4 ms·
> Why they didn't embed an auto-incrementing screen address counter in the controller is beyond reckoning. They did. Page 361 of the Commodore 128 Programmer'
by peterfirefly 4y ago
> Why they didn't embed an auto-incrementing screen address counter in the controller is beyond reckoning.
They did.
Page 361 of the Commodore 128 Programmer's Reference Guide (halfway down the page):
> At this point, the 8563 hardware takes over. It automatically increments the
address contained in the update register pair (R18, R19). You as the programmer do not
increment the update register pair's contents; the 8563 chip does this for you automatically. You can say that the update register pair is auto-incrementing.
You can get the ProgRef here: https://www.pagetable.com/docs/Commodore%20128%20Programmer's%20Reference%20Guide.pdf https://www.pagetable.com/docs/Commodore%20128%20Programmer'...
- deleted 4y ago[deleted]
- greenbit 4y agoIn the PDF at the link you provided, I found what you're referring to at page 311 (in-document numbering) which is page 321 per my pdf viewer. So, yes, it did auto increment. I think what happened is that after 35 years, I just recalled my initial aggravation with addressing the 8563's RAM through that keyhole of R18, R19, R31. But .. looking around in the ol PRG, and finding some of Mr Herd's "choice comments" out on the web, I'd still say the 8563 was a dog. Case in point, having to poll D600 for bit 7 to become set just to make sure the 8563 had cottoned onto your request to set a register. That bottleneck to get to the 8563's RAM was not fun. The bottleneck to get into the 8563s own registers was even goofy. Why not just map them to D600-D61F ?
- peterfirefly 4y agoI have no idea how that ended up as 361.