Search found 4648 matches

by Mike
Thu Sep 05, 2013 1:33 pm
Forum: General Topics
Topic: Wanted: Recommendations for a site to host software releases
Replies: 4
Views: 3100

Hmm... SourceForge and GitHub spring into my mind here.
by Mike
Thu Sep 05, 2013 10:51 am
Forum: Games
Topic: New interpretation of Pitfall! for PAL Vic + 16K
Replies: 81
Views: 46116

I noticed that the stairs are thinner in the original version of the game... is there a reason why in this VIC version they are wider? (not saying that you should modify them of course!) It's a quite simple reason. Many screen elements you are looking at in this implementation of Pitfall do not exi...
by Mike
Wed Sep 04, 2013 3:08 pm
Forum: Games
Topic: New interpretation of Pitfall! for PAL Vic + 16K
Replies: 81
Views: 46116

[...] speaking of which, I've noticed a lot of recent Vic releases have a nice hi-res loader screen. Does anyone want to code one? Well, even a raw convert of the Intellivision game box into 104x256 FLI already would look like this: https://dateipfa.de/.Public/denial/images/games/pitfall.png IMO, t...
by Mike
Tue Sep 03, 2013 11:49 am
Forum: Games
Topic: New interpretation of Pitfall! for PAL Vic + 16K
Replies: 81
Views: 46116

I tried to load it about 5 times with no success [...] That happens because of a wrong load address in the *.prg file. Saved BASIC programs (also ML programs with a BASIC stub) are supposed to start at $120 1 with a +8K (or bigger) RAM expansion. The byte containing 0 at $1200 is not saved along wi...
by Mike
Fri Aug 30, 2013 2:57 pm
Forum: Games
Topic: Usborne Write your own adventure games - haunted house
Replies: 10
Views: 2689

Here's my remark to the cross-posted copy of the type-in listing in another thread: (link) :roll:
by Mike
Fri Aug 30, 2013 2:31 pm
Forum: Other Systems
Topic: Identify the Machine Based on its Color Pallette
Replies: 15
Views: 3219

Now how about this one?

Image

The marked top-left colour is transparent.
by Mike
Wed Aug 28, 2013 12:50 pm
Forum: Hardware and Tech
Topic: Introducing VFLI for VIC-20: 208x256 pixels in 16 colours!
Replies: 107
Views: 65856

freshlamb wrote:Mike has also uploaded a NTSC version of the VFLI disk and tools.
The archive can be downloaded here: vfli_ntsc_prototype.zip.

As I wrote earlier, the resolution of 184x208 pixels is intended as stop-gap measure until I find time to implement the 168x384i display routine.
by Mike
Tue Aug 27, 2013 5:26 pm
Forum: Programming
Topic: 6502 asm - Swapping pairs of bits
Replies: 13
Views: 1629

Hmm..., this one employs an EOR mask, but it's longer and needs two temporaries: STA temp LSR A EOR temp AND #$55 STA temp2 ASL A ORA temp2 EOR temp If you don't mind undocumented opcodes, you can replace the instruction pair ASL A/ORA temp2 with SLO temp2 . The instruction pair LSR A/EOR temp also ...
by Mike
Tue Aug 27, 2013 2:14 pm
Forum: Programming
Topic: 6502 asm - Swapping pairs of bits
Replies: 13
Views: 1629

@wimoos: How about these two? LDX #4 ASL A .loop PHP ASL A ADC #0 PLP ROL A DEX BNE loop TAY AND #$55 ASL A STA temp TYA AND #$AA LSR A ORA temp ;) This would be time critical so perhaps a look up table might be a good idea, although I would need a separate table per required set of mappings I guess...
by Mike
Tue Aug 27, 2013 1:37 pm
Forum: Programming
Topic: 6502 asm - Swapping pairs of bits
Replies: 13
Views: 1629

wimoos wrote:How about this one ? Source and destination both kept in A
It does not work as intended.

%01 and %10 are mapped to %01 and %11 is mapped to %10.
by Mike
Tue Aug 27, 2013 12:35 pm
Forum: Programming
Topic: 6502 asm - Swapping pairs of bits
Replies: 13
Views: 1629

That's a nice solution indeed. It uses the Accumulator as temporary storage for the carry flag (ROL A and LSR A could be replaced by PHP and PLP to illustrate that better, but that would of course cost some cycles). And no need to load A with 0 four times My variant is slightly more flexible though,...
by Mike
Tue Aug 27, 2013 12:10 pm
Forum: Programming
Topic: 6502 asm - Swapping pairs of bits
Replies: 13
Views: 1629

If it has to be fast , don't bother with saving memory. Use a table with all 256 byte values. Otherwise: LDX #4 LDA #0 .loop ASL src ROL A ASL src ROL A TAY LDA table,Y ASL A ROL dst ASL A ROL dst DEX BNE loop .table EQUB &00:EQUB &80:EQUB &40:EQUB &C0 Ideally, 'src' and 'dst' should...
by Mike
Mon Aug 26, 2013 3:55 pm
Forum: Other Systems
Topic: This never made it to VIC?
Replies: 11
Views: 2407

RJBowman wrote:Maybe someone could make a Q-Bert game that doesn't look like crap.

Or Mappy; one of my all time favorites.

Or an all-text downhill skiing game in BASIC. Yeah, someone should do that.
I'm glad you volunteer to spend some of your precious spare time to make all these games happen. :P
by Mike
Mon Aug 26, 2013 3:05 pm
Forum: Hardware and Tech
Topic: Metal lable on older carts for RF shielding?
Replies: 5
Views: 1095

The metal labels cannot shield RF. For this to work well, even connecting the labels to ground would not be sufficient, it also would have required a completely metalized cartridge case. For a similar reason, the metalized cardboard 'RF shield' is not effective, as the RF can leak out to all sides: ...
by Mike
Sun Aug 25, 2013 5:37 am
Forum: Games
Topic: [**Commercial Release Is Now Available**] Realms of Quest IV
Replies: 140
Views: 41708

metalfoot76VIC wrote:I really need to get my creative juices flowing and make something [...]
Albert Einstein wrote:Work is 1% inspiration plus 99% transpiration.
;)