| |
|
Released by : XmikeX
Release Date :
7 December 2018
Type : C128 Release
Proper release: 101%
|
Credits :
Download :
Look for downloads on external sites:
Pokefinder.org
User Comment Submitted by XmikeX on 8 December 2018
For the reoord, Willymanilly provided a summary of the "latest research" on active VIC-IIe 2MHz operation:
The VIC-II is prevented from being able to take control of the bus at any time except for the DRAM refresh cycle
The CPU can also lose cycles with clock stretching during IO access
Bad lines fetches still occur but can't steal cycles from the CPU. Same applies for sprites when they are enabled.
The VICII still fetches data in all it's cycles but can only retrieve what is left on the bus by the cpu which gives the messy display as you already pointed out. | User Comment Submitted by XmikeX on 7 December 2018
From looking at Infocom's autoboot code there, their coders do demonstrate some familiarity with the 128 platform, at least by the time they get to Beyond Zork (the last C128 infocom game). They hammer near/far banking on zero-page well enough to display that they aren't totally ignorant, and yet ...... yet ...... they still screwed up fast mode again !
With Trinity, they completely forgot about fast mode. This time they left out the VIC-II blanking, as noted in production notes. VIC-II will still half-work @ 2 MHz and probably go about its DMA/bus-halting duties as before, so that's about 7% wasted speed on the 128 platform .. unnecessary waste of time/energy for a VDC/80-column game ! |
|
|
|
| Search CSDb |
| Navigate | |
|
| Detailed Info | |
|
| Fun Stuff | |
· Goofs · Hidden Parts · Trivia
|
|
| Forum | |
|
| Support CSDb | |
|
| |
|