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Posted By

gerliczer
on 2015-11-04
03:17:21
 Revival of interesting 'n' funny stuffs

Yesterday I found this. Mesmerising.

Oops, sorry. Link repaired.

Posted By

Chronos
on 2015-11-04
02:33:40
 Re: Revival of interesting 'n' funny stuffs

fix the link pls!

Posted By

Csabo
on 2015-11-04
07:42:19
 Re: Revival of interesting 'n' funny stuffs

TedPlay totally needs this as an option! Also another a boatload of other stuff: display current freq. values, even go as far as translating them to corresponding notes, and displaying the notes being pressed on a piano keyboard.

Posted By

Gaia
on 2015-11-05
13:41:25
 Re: Revival of interesting 'n' funny stuffs

The source is public so everyone's welcome to implement it

Posted By

MMS
on 2016-07-24
14:35:41
 Re: Revival of interesting 'n' funny stuffs

Seems a little off (there will be a new Spectrum Next machine), but surprisingly our machine is mentioned at 3:19 too

https://www.youtube.com/watch?v=HtOsPzwFmeM

Posted By

gerliczer
on 2016-09-08
03:07:00
 Re: Revival of interesting 'n' funny stuffs

Let me recommend you The Warp Zone, if you happen to never heard of them. They make quite decent a capella covers, funny music videos from popular songs' remixes, and part serious, part hilarious sketches.

Posted By

Lavina
on 2016-09-14
02:33:49
 Re: Revival of interesting 'n' funny stuffs

Rátkai István Interjú


EDIT: Warning! the above link points to a site that is in Hungarian. Furthermore, it's an interview about the Hungarian author of Hungarian Adventure games of Hungarian Language. Also, these adventures were originally programmed to Commodore 64 and only converted to Commodore Plus4 after that.

If you are not Hungarian and/or can't read Hungarian and/or don't really care about those legendary Adventure games and/or their Author then don't bother following the above link.

Posted By

czer
on 2016-09-10
07:10:05
 Re: Revival of interesting 'n' funny stuffs

Lavina,

It is probably interesting, but the language barrier makes it less than appealing for most of the site's visitors.

Posted By

gerliczer
on 2016-10-01
03:55:20
 Re: Revival of interesting 'n' funny stuffs

UNCANNY VALLEY

Posted By

Lavina
on 2017-01-29
06:17:14
 Re: Revival of interesting 'n' funny stuffs

Who finds the Easter Egg first? ) I shot this in one of the offices of my workplace.

https://s30.postimg.org/nlfea595d/DSC_0082.jpg


And this one is from Croatia.

Posted By

siz
on 2017-01-29
11:12:44
 Re: Revival of interesting 'n' funny stuffs

Found 'em.

Posted By

Csabo
on 2017-01-29
15:51:14
 Re: Revival of interesting 'n' funny stuffs

The winner is siz, I found them too. The second was obvious This is the perfect opportunity for me to post these then:







Posted By

Lavina
on 2017-01-29
16:59:09
 Re: Revival of interesting 'n' funny stuffs



Actually it was Gerliczer in a pm.

Posted By

Csabo
on 2017-01-29
20:34:16
 Re: Revival of interesting 'n' funny stuffs

Heh, mine must be harder, cause I haven't received any solutions. See, the secret is, if you look at the pictures very carefully, the name of famous Plus/4 sceners can be found on each one!

Posted By

JamesC
on 2017-01-29
21:00:44
 Re: Revival of interesting 'n' funny stuffs

@Csabo - I noticed that in your pictures, but didn't realize it was a "contest". I thought you were simply showing photos. :/

Posted By

Csabo
on 2017-01-30
08:02:11
 Re: Revival of interesting 'n' funny stuffs

It's not, just joking around But at least I hope they fall under the "interesting and/or funny" category.

Posted By

Lavina
on 2017-01-30
13:33:20
 Re: Revival of interesting 'n' funny stuffs

I think this is fun.

Some time ago I saw a Crown Cool logo somewhere on a fridge or freezer (or ice cream machine)

Posted By

gerliczer
on 2017-01-31
11:24:55
 Re: Revival of interesting 'n' funny stuffs

Did you know that two Hungarian guys are working on a SID player with waveconverter for the Enterprise computer?

Posted By

MMS
on 2017-02-27
19:45:45
 Re: Revival of interesting 'n' funny stuffs

Well, I also did not realize there is a need to vote/confirm.
Frankly speaking, all were evident except Lavina's second picture with Korak. Somehow I missed his (?) releases.

OK, an interesting find: in the 2017 John Wick2 there is a Commodore 8bit. Seems not switched on :-)



Posted By

MMS
on 2017-03-19
06:55:50
 Re: Revival of interesting 'n' funny stuffs

Well Istvan did it again

He (with the other guy mentioned too in the link below) programmed a SID emulator on the ZX Spectrum 128 machine playing the native SID musics via AY chip.
(UPDATE: gerlitzer: it is the same engine you mentioned working on Enterprise, but the DAVE chip has 4 independent PCM while AY had no such built-in feature )

https://www.youtube.com/watch?v=Zr1r6FSrsz4

Very faithful sound with no extra HW involved, with only a slight sampling noise.

I suppose it works in the same way as the DigiSID player on Plus/4, and probably the ZX Spectrum had a little more processor power to execute the program than Plus/4 (when srceen is on).
Actually I do not know, how he made it on AY, as it has no real PCM, and the volume control also only 16 resolution, and it should sound worse than a 4bit DAC. But it sounds like a 6 or 7 bit DAC.
Or he may wrote a Viterbi routine to combine the three AY channel into one proper sound frequency?

Anyhow, nice work.

Posted By

MMS
on 2017-03-19
06:49:06
 Re: Revival of interesting 'n' funny stuffs

I just read the last release (#96) of Commodore Free, and checked one of the adverts, justmice.com.
(I had a business with them some years ago, when was looking for Microsoft's RS232 dark blue Home mouse).

Actually it seems they do not sell mouses, but it was interesting, that the Commodore section started with a Plus/4 picture.
Any why it is funny?
Because the mouse is still not fully utilized on our platform (though I found a SID player program that could use an 1351 connected into SID card):


Posted By

gerliczer
on 2017-03-20
14:09:33
 Re: Revival of interesting 'n' funny stuffs

@MMS: IstvanV answered your question in the EP forum:https://enterpriseforever.com/sound/sid-lejatszo/msg62796/#msg62796.

Posted By

MMS
on 2017-03-20
13:00:28
 Re: Revival of interesting 'n' funny stuffs

@gerliczer: thanks for link! Today I was in a hospital, so till I wait, I had some time to read it though.
Well, then the AY 3 channel works like 3 independent 4 bit DAC, and that is pretty nice.
(if you consider, that C64 has one 4bit, and Plus/4 has one 5 bit digi channel with tricks)

So probably thta's why they have better clarity: on Plus/4 we have to force all three SID channels with mixing into one 5bit DAC, while the AY converter has three 4 bit DAC.

OFF
BTW the 8bit DAC idea on Plus/4 User port could not be easier: I just need to modify the ready C64 Digimax circuit's connection to our User port to match to the 8 bit data pins' layout, the rest is the same.
But I found that circuit a little too complex and overdone...
(it uses 4 output IC to create a stereo one, though still the mono would be a challange to get used, even without multiplexed User port data outputs )

ZN428E latched DAC could be a little better than ZN426 resistor ladder, but I am not sure the real benefits, as on all the circuit diagrams put the Enable of the zn428 to ground, so in practice there is no difference to 426E, just more expensive.
(the MSX SCC (Konami Sound Custom Chip) was the same as ZN426E8).

Did I post the one I made 20 years ago for PC? Very small, very cute.
In case of user port even the 5V is avaiable, while on the PC Parallel port you need to get it from somewhere else, like keyboard or RS232 port (I did the later)


Posted By

gerliczer
on 2017-03-20
14:10:27
 Re: Revival of interesting 'n' funny stuffs

@MMS: Could you give a link to that DigiMax expansion you are talking about, please?

Posted By

MMS
on 2017-03-20
16:16:54
 Re: Revival of interesting 'n' funny stuffs

@gerliczer: UPDATE: sorry, I forgot to mention, that the info of the below 8bit DAC came from JamesC in a previous post

I think this is the best summary of the Digimax C64 card, with all the drawing, schematics and how it works in the real life:
https://www.youtube.com/watch?v=Gn1w9tJHtAQ

Actually, there is a C64 MOD player for it, but I hardly believe it would work without a REU or huge extra RAM due to the size of the usual MODs.
(on the other hand our (TLC) SID Digi player output quality could significantly improve if the used DAC has 8 (and not 5) bit final resolution and would make the final processing faster (supposely the internal calcualations done in 8 bit, but in the final step it has to be stretched into 5 bit with lookup tables (as far as I know) )

To play WAVs, the Plus/4 has more processing power than C64 with switched off screen, but frankly speaking it has no real added value :-)

Posted By

IstvanV
on 2017-03-26
10:53:34
 Re: Revival of interesting 'n' funny stuffs

@MMS: The SID player on the Spectrum mixes the three channels (in the range 0 to 63 each) into a single signal, and then it uses table lookup to select the three 4-bit AY volume levels. Because of the non-linearity of the volume control, this method allows for better resolution, but it does also introduce its own kind of distortion, since the volume registers cannot be written at the same time.

By the way, the player has also been ported to the Plus/4 (D64: https://enterpriseforever.com/sound/sid-lejatszo/?action=dlattach;attach=17649, source: https://enterpriseforever.com/sound/sid-lejatszo/?action=dlattach;attach=17650). While there are already similar and not unlikely better players, it might be interesting for comparison with the other versions. This port also has an internal resolution of 6 bits per channel, but the output is converted with a table to TED levels.

Posted By

MMS
on 2017-03-27
18:34:03
 Re: Revival of interesting 'n' funny stuffs

Hi Istvan,

I missed the plus4 version, just read the technical explanation on the ZX version.

I just checked it, and it is awesome; I hear the upper frequencies of the SIDs too
Congratulations, this is a nince achievement!

I dunno how much rastertime it uses up, certainly it should have a cause why you switched off the screen (=more CPU power for the calculations).

Two questions if you still have some time for me:
1) How well it may perform with switched on screen?
UPDATE : I will change it myself in the code, so easy. SORRY :-)

(it could let some re-release to happen, eg. the C64 (or Spectrum) startup screen plus the original SID file can be added to an older Plus/4 release for the startup, if any memory left free)

2) Do you think the 8 bit external DAC would make any difference in the speed of sound transformation?
(I mean if there is no CPU limit, could happen that the internal calculation happens in 8bit, and can be passed directly to 8bit external DAC, or convert (in case on TED available) to 5 bit? )

Posted By

IstvanV
on 2017-03-28
05:56:58
 Re: Revival of interesting 'n' funny stuffs

Hi, if I counted right, the IRQ handler routine currently uses 128 cycles in the best case, and it runs at 11084 Hz. The following can increase the CPU usage:
- crossing the page boundary on wavetable lookup (this happens because of how the PWM effect is implemented for the pulse waveform) may cost up to 3 cycles
- handling video interrupts in the IRQ routine costs 6 cycles, although it is simpler and has lower latency than polling $FF09 in the main program
- the border effect costs 4 cycles
- not using undocumented 6502 opcodes adds 4 or 6 cycles depending on how video interrupts are handled
The version on the D64 was compiled with the slower options, except it does use undocumented opcodes.

So, if we assume 131 cycles per sample (worst case for the fast build), then it can run at about 6.4 kHz on the active part of the screen, maybe with a timer interval of 140 (6.33 kHz) for some safety margin.

Removing the table lookup from the D/A would save 4 cycles with undocumented opcodes, 2 otherwise. The ring modulation effect is only used by some of the tracks, deleting it would save 15 cycles, possibly more if it makes other optimizations possible.

Most of the memory from $0C00 to $F77F is in use, but if the size of the input file is known and not too large, then the buffer reserved for it ($8000-$DEFF) can easily be made shorter. Actually, all the sample files on the D64 are smaller than 16K, and only one needs more than 14K ($8000-$B7FF). Thus, the bitmap data could fit into the area $C000-$DFFF after moving some tables to free the last 256 bytes, and $B800-$BFFF may be available for the attributes. Reducing the number of volume levels at which wavetables are generated from 21 to 15 would free additional 4608 bytes.

Posted By

MMS
on 2017-03-30
06:33:50
 Re: Revival of interesting 'n' funny stuffs

Hi,

many thanks for the details, and the documented source code! I will check it, hopefully I will understand the main parts

Posted By

IstvanV
on 2017-03-29
07:53:14
 Re: Revival of interesting 'n' funny stuffs

For more input files, there is a collection of tunes converted from the HVSC in M64 files part 1-3 here: https://enterpriseforever.com/letoltesek-downloads/egyeb-misc/45/. The same format is supported by sidbasicp4, simply copying the files to the D64 as sidfile1.prg etc. works. The IRQ frequency must be 50 Hz, but other values are rare. The tools that were used for converting from PSID format can be found in the current sidbasic package here: https://enterpriseforever.com/letoltesek-downloads/enterprise-software/15/.

Posted By

IstvanV
on 2017-04-01
06:58:30
 Re: Revival of interesting 'n' funny stuffs

Modified version without blanking the screen:
D64: https://enterpriseforever.com/sound/sid-lejatszo/?action=dlattach;attach=17667
Source: https://enterpriseforever.com/sound/sid-lejatszo/?action=dlattach;attach=17668
This includes all the previously mentioned changes and also a couple of minor fixes that could be applied to the original version as well. The quality is now not quite as good, the sample rate has been reduced to 7151 Hz and there is no ring modulation effect. A simple converted multicolor picture is also loaded and displayed.

Posted By

MMS
on 2017-04-01
11:14:51
 Re: Revival of interesting 'n' funny stuffs

@Istvan,
you are just too kind!

Many thanks! You could be a genie in your previous life. (certainly just kidding)

Evidently the switched off screen version has much more faithful sound (I think that was a kind of breakthrough in my eyes), this version in closer to the usual digi SID player due to the lower sample rate (but easily surpasses the versions made in the 90s). Still shows higher frequencies (with some noise), probably due to conversion method.
Certainly we cannot have everything together. ZX Spectrum's stronger CPU shows the extra power 20-30% in this case.

One question back to the Enterprise version:
what is the added value of the 1 external DAC 8bit channel in case of Enterprise, as the DAVE has independent channels can play 8kHz or 11kHz digi sound?
(or at least Hungarian Wiki states it, while the English does not mention it)

Posted By

IstvanV
on 2017-04-01
11:20:52
 Re: Revival of interesting 'n' funny stuffs

The internal DAC in the Enterprise actually has a resolution of 6 bits per channel, and in practice it is implemented with a simple resistor ladder that can be inaccurate. There are eight 6-bit volume control registers (4 left/4 right), but not all of these can be used for PCM playback, because one of the generators can only output noise. So, the D/A possibilities include:
- only one volume register per stereo channel, this is the "official" D/A mode (disables output from the tone/noise generators)
- high frequency square wave on one or more channels, this allows up to 6 PCM streams in stereo
- one or two sound generators can output a constant logical high level with some tricks, 4 channel playback is possible this way, but without the possible disadvantages of using high frequency square waves
Timer interrupts at a programmable frequency also use one of the tone generators.

There is currently no actual external DAC hardware, although references to one with 4 8-bit channels (2 left/2 right) can be found in an old MOD player, perhaps it was built only as a prototype. Anyway, I added it to my emulator since it is easy to emulate.

Posted By

MMS
on 2017-04-01
17:33:25
 Re: Revival of interesting 'n' funny stuffs

Thanks for the explanation.

Yeah, a mono or stereo 8bit DAC has no real added value to a 4x 6bit channel PCM playback, due to the mixing.
But FOUR 8 bit channels?
Well, I have doubts that even the Enterprise with it's 4MHz Z80 could manage that data stream.
I do remember, how my 286 at 20MHz was suffering when I played a MOD music via my parallel port mono Covox.
And it was under DOS.

Posted By

MMS
on 2017-04-02
17:40:20
 Re: Revival of interesting 'n' funny stuffs

Sorry a completely different topic:

a really hilarous International Karate spinoff video, hopefully you will laugh too
https://www.youtube.com/watch?v=IO5bTdbXZAw&list=WL&index=51

Posted By

Lavina
on 2017-04-07
04:39:31
 Re: Revival of interesting 'n' funny stuffs

wow this is new to me

Commodore_MAX



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