• It expanded the TRS-80 screen from 64 characters wide by 16 characters high to the larger 80 characters wide by 24 characters wide.
• It changed the TRS-80 memory map to allow running the CP/M operating system.

When first introduced in 1982, the Model I VID-80 (the VX-1) cost $179.00 and the Model III version (the VX-2) cost $199.00. Those prices increased to $279.50 beginning January 1, 1983. Although CP/M was supported, CP/M 2.2 was not included and cost an additional $120.00. Holmes Engineering also sold the VID-80 and CP/M as a package for $399.50, although that price was discounted several times to $325.00.]]> http://www.trs-80.org/holmes-vid80/feed/ 0 http://www.trs-80.org/bigmem/ http://www.trs-80.org/bigmem/#comments Fri, 20 Mar 2009 14:57:07 +0000 Matthew Reed http://www.trs-80.org/bigmem/ TRS-80 Model I which increased available memory. It was introduced by Microhatch in early 1982 for $180.00, but the price was reduced to $169.00 by late 1983. Microhatch also sold a utility disk (with print spooler) for $20.00 which could be bundled with BIGMEM. For any user unwilling to perform the modification, Microhatch would install BIGMEM for $199.00.

Much like the Holmes Internal Memory,  BIGMEM replaced the 16K RAM chips inside the Model I with higher-capacity 64K chips. This avoided the reliability problems of the external memory in an Expansion Interface and also worked better with most speed-up kits.]]> http://www.trs-80.org/bigmem/feed/ 0