Hi,
I am a new user of ACA500+. I installed it in my Rev 6. Amiga 500, which only has 512KB expansion under trapdoor and no other gizmos. The ACA works correctly after powering up, the boot menu shows up ok, and I was able to install the OS on the CF card in the "boot" slot. Booting off that card also works fine and gets me to Workbench in no time.
So far so good.
However, the AUX slot misbehaves. If I insert a card into AUX slot when the OS is already running, the computer hangs up after around 1-2 seconds every time.
If I power up with both cards inserted, I can see some activity in the boot slot (white LED blinking) and then everything hangs. If I now reset the machine using Ctrl-A-A, I can again see boot slot activity, then AUX also starts doing something, and then the boot continues, getting me to Workbench, where I can access both cards without any problem. If I now remove AUX card and then reinsert it - everything hangs again.
What I've tried already:
1. Went through basically all combinations of items in the ACA menu, removing RAM, slowing down the CPU, etc. The only thing that has any impact is disabling the AUX slot, which prevents the lockups, but naturally also makes it impossible to use the card.
2. Reviewed the last three years of forum messages on the topic.
3. I tried the pull-up resistor trick, although the POR seems to work well in my Amiga anyway. No change.
4. Seeing the power supply repeatedly suggested as a source of problems, I tried replacing my original 4.5A brick with multiple other power sources, including two distinct bench power supplies. In the end I wheeled out a 12 A linear power supply to feed the 5 V line - to no avail. I naturally adjusted the voltage levels to provide 5.0x V as measured at the plug (using a meter with valid calibration ;)). No change whatsoever.
5. Since my initial theory was that the inrush current on CF card insertion is causing voltage droop that leads to lockup, I carefully measured the voltage fluctuations close to card insertion time, with scope probe attached to source of mosfet Q1. There is a brief droop to 4.5 V lasting around 2 us at the moment VCC and GND pins make contact, but it appears to be harmless - I can cause it repeatedly by moving the card slightly and nothing bad happens. However, around 1-2 seconds after I push the card in fully, everything locks up again. There is no substantial voltage drop at that time.
6. I updated the firmware to the latest version. Did not help either.
When powering up, the final lines dumped to serial are:
ACA500plus scsi.device update 2.2 (30.08.2017)
00FF00FF 00FB592C IDE driver
00000004 flashunpackreloc
00000004 00040000
44415441 00000041 73D7000A
0004F400
44415442 00000042 04D70001
00055700
44415443 00000043 E41B0002
0005DB00
44415444 00000044 FC750003
00064700
44415445 00000045 41800004
FFFFFFFF 00000001 0040C99C 00000000 flashunpackreloc
0040C99C 00000004 IDE driver
ACA500plus CF scsi.device 2.2 (15.09.2017)
which makes me think it could be software problem. But then, with so many other users, certainly someone would see it before me? I tried three different cards from different manufacturers in the AUX slot, so either I am extremally unlucky, or something is wrong with my ACA.
Is there anything else I can try before sending it back? I can do SMD rework if needed.
Thanks,
Milek