Kaypro 4 (81-004 & 81-006)

Processor:	Z80a, 4 MHz
Memory:	64K
Disk Storage:	Two Double Density Double Sided Tandem floppy drives (400K)
Ports:	Modem/RS232C Interface, Centronics parallel printer interface
Keyboard:	Detachable full typewriter keyboard with 14 key numeric pad and 4 cursor control keys. Upper and lower case.

Why 2 model numbers?

This is a little bit of a mystery to me. I have not been able to find a difference between the two model numbers. Also the 81-006 is fairly rare and the 81-004 has serial numbers both before and after the 81-006s that I have seen.

What happened to the Kaypro IV

While there are no Kaypros with the roman numeral IV there is strong evidence that the roman numeral version was strongly considered as the name during it's development. Some software had it printed on it and the early versions of the screen text included it as Kaypro IV. There is marketing material that labeled it as the Kaypro IV.

News

Non-Linear Systems, Inc., manufacturers of the fast-selling line of Kaypro portable personal computers, has announced the introduction of the Kaypro 4 portable personal computer, featuring a total floppy disk capacity of 788K. ...

The new Kaypro 4, which will be priced at $1,995, is designed for use with double-sided double-density disks with 394K memory per disk for a total of 788K for the unit;s two disk drives. As with all computers in the Kaypro line of personal portables for the business market, the machine will be sold with all programming bundled and packaged with the machines on delivery from the factory. The programming itself, which is provided at no additional charge, is itself worth over $2,800 if purchased seperately.

The Kaypro 4 employs the 8-bit Z-80 microprocesor and features a full-featured, standard professional keyboard with 72 keys including 20 programmable keys plus a 14 key calculator-type numeric keyboard. The portable machine has a high-resolution 9-inch green phosphor screen which offers the optimum full page display capable of 80 columns across by 24 lines deep, the characteristics required of a computer that displays a full page of typewritten information.

According to David Kay, "the Kaypro 4 is completely compatible with the existing lines of Kaypro II and Kaypro 10 machines. The double-sided double density disks for the Kaypro 4 can be used interchangeably with the single-sided double-density disks normally used on the Kaypro II."
(NLS Introduces Expanded-Capacity Kaypro 4 Computer, June 1983)

"We just started shipping the KAYPRO 4 which has double sided floppy disks for more memory."
(CommuniKay, June 1983)

"Like the Kaypro II, which competes directly against Osborne computers, the new Kaypro 4 contains 64,000 bytes, or characters, of internal memory and is powered by an 8-bit microprocessor. But the new model contains twice the memory capacity in its disk drives, which transfer information for permanent storage on floppy disks. The new drives have a maximum capacity of about 800,000 characters. ... The new machine will sell for $1,995, the company said."
(New York Times, June 4, 1983)

Since this review was completed, Non-Linear Systems has revamped its product line for 1983 with two new system configurations (the Kaypro 4 and Kaypro 10)...

The Kaypro 4 is essentially an upgrade of the earlier model. Like its forebear, the Kaypro II, the Kaypro 4 is a portable, CP/M-based system with 64K bytes of RAM and two double-density floppy disk drives. The three major differences are that (1) it has doublesided disk drives (each offers 380K bytes of storage), (2) it is packaged in a dark gray case, and (3) it costs $1995. A minor, if inexplicable difference, is in the product name. NLS has shifted from using roman numerals (e.g., II) to arable numerals (e.g., 4)— a change not without historic precedent. (Byte Magazine, September 1983)

"The Kaypro Corporation, a Solana Beach, Calif., computer manufacturer, announced that it had reduced the price of its Kaypro 4 personal portable computer by $200, to $1,795. Kaypro said the price reduction, which does not affect the Kaypro 10 model, is a result of supplier cost reductions in both disk drives and video display screens, coupled with increasing volume orders. The Kaypro 4, which uses double-density disks, features 392K of formatted storage per disk for a total of 784K for the unit's two disk drives."
(New York Times, October 8, 1983)

FCC ID

This machine's FCC ID was issued Jan. 4, 1984.