27C400/27C800 EPROM emulator

[patracy]

I am running a Rev. 4.4 motherboard.

Cmorley and I have exchanged a number of messages back and forth over the past few days. I goofed on the solder jumper. As well as the roms needed to just be transfered without byteswap. As well as a few other configurations I had wrong as well. But thankfully he worked with me to get all this sorted. But I'm happy to report it's working great now!

I was very interested in this setup when I learned it could be hard wired to select the rom instead of relying on the RST signal. I'm running a GVP Combo II 030 accelerator that "hijacks" the RST from the motherboard. I was able to get it to work most of the time with the romulator with diagrom and some of the time with 3.1.4. This setup just simply works every time. While I don't get a fancy boot screen to select roms with a keyboard, I do get the simplicity of the system working as it was intended without the rst issue. I'm going to simply mount the switch on the back of the case in one of the card slot blanks. (I also have a switch to install for floppy DF0/DF1 swap to do as well)

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[demon-knight]

Firstly I would like to thank Chris, I got to of these from you last week and they work great so thanks.

I have a question, can i flash a custom 1mb rom on my 1200 and still use the remaining slots for another couple of roms?

Thanks

[cmorley]

I have a question, can i flash a custom 1mb rom on my 1200 and still use the remaining slots for another couple of roms?

I imagine so but I have never done such so can't give you a step by step guide.

I don't know how the bigger ROMs work on an A1200. In 27C400 mode you get 2x 512KB (two ROMs) for 1MB and 4x switching... I guess this would put ROM image in the F00000 and F80000...

There seems to be a "first 512KB of 1MB ROM" region labelled in the memory map... you'd have to hook up A18 for that I think and configure as 27C800. Someone asked me to do this for their dual ROM CD32 but I don't know why or what they were doing... I just soldered the wire they asked for :|

I really don't know anything about extended Amiga ROMs.

[demon-knight]

Thanks for getting back to me, I will play around with them over the weekend and see where I end up.
I will do a bit more reading on the subject as im not too sure myself on custom or extended roms.

[AllanL]

I have been looking for a nice in-situ flash-able rom adaptor for a little while...

Just wondering if this solution could have the feature added of flashing from the Amiga itself found in this project: https://github.com/PR77/68000_Relocator_FLASH_Kickstart

Seems like a nice solution... please feel free to shoot me down in flames, highly aware I'm out of my depth here!

Cheers,

Allan

[cmorley]

Technically possible with the hardware but would require a large firmware rewrite.

As the module is at the moment, you could program it from the Amiga with an Amiga USB interface.

[quantum8]

Such a shame there's a worldwide chip shortage and that these CPLDs are basically unobtainable for the next year, making these devices impossible to build for the time being :/

Hopefully a solution presents itself sooner than that, but I don't hold much hope!

[terriblefire]

@cmorley is there anywhere i can get the latest firmware. I seem to have 2 Boobip's with different firmware versions which makes automation annoying.

[cmorley]

@terriblefire email me & I'll send you it.

[terriblefire]

@terriblefire email me & I'll send you it.

Done.