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Jul 2023

C64 Cartridge on a Stripboard

Anonymous
Sat 1-Jul-2023 09:01
This is a really nice solution to get data from an AVR into the C64. Once tried that using DMA but that required a whole breadboard full of logic to handle the VIC bus sharing and has not been very stable though.
lft
Linus Åkesson
Sat 1-Jul-2023 14:16
Like, say you know stage1+stage2+payload transfers in 16ms, set the watchdog before 32ms before dropping into the transfer loop.

That's an excellent idea. Either the watchdog timer or a regular timer (with a prescaler) and an interrupt.

Couldn't you move one more byte (the F7 of BNE $6000) to stage2?

Yes, you're right. Very good!
Anonymous
Sat 1-Jul-2023 15:46
Why are you not loading stage 2 to the zero page so you can write the bytes using zero page STA instructions? Also why aren't you using LDX then STX for one of those writes to save the two bytes in stage 1 that initialize X?
Anonymous
Sat 1-Jul-2023 23:41
I'm not sure why the table has to store the assembly, requiring 5 bytes per C64 RAM byte. Could you keep an address counter and just load the immediate data values from the table, returning the same opcodes each time? Or is that too slow for the 1 MHz data fetch rate at 8 MHz?
Anonymous
Wed 5-Jul-2023 23:59
I've occasionally used a program called VeeCAD to design strip-boards like that. Worked reasonably well.
lft
Linus Åkesson
Fri 7-Jul-2023 11:19
Why are you not loading stage 2 to the zero page so you can write the bytes using zero page STA instructions?

The reason for putting Stage 2 immediately before the application is to avoid the need for a JMP. But you have a point; it's possible that switching to zero-page instructions would save enough bytes to compensate for this. To be investigated.

Also why aren't you using LDX then STX for one of those writes to save the two bytes in stage 1 that initialize X?

That's only because the byte $09 didn't appear in the Stage 2 code. Otherwise I would have done it.
lft
Linus Åkesson
Fri 7-Jul-2023 11:26
I'm not sure why the table has to store the assembly, requiring 5 bytes per C64 RAM byte. Could you keep an address counter and just load the immediate data values from the table, returning the same opcodes each time? Or is that too slow for the 1 MHz data fetch rate at 8 MHz?

The loop on the AVR already needs eight cycles per iteration, so in order to add more complexity one would have to unroll the loop: Send $a9, send a byte from the table, send $8d, send the address LSB, send the address MSB, increment the address, and loop back to the beginning. The unrolled AVR code would also consume a lot of flash space, probably more than the table of opcodes and operands.

Glyptodont performed on the... Qwertar?

knoxg
Greg Knox
Sat 8-Jul-2023 02:35
Rock on

\m/ ( -_- ) \m/
ralph
Ralph Corderoy
Sat 8-Jul-2023 07:47
How about rodstar. Based on rock star.
Anonymous
Sat 8-Jul-2023 09:42
The three rod solution looks a bit like the super hero Wolverine, who has three metal claws. The suffix -ine already sounds like an instrument (like tambourine) so I suggest you simply call it Wolverine.
Anonymous
Sat 8-Jul-2023 13:29
When in a possible future you 'll build c64 based Droid machine and need a name for it ,it will be an easy one.
"C6T4" a C3PO variation which will sound exactly right ~ Si-Six-Ti-For .

But for this instance with the special C64 instrument with a .... Trident?
How about something includes Treudd (Trident in Swedish) for the new instrument name?
Like
Treuddont (as the first instrument's song was Glyptodont)
(which will sound Triudont)

or Treudd-(t)ar (which will sound Triud-ar).
I have to admit other suggestion sound a lot better though .
Anonymous
Sun 9-Jul-2023 09:50
How about Sidberus? a play on Cerberus the three headed hell hound from Greek mythology.

PS! Great stuff 10/10 as usual
Anonymous
Sun 9-Jul-2023 21:24
I was thinking about "Flying-C" in reference to a Flying-V and the Commodore, but on Youtube "PitchFork" came up and it's much better, I think.
Keep up the very very creative work you're doin'
/Kuddel
Anonymous
Mon 10-Jul-2023 00:18
Neat project. I was thinking:

* Theremon - theremin + ML monitor
* CIAtar - for the 6526 + guitar

The bitbuf

darwiniandude
Rowan Pope
Sat 15-Jul-2023 02:00
This is fantastic. It reminds me more than a little of your PO-20 Arcade pocket operator, or should I say the pocket operators in general. I have to wonder how much of the pocket operator idea was inspired by this project? As of yesterday they have the PO-20 in stock again, I've always wanted one so i've just ordered, even though the price is more now than it originally was. Love your work, especially your musical instruments made with C64 tech :)

Glyptodont performed on the... Qwertar?

Anonymous
Sat 15-Jul-2023 20:45
How about Tar SiDious ?(from Darth Sidious) If someone wants to follow a Star Wars path in the instrument's namesgiving procedure.
Anonymous
Wed 19-Jul-2023 07:17
Bender SID'o Qwerty

C64 Cartridge on a Stripboard

Danesh121
Homay Danesh
Fri 28-Jul-2023 13:34
Hi:
I am beginner
The hardware discussion was wery simple and I have made it.
How can apply the software on avr and how can transfer programs to C64?
Step wise

Glyptodont performed on the... Qwertar?

Anonymous
Sat 29-Jul-2023 12:22
thank you lft for this performance. your light shines strong to reach me in a dark place and I am elevated already!

The TTY demystified

Anonymous
Sat 29-Jul-2023 23:47
Extremely good info, I can't thank you enough! I've only recently begun to get serious about learning how to use Linux/BSD and for months I've played this weird game of learning how about shells, editors, shell languages and kernel specifics. Each google search left digging in a new area but nothing tied it all together - until I read this!! Please write a book someday, you are incredibly good at explaining arcane topics and putting the pieces into perspective.