Search found 4673 matches
- Wed Feb 14, 2024 10:15 am
- Forum: Hardware and Tech
- Topic: Powering a C64 (or VIC-20) with a USB Power Bank
- Replies: 8
- Views: 4055
Re: Powering a C64 (or VIC-20) with a USB Power Bank
@JonBrawn: PM sent
- Tue Feb 13, 2024 4:15 pm
- Forum: Programming
- Topic: Line drawing algorithm
- Replies: 20
- Views: 1859
Re: Line drawing algorithm
... uses overlapping sprites to render filled vectors on the C64 which is a method that does not transfer at all to the VIC-20 (again, that method is nothing spectacularly new. The demo "Snapshot" already did so in 2010, see the part at 7:14).MrSterlingBS wrote:the Demo [...]
- Tue Feb 13, 2024 12:10 pm
- Forum: Programming
- Topic: Line drawing algorithm
- Replies: 20
- Views: 1859
Re: Line drawing algorithm
http://www.quiss.org/boo/ "BRR" is nothing new and effectively is an 8-bit 'randomized' DDA . It is illusory to assume a line routine plots ~200000 pixels/second just because the 'deciding' part within it executes in 5 cycles. This is completely ignoring the other necessary parts of the r...
- Mon Feb 12, 2024 12:39 pm
- Forum: Collecting and History
- Topic: How to convert Tap files to D64?
- Replies: 11
- Views: 504
Re: How to convert Tap files to D64?
Transferring all these files from *.tap to *.d64 is only doing half the job. The tape original very likely assumes (and can rightfully do so!) it was run from tape, and issues further load commands from tape. You would at least need to identify those code sections that load the next files and adapt ...
- Mon Feb 12, 2024 11:20 am
- Forum: Collecting and History
- Topic: How to convert Tap files to D64?
- Replies: 11
- Views: 504
Re: How to convert Tap files to D64?
When this can't be done by just LOAD from tape and SAVE to disk (within VICE, for example), this more or less amounts to do a full crack. Even when there's no fast loader involved, the game can feature an autostart, binary non-BASIC program data (like machine code, character sets or level data) and ...
- Sun Feb 11, 2024 2:57 pm
- Forum: Emulation and Cross Development
- Topic: Corrupt end of basic program
- Replies: 7
- Views: 440
Re: Corrupt end of basic program
And I start the program with setting the pointers after chaining. The values in addresses 174 and 175 are only valid immediately after LOAD ! If you in-between edit the program and re-start it, indiscriminate copying of 174/175 to 45/46 will reference the old values, possibly truncating the program...
- Sun Feb 11, 2024 2:40 pm
- Forum: Programming
- Topic: Line drawing algorithm
- Replies: 20
- Views: 1859
Re: Line drawing algorithm
That should be 55 cycles/pixel.MrSterlingBS wrote:00,00 to 99,99 5516 per pixel 39
You are improperly using the Euclidian distance here to pretend the line was 141 pixels long. The rasterization of lines with Bresenham plots max(dx,dy)+1 pixels, which is also 100 in the diagonal test case.
- Sun Feb 11, 2024 2:37 pm
- Forum: Programming
- Topic: VIC-20 joystick - which is the real way?
- Replies: 5
- Views: 401
Re: VIC-20 joystick - which is the real way?
I did not know much about VIC-20 hardware during the time I had one, but on my Radio Shack Color Computer I am aware that there were certain I/O registers that were ghosted, [...] ... or mirrored ... [...] and would appear in multiple places. Is something like this happening here? Not here, in a ce...
- Sun Feb 11, 2024 5:07 am
- Forum: Emulation and Cross Development
- Topic: Corrupt end of basic program
- Replies: 7
- Views: 440
Re: Corrupt end of basic program
Hi, I only use VICE. It happens 10% of the savings, and mostly at the end of the disk-directory or at the end of the tape. I made backups. I made a backup of this program with this error and didn't touch it after that. The backup is fine, curious. Other strange thing: I make backups of the floppies....
- Sat Feb 10, 2024 6:36 pm
- Forum: Emulation and Cross Development
- Topic: Corrupt end of basic program
- Replies: 7
- Views: 440
Re: Corrupt end of basic program
What tool did you use to create the program file in first place? This error is typical for a BASIC program file that for whatever reason was saved with a missing last byte . By itself, the SAVE command of BASIC does not produce that problem - but once a BASIC program is loaded that has been produced...
- Sat Feb 10, 2024 6:26 am
- Forum: Programming
- Topic: "Ultimate Expansion" - new firmware for FE3
- Replies: 59
- Views: 10417
Re: "Ultimate Expansion" - new firmware for FE3
This.srowe wrote:I guess [the RTC is] used to set the timestamps of files written to the SD card.
Unfortunately, many other (commercially available) SD2IEC drives economize on this aspect.
- Sat Feb 10, 2024 6:20 am
- Forum: Programming
- Topic: Recommendations for VIC-20 assembly tutorial, tools
- Replies: 10
- Views: 837
Re: Recommendations for VIC-20 assembly tutorial, tools
To be specific, I have a copy of some VIC 20 Diagnostic firmware that has a bug when it comes to determining how to display on the screen (I get odd colors). Are you sure this is not due to a hardware bug (faulty colour RAM, for example) in your VIC-20 itself? In that case it would be a waste of ti...
- Sat Feb 10, 2024 5:42 am
- Forum: Programming
- Topic: Line drawing algorithm
- Replies: 20
- Views: 1859
Re: Line drawing algorithm
I was able to get it down to under 15 cycles per pixel on average? That would imply your routine accesses/modifies each involved bitmap byte only once, i.e.: having LDA - ORA/EOR/AND #imm - STA present and inlined for all 36 possible horizontal line segments, removing all further address arithmetic...
- Sat Feb 10, 2024 5:11 am
- Forum: Hardware and Tech
- Topic: Another ram expansion? Yes it is
- Replies: 25
- Views: 4586
Re: Another ram expansion? Yes it is
Mike sum[s] up the challenge with adding memory visible to the VIC chip, but, I made a prototype circuit that will fix this problem. Just for the record, I solved said "challenge" or "problem" years ago already with aforementioned VFLI mod, by installing the RAMx range memory on...
- Sat Feb 10, 2024 2:45 am
- Forum: Programming
- Topic: Need help with adding custom character set
- Replies: 6
- Views: 320
Re: Need help with adding custom character set
How can I make sure the font file has the proper load address? The load procedure with SYS57809 ... SYS65493 that I highlighted above forcibly loads the font file to $1400, yet still a load address needs to be present as first 2 bytes of the file (making it 2050 bytes total). I have checked the fil...