Denial

Revisiting my X-Pander 3 VIC design as I plan to get it up on Github and perhaps consider a re-run. It had bugs and I'd like to get them fixed before I put something into the wild. Is there a preferred port spacing? Also, as I recall, pin 20 and pin Y, though noted as N/C on many pinouts, were in ac...

As I remember Jim made 100 of these, but noticed the dip-switches were to close to the cartridge slots, so you could not plug in a standard cartrdige fully. You can still buy this for $22 a piece and I got one some years ago: https://store.go4retro.com/non-functional-goodies/ See the notes at the b...

Sorry I didn't see this earlier. It's very much appreciated!

Let me know how I can help get this working on real HW.

Jim

As the linked posting illustrates, the inverters are open collector, which is very important for the bus. You could somewhat accomplish the same thing by putting pullup resistors on all the VIA pins connected to the bus and switching the output to an input when you want to send a '1',, but the 6522 ...

Does the ARM automatically connect to the DRAM and handle refresh, or do you implement your own refresh scheme?

Jim

Does the cart allow FLASH in any bank besides 5?

Jim

I'd fix this by using an 29F040b, which only requires 12 bit unlock codes. It's still 512kB, and I believe it still available. That way, the unlock can be done from any bank.

And, I think they are less expensive that your current option.

Jim

Here's the repo for UltiMEM: https://github.com/go4retro/UltiMEM And, the register description is here: http://www.go4retro.com/products/ultimem/ Essentially, each of the various memory segments (RAM 1,2,3 | BLK1 | BLK2 | BLK3 | BLK5 | IO2 | IO3) can be set to read/write RAM, R/O RAM, ROM, or nothin...

I'll put the UltiMEM schematics and such into github, as it sounds a lot like your current project (8MB FLASH, 1MB RAM, bankable blocks and rams and IO segments)

Jim

Ingo's dedicated opinion is not a good basis to get things done, Well, given that these things are passion projects, not financial items, I think it's as good a basis as any if one expects Ingo to do the work. The promise of open source was that lots of people would contribute to source code, but t...

Jim, I think it would be best to modify the implementation to not use 1581 sub-partitions, quite honestly. sub partition support in sd2iec requires a ton of code to make it work (one has to implement formatting inside an image, and the code for sub-partitions cannot be shared with any other drive t...

I think it would be best to modify the implementation to not use 1581 sub-partitions, quite honestly. sub partition support in sd2iec requires a ton of code to make it work (one has to implement formatting inside an image, and the code for sub-partitions cannot be shared with any other drive type), ...

With apologies to those who think $ffff should be at the bottom, it is more common for 0 to be at the bottom and $MAX to be at the top: https://www.google.com/search?q=memory+map&client=firefox-b-1-d&tbm=isch&source=iu&ictx=1&fir=KdgyaK_ZB_qykM%252C-IK5sMTdXGbYiM%252C%252Fm%252F0...

For the brave, the adventurous, the ones willing to try new things, after an incredibly long wait, I present the MasC=uerade. This unit remaps control lines from the VIC-20 onto a pseudo C64 cartridge socket, potentially allowing C64 I/O cartridges to operate in the VIC-20. At $11.00, it's almost to...

Ah, I missed that those are JOYPORT 1 pins. Duly noted.

Back in the day, there were second joyport adapters for the VIC. That's what I thought those were. IN any case, I wonder what pinout they used. (Can't check right now, but I know it was a thing).

Jim