Adding a high-res mode to this composite color monitor (Philips / Magnavox monitors) @adriansdigitalbasement2
Adding a high-res mode to this composite color monitor (Philips / Magnavox monitors)  @adriansdigitalbasement2
Uploaded June 2025 | Updated September 2026, 3 weeks ago
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:
youtu.be/4p_2ysRjsD4

Schematics:
archive.org/details/commodore-1084-p-monitor-service-manual

Extras Channel:
youtube.com/@adriansdigitalbasementextras/featured

My profile on Bluesky:
https://bsky.app/profile/adriansdigitalbasement.com

Adrian's Digital Basement Merch store:
my-store-c82bd2-2.creator-spring.com

Support the channel on Patreon:
patreon.com/adriansdigitalbasement

Adrian's Digital Basement (Main Channel)
youtube.com/channel/UCE5dIscvDxrb7CD5uiJJOiw

My GitHub repository:
github.com/misterblack1?tab=repositories

-- Tools

Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/s.nl/it.A/id.1602/.f

O-Ring Pick Set: (I use these to lift chips off boards)
amzn.to/3a9x54J

Elenco Electronics LP-560 Logic Probe:
amzn.to/2VrT5lW

Hakko FR301 Desoldering Iron:
amzn.to/2ye6xC0

Rigol DS1054Z Four Channel Oscilloscope:
rigolna.com/products/digital-oscilloscopes/1000z

Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
amzn.to/3adRbuy

TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
amzn.to/2wG4tlP
aliexpress.com/item/33000308958.html

TS100 Soldering Iron:
amzn.to/2K36dJ5
ebay.com/itm/TS100-65W-MINI-Digital-OLED-Programmable-Soldering-Iron-Anti-static-Structure/113382669853

EEVBlog 121GW Multimeter:
eevblog.com/product/121gw

DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
ebay.com/itm/USB-Logic-DSLogic-Basic-Analyzer-16Ch-100MHz-4Ch-400MHz-Xilinx-Spartan-6-FPGA/202543965672

Magnetic Screw Holder:
amzn.to/3b8LOhG
harborfreight.com/4-inch-magnetic-parts-tray-90566.html

Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
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)
retrotink.com

Plato (Clone) Side Cutters: (order five)
ebay.com/itm/1-2-5-10PCS-Micro-Scissor-125mm-PLATO-170-Electronics-Cutter-Side-Cutting-Pliers/163458746184

Heat Sinks:
aliexpress.com/item/32537183709.html

Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI

--- Instructional videos

My video on damage-free chip removal:
youtube.com/watch?v=XQVjwPsVFd8

--- Music

Intro music and other tracks by:
Nathan Divino
@itsnathandivino
Adding a high-res mode to this composite color monitor (Philips / Magnavox monitors)0066 A pretty rare Atari computer shows up in the basementThis easy IBM 5170 upgrade was anything but easy!Testing an unknown Atari 2600 Jr.0090 A modern IBM CGA card clone, a new thermal camera, hemostats, chips and more!Testing 12 mystery PC floppy drives0063 A boxed CoCo 1 and a fun read-through of a 1983 Radio Shack catalogThe first affordable home automation platform and digital storage scope? (ADC-1/Wavesaver 10)Trying to resurrect a broken 920 in 1 Famicom multi-cartWait, you can overclock the NES CPU?Sorting out and testing my broken Commodore floppy drives (Enhancer 2000, 1541C, 1550)I thought this $4 8-bit game console was going to be total junk
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Adding a high-res mode to this composite color monitor (Philips / Magnavox monitors)

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