Help fixing Vector-06c

[KTSerg]

D9 is a PT5, the 512 byte ROM. Are there instructions on how to upgrade this to a larger ROM? Since it uses two Chip Select lines I'm not sure if I could directly replace it with a 27256? I'd definitely like to use the "Combodevice" so I can load software faster and try out some Demos.
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I already gave a link to the instructions for replacing the ROM.
You can change it to any ROM, I wrote that now 27512 is installed on my computer, and previously I installed 290011. I installed a socket in the computer and change the microcircuit when necessary. I installed jumpers on the ROM, and several different programs were written into it at once.

cyb2600, write what kind of ROM you have, here they will tell you how to connect it.