OIS System Hardware


The OIS systems are divided into three groups: the 125/130 models, which used the 8080 microprocessor, the 115/130A/140 systems (sometimes referred to as '140-series' machines), which used the Z80 microprocessor, and the 45/50/60/70 machines, which use the Z80 and are contained in a smaller 'tower' cabinet. These are sometimes referred to as '40-series' machines.

OIS 125/130

The OIS 125/130 machine was developed from the WPS (Word Processing System) 25/30, with a few changes to the hardware. It uses a different CPU board and data link board than the WPS system.
The PROMS on the CPU allowed it to function as an OIS or a WPS depending upon the software that was IPLed.

The basic storage for the system is a CDC Hawk drive, with either 2.5Mb or 5Mb (one removable and one fixed surface) capacity. The system supported up to two of these drives, as well as the internal 8-inch hard sectored floppy drive.

These machines used the Intel 8080 microprocessor.

140 Series

The 140 series includes the OIS 105/115, the OIS 125A/130A, and the OIS 140/145. These machines used the Zilog Z80 microprocessor, and were available with 64k (4k is PROMs and I/O) of memory, which could be upgraded to 128k by changing the CPU board. All of these systems support the standard 8-inch hard-sectored floppy drive, and two CDC Hawk units.

OIS 125A/130A

These systems are contained in a 'desktop' cabinet, and only supported CDC Hawk drives for external storage. They supported up to 16 serial devices. These are the simplest of the 140-series systems.

OIS 105/115

These systems included an internal 8-inch fixed disk drive and a controller board set. There were several models, each offered with a different disk capacity:
OIS-105
 2.4MB disk, 8 serial I/O channels
OIS-105-1
 4MB disk, 8 serial I/O channels
OIS-115-1
 4MB disk, 16 serial I/O channels
OIS-115-2
 8MB disk, 16 serial I/O channels
OIS-115-3
 16MB disk, 16 serial I/O channels
OIS-115-4
 32MB disk, 16 serial I/O channels
The 2,4, and 8 MB disks were 8-inch Shugart drives. These were stepper motor drives with SA1000 interface. These used the standard controller board set.
The 16 and 32 MB disks were Quantum drives which used servo head positioners. These were faster than the Shugart drives, but required an updated control board set.
These systems used the same 'desktop' cabinet as the OIS 125A/130A.

OIS 140/145

These are the largest OIS systems. They are in a larger cabinet with wheels on the bottom to move it around. These machines supported 32 serial I/O channels and external disks with SMD interface. They also contained the standard 8-inch floppy drive. Two other systems were available that used the same Master unti as the OIS 140/145: the Alliance system, which differed only in software, and DVX (Digital Voice Exchange) which used different software and added some additional hardware.

OIS 140 Turbo

This is a CPU board set based on the Motorola 68020 processor that was installed into the OIS 140 chassis. It replaced the CPU board and the two data link boards, and could support up to 64 devices. There are spaces for four SIMM modules (1MB each), and the board contained an integrated SCSI controller, and a standard RS-232 serial port for diagnostics. Here are some pictures of the OIS 140 Turbo board set.
Because of the Motorola CPU, the Master software is different. I do not have any software for the Turbo, so I do not know if it even works.

40 Series

These systems used multilayer circuit boards and newer disk drives, as well as a switching power supply instead of the old linear power supplies with their heavy transformer. They contain up to seven boards, two being the RMU (Z80, memory, and NEC 765 floppy controller), and the RCU (This contained a 8x305 microcontroller to interface a ST506/412 MFM hard disk). The other slots could be used for options including RS-232 serial printer controllers, WISE (Wang Inter Systems Exchange, a network), or IWS (Internal Work Station). IWS put the workstation CPU on an internal card, and connected to the monitor and keyboard by a 15-pin cable (similar to PC joystick port connector). The connection was limited in distance, up to 200 feet. These systems used a 5 1/4" floppy disk with 256-bytes per sector, but you could select 512-byte sectors to read and write DOS-formatted floppy disks.

The 40-series machines were available with 64k memory and several different 5 1/4" hard disk drives. The OIS-40 did not offer any serial I/O channels, the OIS-50 had four, the 60 had eight, and the OIS-70 had 16 (?).



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