Search found 4671 matches

by Mike
Tue Dec 03, 2013 5:26 pm
Forum: Hardware and Tech
Topic: Image quality? Raster pattern artifact
Replies: 4
Views: 780

Re: Image quality? Raster pattern artifact

What is the easiest way to transfer the program to my vic? I have just the vic and a Mac and a PC. No disk drive yet. If you don't have a disk drive (yet), a SD2IEC is most probably the best bet. With this device, you can use SD cards to transfer programs and disk images between PC and VIC-20. [......
by Mike
Tue Dec 03, 2013 3:58 pm
Forum: Hardware and Tech
Topic: Image quality? Raster pattern artifact
Replies: 4
Views: 780

Re: Image quality? Raster pattern artifact

Even though the sample image is missing in the other thread, that's pretty much the same thing jibberjabber encountered on his VIC-20. See the thread ' Gaps between characters on video output ', and the answer by me. In short: Yes, it's quite normal. It's aggravated on most modern displays. The S-Vi...
by Mike
Tue Dec 03, 2013 1:39 pm
Forum: Programming
Topic: Challenge: Create or Delete Lines from inside a program
Replies: 27
Views: 4593

Re: Challenge: Create or Delete Lines from inside a program

How about [...] The 'canonical' solution for this kind of memory management is a two-filer: The first part POKEs user-defined characters, machine code, and other data into memory, perhaps displays a title screen and instructions, and then the main program is being loaded and run. Freeing memory by ...
by Mike
Mon Dec 02, 2013 4:26 pm
Forum: Programming
Topic: Challenge: Create or Delete Lines from inside a program
Replies: 27
Views: 4593

Re: Challenge: Create or Delete Lines from inside a program

The program would be a collection of BASIC line[s] I commonly use (joystick routines and such). That's an interesting application for itself. I'm assuming that this is also supposed to run on the real iron. :) Of course you could keep the different code snippets as single files on a disk (or disk i...
by Mike
Sat Nov 30, 2013 4:01 pm
Forum: Hardware and Tech
Topic: Why is the 40/80 col. display manager slowing the VIC?
Replies: 34
Views: 3073

Re: Why is the 40/80 col. display manager slowing the VIC?

i don't know that "40 columns manager" - but i'd assume that it creates a 40 columns display in software, which is quite a bit slower than normal text screen (and the test also takes PRINT speed into account, even including scrolling the screen - which will have a huge impact on speed) MG...
by Mike
Sat Nov 30, 2013 3:17 pm
Forum: Games
Topic: New interpretation of Pitfall! for PAL Vic + 16K
Replies: 81
Views: 46310

Re: New interpretation of Pitfall! for PAL Vic + 16K

This says PAL only?? [...] Glen already stated the reasons for this in this thread: An identical NTSC version isn't really possible - *every* [cycle] is used in a raster line, with no branching. To write this for NTSC would mean dropping the dynamic colouring for the main character. and Perhaps the...
by Mike
Sat Nov 30, 2013 2:54 pm
Forum: Programming
Topic: Challenge: Create or Delete Lines from inside a program
Replies: 27
Views: 4593

Re: Challenge: Create or Delete Lines from inside a program

Jeff, for what reason would you want to delete, add, or possibly also modify lines from within a program, besides the odd 'insert expression for a function plotter', 'create a data loader', or 'tokenize a PETSCII SEQ file'? We had a similar discussion about this some time ago, see 'Reflection in BAS...
by Mike
Wed Nov 27, 2013 4:36 pm
Forum: Programming
Topic: Checking Free RAM in ML
Replies: 21
Views: 3997

Re: Checking Free RAM in ML

For those concerned, here's an updated data loader for the streamlined version at 673, *including* the CLD, but leaving out save/restore for the ZP bytes. I could strip off another few bytes: bit 8 of $9003 does not contain bit 9 of the screen start address in the VIC bank, but bit 0 of the raster c...
by Mike
Wed Nov 27, 2013 11:36 am
Forum: Hardware and Tech
Topic: Strange video problem
Replies: 18
Views: 1461

Re: Strange video problem

I took another look at the garbled display. It is possible, that the VIC registers are wrongly initialised, so the screen display start address now points to uninitialised memory. For a short explanation, '@' and the checkerboard character are 0 and 255, respectively. You find this two-byte pattern ...
by Mike
Wed Nov 27, 2013 10:59 am
Forum: General Topics
Topic: Forum moved to new host
Replies: 78
Views: 18194

Re: Forum moved to new host

Good job with all the lastest adjustments! :D

I found the link of the picture 'until 5 posts, possible spammer' displays as broken (at least on my web browser). Unless it is planned to revive that picture, it should now possibly replaced by a suitable non-vanity Rank.
by Mike
Tue Nov 26, 2013 3:49 pm
Forum: Programming
Topic: Checking Free RAM in ML
Replies: 21
Views: 3997

Re: Checking Free RAM in ML

Just like the Zp $03-$06 and $FB-FE are never used in CBM Basic or the Kernal, there is no instance of a SED. So a CLD would not be needed.... :D I know that. Don't you think that doesn't preclude that user programs might use decimal mode? That consideration is especially important, as the free mem...
by Mike
Tue Nov 26, 2013 1:01 pm
Forum: Programming
Topic: Checking Free RAM in ML
Replies: 21
Views: 3997

Re: Checking Free RAM in ML

The code below takes 92 bytes and fits in the 673-767 area. Start with SYS673. Now, that's quite a feat. And you even kept the niceties I put in to adapt to the different RAM configurations, especially regarding the screen and colour RAM base addresses. 8) I'd still keep the CLD in front of the int...
by Mike
Mon Nov 25, 2013 6:18 pm
Forum: Other Systems
Topic: Why were BASIC interpreters incompatible on old machines?
Replies: 7
Views: 1768

Re:

why didn't they make the most generic parts of the BASIC language (write to the screen, read from the keyboard, add numbers, concatenate strings, etc.) compatible across different machines You're talking bullshit here. Of course these operations you cited worked source-code compatible across most p...
by Mike
Mon Nov 25, 2013 5:59 pm
Forum: Hardware and Tech
Topic: Strange video problem
Replies: 18
Views: 1461

Re: Strange video problem

Ouch, sorry to hear about the new problems you got. The ram I got was labeled NEC 8402A5 μPD2114LC Those *are* SRAMs. However, I've seen photos of NEC µPD2114LC in the 'net with '-5' behind the type, i.e. 500 ns. If there is no indication of access time behind a hyphen, this most probably means you ...
by Mike
Mon Nov 25, 2013 4:28 pm
Forum: Programming
Topic: Checking Free RAM in ML
Replies: 21
Views: 3997

Re: Checking Free RAM in ML

I thought it might be a good idea a post a working solution before this thread dies of old age ... 10 FORT=828TO951:READA:POKET,A:NEXT:SYS828 11 DATA 120,169,83,141,20,3,169,3,141,21,3,173,3,144,41,128,9,48,141,3,144,88,96,216,56 12 DATA 165,51,229,49,133,251,165,52,229,50,133,252,248,169,0,133,3,13...