First of all i have to thank Ralf Schmitz for this gift. (Grazie Ralf).

Short description taken directly from Wikipedia of the Saba Videoplay console (Fairchild Channel F):

The Fairchild Channel F, short for “Channel Fun”, is a video game console, the first to be based on a microprocessor and to use ROM cartridges (branded ‘Videocarts’) instead of having games built-in. It was released by Fairchild Camera and Instrument in November 1976 across North America at a retail price of US$169.95 (equivalent to $910 in 2023)

The console come in a fair state of preservation but still had the following problems:

• Broken reset button.
• Both joysticks did not work properly.
• A small part of the corner of the PCB of the power switch side was broken.
• Rough repair with adhesive tape of the cable of both joysticks.

The repair was quite simple but boring, fixing the joystick cable was not exactly fun, i had to cut the cable because one or more wires inside are broken, i also had to invent a cable gland for a missing joystick and drill a cable gland with the broken cable right inside to then insert the cutted cable and solder the wires inside the joystick. (see photo)

The reset button was enough to glue it. (see photo)

I polished the console case that had the classic matte and dry black color of 70s plastics with linseed oil, a little is enough on a makeup remover PAD or a cotton rag, the result is amazing.

For completeness i also installed the e5frog composite video modification that works well, i only had to bring an auxiliary ground (although the ground of the negative power supply is already connected) from the PCB to the metal body (see photo) because it gave me video noise, now it’s perfect.

Below the photo gallery:

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I purchased the Texas Instruments Grillo Parlante Più (Super Speak & Spell) for a few euros and fully aware that the contact plates for the batteries due to an acid leak has been destroyed (see photo).

After testing it if actually still worked, i did a good cleaning of the battery compartment, body and display.

I replaced the contact plates for the batteries with similar ones recovered from an old dead and defunct cassette recorder.

The final result is perfect, it looks like the original, even better because i put the battery negative spring in the correct side, the original has the springs all on one side, both for the positive and negative of the battery.

Gallery of work done:

Video:

First of all, i thank my friend who gave me his Sega SC-3000 found in the attic.

After a thorough cleaning of the cartridge connector, keyboard contacts and general cleaning of the internal/external case, the computer started working perfectly again.

Gallery:

I have nothing else to say except that i miss the old days. :’(

Brazilian Odyssey 2 (Philips Videopac+ G7400) Games:

• 06 AV 9448 Serpente do Poder! Translation: “Power Snake!”
• 06 AV 9475 Comando Noturno! Translation: “Night Commando!”

source: the-nextlevel.com/odyssey2/faq/brazil/

Some time has passed since the last and useless purchase and like the previous ones there is little to say all the “mini” are practically identical, change the external box, the menu and some chips inside that for the occasion are the latest version (more or less).

I used a very lame HDMI to Composite Video converter to try it with a CRT monitor.

Gallery:

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Against all trends, a simple photo without unboxing.

Bildschirmtext (Btx) was a German online service that existed from 1983 to 2001.

To use the service with a C64, this decoder cartridge was required, which connected to the expansion port.

The cartridge is actually a Siemens product, it’s just Commodore-branded.

The sticker says:

• SIEMENS
• Universal Btx Decoder
• S30817-S721-B101-7/02 EX/W8
• A30817-X732-B100-4-11
• Commodore Artikel Nr. 606491

The box with the Deutsche Bundespost logo is the registration (A506 131V). At the time, only explicitly Post-approved devices and software were allowed to be used for participating in Bildschirmtext.

(This is the “Btx Decoder Modul II”, even though the cartridge doesn’t say so. There was a completely different first model.)

There are three DIN ports at the back, from left to right:

• Modem: This connects to the proprietary Deutsche Bundespost “DBT-03” modem (1200 baud down, 75 baud up).
• RGB: This is for connecting an analog RGB monitor.
• FBAS: This port is identical to the C64 video port and allows using a C64 monitor.

The Post-approval for participating in Bildschirmtext required the decoder to be able to show a pixel-exact image of the service (480×240 pixels with 32 out of 4096 colors)1. Since the VIC-II in the C64 could not meet this, the decoder cartridge had its own video controller and therefore its own video ports.

The board reveals that the cartridge doesn’t only have its own video chip, it also has its own CPU, RAM and ROM – it’s a complete computer that only connects to the C64 in order to reuse the keyboard and the disk drive.

These are the major chips:

• Motorola MC6803: a 6800-family microcontroller
• Motorola MC68HC34: Dual-Port Memory Unit
• 64 KB RAM (two 41464 64Kx4 DRAM)
• 32 KB EPROM
• D65040GF206: NEC µPD65000 series CMOS gate array

The communication with the modem, the decoding of the CEPT data stream and the interaction with the Btx service are handled by 6800 CPU and the software in the EPROM.

I am assuming the software writes the RGB values of every single scanline into the dual-port memory in real-time, which the gate array then reads to generate the video signal – like on the Atari VCS and the Sinclair ZX81. This keeps the complexity of the video hardware minimal.

The chipset and the firmware are probably very similar to the technology used in dedicated Bildschirmtext terminals.

Gallery:

source: pagetable.com

Selcom Lemon II Floppy Drive Repair and Clean.

Defect: The Floppy Drive motor spins and the LED stays on but the R/W head does not move and don’t read anythings. This is a classic failure due to incorrect insertion of the Floppy Drive connector into the male connector on the side of the Floppy Drive Controller card.

By inserting the connector moved one row externally the supply consequently go to in the wrong places and the first IC to explode in the true sense of the word is the 74LS125 (see photo).

Replaced the component, everything has started to working again.

Taking advantage of the repair, i have cleaned the inside of the LEMON II Computer and done a DUMP of the EPROM, i also cleaned and lubrificate the mechanical parts of the Floppy Drive.

Gallery of the repair:

Download: Selcom Lemon II ROM EPROM Dump (1387)

2 x Atari Lynx II Repair and Recap.

The first Atari Lynx II did not turn on but when powering the console at 5v bypassing the power stage it worked properly.

I had to replace all the electrolytic capacitors and the critical components of the power stage.

• 1 x MOSFET MTDJ055E with a equivalent one.
• 2 x Transistor 2N3906.
• 1 x Zener Diode 1N5991B.
• 1 x 120 Ohm resistor.

The second Atari Lynx II working correctly so consequently i have only replaced the electrolytic capacitors.

Gallery of the repair: