Search found 99 matches

by Euphoric
Thu Jan 26, 2006 6:35 pm
Forum: General Discussion
Topic: here I am
Replies: 5
Views: 8462

but somethng which has been very time consuming is this:
Wow ! Two at once, I understand it is time consuming !!
Congratulations, Romuald ! (and congratulations to the mother too !)

On the other hand, you can say it's the most efficient way to have children ! :-)

Cheers,

Fabrice
by Euphoric
Tue Jan 24, 2006 10:12 am
Forum: Tape and floppy disk converters
Topic: Disk tools.
Replies: 6
Views: 14100

I have just put NIBBLE.zip in http://oric.free.fr/DISKS

Cheers,

Fabrice

PS: I don't recommend BDDISK, I think I only used it once and damaged a disk with it...
by Euphoric
Tue Jan 24, 2006 10:04 am
Forum: 6502 assembly coding
Topic: IRQ interupt
Replies: 23
Views: 36651

Par contre je ne suis par sur que 19968 soit la meilleur valeur. Anyway I am not sure that 19968 is the best possible value. 19968 = 64*312 is the precise number of cycles of the screen raster. However, to get an interrupt every 19968 cycles, you must program the VIA timer with a value of 19966, be...
by Euphoric
Mon Jan 23, 2006 12:07 pm
Forum: AY sound chip
Topic: AY Crudentials: 4 Bit Samples
Replies: 7
Views: 17531

Of course changing the IRQ adress itself takes time, but we solved the problem by just using INC and DEC on the high byte of the adress
Very clever !!
I can't see a faster way, except without using interrupts of course...
by Euphoric
Mon Jan 23, 2006 12:04 pm
Forum: AY sound chip
Topic: AY Crudentials: 2 Bit Samples
Replies: 3
Views: 11191

What about using some sort of ADPCM coding to keep a higher resolution of samples, and still use only 2 bits per sample ?

Cheers,

Fabrice
by Euphoric
Mon Jan 23, 2006 11:59 am
Forum: AY sound chip
Topic: AY Crudentials: 8 Bit Samples
Replies: 4
Views: 12579

Hello Jon, are you sure of that ? I would have imagined that two channels would produce a louder sound that a single one (more decibels)... How have you get this value of "between 6 and 7" ? By hearing the two cases one after the other ? Or with an oscilloscope ? If you are right, I might have to ch...
by Euphoric
Mon Jan 23, 2006 11:48 am
Forum: 6502 assembly coding
Topic: IRQ interupt
Replies: 23
Views: 36651

Salut, une IRQ c'est une interruption matérielle, donc normalement ça ne se génère pas de façon logicielle... Sur le 6502, on peut toutefois utiliser l'instruction BRK, qui simule "presque" l'apparition d'une IRQ (la différence est minime: un bit est différent dans les flags sauvés sur la pile). Mai...
by Euphoric
Fri Jan 20, 2006 5:48 pm
Forum: Operating systems, utilities and other serious software
Topic: Contiki on Oric Atmos?
Replies: 13
Views: 26694

Here is a rough memory map for the Oric: page 0: variables, pointers, etc. used by the Microsoft Basic core page 1: stack (you knew) page 2: variables used by Tangerine's extensions to the Basic kernel page 3: I/O page (hardware) page 4: free if no disk controller is present, otherwise contains rout...
by Euphoric
Tue Jan 17, 2006 10:58 am
Forum: Games
Topic: Lode Runner thoughts
Replies: 17
Views: 36923

A real company still selling games for the Intellivision nowadays ?? Astonishing ! :-)
by Euphoric
Tue Jan 17, 2006 10:37 am
Forum: Audio tools
Topic: MYM Player
Replies: 7
Views: 18564

And MSX, ZX and CPC have the Z80 processor in common, so any music formats developed natively on these computers would still not work on the 6502 Oric without a Z80 emulator. I've done some work on emulating the 8080 and the Z80 on 6502 and 65816 cpus... I wanted to emulate some classic arcade game...
by Euphoric
Sat Jan 14, 2006 10:53 am
Forum: Games
Topic: Lode Runner thoughts
Replies: 17
Views: 36923

Hello Simon, yeap we are talking about a really faithful Lode Runner version... From memory, the version you are refering too is a text version (with the character jumping six-pixels at each move)... I think it was written by François Schuller... It's nice, but it doesn't behave like the original ve...
by Euphoric
Fri Jan 13, 2006 5:42 pm
Forum: Audio tools
Topic: Your AY playroutine Mike :)
Replies: 13
Views: 23740

Nice to see we are beginning to convert a VIC-20 to the Oric
I meant "a VIC-20 fan/supporter", you guessed it... :-)
by Euphoric
Fri Jan 13, 2006 5:41 pm
Forum: Audio tools
Topic: Your AY playroutine Mike :)
Replies: 13
Views: 23740

Hello Anders, is this a recent photograph of you, or are trying to have us believe you're that young ;-)

Nice to see we are beginning to convert a VIC-20 to the Oric :-D
Do you have an Atmos ? I could try to repair one of those faulty Atmos'es I have here and send one to you...

Cheers,

Fabrice
by Euphoric
Fri Jan 13, 2006 5:35 pm
Forum: 6502 assembly coding
Topic: Size optimisation: Compact subroutines
Replies: 6
Views: 11395

- Is it safe to write a value in $245/$246 without disabling the interuptions ? Is there no chance that some interrupts will be called in between the STA and the STY ? Taken out of context, you're right, there's absolutely a chance that an interrupt happens between the STA/STY (let's say, one chanc...
by Euphoric
Thu Jan 12, 2006 6:52 pm
Forum: 6502 assembly coding
Topic: Size optimisation: Compact subroutines
Replies: 6
Views: 11395

In Cube, I had so many calls to the "string display routine" that I indeed use BRK to display messages. At first, I used BRK #n to display message number n, which took only 2 bytes. Using a single byte to refer to a message allows to gain one byte compared to passing the message address. However, I ...