Spivkurl

So I finally got the 390 ohm resistors which the schematic called for, and installed them in place. I made a new board for one of the RAM chips and rewired each ribbon connection between the cartridge slot and my RAM boards. It should be working but it is reacting exactly the same way as with the 1k resistors. I'm using a 3v cell battery, but when I plug my boards in, the CMOS chips supply pins only read about 3.9v... this seems weird, as the ideal supply for the ram chips is from 4.5 to 5.5v. If anyone has an idea of something else to check out which I might have done wrong, I would appreciate it!

iPad and Casio CZ... For some reason hilarious!

They are quite rare it seems. That is why I decided to build my own for my CZ-101. The link for the schematic is in the only thread I've started since joining a couple days ago. As far as I've seen, the pre-made cartridges either held 16 or 32 presets. The design I'm working on hold 64, which would be so nice. Just need to get the correct resistors to make it work...I hope. Other than that, ebay really seems like the only place to find them, and as with anything on ebay, you have to be lucky to get a good price for something useful.

Okay, thank you happyrat1! Between your reply, and some on another forum, it seems like the general consensus that this is the trouble. I guess I will be making a another small parts order. I was taking into account the supply voltage from the CZ which connects to the cartridge, so if the card is not in standby (just battery storage) then the chips are supplied with closer to 5v... Don't know for sure what the actual data signals are as far as level goes. Thank you for your help. I hope to get this working soon!

Hello all, I am new to this forum, and have been searching around for someone with more experience with Casio CZ-101 troubles. Have had this synth for quite a few years, and I love it so much! I finally got around to doing some updates, like a backlit LCD. Then I moved on to building a 64 patch memory card, which is mentioned in the article down this page: http://www.vintagesynth.com/forum/viewtopic.php?f=1&t=59847 I have it constructed, only using 1k ohm resistors in the place of the 390 ohms, just because I had them on hand. I have made sure it is all connected properly and there is continuity between the cartridge pins in the Casio and the card. Whenever the card is connected to the synth, and I power it up, there is just a row of boxes on the LCD top row, and many of the LED's are lit up, but no functions are available on the keyboard. If I turn it off and remove the cartridge, everything works fine again. I guess I'm just wondering if anyone here has experienced this with a CZ... as I noticed one person on another forum stating they had this problem before, but did not mention ram cartridges or any solutions. If anyone has more understanding here, would the current limiting of the higher value resistors cause the card to be unusable, or is there a deeper problem with the cartridge circuitry within the keyboard itself? Any help or suggestions would be greatly appreciated! Thank you, Pat(Spivkurl)