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Any info on Video Technology Laser 500 computer?

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Please prior to sending me any pictures, send me an email.

 

I will then reply and include a "how-to" and a couple of nice pictures I shot/I got from contributors, which you can use as "examples".

 

I dont want you to waste your time taking pics which I won't be able to use. :)

 

As for the code, if your box is complete, it's printed on one of the internal flaps. This is typical for every item printed at VTech's.

 

Thanks :)

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Sure thing ;) I'll try to get a better camera. My phone is fine, but not very excellent for taking close shots, as there is no way to get it to focus where you want it and no white balance control.

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The label on your 500 even says VTCL while it should be VTL or perhaps VTech.

 

Anyway, so you've got a demo tape which means at least there is some ready-made software out there, even if the games are crude. You know in the land of the blind, the one-eyed is king.

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Yep. I'm going to plug that in the computer and capture the audio, if my stupid crappy sound card allow it. Or I'll transfer it on MiniDisc, so I could share it eventually.

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Hi guys,

 

I just found one of these babies at a fleamarket it is a Laser 700. It seems to have more connectors then the 500 including a floppy drive connector. There are still ports unused. I sad that I can find zero info on the web about this computer. This thread seems about the most informative thing out there. We now at least one more guy is looking for games!

 

Does anybody now how to make an rgb scart cable for this thing ?I tried my spectrum 128 cable and that gives a dodgy image I'm thinking it won't go in deep enough, my commodore 64 cable seems to give the colours wrong I get green and black .

 

BTW I typed in a hello world in basic and my god is the keybord so unresponsive, is it the case for all LAser computers?

 

Belgium keyboards are always Azerty.

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How "unresponsive" it is?

I tried both Laser I have and while it's not the best keyboards around, they work.

Maybe yours need some cleaning.

I think the RGB is the same than on Philips Videopac+ and Philips MSX.

Anyway you don't put your TV at risk with trying of you know how to do some basic soldering.

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The L700 was the more powerful version, at the time we heard about it but the only unit around was the 500. Yes, the keyboard has a very bad touch and looks so plastic-cheapo.

 

As for the video cable, the L500 had a very clean video composite output (I remember working in 80-column mode for BASIC editing), so I guess you can build a scart cable for it. Perhaps there are connectors/adapters already made (from video composite to scart).

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FWIW the ZX Spectrum 128 outputs TTL RGBI, so if you've got a SCART cable it probably contains some resistors acting like voltage dividers. The C64 outputs S-Video, and not all pins are used, so trying to use it as a RGB cable probably will be a bit of hit and miss. I don't know if a MSX RGB cable would work, but it is worth a try.

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Thanks for the reply guys. My sony MSX rbg cble doesn't work so I assume it has a different pin-out. I just discovered the composite out :). It is okay but I still want my rgb goodness. Anybody now the pinout so I can solder up my own cable?

 

By the way, is the tape-in standard or does it use some sort of special cable? How can you record to tape as it has only on plug.

 

The keyboard works but it seems there is some lag whilst typing or that you have to press down the buttons really long for it to correspond to the screen.

My PSU also hums like crazy.

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according to my wikipedian knowledge, the scart pin #20 is for video composite, but instead of messing with soldering I would use a RCA to scart adapter and connect it in the yellow plug.

 

The keyboard should show no lag, it has a bad touch yes, but no lag.

 

As for the tape, it's a standard audio jack plug (mono). I remember once we did a simple experiment by CSAVEing a program on my L500 and CLOADing it on a remote L500 located in another apartment on another floor. The two Lasers were connected by a very long twister pair telephone cable with mono audio jacks at the ends. The program loaded correctly at first attempt. Later we used that long cable to send L500 composite video signal output, so that when I was editing a BASIC program, my friend could see it in his monitor in his house. We then improved this system by having other two twisted pairs running from his house to mine and using Laser 500 tape recorder as microphone/amplifier for the voice. It was 1987 and we had invented both Skype and Teamviewer!

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But i don't want composite out. I want rgb out. So I need to find the pinout for the rgb port.

 

That is an amazing story. And really smart of you guys! So you can load and save through the same audio jack! Did you have to switch the cable on the audio tape player then?

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I have two Laser at home. It feel Vtech used the same pinout on all of their comps, so I'll check my SCARt cable and tell you what the pinout is.

But I can't do that befoer the end of month.

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as far I can remeber, CLOAD and CSAVE was done on the same audio jack, but honestly we didn't used it much on the 500 because we all had disk drives.

 

Regarding the magazine scans, I'm scanning the three issues I have in my possession and submitting to a retrocomputing website for publishing. I'll post a link when the work is done.

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in this video you can clearly see what I was telling some posts ago: text is printed SLOWLY while in graphic mode because they used a set of DRAW commands that were previously manually encoded. This because the charset was not available -- it was not stored in the ROM (as in commodores) but in the video chip directly. So we had this basic subroutine we GOSUBed when we needed to print text in graphic modes. That's just one of the oddities of the Laser computer family.

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The Apple ][ was the same way.

But Apple II shape tables were faster than that.

 

Not many machines had commands for drawing text on a raster graphic display.

 

The DRAW command on the CoCo was sort of an updated version of shape tables that used strings to hold the shape data which was a lot more useful and they were much faster than that video. The CoCo 3 added a command for printing bitmapped text on the graphics screen and it was pretty fast.

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I suppose DRAW on a CoCo worked like GW-BASIC?

 

Of course, with the Apple ][ you could write a machine code function to plot text on the HGR screen and then hook the read/write hooks, making it transparent to the user. Prolly couldn't do that on a Laser 500.

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The ZX Spectrum entirely operates in high resolution mode. All text is plotted to screen, and much faster than the Laser in the picture. Both being Z80 systems at similar speeds, but of course the surrounding graphics circuitry, how the CPU can address the graphics and in particular how the implementation was made will depend on the outcome.

 

Does this machine have a VRAM similar to TI VDP based machines where you can load a custom character set into its memory, or are you limited to text mode with built-in character set plus a high resolution mode?

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Text modes had builtin characters stored in the video chip ROM that were unreadable by the user, e.g. for plotting in one of the graphic modes. That's why they had the infamous DRAW subroutine. The reason why they did not use ML instead of a BASIC subroutine most likely is because they wanted to stay with BASIC at first, but later that became a sort of "standard" and the subroutine became embedded in all programs.

 

Of course having ML would have been much faster, but more complex because but you had to embed the character table anyway. At the end of the Laser age, even myself managed to write some ML code for drawing bitmaps and sprites (it was a Z80 after all), but sadly it was too late--the computer school that gave us all the hardware went out of business and even the magazine ceased to be printed.

 

Other details I remember about the "DRAW subroutine" are: we obtained it by listing a program called "Magic Paint", I don't know who wrote it, but it must have been someone of the Laser designer team because the charset reflected exactly the one displayed by the video chip.

 

"Magic Paint" was a painting program that was also sold on tape, but was mainly a tool for writing graphics for games. Indeed after "magic paint" appeared on the scene, several nice-looking games were crafted and started to be sold. "Magic paint" was written in BASIC but had a ML routine for loading and saving the bitmap from/to RAM. We later found the same routine in all the nice-looking games. I remember we did a big work extending "magic paint" adding lot of painting tools (like the "fill" function that was not available in BASIC) to the point that our modded version of paint became our main application. We had dozen of disks with pictures manually drawn with that program.

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I suppose DRAW on a CoCo worked like GW-BASIC?

 

Of course, with the Apple ][ you could write a machine code function to plot text on the HGR screen and then hook the read/write hooks, making it transparent to the user. Prolly couldn't do that on a Laser 500.

GW-BASIC was pretty much identical to Extended Color BASIC. Porting programs between the machines was fairly easy.

 

Beagle Brothers sold several Apple II programs related to this. First a program to build shape tables which I think included an example that drew text (that *may* have come from a user group later) and later a program that printed text from the standard text screen on the HGR screen pretty much like you suggest.

 

COMPUTE! magazine was famous (notorious?) for making games using printable characters and custom character sets. To make supporting Apple II ports easier, one of their Apple II developers created a bitmapped font editor and bitmapped text drawing routines in machine language. If I remember right, it was used by several game ports once it was published. I think it used the CALL function.

 

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Beagle Brothers sold several Apple II programs related to this. First a program to build shape tables which I think included an example that drew text (that *may* have come from a user group later) and later a program that printed text from the standard text screen on the HGR screen pretty much like you suggest.

Apple Mechanic, I think, might have been the former example?

 

Flex Type was the latter program. Apple themselves made such a program too which was pretty commonly used (Shifty Sam and Word Attack, for example, used it; it was called HRCG).

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The ZX Spectrum entirely operates in high resolution mode. All text is plotted to screen, and much faster than the Laser in the picture. Both being Z80 systems at similar speeds, but of course the surrounding graphics circuitry, how the CPU can address the graphics and in particular how the implementation was made will depend on the outcome.

 

Does this machine have a VRAM similar to TI VDP based machines where you can load a custom character set into its memory, or are you limited to text mode with built-in character set plus a high resolution mode?

The Speccy print routine was in machine language and uses bitmapped fonts rather than drawing characters by drawing lines like the DRAW command.

 

You can actually find a faster font routine than the Spectrum ROM routine over on the World of Spectrum forum.

I created versions of that for the MC-10 and VZ200, both of which need hardware mods to actually use the 6847's hi-res graphics.

I posted the code on the yahoo groups but I've never seen the code used.

It should be portable to the Laser but it's only fast if the video RAM is memory mapped off of the CPU. Machines like the TI and ADAM would have performance issues.

 

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