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Re: 27C400/27C800 EPROM emulator
Posted: 28 May 2024 16:52
by 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"
Re: 27C400/27C800 EPROM emulator
Posted: 29 May 2024 08:10
by 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.
Re: 27C400/27C800 EPROM emulator
Posted: 29 May 2024 15:06
by BennehBoy
terriblefire wrote: 29 May 2024 08:10
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....
Re: 27C400/27C800 EPROM emulator
Posted: 29 May 2024 17:09
by terriblefire
BennehBoy wrote: 29 May 2024 15:06
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.
Re: 27C400/27C800 EPROM emulator
Posted: 29 May 2024 17:24
by BennehBoy
I'll have a fiddle and report back.
Re: 27C400/27C800 EPROM emulator
Posted: 10 Jul 2024 20:16
by BennehBoy
Re: 27C400/27C800 EPROM emulator
Posted: 11 Jul 2024 19:21
by 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.
Re: 27C400/27C800 EPROM emulator
Posted: 11 Jul 2024 19:28
by BennehBoy
Hi, the above post was simply in lieu of these no longer being available. Certainly can understand the support nightmare though, PEBCAC!
Re: 27C400/27C800 EPROM emulator
Posted: 12 Jul 2024 05:39
by 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:
Re: 27C400/27C800 EPROM emulator
Posted: 12 Jul 2024 13:46
by cmorley
dalek wrote: 12 Jul 2024 05:39
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 (211.27 KiB) Viewed 1836 times