Uploaded February 2023 | Updated September 2026, 3 weeks ago
My TRS-80 Model 16B could use more 68000-side RAM for XENIX. A group of former Tandy engineers called Tandy Emeritus has designed a 3-bit MMU board and companion 8 MB SRAM board for these systems for just that purpose. These boards are not generally available for sale. If you wish to contact Tandy Emeritus members for availability, join the Tandy Discord server. For part one, let's build the boards and talk about next steps!
This video is more akin to my older ones with lots of time-lapse/music. These projects are a lot of work, and take a lot of patience and time. That's hard to convey if I gloss over it...as it is only about 60% of the footage made it into the video.
And for some reason, I kept saying SRAM card while referring to the MMU board mid-video. I don't know what was wrong with me that day. Hopefully I caught them all.
Music (in order)
Disco Knights by Quincas Moreira
Who's using who? by The Mini Vandals
Paradox by Quincas Moreira
Chapters:
Project & Series Intro (0:00)
New Work Area & Looking At The Boards (1:43)
SRAM Board: Install SRAM/Jumpers/Sockets (2:27)
Caps/Voltage Regulator/Resistor Networks (8:00)
Logic Chip Testing & Install (11:12)
MMU Board CPU Headers/Socket (13:07)
Protecting CPU Header Pins (15:40)
SRAM Sockets/Caps/Resistors (16:13)
Completed MMU Board & Parts Stuffing (17:11)
Finished Product & GAL Programming (18:25)
Pulling 68000 Cards & A Look (19:59)
What's Next / Outro (22:07)
I do these videos unscripted, so I apologize if the in-the-moment descriptions of things are a bit scattered. If you have any questions/comments about this video, you can find me in any of these fine locations:
The Tandy Discord Server
The CoCo Nation Discord Server
The TRS-80 Color Computer (CoCo) group on Facebook
The CoCo Crew Podcast group on Facebook
On the Vintage Computer Forums (vcfed.org)
The TRS-80 Models I-4/4P Group on Facebook
Tandy / Radio Shack Model II /12 / 16 / 16B / 6000 Owner's Group on Facebook
Twitter (I'm TJBChris there...)
The Level29 BBS (I'm TJBChris there, too.)
Particles BBS (Guess who I am here? Yeah, TJBChris.)
Thanks for watching!
My TRS-80 Model 16B could use more 68000-side RAM for XENIX. A group of former Tandy engineers called Tandy Emeritus has designed a 3-bit MMU board and companion 8 MB SRAM board for these systems for just that purpose. These boards are not generally available for sale. If you wish to contact Tandy Emeritus members for availability, join the Tandy Discord server. For part one, let's build the boards and talk about next steps!
This video is more akin to my older ones with lots of time-lapse/music. These projects are a lot of work, and take a lot of patience and time. That's hard to convey if I gloss over it...as it is only about 60% of the footage made it into the video.
And for some reason, I kept saying SRAM card while referring to the MMU board mid-video. I don't know what was wrong with me that day. Hopefully I caught them all.
Music (in order)
Disco Knights by Quincas Moreira
Who's using who? by The Mini Vandals
Paradox by Quincas Moreira
Chapters:
Project & Series Intro (0:00)
New Work Area & Looking At The Boards (1:43)
SRAM Board: Install SRAM/Jumpers/Sockets (2:27)
Caps/Voltage Regulator/Resistor Networks (8:00)
Logic Chip Testing & Install (11:12)
MMU Board CPU Headers/Socket (13:07)
Protecting CPU Header Pins (15:40)
SRAM Sockets/Caps/Resistors (16:13)
Completed MMU Board & Parts Stuffing (17:11)
Finished Product & GAL Programming (18:25)
Pulling 68000 Cards & A Look (19:59)
What's Next / Outro (22:07)
I do these videos unscripted, so I apologize if the in-the-moment descriptions of things are a bit scattered. If you have any questions/comments about this video, you can find me in any of these fine locations:
The Tandy Discord Server
The CoCo Nation Discord Server
The TRS-80 Color Computer (CoCo) group on Facebook
The CoCo Crew Podcast group on Facebook
On the Vintage Computer Forums (vcfed.org)
The TRS-80 Models I-4/4P Group on Facebook
Tandy / Radio Shack Model II /12 / 16 / 16B / 6000 Owner's Group on Facebook
Twitter (I'm TJBChris there...)
The Level29 BBS (I'm TJBChris there, too.)
Particles BBS (Guess who I am here? Yeah, TJBChris.)
Thanks for watching!
