TRS-80.org » Larry Holmes http://www.trs-80.org TRS-80.org is a source for information about the Radio Shack TRS-80 line of computers, hardware, and software, with articles, interviews, and more! Thu, 29 Dec 2011 16:36:27 +0000 en hourly 1 http://wordpress.org/?v=3.2.1 The Holmes Internal Memory http://www.trs-80.org/holmes-internal-memory/ http://www.trs-80.org/holmes-internal-memory/#comments Mon, 12 Jan 2009 16:07:46 +0000 Matthew Reed http://www.trs-80.org/?p=143 TRS-80 Model I supported up to 48K of memory, there were only sockets for 16K within the Model I itself. The only official way to add more memory was to buy the Radio Shack Expansion Interface, which had sockets for an additional 32K of memory, for 48K in total. The Expansion Interface (without any memory) cost $299, making any kind of official memory expansion very expensive.

The other important feature of the Expansion Interface was the built-in floppy disk controller. But not everyone was interested in or could afford floppy drives, which cost hundreds of dollars per drive. Many people used cassettes or other alternative storage devices, such as the Exatron Stringy Floppy, the TC-8, or the BETA-80. What option was there for the Model I user who wanted to maximize memory but without the extras (and expense) of the Expansion Interface?

One answer was the Internal Memory, introduced by Holmes Engineering in 1981. Designed by Larry Holmes, the Internal Memory added memory entirely inside the Model I without requiring an Expansion Interface. It could be easily installed by the user without any soldering or trace cutting. The Internal Memory came in three versions:]]> http://www.trs-80.org/holmes-internal-memory/feed/ 0