Uploaded June 2026 | Updated September 2026, 2 weeks ago
Caverns of Titan would not start on my ColecoVision, even after I built the cartridge correctly. The missing piece was the ColecoVision Super Game Module - Something I know very little about!
In this video I build a modern DIY ColecoVision SGM-compatible expansion, using 32KB RAM, an AY-3-8910A sound chip, a 62256 SRAM, 74-series logic and the front expansion port. Then, because nothing is ever that simple, the first test fails and I have to fault-find the module before the game finally boots.
This is not Coleco’s cancelled 1980s Super Game Module. Opcode Games created and sells the official modern ColecoVision Super Game Module, which was listed as available on backorder when I checked. This build uses Eric Chartré’s community through-hole SGM-compatible PCB, so I can build, inspect and fault-find the hardware on camera rather than just plug in a finished unit.
Last time, I built the cartridge.
This time, I had to build the thing the cartridge was waiting for.
Thanks to PCBWay for supplying the boards for this build. This was exactly the sort of project where a decent manufactured PCB makes soldering a joy. The board used here is a shared PCBWay project, ordered as a bare PCB and built up with through-hole parts.
In the video:
- Building a DIY ColecoVision Super Game Module compatible expansion
- 32KB RAM expansion using a 62256 SRAM
- AY-3-8910A sound chip installation
- 74-series logic and ColecoVision expansion port hardware
- Suspect AliExpress AY chips and possible blacktopping
- Diagnosing a failed first test
- Finding the the SRAM is bad with a thermal camera
- Finally booting Caverns of Titan on real ColecoVision hardware
Chapters:
0:00 Caverns of Titan needs a Super Game Module
0:58 Coleco’s unreleased Super Game Module vs the modern SGM
1:44 What is on this DIY ColecoVision SGM PCB?
2:02 32KB SRAM and AY-3-8910A sound
3:00 74-series logic and address decoding
3:39 Checking the resistor values
4:18 Wrong-size resistors and honest mistakes
5:08 Oversized capacitors and first soldering
6:28 Soldering the IC sockets
8:06 Patreon support and sore hands
9:15 Fitting the SRAM and AY sockets
9:54 Thanks to PCBWay
10:14 Fitting the 60-pin ColecoVision expansion connector
11:23 Installing the 74-series logic chips
12:19 Fitting the 62256 SRAM
12:47 Are these AY chips blacktopped?
14:10 First test on the ColecoVision
14:58 Testing Caverns of Titan without the SGM
15:32 Installing the Super Game Module
16:16 Fault-finding with the thermal camera
16:52 Bad SRAM found
17:28 Caverns of Titan finally boots
17:47 Playing Caverns of Titan on ColecoVision
18:36 Patreon thanks and spare PCBs
19:37 Abstract 80s band quiz
20:15 End screen
Credits and links:
Project / PCB credit: Eric Chartré
Caverns of Titan: Team Pixelboy
Official modern commercial Super Game Module: Opcode Games
Previous video, building the Caverns of Titan cartridge:
youtu.be/NSS8rnp0r58
PCBWay shared project:
pcbway.com/project/shareproject/colecovision_super_game_module_ttl_sgm_16deba76.html
Support Mark Fixes Stuff:
Website: markfixesstuff.com
Patreon: patreon.com/markfixesstuff
iFixit FixHub used during the build.
#ColecoVision #RetroGaming #MarkFixesStuff
Caverns of Titan would not start on my ColecoVision, even after I built the cartridge correctly. The missing piece was the ColecoVision Super Game Module - Something I know very little about!
In this video I build a modern DIY ColecoVision SGM-compatible expansion, using 32KB RAM, an AY-3-8910A sound chip, a 62256 SRAM, 74-series logic and the front expansion port. Then, because nothing is ever that simple, the first test fails and I have to fault-find the module before the game finally boots.
This is not Coleco’s cancelled 1980s Super Game Module. Opcode Games created and sells the official modern ColecoVision Super Game Module, which was listed as available on backorder when I checked. This build uses Eric Chartré’s community through-hole SGM-compatible PCB, so I can build, inspect and fault-find the hardware on camera rather than just plug in a finished unit.
Last time, I built the cartridge.
This time, I had to build the thing the cartridge was waiting for.
Thanks to PCBWay for supplying the boards for this build. This was exactly the sort of project where a decent manufactured PCB makes soldering a joy. The board used here is a shared PCBWay project, ordered as a bare PCB and built up with through-hole parts.
In the video:
- Building a DIY ColecoVision Super Game Module compatible expansion
- 32KB RAM expansion using a 62256 SRAM
- AY-3-8910A sound chip installation
- 74-series logic and ColecoVision expansion port hardware
- Suspect AliExpress AY chips and possible blacktopping
- Diagnosing a failed first test
- Finding the the SRAM is bad with a thermal camera
- Finally booting Caverns of Titan on real ColecoVision hardware
Chapters:
0:00 Caverns of Titan needs a Super Game Module
0:58 Coleco’s unreleased Super Game Module vs the modern SGM
1:44 What is on this DIY ColecoVision SGM PCB?
2:02 32KB SRAM and AY-3-8910A sound
3:00 74-series logic and address decoding
3:39 Checking the resistor values
4:18 Wrong-size resistors and honest mistakes
5:08 Oversized capacitors and first soldering
6:28 Soldering the IC sockets
8:06 Patreon support and sore hands
9:15 Fitting the SRAM and AY sockets
9:54 Thanks to PCBWay
10:14 Fitting the 60-pin ColecoVision expansion connector
11:23 Installing the 74-series logic chips
12:19 Fitting the 62256 SRAM
12:47 Are these AY chips blacktopped?
14:10 First test on the ColecoVision
14:58 Testing Caverns of Titan without the SGM
15:32 Installing the Super Game Module
16:16 Fault-finding with the thermal camera
16:52 Bad SRAM found
17:28 Caverns of Titan finally boots
17:47 Playing Caverns of Titan on ColecoVision
18:36 Patreon thanks and spare PCBs
19:37 Abstract 80s band quiz
20:15 End screen
Credits and links:
Project / PCB credit: Eric Chartré
Caverns of Titan: Team Pixelboy
Official modern commercial Super Game Module: Opcode Games
Previous video, building the Caverns of Titan cartridge:
youtu.be/NSS8rnp0r58
PCBWay shared project:
pcbway.com/project/shareproject/colecovision_super_game_module_ttl_sgm_16deba76.html
Support Mark Fixes Stuff:
Website: markfixesstuff.com
Patreon: patreon.com/markfixesstuff
iFixit FixHub used during the build.
#ColecoVision #RetroGaming #MarkFixesStuff
