This mod removes the silly "green" mode that is on most of these Philips/Magnavox composite monitors and modifies it to be a high resolution monochrome mode, perfect for pairing with an Apple II.
Should apply to any Philips / Magnavox monitor that has the green switch on the front.
Instructions:
SK4: Green switch – high resolution monochrome luma mod
One side feeds 12v to disable R and B drive via diode D604 and D605.
Other side disables the color decoding on IC 502 be grounding the color control, which turns it off.
- Remove wire jumper link from triangle 48 to 27 (Green wire near SK4) This will disable "green only mode"
- Cut 12v from PCB edge side of SK4 (it goes to two pins, the pine closest to the front edge of the PCB and the middle pin.)
- Ground the pin on SK4 closest to the front edge of PCB. (That originally has 12v going to it.)
- Cut trace between SK4 pins that originally had 12v. (The PCB edge pin and middle pin)
- Remove jumper link 9252 near S533 to disable the luma filter (this normally grounds the coil S533 all the time, enabling the filter)
- Run a jumper from middle pin of SK4 switch (PCB edge) to jumper link 9252 pad on PCB edge (same edge as SK4) This will ground S533 when the switch is in the out positiion, and will leave S533 floating when the switch is pushed in.
This will "turn on" the luma filter when the Green switch is out. Color will work normally.
Pushing IN the switch will disable the filter, giving you high res luma signal without filtering.
With the switch IN, the other half of the switch will work as normal and disable the color decoding, giving you a proper monochrome signal without any fringing.
— Video Links
Original video where I showed off this monitor:
Schematics:
https://archive.org/details/commodore-1084-p-monitor-service-manual
Extras Channel:
https://www.youtube.com/@adriansdigitalbasementextras/featured
My profile on Bluesky:
https://bsky.app/profile/adriansdigitalbasement.com
Adrian’s Digital Basement Merch store:
https://my-store-c82bd2-2.creator-spring.com/
Support the channel on Patreon:
https://www.patreon.com/adriansdigitalbasement
Adrian’s Digital Basement (Main Channel)
https://www.youtube.com/channel/UCE5dIscvDxrb7CD5uiJJOiw
My GitHub repository:
https://github.com/misterblack1?tab=repositories
— Tools
Deoxit D5:
https://amzn.to/2VvOKy1
http://store.caig.com/s.nl/it.A/id.1602/.f
O-Ring Pick Set: (I use these to lift chips off boards)
https://amzn.to/3a9x54J
Elenco Electronics LP-560 Logic Probe:
https://amzn.to/2VrT5lW
Hakko FR301 Desoldering Iron:
https://amzn.to/2ye6xC0
Rigol DS1054Z Four Channel Oscilloscope:
https://www.rigolna.com/products/digital-oscilloscopes/1000z/
Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
https://amzn.to/3adRbuy
TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
https://amzn.to/2wG4tlP
https://www.aliexpress.com/item/33000308958.html
TS100 Soldering Iron:
https://amzn.to/2K36dJ5
https://www.ebay.com/itm/TS100-65W-MINI-Digital-OLED-Programmable-Soldering-Iron-Anti-static-Structure/113382669853
EEVBlog 121GW Multimeter:
121GW Multimeter
DSLogic Basic Logic Analyzer:
https://amzn.to/2RDSDQw
https://www.ebay.com/itm/USB-Logic-DSLogic-Basic-Analyzer-16Ch-100MHz-4Ch-400MHz-Xilinx-Spartan-6-FPGA/202543965672
Magnetic Screw Holder:
https://amzn.to/3b8LOhG
https://www.harborfreight.com/4-inch-magnetic-parts-tray-90566.html
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
https://www.ebay.com/itm/14-16-18-20-24-28-32-40-pin-IC-Test-Universal-ZIF-Socket-Fs/303206721971
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
http://www.retrotink.com/
Plato (Clone) Side Cutters: (order five)
https://www.ebay.com/itm/1-2-5-10PCS-Micro-Scissor-125mm-PLATO-170-Electronics-Cutter-Side-Cutting-Pliers/163458746184
Heat Sinks:
https://www.aliexpress.com/item/32537183709.html
Little squeezy bottles: (available elsewhere too)
https://amzn.to/3b8LOOI
— Instructional videos
My video on damage-free chip removal:
— Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino
About The Author
