HI Yes they are 8K modules and there are a few options to build or buy new modules :)
The Tandy Wiki http://tandy.wiki/Model_100_RAM is a great resource for information on parts etc for the Model Ts. A few people on the list create Model T parts in their spare time, as hobby, they might have some for sale. Blank PCBs are available on the PCB sharing part of OSHPark https://oshpark.com/shared_projects if you want to build your own, searching the sharing archive can be painful though. You could check out Arcade Shopper for prebuilt modules at https://www.arcadeshopper.com/wp/?page_id=11#!/100-102-200/c/28313042/offset=0&sort=nameAsc they sell parts for the Model T and other classic machines. eBay sometimes throws up individual parts for the Model Ts. From: M100 <m100-boun...@lists.bitchin100.com<mailto:m100-boun...@lists.bitchin100.com>> on behalf of Ed Graffius <quaddri...@aol.com<mailto:quaddri...@aol.com>> Reply-To: <m...@bitchin100.com<mailto:m...@bitchin100.com>> Date: Saturday, May 18, 2019 at 5:49 AM To: <m100@lists.bitchin100.com<mailto:m100@lists.bitchin100.com>> Subject: [M100] M100 memory Ok, Its working well and I have been poking around (but not peeking if bad BASIC puns are allowed). I need another 8K each module must be 8 k right? is there a source for them today? likely not new...but used? NOS? salvage? I need to find the cassette adaptor pinout and a plug - have a solution to try....save files in thru the media player on THIS machine as .wav using the mic in jack and loading using the speaker out....a sort of 'virtual cassette'