ACA500PLUS startup issue with rev3 motherboard

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.

    Hello there


    I received the ACA500Plus today.

    i installed it in the side slot as instruction and turned on my amiga 500 (rev3 motherboard)

    the animation of the rotation "on DISMO runs completely

    the led starts as red and after the DISMO animation it becomes blue

    but on video out (rgb to scart) i have only a black screen


    inside amiga i have the following modification :

    i changed 8270 with 8372A (pin 41 insulated)

    i installed one dip socket under 68000 (with pin 52 cutted) and one dip socket under gary(with pin 39 cutted)

    the pin cutted is for insulate pin 52 cpu and pin 39 gary from 59 agnus

    the pins 52 cpu and 39 gary at the chips side it si reconneted with one wire solderd betwen the dip sockets cutted pins

    i solderd one wire for connect pin 59 agnus with line betwen pin 47 cpu and pin 35 gary

    at the end on internal expansion port i have one A512 with JP1 open

    in this way i have 1mb chipram

    i have attached document that i followed for modification


    at last i have also installed an internal dfo df1 selector for connect a external gotek as df0


    awaiting any suggestion for solve the problem

    ever that it is possibile to solve;(

    Files

    • Xform-A500.pdf

      (751.3 kB, downloaded 132 times, last: )

    Commodore Forever , "We need to build computers for the masses, not the classes."J.T.

    Edited once, last by iacesat ().

    This modification won't work with the ACA500plus, as it messes around badly with the memory map of the computer. From your description, the address lines A19 and A23 are shorted, but it'll work without an external accelerator, because A23 is only used by Gary, which has the direct connection with your free-air-wiring.


    This MUST be removed. Pray that you didn't destroy the ACA500plus with it.


    Next time, please do read and follow the instructions: Before you use the ACA500plus, anything on the 68000 socket must be removed. The CPU must sit directly in the socket. You won't need this modification any more if you get the ACA500plus to work. You'll be able to switch between 512k and 1M chip ram in the startup menu.


    BTW, the document you've attached does not show any instructions for the Rev.3 board. At least not what you've made.

    Quote from iacesat

    i have also installed an internal dfo df1 selector for connect a external gotek as df0

    This is something you also won't need any more if you get the ACA500plus to work. You can leave it in, but it'll be more convenient to switch drives in the startup menu :-)

    I'm sorry to contradict you but what I did is described on page 4 of the attached document (the page with photo agnus)

    the dip sockets I introduced are a gimmick to avoid damaging the precious pcb rev 3.

    However i removed the sockets and i inserted JP1 on A512

    now ACA500 + works, and i have 1mb chipram too

    the only thing i am noticing is instability with boot kickstart (F2 ) and sysinfo program, it loaded with artifacts and after some seconds that it run goes into error

    (see attached picture)


    if start with F3 and in this way select F3 work only chipram 1.0 and 1.3 kickstart or F1/F4work 512 chipram and 512 slow the software works god


    i tried to load other programs and i not have any problem with F2 start

    Quote from iacesat

    I'm sorry to contradict you but what I did is described on page 4 of the attached document (the page with photo agnus)

    I didn't read it all, but only did a text search for "rev.". Since the word "revision" is not abbreviated, I didn't find it. So yes, it's described there, and yes, it needs to be removed :-) The article is written a without much hardware understanding. As if the speed of memory chips needs to be different for use as chip mem versus ranger mem.. this feels like the author either has no clue, or was paid by word count and wanted to get a bit more. The questionable advice of essentially creating a short between the A19 and A23 lines is a hint to take more things of the article with a huge grain of salt.


    The Sysinfo screenshot looks like there's a contact problem of the Agnus chip in it's socket. This may be limited to certain chipmem areas, and therefore only show if you're launching with Kickstart 1.3. So the fault may be there, but hidden by the affected memory portion not being used. Take ths chip out, check all pins, carefully bend corner pins inside, clean the chip and socket with IPA and re-insert the chip while it's still wet.


    Jens

  • 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