Chillobits demo incompatible with ACA500plus

Caution: Non registered users only see threads and messages in the currently selected language, which is determined by their browser. Please create an account and log in to see all content by default. This is a limitation of the forum software.


Also users that are not logged in can not create new threads. This is a, unfortunately needed, counter measure against spam. Please create an account and log in to start new threads.

Don't Panic. Please wash hands.

    This is not big deal but I noticed an incompatibility of ACA500plus menu system with the OCS demo "Chillobits". This production won the amiga demo competition at Revision 2020 : https://www.pouet.net/prod.php?which=85300

    Note : this demo requires Kickstart 1.3 and 512 K fast/slow memory.


    This demo crash a few seconds after the beginning (of the AmigaDOS fader) with :

    • the standard A500 profiles accessible through F3 ACA500plus menu
    • and the cloaking expert profiles accessible through F9 ACA500plus menu

    The ACA500plus must be switched into de-brick mode (with a long press on the DisMo button of the expansion and Ctrl+A+A reset ) to run this demo properly.


    Is the code of the demo completely incompatible (bugged ?)

    Did I miss some option in the expert cloaking profiles menu ?


    My configuration is :

    • Amiga 500 rev 6A equipped with its original kickstart 1.3 ROM
    • with 512 kb trapdoor extension
    • and ACA500plus (bought nov 2020) updated with v0.141 menu system

    Amiga 500 rev 6a + 512 k + ACA500plus (2018 version with 68sec000) + Gotek as external drive

    Edited once, last by brunof ().

    In de-brick mode, the CPU runs at 14MHz and uses the host's Kickstart ROM. It's very hard to believe that this mode is more compatible, as it adds the CF card slots to the memory map, making it even less compatible (on top of the too-high speed).


    Timm is our demo expert, he can take a look at it, but not on top priority. We've got some other things higher on the list right now. I see someone also reported it in the Pouet thread during the weekend - was that you?


    Checking through the pouet comments, it seems like the demo reserves "fast", and it does not work on chipram-only machines. Is your computer modded for 1M Chip ram? If so, clocking mode should be set to add trapdoor mem. If you have an external disk drive, you should switch that off, as it consumes memory. Not sure how much mem the demo actually requires.

    I have indeed made the report on the Pouet thread.


    My A500 computer itself is not modded for 1 M chip RAM. I use the ACA500plus "1M Chip RAM expansion" function for this purpose, only when I need it.

    Amiga 500 rev 6a + 512 k + ACA500plus (2018 version with 68sec000) + Gotek as external drive

    So at first I tried this demo on my A500 ++ replica board + ACA 500 Plus. Trying various configs. No go. Demo not working.


    Then I tried both an A500 Rev. 6A 512KB chip/512KB slow and an A500 Rev. 5 512KB chip/512KB slow. Both using kickstart 1.3. And no ACA 500 Plus on these setups. Demo would still lock up on loading.

    I first thought "that's different of what the original poster reported", but reading his postings again, he never actually tried completely without the ACA500plus. brunof could try that, just to confirm that the only way to actually make it work is the De-Brick mode of the ACA500plus.


    We should probably contact the author(s) of the demo - and if that's not successful, I could ask the Revision organizers for their binary file. After all, the demo was shown, so they must have some working binary, even if it's not labelled "final".

    I have not tried unplugging the ACA500plus from my Amiga.


    However I made additional tests with the cloaking expert profiles accessible through F9 menu and I have successfully run the demo Chillobits. It works when I set "Kickstart ROM" to "Mainboard ROM".


    And I guess the demo works in de-brick mode because de-brick mode uses my mainboard ROM.

    (my mainboard ROM is original Kickstart v1.3 r34.005)


    I made a poor video showing the test (switch to HD 1080p to be able to read texts) : https://youtu.be/5wziVh6j0EY


    0 min 11 sec : details on my hardware configuration, my mainboard ROM version

    0 min 26 sec : the cloaking expert profile that works

    1 min 35 sec : the cloaking expert profile that crash (maprom enabled)

    Amiga 500 rev 6a + 512 k + ACA500plus (2018 version with 68sec000) + Gotek as external drive

    Edited 2 times, last by brunof ().

    Could you make a binary comparison between your mainboard Kick rom and the ROM that we have in the flash of the ACA500plus? Use Grabkick for easy saving.

    I haved dumped my Mainboard ROM and ACA500plus Kickstart 1.3 ROM with grabkick under a minimal AmigaOS 1.3 shell environment.
    I have attached pictures of the ACA500plus parameters I set to save the ROM.


    The resulting files are strictly the same (compared with WinMerge) and both have the same hashes

    SHA-1 : 891e9a547772fe0c6c19b610baf8bc4ea7fcb785

    CRC-32 : c4f0f55f



    I made other tests of the Chillobits demo on my Amiga 500 + ACA500plus, and I noticed :

    • demo works when I set in Cloaking expert options :
      Map ROM : Off
      Kickstart ROM : Mainboard ROM
    • demo crashes a few seconds after the AmigaDOS screen fader with options :
      Map ROM : On
      Kickstart ROM : Mainboard ROM

    Can Map ROM cause incompatibility ?

    Quote from brunof

    Can Map ROM cause incompatibility ?

    Your results indicate that. I've asked the programmer if 256K Kickstarts are "doubled" in the 512k MapROM area (they should!). I do know that I'm putting a 512k mirror ti $e0.0000, so that can't be the cause.


    Timing-wise, I wouldn't expect any difference, as both the on-board ROM and the MapROM area are 0-wait for a 7MHz CPU. That's really 0-wait, even with refresh cycles. These are so fast on SD-Ram that the 68000 CPU won't see that.

    Regarding timings, I did all my tests yesterday with CPU Speed set at 7 MHz and the demo freezed when map rom was On (a few seconds after the AmigaDOS screen fader)


    Today, I have just tried to rise the CPU speed to 14 Mhz and the demo seems to work better when map rom is On... damn what at capricious demo !


    So an easy method to launch the demo through the standard A500 profiles of ACA500plus menu seems to be :

    • Standard A500 KS 1.2 or 1.3 + 0.5M/0.5M
    • CPU set to 14 MHz

    Amiga 500 rev 6a + 512 k + ACA500plus (2018 version with 68sec000) + Gotek as external drive

    Edited once, last by brunof ().

    I've tried it again and written the demo to another disk, and this time it works on my OCS A500 512k+512k, Kick1.2.

    And I can confirm that it doesn't work with the ACA500+, Standard A500 Profile menu, neither F1 nor F4 Standard A500 KS1.x + 0.5/0.5M. The demo freezes when setting up the logo on the fake DOS screen.

    Resetting the computer then freezes in the ACA500+'s dark blue screen. Nice find!

    Same here. Working on A500, Kick 1.2 - not working with ACA500+.

    Commodore: A1200/1B, ACA1234/50/68882, Indi AGA MK3, Gotek, OS3.2.1 | A1200/1D.1, ACA1221lc/26,67, OS3.1 | A500/6a, ACA500+, Indi ECS V3, OS3.1 | A500/8A, Vampire v2+, Indi ECS V2, A2048, Gotek, OS3.9| A500/5, 512kB Trap, sealed, Kick 1.2 | 2×C64C, U II+, Turbo Chameleon V2, 2×1541II, Datassette | 1084S-CRT ······· Atari: Falcon030 | 1040STE | 800XL

    Hi guys. I just tested this demo on my A500 with ACA500+ and it ran fine with a custom profile, 1MB chip, MapROM KS1.3, 42Mhz.

    Tried some of the standard profiles, but it kept crashing.

  • The last reply was more than 365 days ago, this thread is most likely obsolete. It is recommended to create a new thread instead.

    • :)
    • :(
    • ;)
    • :P
    • ^^
    • :D
    • ;(
    • X(
    • :*
    • :|
    • 8o
    • =O
    • <X
    • ||
    • :/
    • :S
    • X/
    • 8)
    • ?(
    • :huh:
    • :rolleyes:
    • :love:
    • 8|
    • :cursing:
    • :thumbdown:
    • :thumbup:
    • :sleeping:
    • :whistling:
    • :evil:
    • :saint:
    • <3