For correction: Carry out - I can't say that my English is so good that it is true translate.
I'm long time searching for Commodore 1750 REU for one purpose only: its EPROM socket which C128 identifies as external ROM. Sadly never found for sale. So I'm searching for way to make easy exchanging ROM in U36 socket without opening case. I have there Megabit ROM, which is for me less important than my own ROMs. Is possible to create any ?adapter? which allows by wires to carry out socket and by this way easy exchangeable U36 without opening case?
My offer is maybe not so high but simple: If anyone of you can create it for me, I give him/her gift in form of Megabit ROM.
Thank you for understanding and I hope that my English was at least so correct that is understandeable.
Commodore 64 was great, Commodore 128 is bigger, better, faster and more powerful... Commodore 65 was almost here, now is back in Mega 65 and is more than ever was...
The easiest way to bring the socket outside the machine is to cut a rectangular hole in the case directly above U36. This hole will allow a 28 pin ZIF socket to extend above the case. If you need more lead length for the ZIF socket pins to reach the board mounted socket you can stack wire wrap sockets or solder individual wire wrap header pins to the ZIF socket pins. Good Luck.
Cut a hole in the case I agree, that may be simplest solution! I just find it amusing that you would say that, or that anybody would do it. I must say you are gifted with thinking "outside the box", Robk.
There was somebody selling "raw" cartridge boards for C64/128... sorry I don't have a link saved or know the seller's name... but it was just a "blank" circuit board that fit the expansion port of 64/128... if you can still buy one, all you would need to do is solder a (EP)ROM socket onto the board. Then you could plug any ROM into the socket, and the C128 would see it as external ROM.
I'm thinking maybe it was the same person who was selling stereo-SID adapter? Sorry I don't remember...
I think that Miro wants to keep his RAM expansion board connected to the cartridge port and at the same time have an easy way to experiment with custom ROMs without opening the case everytime. That's why he's looking for a 1750 (REU + ROM socket), IMO
My response included a ZIF (zero insertion force) socket for just that purpose. Burn an eprom on a PC burner and test it in the ZIF socket on the C=128! Several binary files (ready to burn) of older commercial accessory ROMs are readily available on the net or burn your own, either write your own program or create a ROM for software that was only available on disk.
Note: not all wire wrap sockets will accept the wider pins of a ZIF socket. As I recall I used to pry the top of certain sockets that would then allow me to insert a ZIF for wire wrapping. (the use of wire wrap sockets is simply because they have longer leads)
There was somebody selling "raw" cartridge boards for C64/128... sorry I don't have a link saved or know the seller's name... but it was just a "blank" circuit board that fit the expansion port of 64/128...
You may be thinking of England's Tim Harris. You can see the various C= bits he distributes at
Might have been Vanessa Ezekowitz’ Digital Audio Concepts (no longer open for business). Too bad she had more urgent concerns intrude; I bought one of her excellent Stereo SID adapters and would happily buy another. I believe the Eagle files were on her site if you have the ability to make one of those cartridge boards up yourself. Can’t remember if her site is still up but it’s saved in the Wayback Machine anyway.
The world’s only gsteemso
Agitator-in-chief for the Seattle Retro-Computing Society
I was thinking of Vanessa's site gsteemso (thanks for the mental refresh).
buzbard, your ribbon-cable option sounds like a nice alternative... the only question I have is, how do you keep the 2 rows of pins from the socket from penetrating the same wires in the ribbon cable? Is the socket at a slight angle? or maybe it is a special socket with the 2 rows slightly offset?