Colecovision Module

Discuss computers from the Laser series, Time & Fun handhelds, etc.
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MADrigal
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Colecovision Module

Post by MADrigal » Wed Nov 21, 2018 10:28 am

Hi all
After years and years of searching, I finally had the opportunity to buy a 'Salora Manager - Expansion Module 1' that is the one that allows playing ColecoVision games on the Laser 2001 and Salora Manager.
The item was purchased thanks to the help of a Finnish friend, Jarkko, who also kindly tested it on his Salora Manager soon after the purchase.
Unfortunately the item was faulty, so it was sent to Thomas (Scouter3D) for investigation and repair.
Thomas has done quite a few great findings on this particular unit
1. the unit is powered by the Manager computer, however it was originally designed to work with an external power supply. There is a cut trace in the PCB, that demonstrates that the PCB was originally designed not to get power from its connector cable (that is the Manager Expansion Port), but from a jack on its side. After some research, we believe that this is the result of the PCB being designed originally to work on the CreatiVision Mk2 (which does not provide enough power from the cartridge connector, and therefore the module would have needed additional power from an external power supply)
2. by soldering this trace back, it is now possible to use an external power supply. Tom was kind enough to add a jumper to this 'cut' trace, so now I can select whether I want to use the original power (from the Manager), or the external power supply (in case the module is connected to a CreatiVision Mk2)
3. the item definitely was not designed to work on the first model of the CreatiVision. After doing some reverse-engineering, myself and Tom can now confirm that the item was designed to work on the CreatiVision Mk2, and the Mk2 was very likely designed specifically for this purpose. The Mk1 in fact does not have enough signals to allow for the module to work
4. the module has its own BIOS. The BIOS is NOT the original ColecoVision BIOS, it is custom! It shows a welcome message reading 'Laser 2001' and either 'switch off, insert cartridge and restart' or the welcome message of the ColecoVision game, if it is inserted. The BIOS is 8K, like the one of ColecoVision. I suspect it is a modified version of it, I look forward to dump it
5. the module has 2K of RAM. The original ColecoVision uses 1K of RAM, it is not yet clear why the module has double the needed RAM.
6. the module obviously has a Z80, as you know the module replicates a ColecoVision and uses parts of the Salora Manager (namely, all the video circuitry) whereas the 6502 in the computer is disabled when the Z80 is in action
7. unexpectedly, the module has a sound chip - identical to the one in the Laser 2001/Manager. So why is there such 'duplicate'? Because the sound chip in the computer cannot be connected to the module. So the module uses its own chip. The signal is then brought out back into the console and then the RF modulator
8. the video chip and RAM of the computer is 'shared' with the module, basically it is the only shared thing!
9. the module allows use of 2x standard 'Atari'-compatible joysticks via 9-pin ports. However its PCB also have space and traces for 2 connectors, that look EXACTLY like the CreatiVision ones! This also seems to confirm that the module was originally intended for use with the Cv Mk2!
10. the BIOS reads 'Laser 2001' in its welcome message, although the module is the Salora Manager model. AFAIK the Laser 2001 version of this module was never released.

See attached photos of the unit and diagrams prepared by Thomas.

The unit will shortly be sent to me and I will attempt to design an interface to make it possible to use it on a real CreatiVision Mk2!

*** I WISH TO EXPRESS MY GRATITUDE TO JARKKO AND THOMAS FOR THEIR PRECIOUS HELP!!! ****

ENJOY THE PHOTOS!
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carlsson
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Re: Colecovision Module

Post by carlsson » Wed Nov 21, 2018 11:01 am

Great write-up!

I'm forgetting, do the Salora branded game cartridges say Manager somewhere on the screen instead of Laser 2001 or CreatiVision? From what I understand, quite a bit of the interior electronics in Salora products were manufactured elsewhere (e.g. Siemens, Luxor) and possibly just assembled at Salora but I may have been misinformed here. If however that was the case, it would make perfect sense if VTech supplied the interior electronics and Salora just putting it together, not able to reprogram any ROMs or other modifications.
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MADrigal
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Re: Colecovision Module

Post by MADrigal » Wed Nov 21, 2018 11:06 am

The Laser 2001 and Manager versions of the games are exactly the same ROMs as the CreatiVision games. Not a single different byte.
As per the manufacturing process of the Manager, I am reasonably sure it was 100% made by VTech in HK, and Salora just provided the brand.
The Manager PCB and box were definitely produced in HK, and also the BIOS is almost identical to that of the Laser 2001, except a very few routines, making it a sort of 'revision' of the Laser 2001 BIOS.
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Re: Colecovision Module

Post by @username@ » Wed Nov 21, 2018 5:41 pm

Nice article - congrats all round!

Looking forward to the BIOS dump :)
˙uʍop-ǝpısdn sı ɹoʇıuoɯ ɹnoʎ 'sıɥʇ pɐǝɹ uɐɔ noʎ ɟı

The creatiVision Emulator 16.04.24
Salora Manager / Laser 2001 BLOAD utility 0.9
CSL Cartridge middleware
http://sourceforge.net/projects/creativisionemulator
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MADrigal
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Re: Colecovision Module

Post by MADrigal » Thu Nov 22, 2018 7:37 am

I will try my best to dump the BIOS asap
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