27C400/27C800 EPROM emulator

[BennehBoy]

Sorry for a thread resurrection!

Thought it may be useful for any other linux users to know that they can get this device to automatically map as a tty device by adding a udev rule similar to the following:

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="5740", GROUP="users", MODE="0666"

[terriblefire]

I recall trying to get this device setup in a way i could switch between DiagROM and AmigaOS for the Amiga 4000 and i couldnt get it to work. It was like the first half of the ROM worked fine but the second was trash. Its a shame because i really wanted to have something like this but it didnt work for me. I assume its just me as others seem to have had OK results.

[BennehBoy]

I recall trying to get this device setup in a way i could switch between DiagROM and AmigaOS for the Amiga 4000 and i couldnt get it to work. It was like the first half of the ROM worked fine but the second was trash. Its a shame because i really wanted to have something like this but it didnt work for me. I assume its just me as others seem to have had OK results.

I've only used mine in my A500, I have a spare 2nd sat about... I was thinking of burning an EPPROM for the 500 and moving both into my A1200 as I've just bought a 1232, but if there're problems with dual roms....

[terriblefire]

I've only used mine in my A500, I have a spare 2nd sat about... I was thinking of burning an EPPROM for the 500 and moving both into my A1200 as I've just bought a 1232, but if there're problems with dual roms....

I honestly dont know whats up. It may be me being an idiot but i could never get it to work reliably.

[BennehBoy]

I'll have a fiddle and report back.

[BennehBoy]

This may be of interest -> https://github.com/cdhooper/kicksmash32

[cmorley]

I think a couple of modules might have had faulty vias to the front pads or cracked later - perhaps I was too racey for the JLC 4 layer process in my via and trace widths in the layout. Most people got them working in 32 bit mode who asked for support - they'd not followed the instructions precisely or assumed some function instead of reading the docs. This is the main reason I didn't continue the project - lots of people don't read docs and the modules weren't intuitive enough to use without docs for some... so they were a support nightmare.

Maybe I'll do another version in the future but I'm too busy with the day job to do any retro stuff at the moment. Emulating a MSC device RPi Pico style might be a better interface... ditch the CPLD and make it robust to people inserting it backwards or 1 pin out. I just don't have the time though sadly.

[BennehBoy]

Hi, the above post was simply in lieu of these no longer being available. Certainly can understand the support nightmare though, PEBCAC!

[dalek]

If you do another batch could I suggest changing the smd pads for extra signals like reset in to through holes?

I stupidly forgot reset was connected and ripped the pad right off when removing mine for programming... users are so dumb :swave:

[cmorley]

If you do another batch could I suggest changing the smd pads for extra signals like reset in to through holes?

I stupidly forgot reset was connected and ripped the pad right off when removing mine for programming... users are so dumb :swave:

That just wasn't possible, the PCB is too busy. In the following image you can see that the chips on the bottom overlap the top pads.

Screenshot 2024-07-12 134337.png