Search found 523 matches

by brain
Tue May 25, 2021 10:13 pm
Forum: Emulation and Cross Development
Topic: libultimem for cc65 (C/asm)
Replies: 9
Views: 776

Re: libultimem for cc65 (C/asm)

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
by brain
Sat Mar 27, 2021 12:06 am
Forum: Hardware and Tech
Topic: Question on serial port
Replies: 2
Views: 311

Re: Question on serial port

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 ...
by brain
Wed Feb 24, 2021 2:01 pm
Forum: Hardware and Tech
Topic: My hardware project :: GCart 2011
Replies: 154
Views: 89750

Re: My hardware project :: GCart 2011

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

Jim
by brain
Mon Feb 22, 2021 11:44 am
Forum: Hardware and Tech
Topic: My hardware project :: GCart 2011
Replies: 154
Views: 89750

Re: My hardware project :: GCart 2011

Does the cart allow FLASH in any bank besides 5?

Jim
by brain
Fri Feb 19, 2021 8:38 pm
Forum: Hardware and Tech
Topic: My hardware project :: GCart 2011
Replies: 154
Views: 89750

Re: My hardware project :: GCart 2011

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
by brain
Sun Jan 24, 2021 1:13 am
Forum: Hardware and Tech
Topic: My hardware project :: GCart 2011
Replies: 154
Views: 89750

Re: My hardware project :: GCart 2011

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...
by brain
Mon Jan 18, 2021 10:53 pm
Forum: Hardware and Tech
Topic: My hardware project :: GCart 2011
Replies: 154
Views: 89750

Re: My hardware project :: GCart 2011

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
by brain
Sat Dec 12, 2020 1:22 pm
Forum: General Topics
Topic: Bible Series I and II reviewed - and possible problem
Replies: 15
Views: 1574

Re: Bible Series I and II reviewed - and possible problem

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...
by brain
Sat Dec 12, 2020 11:39 am
Forum: General Topics
Topic: Bible Series I and II reviewed - and possible problem
Replies: 15
Views: 1574

Re: Bible Series I and II reviewed - and possible problem

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...
by brain
Fri Dec 11, 2020 7:07 pm
Forum: General Topics
Topic: Bible Series I and II reviewed - and possible problem
Replies: 15
Views: 1574

Re: Bible Series I and II reviewed - and possible problem

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), ...
by brain
Tue Nov 10, 2020 10:18 pm
Forum: Hardware and Tech
Topic: Need Help with VIC Hardware Diagrams
Replies: 19
Views: 1212

Re: Need Help with VIC Hardware Diagrams

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...
by brain
Sat Oct 10, 2020 5:15 pm
Forum: Buy, Sell, and Trade
Topic: MasC=uerade!
Replies: 0
Views: 513

MasC=uerade!

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...
by brain
Thu Aug 06, 2020 1:40 pm
Forum: Programming
Topic: does the protovision 4 player adapter work with the vic?
Replies: 20
Views: 1006

Re: does the protovision 4 player adapter work with the vic?

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
by brain
Thu Aug 06, 2020 11:36 am
Forum: Programming
Topic: does the protovision 4 player adapter work with the vic?
Replies: 20
Views: 1006

Re: does the protovision 4 player adapter work with the vic?

PA2 on the 64 (M) is VIC CB2 SP2 on the 64 (7) is LIGHTPEN (PA5) on the VIC. So, SP2 is easy to grab, and it looks like you can coax CB2 into providing the needed result. Interestingly, though, VIC already plans PA2,3,4,5 as joystick #2 direction pins, so If you're already using the VIC second joypo...
by brain
Thu Aug 06, 2020 8:11 am
Forum: Programming
Topic: does the protovision 4 player adapter work with the vic?
Replies: 20
Views: 1006

Re: does the protovision 4 player adapter work with the vic?

That was the only reason I could see for such variety.

With the differences between the CIA and VIA, can the same process the code uses to read SP2 and CA2 in the 64 be used to read the respective lines in the VIA?

Jim