ACA500plus hardware modifications for a case

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Don't Panic. Please wash hands.

    Hi,


    I am tinkering on 3D printing a case for my ACA500plus + X-Surf 500 + ACA1234 combo. While designing this, I am getting a crazy itch to actually intrusively modify the hardware to make the integration with the case more seamless (of course forfeiting warranty). That is, I'm looking to detach the 7-segment display and move it up to be flush against the case, and to remove the Action Replay button and relocate that on top of the case too. Because why not, that's the hardware tinkering hobby :D


    For X-Surf I'm looking to get a short Ethernet extension cable and socket so I can get the cable routed to the back of the case.


    If I am being super careful with soldering, I presume those would be modifications that should not expect many surprises?


    Thinking about all this design got my creativity flowing. What I would love to do is to be able to get a LED board with original Amiga 500 LEDs and put that on the case too, and then connect that to see Power (accelerator enabled), Compact Flash (HDD) Activity, and Network activity of the accelerator combo. This would nicely mimic the Amiga 500 lights on the expansion case :)


    Though that would take some careful snooping in parts of the ACA500plus board to make it possible. E.g. I see that X-Surf has a Link/Act surface-mounted LED on the left side, that I presume could be removed and relocated, although power delivery would probably need to be adjusted for driving such case LEDs? I wonder if pulling power for LEDs of this type might be feasible from the Amiga expansion bus directly? Or would that be expected to disrupt the accelerator?


    Something I also started to ponder is whether it would be an absolutely ridiculous idea to modify the board to build a physical switch on top of the case to "disable" the accelerator on the fly while the Amiga is powered on? :) E.g. by adjusting the accelerator cpu speed between 7 and 50 MHz? I would love to have a physical enable/disable switch like GVP A530 had, to be able to play around with adjusting CPU speed on the fly. Though I presume that would become a somewhat complicated mod.. or any way there would be to hack that kind of functionality into a custom switch control?


    I don't suppose there is a PCB diagram to help find one's way for these types of hardware mods? Any other ideas on what kind of functionality would be possible to customize into a 3D printed case?


    Cheers,

    Quote from clbri

    That is, I'm looking to detach the 7-segment display and move it up to be flush against the case, and to remove the Action Replay button and relocate that on top of the case too. Because why not, that's the hardware tinkering hobby :D

    You can of course cut the silicone that's holding the two parts together, but you should not extend the connection between them too long. You can use a few more cm of pin headers, but you should avoid using a cable at all cost, as the signals are unbuffered.


    If you really want the display at a different position, you need to de-solder the actual display and keep the other components on the small circuit board connected with the original pin header that connects the two boards.


    The button can be removed and used with a 10-15cm cable - that's not critical.


    Quote from clbri

    For X-Surf I'm looking to get a short Ethernet extension cable and socket so I can get the cable routed to the back of the case.

    That'll work. The connection method of X-Surf-500 and the DisMo is identical, and these are also unbuffered signals. They MUST remain as short as they currently are.


    Quote from clbri

    I see that X-Surf has a Link/Act surface-mounted LED on the left side, that I presume could be removed and relocated, although power delivery would probably need to be adjusted for driving such case LEDs?

    Drive strength is 20mA for the link/act LEDs.


    Quote from clbri

    I wonder if pulling power for LEDs of this type might be feasible from the Amiga expansion bus directly? Or would that be expected to disrupt the accelerator?

    You should never connect LEDs directly to the 680x0 bus.

    Quote from clbri

    Something I also started to ponder is whether it would be an absolutely ridiculous idea to modify the board to build a physical switch on top of the case to "disable" the accelerator on the fly while the Amiga is powered on? :) E.g. by adjusting the accelerator cpu speed between 7 and 50 MHz? I would love to have a physical enable/disable switch like GVP A530 had, to be able to play around with adjusting CPU speed on the fly. Though I presume that would become a somewhat complicated mod.. or any way there would be to hack that kind of functionality into a custom switch control?

    I've gone to great lengths to avoid any mechanical switch on the new accelerators, especially because I don't want to encourage people to cut holes into their computers to add switches. So I want my accelerators to use soft-switches only - however, if you're in 68000 mode, you can program the DisMo button to switch between CPU speeds, so you "kind-of" already have what you are looking for. It just won't switch between 68030-50 to 68000-7 on the fly, as that always requires a reboot. So why not reboot, hold down the LMB and switch to the CPU you want to try next?


    I doubt that the GVP expansion allowed to switch between CPUs on the fly - that would be an enormous amount of development work, not just on the hardware side, but also huge patches to the operating system to update structures that are built during the boot process. This hasn't been done in Amiga history - at least not to my knowledge.


    Jens

    Thanks, and good point about the GVP A530 switch, maybe it too was a soft switch that only applies on the next reboot. (or would crash if toggled at runtime, who knows :D ) It would be nice to be able to do something like that, since a physical switch would look oh so vintage, but also it will then be discoverable by the user. (physical user interface "affordances" and all that) I'll have to play around with programming the DisMo and see how much I'm able to customize there.


    Anyhow, I'll proceed with baby steps from the easier items first. I've now got the first iteration of my case modeled, and now setting up 3D printing to try it out, to get the clearances all right.


    Thanks again for the tips!