MDCMC - Mono Double Chaos Music Composer

[MDCMC - Mono Double Chaos Music Composer]

Are you aware of CMC DoublePlay made by Greg in the '90s?

[How to run code assembled with Atari Macro Assembler]

18 hours ago, nuadok said:

How did you learn this? 

I learned that in the 80s. There were these excellent books in Polish: "Asembler 6502" by Jan Ruszczyc and four parts of "Mapa pamięci Atari XL/XE".

 

AMAC is not a friendly environment to study the 6502 asm. Try Quick Assembler (QA) instead. It's an IDE. For the start:

 opt 21
 org $600
loop lda $d40b
 sta $d01a
 jmp loop

In the "Setup" menu set the run address to 0600. Then select "Assembly" and "Run". Shift+Break to terminate your program.
 

[How to run code assembled with Atari Macro Assembler]

Apparently, the people here are not familiar with the AMAC syntax.

1. Select a memory location for your program with ORG.
2. Terminate your program somehow (e.g. RTS for return to DOS).
3. Specify the run address as an argument to END.

 ORG $6000
MAIN LDA 710
 STA 712
 LDY #1
 RTS

 END MAIN

This program changes the border color to the background color and returns to DOS.
LDY #1 is not essential. If missing, some DOSes will report an error when they get back control.
 

[question about Gr.10 colors]

Yes, you can safely use the values 9-15 if you need to. Your interpretation is correct and now that we have internal GTIA schematics, we know that this is how it works. Emulators have no problems either.

[Continuous Integration]

You can have Continuous integration for your xasm projects on GitHub.

 

Here's how to setup it:

 

1. Login to Travis CI and opt-in for your project(s).

 

2. "git add" .travis.yml with the configuration and optionally add a badge to README.md.

Here's an example: https://github.com/pfusik/datamatrix6502/commit/0e8737db5568baaf3a5cef411a032ac961ca5fd4
The "script" line contains your build command.
Commit&push and you're done!
 

[Altirra to YouTube quality]

Thanks for upscaling from within Alitrra! That's more convenient than an external recorder or postprocessing.
Are there plans for VirtualDub updates?

[Altirra to YouTube quality]

Thanks!
First I tried to upscale with VirtualDub, but it couldn't open the file ("Couldn't locate decompressor for format 'ZMBV' (unknown)") and I couldn't google the codec.
Then I tried Altirra 3.90 test 20. With 960x720 upscaling it looks much better:
 

 

[Altirra to YouTube quality]

I made a video of my 256-byte intro using Altirra 3.20 and default video recording settings:

 

 

You can see awful compression artifacts. How to avoid them?

[FujiConvert 0.1]

Something's wrong with the RAM option. I convert a ~40 second MP3 changing just the frequency to 15kHz.
The!Cart plays fine, but RAM XEX is trimmed (just the beginning of the audio plays) and with high noises.
I'm testing on Altirra 3.20 XE PAL 320K Rambo and both files are ~230KB.

[Atari graphics viewer for Android/Windows/macOS/Linux/browsers]

My project called Retro Computer Image Library (RECOIL) supports 100+ graphics formats of Atari ST/TT/Falcon, plus 100+ formats of Atari 8-bit, plus 200+ formats of other 8- and 16-bit computers such as Amiga and C64.
Download from http://recoil.sourceforge.net/ or the Android and Windows 10 stores. 

[xasm 3.1.1 released]

Last week I made a minor release of xasm - a 6502 cross-assembler with original syntax extensions, running on Windows, macOS and Linux.
Visit https://github.com/pfusik/xasm for downloads, docs and full source code. 

 

Changes from 3.1.0:

• remove partial object file on error (requested by Bill Kendrick)
• report label name in the unused label warning (requested by Peter Dell)
• support a:/f: modifiers for RUN/INI
• improved performance with network drives (reported by Marek Pavlik)
   

[Play a note via MIDIMATE]

Thanks for clarifying.

[5-color mode with almost no restrictions]

As expected, non-bad lines are affected by ANTIC's 48 bytes of RAM:

[Play a note via MIDIMATE]

I'm confused because you just contradicted your previous post: "The motor control is only used to gate the external clock".

[5-color mode with almost no restrictions]

The shape of the triangle is not helpful in determining if it's an OR or a full load. But with the inverse logic happening afterwards, it's not an AND.

[5-color mode with almost no restrictions]

Shift data may be a problem. The playfield shift register already runs at maximum speed in ANTIC 4 so doubling the fetch rate won't speed up the shifter; this means that it will only get a chance to shift out four bits before it is reloaded again. Tests I did years ago suggested that when this happens the new byte is merged into the shift register similarly to when players are reloaded. Since the playfield shifts out bits MSB first, this will cause bit 7 from the name to merge with the character data. I don't remember offhand if the effective result is an AND or an OR.

Take a look at the 4-pixel wide right-pointing triangles:

Is inverse video applied on the shift register output or the load value?

[Play a note via MIDIMATE]

In this case I would expect Altirra to accept MIDI commands sent with AUDF=$15 and no motor signal. I'm using Altirra 2.99-test24.

[Play a note via MIDIMATE]

So it's for a regular tape recorder?

Regarding the motor control signal: should there be a delay between activating it and starting to send? If so, how long? Should I turn it off after I send all the notes?

[Play a note via MIDIMATE]

Audio tape? Where do you put it?

[Play a note via MIDIMATE]

Thank you.

[Play a note via MIDIMATE]

I confirm that Altirra 2.99-test24 doesn't require the padding byte.

What's the use of SYNC input? SIO INTERRUPT is a PIA IRQ?

I think that MIDI devices have to sync on the start bit, otherwise they could be probing at the signal edges. And the clocks aren't probably perfect.

Thanks for pointing out the problems with analog distortions and awaiting completion.

More complicated example, those bytes: 0x90 0xfa 0x41 0x00 0x43 0xfc 0x00 are really four messages

midiOutShortMsg(out, 0xfa);

midiOutShortMsg(out, 0x4190);

midiOutShortMsg(out, 0xfc);

midiOutShortMsg(out, 0x43);

 

Messages 0xfa and 0xfc are MIDI real-time messages they can be interspersed with any other message and they don't cancel running status.

Doesn't 0x43 have the implicit command 0x90? If so, why is it reordered with 0xfc?

[HCM & HARDBASS tools]

 

I attached the example files I'm going to try your viewer with. It's a mix of HCM Mode 0 and Mode 2 pics.

 

hcmpics.zip

Thanks, I already found them in your repo. I updated the HTML5 viewer, so you can try it: http://recoil.sourceforge.net/html5recoil.html

[HCM & HARDBASS tools]

 

WOW, you're fast! Thank you, I'll check it out on Win 10.

Either build from Git or wait for a release.

[Play a note via MIDIMATE]

Thank you! It works.

 

I noticed that MIDI Sequencer by Maciej Sygit uses the $15 divisor. The difference seem small enough to transmit one byte if the MIDI device synchronizes on every start bit - does it? Is the 4MHz/128 clock internal to MIDIMATE? I don't know what's inside MIDIMATE, but I know that in the '90s people used a simple "wires-only" SIO-MIDI interface.

 

The minimum set of changes was: motor on, a padding byte and waiting for transmission to complete:

	org	$6000
main
	sei
	mva	#$34	^32	; motor on
	ldy	#7
	lda	#0
	sta:rpl	^20,y-
	mva	#$28	^28
	mva	#$15	^24
	mva	#$23	^2f

	mva	#0	^2e
	mva	#$10	^2e
	mvx	#$c0	^2d
	ldx	#$01	; instrument
	jsr	send
	ldx	#$00	; padding needed for Altirra
	jsr	send

	ldx	#$90
	jsr	send
	ldx	#$3c	; middle C
	jsr	send
	ldx	#$7f
	jsr	send

	lda	#8
	and:rne	^2e	; wait for transmission complete

	mva	#3	^2f
	mva	$10	^2e
	cli
	rts

send
	lda	#$10
	and:rne	^2e
	sta	^2e
	mva	#$10	^2e
	stx	^2d
	rts

	run	main
	end

[HCM & HARDBASS tools]

I have added HCM to http://recoil.sourceforge.net/