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randyrossi / bmc64

A bare metal Commodore 64 emulator for the Raspberry Pi with true 50hz/60hz smooth scrolling, low input latency and better audio/video sync.
GNU General Public License v3.0
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Feature Request: Hardware I/O #249

Open Monotoba opened 1 year ago

Monotoba commented 1 year ago

I would love to see some kind of emulated USER PORT. Perhaps using some of the I2C or SPI to parallel interface chips. I have some old hardware projects that interfaced with the C64 that I would love to use. What I would love to see is the USER PORT emulated. No need for 9VAC. Just the I2C or SPI interface chips on a daughter board or pi-place with the 24-pin connector with original pin-outs. Of course these pins need to be addressable at the same address(s) the original user port was, and needs I/O configurable. No emulator contains anything like this. But imagine being able to use a few of the old original peripherals!

randyrossi commented 1 year ago

There is some support for configuring GPIO pins as a user port. I think it can CIA2 port B from within the C64 emulation. But you would have to look at the changes to be sure. It was added by Mark Bush for his side-project. See https://github.com/randyrossi/bmc64/blob/master/README.md#gpio-config-4--userport-and-joysticks

It has limitations though. It might be okay for turning LEDs on/off but I would not expect to be able to talk to real devices due to timing as described in the link.

On Fri, Oct 27, 2023 at 7:44 PM R Morgan @.***> wrote:

I would love to see some kind of emulated USER PORT. Perhaps using some of the I2C or SPI to parallel interface chips. I have some old hardware projects that interfaced with the C64 that I would love to use. What I would love to see is the USER PORT emulated. No need for 9VAC. Just the I2C or SPI interface chips on a daughter board or pi-place with the 24-pin connector with original pin-outs. Of course these pins need to be addressable at the same address(s) the original user port was, and needs I/O configurable. No emulator contains anything like this. But imagine being able to use a few of the old original peripherals!

— Reply to this email directly, view it on GitHub https://github.com/randyrossi/bmc64/issues/249, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAI3HKEAWWP4HWUEXRNPEULYBRBMLAVCNFSM6AAAAAA6TP3KJOVHI2DSMVQWIX3LMV43ASLTON2WKOZRHE3DMMZQGY3DONI . You are receiving this because you are subscribed to this thread.Message ID: @.***>

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Monotoba commented 1 year ago

Thanks! I'll look into it. I think timing issues could be dealt with. I expect the kernel does maintain a clock. And as fast as the PI is, keeping the port timing should be doable.But I am only guessing as I have not looked at the code.

On Sat, Oct 28, 2023 at 8:33 AM randyrossi @.***> wrote:

There is some support for configuring GPIO pins as a user port. I think it can CIA2 port B from within the C64 emulation. But you would have to look at the changes to be sure. It was added by Mark Bush for his side-project. See

https://github.com/randyrossi/bmc64/blob/master/README.md#gpio-config-4--userport-and-joysticks

It has limitations though. It might be okay for turning LEDs on/off but I would not expect to be able to talk to real devices due to timing as described in the link.

On Fri, Oct 27, 2023 at 7:44 PM R Morgan @.***> wrote:

I would love to see some kind of emulated USER PORT. Perhaps using some of the I2C or SPI to parallel interface chips. I have some old hardware projects that interfaced with the C64 that I would love to use. What I would love to see is the USER PORT emulated. No need for 9VAC. Just the I2C or SPI interface chips on a daughter board or pi-place with the 24-pin connector with original pin-outs. Of course these pins need to be addressable at the same address(s) the original user port was, and needs I/O configurable. No emulator contains anything like this. But imagine being able to use a few of the old original peripherals!

— Reply to this email directly, view it on GitHub https://github.com/randyrossi/bmc64/issues/249, or unsubscribe < https://github.com/notifications/unsubscribe-auth/AAI3HKEAWWP4HWUEXRNPEULYBRBMLAVCNFSM6AAAAAA6TP3KJOVHI2DSMVQWIX3LMV43ASLTON2WKOZRHE3DMMZQGY3DONI>

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