Post by jusalak on Dec 25, 2023 18:09:25 GMT
I have done some real hardware tests of 1541 compatibility of real 1571. I chose the top 100 demos at The C-64 Scene Database as ranked on 20th August 2014 as the test material - 100 demos should provide a large enough sample to be meaningful. They also implement different types of loaders.
Those demos which displayed problems in emulation were selected for real hardware testing. Compared emulators were: UII+ as implemented in U64, firmware V1.42 - 3.10j; VICE x64sc 3.7.1 r44522; Z64K C64 Build 20230617.0852 and also Denise 2.1, all with drive 8 set to 1571. The results of real hardware tests are listed below. The new drive ROM 310654-05 was used as a default, but old ROM 310654-03 was also tested with real hardware tested demos. ROM verson made no difference in none of these real hw tested demos.
Those demos which displayed problems in emulation were selected for real hardware testing. Compared emulators were: UII+ as implemented in U64, firmware V1.42 - 3.10j; VICE x64sc 3.7.1 r44522; Z64K C64 Build 20230617.0852 and also Denise 2.1, all with drive 8 set to 1571. The results of real hardware tests are listed below. The new drive ROM 310654-05 was used as a default, but old ROM 310654-03 was also tested with real hardware tested demos. ROM verson made no difference in none of these real hw tested demos.
Of the current up-to-date versions of the listed emulators, Denise 2.2.1 (which implemented corrections based on these tests) has the closest match to real hardware behaviour. (Denise is not a C128 emulator, but it does emulate the 1571 drive.) Z64K and UII+ are not as good, several demos fail which run on a real 1571 - VICE runs several demos which did not run on a real 1571.
Commodore 1571 Disk Drive real hardware compatibility tests of Commodore 64 demos
1571 compatibility of followind demos was tested by copying following demos from .d64 floppy disk images to real floppy disks and then running the demos on 1571.
Real hardware setup: Commodore 64 PAL with 250469 Rev.4 motherboard and Commodore 1571 disk drive with 310654-03 ROM
| Name of the Demo (with ”The Top 100 Commodore 64 demos” ranking as voted on csdb.dk 20th August 2014) | The C-64 Scene Database ID (csdb.dk/release/?id=) | Demo behavior on a real 1571 | Comment on demo behavior on a real 1571 |
| 1. Edge of Disgrace | 72550 | fails | Failed at the beginning – disk swapping not recognized. |
| 3. Wonderland XII | 120907 | fails | Failed at the end of disk s1. |
| 4. We are all connected | 129091 | runs (with some parts skipped) | Ran to the end, but 2 parts were partially skipped. |
| 8. and 77. A Press Space Odyssey | 103742 | fails | Failed at the beginning. |
| 9. Continuum | 129088 | runs | |
| 10. Musik Run Stop | 129090 | runs | |
| 12. Scrollwars | 120908 | runs | |
| 13. Trick and Treat | 112424 | fails | Failed at the beginning. |
| 14. Artphosis | 112337 | runs | |
| 17. Pearls for Pigs | 72553 | fails (unstable) | Crashed at a seemingly random place. |
| 19. Wonderland XI | 112423 | runs | |
| 21. Revolved | 115653 | runs | |
| 26. We Are New | 94445 | fails | Failed at the beginning. |
| 27. Amplifire | 72559 | runs | |
| 29. Serpent | 129098 | fails (unstable) | Crashed at a seemingly random place. |
| 35. Another Beginning | 94448 | fails | Failed at the beginning. |
| 39. Apparatus (appf1.d64) | 102318 | fails | Failed at the beginning. |
| 39. Biba 3 | 112335 | runs | |
| 39. Vicious SID 2 | 112365 | runs with some instability | Successfully ran to the end. |
| 51. Still Ready | 81158 | runs | |
| 62. Toxyc Taste | 101511 | fails | Failed at the beginning. |
| 67. Sidelined | 118375 | runs | |
| 69. Black Spark 100% | 91494 | fails | Failed at the beginning. |
| 69. Too Old to Ror and Rol | 115677 | fails | Failed at the beginning. |
| 97. Error 23 | 32411 | fails | Crashed after a few parts. |
| 98. Frontier [REU] | 120458 | fails | Failed at the beginning. |