Radio Shack TRS-80 Model 4

This is the last of the original TRS-80 line, as well as the last to include the Z80 processor and ran at 4mhz opposed to 2mhz that the previous revision ran at. This model also came with an option to upgrade to 128K of memory as well as an RS-232C port as standard. Rather than the Model III’s grey and black plastic, the Model 4 had a beige and black color scheme, looking still very similar to the Model III’s form factor. Included on its ROMs is “Level III Basic” however you can also load LS-DOS or TRSDOS through floppy. The early models of the Model 4 had a white on black display and used Programmed Array Logic Chips rather than Gate Array Logic Chips and were referred to as the “NGAL” model, The later models use Gate Array Logic Chips and have a green on black display and goes by “GAL”. There was also a luggable version called the Model 4P which had all of the same specs only the screen was smaller and was in a more “portable” form factor.  The Model 4 was backwards compatible with all Model III software and retailed at $1699 for the base model with 1 floppy drive, and $1999 for the model with 2 floppy drives.