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This is the Kaypro 4 released in 1984, usually refered as Kaypro 4/84, as opposed to the Kaypro IV released one year earlier, and refered as Kaypro IV '83.

The main differences between the Kaypro 4 '84 and the Kaypro IV '83 were :
- A faster CPU, Zilog Z80A running at 4Mhz,
- A real time clock which can be used by programs (uses National MM58167),
- A better built-in monitor resulting in a very sharp display. The character matrix has also evolved from 5 x 7 on the Kaypro II and IV '83 to 8 x 16 pixels on the Kaypro 4 '84,
- the system had rudimentary graphics through graphical characters resulting in a virtual 160 x 100 resolution,
- characters could be displayed using two brightness levels and reverse attribute,
- the new prompt was a blinking square,
- like on modern keyboards, J and F keys were slightly different in shape from the other keys, so it was possible to spot them while staring at the screen,
- there was a built-in modem (300 baud, Bell System 103 compatibility, uses Texas Instruments TMS99537/TMS99532),
- the system had two DS/DD half-height floppy drives (390 kb)

The system was bundled with Wordstar, dBase II, MicroPlan, Microsoft Basic, S-Basic, SuperCalc, C-Basic and CP/M 2.2 !

In 1984, in order to be compatible with IBM software, a special version was marketed with an Intel 8088 CPU in addition of the Z80A. It was called Kaypro 4 Plus 88!

Walter J. Dickie reports:
The Plus 88 was a dual-processor machine. First you booted up in CP/M, then inserted an MS-DOS (not PC-DOS) disk and booted the 8088. The really slick thing about the Plus was that in CP/M you could run the 8088 and it's associated 256K of RAM as a ramdisk. My standard boot routine involved booting in CP/M, firing up the 8088 as a ramdisk, copying all the WordStar overlay files onto the ramdisk (they just fit), then running WordStar on the Z80. With WordStar calling its overlays from the ramdisk the damn thing just flew!