Those look expensive for just two rom chips. I usually buy in bulk (like 30 at a time) so I am usually only paying $1 per chip. but when buying one or two at a time 2-4 dollars is what I would be looking for. The commodore is a very old machine so buying vintage eproms is fair game too if you see any.

also if you're feeling adventurous you can load up a larger eprom with several small prg files and use dip switches to access the various addresses.

These boards will give you 2 roms on one cart switchable with the dip switch: http://www.ebay.com/itm/commodore-64-12 … 25a3967ac7

Theres also board variations for up to 8 roms on one cart.

(if you're curious how to prepare the rom files, you just have to combine them using a command prompt window. something like:

copy /b rom1.bin+rom2.bin output.bin

and burning that output rom to a larger eprom will put both the programs in the right addresses for that dip switchable board.

admittedly this might be overkill if all you care about is getting cynthcart in an economical way.

Hmmm, do you have a source for those? Something like this? http://www.ebay.com/itm/SIGNETICS-27C64 … 3aa175228a

BTW, I personally have always used 27C64A chips from Philips, so I can vouch for those.

Check the datasheets for each, if the pinouts and timings are the same they should be compatible with the same programmer (although certain programmers can occasionally be quirky).

Sounds like they plan on buying an EPROM, which is erasable.

You won't be able to harvest from an old cart cause these are all going to be mask roms. Which are not erasable/programable and will likely have a different pinout. (I know for NES this is true, but I'm not as savvy in the way of c64 repro carts, so grains of salt should be taken)

Thanks a lot for confirming that for me.

Is it okay if I ask just one more question? The programmer I'm going to be using is a TOP2004. Info can be found here: http://www.ebay.com/itm/TOP2004-EPROM-U … 7675.l2557

It looks like this exact chip (from this manufacturer) isn't supported (or at least not on the list), but the exact same model from AMD is. Am I safe to assume that this programmer will still work fine with the eprom? Or is it very specific?

In general, how particular are eproms? Would anything from the 27C64 "family" be compatible with each other, or are the exact variants unique?

That's the access timing. For the C64 this needs to be faster than 500ns. EPROMs will commonly come in 450 ns models and these will do just fine.

Ah, thanks for that info. I still just think it's beyond the scope of what I'm capable of at this time, as well as out of my price range. That would be a great next step though, if cynthcart gets too limited for me.

I have confirmed I'll have access to an eprom programmer, so I'm looking at chips to flash it with. I've found this site http://www.futurlec.com/ICEPROM.shtml

They sell the 27C64 eproms that it looks like I'll need, but I'm unsure on which one I should get. They offer 120, 150, and 200ns versions. I sort of assume the 200ns would be fine for something as old as the commodore, but I really have no idea what those timings actually mean. Can anybody confirm that these chips will work, and if so, which one I will need?

To be fair, Kerb does a lot more than just midi. It does come with a MIDI-enabled version of Cynthcart but includes other software as well - including Steinberg's Pro-16 - and allows you to upload your own PRG files to the 2MB flash memory.

That's true, I failed to mention I (probably) have access to a flasher. The viability of attempting to make this on my own depends on that factor alone! Assuming I do, where can I pick up the eprom? Are they something readily available on ebay, or do I need to harvest an old cartridge?

I have no idea what that is! Is it some kind of multicart that also includes midi? The only midi cart I'm really familiar with is the MSSIAH. That being said, I think I'd rather just play the C64 like a synth than try to control it with midi or a tracker.

i was just looking at these. definitely the most straight forward option for c64 stuff

Or it might be cheaper to just get:
http://www.frank-buss.de/kerberos/buy.html

It certainly seems that way. Though getting the flasher, the uv eraser, the eproms and that board would all cost more that just getting the AtariAge production.

So I'm going to have a C64 in my possession very soon, and I think a cynthcart is the way I want to go. I can see that atariage sells them for about $30, but I being cheap was looking at other solutions.

I found this on ebay: http://www.ebay.com/itm/NEW-Commodore-6 … &rt=nc

I'm just curious, would it be as simple as buying that pcb, an EPROM, flashing it, and soldering it together?

If you have any other C64 tips for me as a noob, I'd appreciate that as well.

Thanks!