27C400/27C800 EPROM emulator

Any 8bit repairs, images, cool things, upgrades etc.
Posts: 4
Joined: Mon Jan 25, 2021 3:29 pm

Re: 27C400/27C800 EPROM emulator

Post by patracy » Fri Feb 05, 2021 2:33 am

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)

received_452399545894059.jpeg (102.43 KiB) Viewed 289 times
received_3089185581310156.jpeg (82.67 KiB) Viewed 289 times

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