009_register_overwrites.mdwn index 396e4c0..e89e0c5 100644 --- a/updates/009_register_overwrites.mdwn +++ b/updates/009_register_overwrites.mdwn @@ -143,6 +143,12 @@ allow the prior Function Unit (the "overwritee") has just been destroyed. There is a simple solution to that: provide a *Queue* of Q-Table entries. +Below is what a 6600 Q-Table looks like (image courtesy of Mitch Alsup). +In the original 6600 it is a binary table with a unary decoder on the +left and a pair of unary encoders on the right. + +{{6600_q_table.png}} + Now we have exactly the information needed to "roll back", should an exception occur. Like many augmentations and enhancements to the 6600 Scoreboard system, it's kind-of obvious in retrospect. However the *real*