Hi,
The remaining address lines should be tied either to ground or Vcc thru a resistor (pull-down or pull-up), say 10K~47K. Then thee dip switched are used to apply wether Vcc or gnd, depending on what you previously decided.
Look at this schematic if you don't understand :
http://www.maximintegrated.com/images/appnotes/238/238Fig01.gif
Regarding the Eprom, you have to make your own binary file, including the 8 binaries you want in a row. This can be easily achieved with an hex editor. Programing the Eprom 8 times would not result in what you need, unless you're able to tell your programmer which area to fill. I'm assuming you're using UV erasable eproms. If you're using OTP eproms, be sure about your binaries first!
Regards,
Michel
2013/2/25 swekompatibel
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swekompatibel@...
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Hello!
I have made the custom rom mod to my Roland TR-707 and now i want to use a 27C4001 EPROM and switch banks with a DIP-switch.
Please would you help me, Adress A16 A17 A18 goes separeted to the DIP switch, but what should i connect the other side of the DIP-switch, Ground
A15
.
And how should i program the chip, switch banks with the DIP and program 8 times with 8 separated rom binaries
no
Kind regards and thaks in advance!
Johan