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Also sold my Philips MSX CD-rom player together with the original Philips MSX cds. Too bad, this prototype of the first CD-Rom player in the world (1982) would be a nice to have nowadays.

O.o
What Quibus said, but then repeated ten times!
o.O
I hope you didn't sell it to some dumb collector...

The Philips CD-ROM prototype was just mentioned on #msxdev (@ irc.rizon.net) yesterday.

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But, who are you actually ? I am quite bad in names, but might remember you.

I'm Patriek Lesparre, we talked a few times. I think you might've even logged in on TNI BBS.

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I'm Patriek Lesparre, we talked a few times. I think you might've even logged in on TNI BBS.

I did a few times... Remember them marble pics? They ended up on FD29 Never got round to making SS DejaVu tho... Too bad, even had basics of the RPG engine down... I remember logging in from time to time tho... I think there were like 7 users... Which I guess was more than the internet had in those days

About the CD player: It came with a SCSI/SASI interface (NMS 00xx) for MSX2 and a black no label SASI interface for MSX1. And a 43 cm CDRom player P1000X. On the bottom of the player it said "prototype". It came with usermanual which listed all SCSI commands and the following CDs:
- ALH Routeplanner Netherlands
- Philips MSX2 Demo disc:
- Philips Demo Disc (CD-Single)

The player itself was dated 1982, but I think the software is more recent, because of the MSX2 demo disc, which must be 1984 or later.

SASI seemed to be a predecessor of SCSI and was largely compatible.

The CD rom player had no audio output and supported data type cd-roms only (ISO9660 format).

I bought all stuff once from an ex-Philips employee

I sold it to an (ex-) employee of Sunrise Netherlands, but don't remember his name.

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>>I'm Patriek Lesparre, we talked a few times. I think you might've even logged in on TNI BBS. << *cut* I remember logging in from time to time tho... I think there were like 7 users... Which I guess was more than the internet had in those days

Yeah, I know... I recently found some old messages by you from the message boards
Actually IIRC, TNI BBS had +/-100 visitors, but not all of them posted on the message boards ofcourse.

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About the CD player: It came with a SCSI/SASI interface (NMS 00xx) for MSX2

For the record: you don't remember the full product code?

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- ALH Routeplanner Netherlands - Philips MSX2 Demo disc: - Philips Demo Disc (CD-Single)

So, what did this software do? The demo discs, I mean
Did it work nicely?

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I sold it to an (ex-) employee of Sunrise Netherlands, but don't remember his name.

Do you mean the Sunrise Foundation? The current Dutch members are Rob Hiep and Koen van Hartingsveld, AFAIK. When did you sell it? (Might help me to pinpoint the person...)
Other ex-Sunrise people: Kasper Souren, Stefan Boer, Rob Augusteijn (SHS), Tim Brugman (SHS) and there are many more related guys like Remco Schrijvers.
By the way: I don't know who of these people were actually part of Sunrise and when. It's just that one of them may be the person you sold that CD-ROM stuff to

Have been digging in my MSX archive this afternoon. Found the following info on the CD player:

- "Philips CD-Rom Interface NMS 0210"
- CD Rom player: CDR-X 1000

The software was not very spectaculair, just the usual Philips demo's.
The ALH routeplanner was nice ! Netherlands map included, worked just like current alh.nl

I must say, I don't remember the name of this guy, but I know part of the deal was trading it in for a SCSI cd-rom drive with audio output.

I can make a scan of the black/white pictures I have from the interface and player ? Just let me know.

Welcome to the MRC, Michel!

A scan would be very nice indeed. And.. be honest.. how many times have you cursed yourself for making that deal?

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A scan would be very nice indeed. And.. be honest.. how many times have you cursed yourself for making that deal?

Well, I am still sorry for it today...

Anyway, I've put 2 scans on my website, note that the original pictures have been made 12 years ago ! So, don't complain about the quality.

www.denwa.nl/images/MSXCD1.jpg
www.denwa.nl/images/MSXCD2.jpg

These links are fullscreen and 512 kB each.

This time, I'll capture this topic back!

It seems, that I messed up SCC and PSG volumes back in the previous post (22.7.2003). So it was PSG that was logarithmic... So... The idea above works for SCC (I think!)

If this volume = 2^-((15-n)/2) is correct for PSG there are plenty of possibilitys to make sample playback tables. Here are two examples of lo-volume 3bit sample playback tables. They are both easy update quite a much larger to gain more volume and accuracy:

PSG Channel
ALT 1   ALT 2
A B C   A B C
-----------------
1 1 1   0 0 0  =0
3 0 0   1 1 0  =1
3 1 1   2 1 0  =2
4 1 0   3 1 0  =3
3 3 1   3 2 0  =4
4 2 0   3 3 0  =5
3 3 3   3 3 2  =6
5 1 0   5 2 1  =7

I think, that these tables are actually "too accurate". To get best possible result I think that table up to 10bits should be calculated and then estimate good amount of playback bits and cut part of upper and lower bits away of the table.

@NYYRIKKI
do not run too fast :-)
There are better strategies.

One of them is to use successive refinements in quantization.

The basic idea is
quantize a sample x using single channel, play it on ch A
compute the quantization error y = x - Q(x) and quantize it, play the error on ch B
compute the new quantization error y = x - Q(x) - Q (x - Q(x) ) and play it on C

You'll see soon more details on Grau's website
AR

Hmm... Is it always the closest possible solution when biggest possible number is selected first?

Right . Check out the MSX Assembly Page now. It explains about 8-bit samples, with the help of ARTRAG.

~Grauw

Very interesting table... too bad, I don't read C in any form...

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there are only 19 deviations past a certain threshold

Did you calculate what is the error %?
Did you test, do you get any better results, if you try to add for example sqrt(2) or 0.5 to every sample value?

I just noticed, that there is "DB" in front of table rows... that should be "DW"

Here is (untested) example routine, that plays sample using that table:

; 	HL	= SAMPLE TO PLAY (8bit unsigned)
;	DE	= LENGHT TO PLAY
;	TABLE	= ADDRESS OF SAMPLE TABLE
;	RATE	= DELAY BETWEEN SAMPLES
;
	LD C,#A1

LOOP:
	PUSH DE
	PUSH HL
	LD DE,TABLE
	LD A,8
	LD L,(HL)
	LD H,0
	ADD HL,HL
	ADD HL,DE
	RLD
	LD D,A
	RLD
	LD E,A
	RLD
	INC HL
	LD B,(HL)
	OUT (#A0),A
	INC A
	OUT (C),B
	OUT (#A0),A
	OUT (C),D
	INC A
	OUT (#A0),A
	OUT (C),E
	POP HL
	INC HL

	LD B,RATE
DELAY:
	DJNZ DELAY

	POP DE
	DEC DE
	LD A,D
	OR E
	JP NZ,LOOP
	RET

Ps. This works only, if table is in RAM

Ah, DW, hehe . Corrected it.

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Did you calculate what is the error %?

No, not really... I think I still need to improve it a little, because the means to determine the best set is still sub-optimal.

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Did you test, do you get any better results, if you try to add for example sqrt(2) or 0.5 to every sample value?

No... How would that improve results? The PSG has the most accuracy in the lower areas (due to its logarithmic scale).


~Grauw