Upgrading computers and networks in K-8 Schools, Ideas, 951119

OVERVIEW

Many school campuses have a wide array of early Apple (prior to MC680X0 CPU) and / or PCs (*or PC Clones*) which predate Intel 80386 or MC68020, their memory addressing and abilities to run large and CPU intensive programs.

Some such sites also have minimal, outdated or NO internal networks. Some early Apple nets are in the under 250kbits / second and some PC nets are in the 2.5 megabit class.

STARTING FROM ARCNET or NO NET

ARCNet Technology:

Is a quarter the speed of modern ethernet (2.5 megabits per second versus 10 megabits per second).
It is very limiting for a local network, and,
If Novell is your network of choice, even V 2.15 will allow the upgrade.
If you now have ARCNet coax it is likely a variety that will not support above 2.5 mbit for much distance.
Under very limited conditions short distance the wire might work for 10 megabit ethernet.

ETHERNet Technologies:

Ethernet installed today is mostly on 10-Base-T at under a dollar a foot for Category-5 wire, known as the stuff with the telco RJ-45 (8 pin connector on the end) or as Unshielded Twisted Pair (UTP).
That is able to later run at 100 mbits when that technology comes down in dollars. That is data standard 100-Base-T vs 10-Base-T.
It can run up to 100 meters (300+ feet) to a hub and up to 4 tiers of hubs have been used.
Those hubs are from $500 to $1500 varying with ports and qualilty. Asante and Cabletron, resp., are among those in popular use, today in schools and government.

Higher costing coax, while much less fault safe, will still work but with less of a future. 10 Mbit vs 100, later.

Fiber (Fibre)

Ideally buildings not bonded together electrically should consider use of

Fiber optic (6 strand, 6-8 micron (u) or 62u fiber bundle)
It is also in the same price per distance as 10-Base-T UTP,
More expensive to terminate.
Note we dont terminate each client station with 10-Base-FO for that reason,
Just connect buildings.

INTEL 286 or other DOS CLONES

Such early systems are much better than none at all. However, when their usefulness passes by, an affordable (by contrast to new) option may be a limited upgrade. Such an upgrade depends upon still having some reuseable parts:

Cabinets with power supplies are worth $75 to $200.
Video cards at least VGA+, reasonable monitors, $350 to $750+
Any other peripherals of recent generation like sound cards, CDROMs are often close to their $200 to $700 new values.

some more memory,
a faster CPU , and,
an ethernet card

For windows and networking applications, then an upgrade, a few at a time or many at once may be very worth while. Bulk buys can net you 10 to 30 percent better prices on hardware. Remember a reputable brand and seller are very valuable.

For $600 - to - $750 with

a Pentium-100,
4MB RAM
some built-in PCI controllers for SCSI and other disks, and
ethernet card for both 10-Base-T (the RJ45 phone-like connector) or/and Thin-Net (10-Base-2, thin coax with BNC, the quarter turn twist lock connector).

This is a contrast against $1500 to $2000 for a complete PC replacement. You might still keep your old CPU board for some other uses.

INTERNET CONNECTION

A minimum internet connection is a single host with a modem doing a dial up single user, serial session without any graphics. (Typically 14.4 to 28.8 Kbits per second)
A minimum network internet connection is a single host with a modem doing a dialup serial internet protocol over SLIP or PPP, such as to GINA, VCNET or other connection point. A graphic session and multiple events at once are possible, like GINA, file transfer, email and Web services, simultaneously. (Typically 28.8 Kbits per second)
A not-so-minimum but limited capability uses a comm server (ethernet on one side and slow serial on the other side box) may easily run over a dialup and connect more than one host to a remote (such as OSD) network. Such an interim step is in the $3000 class and parts are useable later. It use dialup phone lines. (Typically 28.8 Kbits per second though 56K or more can be obtained)
A standard (within OSD) connection uses a Cisco Router and Data Set (called CSU/DSU) at under $5000 plus $200 / month with possibility of subsidy. That fetches at least 128Kbits and now handles Fremont and Cesar Chavez to the DO. DO is 384Kbit for now to CSU, Los Alamitos.

These are thumbnail sketches. They can be much less expensive in larger quantities as through group buys of 25 to 100. The technical training to operate and maintain the local area networks (with proper vendor service agreements for hi-tech items, 10-15% of purchase per year) is free within the district.

Means of supporting the computers and periperals should be a major consideration in the overall design plan.