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Laser 286/2 SANET


Aug 7, 2023
Hello all.

I myself have two Laser 286/2 vintage computers on which I run SANET.

SAnet PC (which came out in 1986), SA was way ahead of its competitors)Stage control V1.0:The PPA 1200 amplifier, the PPE 2410 and the Blue Box are controlled by an internal microcontroller. In all devices, the microcontroller is used to control actions, such as when the user touches a button. It is also used to view and control the electronic circuits e.g. check signals against limits, activate driver digital to analog converters and relays. And last but not least, it serves the SAnet interface. Every microcomputer needs software to guide it. This software defines within limits the nature of the operation of the device, in other words the behavior of the device. The microcontroller software will be updated regularly. This is due to the continuous software developments to improve device behavior.
Certainly a well thought-out protocol for that time.
You could control a maximum of 256 SA devices at the same time, such as the Blue Boxes, PPA 1200s, PPE 2400s and PPE 2410s.
All functions on the control panel of the devices could also be controlled via SAnet.



Image off the progam SANET PPE2410
Some more info about the SANET from Stage Accompany.
SC250A, SAnet (ISA)
Stage Control 1.0 (DOS 6.22/GEM)
Device Software Download Utility V2.0 (DOS 6.22
In 1985 Stage Accompany introduced the PPE 2400; the first commercially available digitally controlled analog parametric equalizer. To allow remote control of presets, the EQ came with a MIDI interface.
During the development of new devices such as the Blue Box, it became necessary to control the full set of system parameters remotely. We were also looking for a way to effectively control all of the major blue box sound systems.
This section provides a brief overview of key design specifications, existing interfaces, and the final decision to develop SAnet.
The main interface specifications were as follows:
• The interface must work with a network-like character (multipoint) to enable efficient connections.
• The number of individually controllable devices must be at least one hundred, for example to control a sound system of one hundred blue boxes.
• Data transfer must be transparent and error-free.
• The maximum distance between connected devices should be 500 meters (1600 feet).
The MIDI interface allows individual control of system parameters with "Excusive Message Mode". But MIDI and other existing interfaces such as RS-232 are not suitable for making efficient connections because they require huge bundles of cables. Also, with these interfaces, it is not easy to implement a protocol that provides error correction. Finally, the maximum allowed distances between devices are too short.
In addition, synchronous interfaces known from administrative applications such as Ethernet, Starlan, etc. may be less suitable due to their high complexity and hence high cost.
After evaluating the existing interfaces, we decided to develop a simple and professional network around a special part of Intel; the 8344 serial interface controller.
This controller uses a subset of the standard IBM Synchronous Data Link Control (SDLC) protocol. The simplest application only needs an external component; a cheap line driver.
The main features of this network, called SAnet (Stage Accompany Network), are:
• Serial multidrop configuration (efficient cabling)
• Asynchronous bulk transmission (low overhead)
• Error-free data transfer (correction for retransmission)
• High transmission speed (375 kbits/second)
• Distances up to 500 meters (1600 feet)
There are two basic configurations for a communication channel: point-to-point and multipoint. RS-232 is an example of a point-to-point configuration; one device sends information to another device. However, a multipoint configuration is a data connection with three or more devices.
Also, a point-to-point or multi-point configuration can work simultaneously or concurrently. In alternating two-way traffic, the stations alternate, one by one. Two-way simultaneous operation allows two stations to transmit and receive at the same time.
A simultaneous two-way configuration is called duplex. An alternative two-way configuration is called half-duplex. SAnet uses a half-duplex multipoint configuration.
A multipoint configuration means that all network devices and the network controller are connected to each other. This is an advantage because the SAnet cable can be routed from controller to controller, device to device, and so on. Therefore, SAnet is just a connection that goes from device to device, where each device has a SAnet input and a SAnet output connected internally without any buffering electronics.
Since all SAnet devices are connected to the network controller with the same cable, there must be a way to tell them apart. This is achieved by entering a unique identity code per device consisting of a manufacturer code, device type and serial number.
A maximum of 256 vendor codes can be used to connect devices from 256 different vendors to SAnet. Per manufacturer, 256 different device types can be used for 256 different device types such as equalizers, amplifiers, etc. Per device type, 65536 different device types can be used, so 65536 identical devices can be addressed in a unique way.