ARC50

8052 AH-BASIC development computer with EPROM programmer, real-time clock/calendar and buffered I/O.

The ARC50 packs more power into a single Eurocard than any other development computer. You can go through the complete development cycle with just this board, an RS232 terminal and a power supply. It has an 8K BASIC, massive memory capacity, EPROM programmer, battery-backed real-time clock, serial and parallel I/O and a bus connection on one board.

Features

• 8052 AH-BASIC CPU with 8K on-chip BASIC ROM
• EPROM programmer for 8 and 16K EPROMs with fast programming algorithm
• 22 I/O lines on Arcom’s standard signal-conditioning connector, including 8 buffered in, 8 buffered out, counter I/O, interrupt in and square-wave out lines.
• 16K RAM on-board (expandable to 24K)
• up to 24K EPROM
• real-time clock calendar with battery back-up and 50 bytes of internal RAM
• two RS232 ports, for terminal and printer.
• autobaud for terminal baud-rate detection or autostart with no terminal.
• buffered ARCbus interface.

Memory

There are four 28-pin memory sockets for two or three 8K RAMs and a 16K EPROM or two 8K RAMs and 24K EPROM. BASIC programs can be programmed into an EPROM using the on-board EPROM programming hardware and executed without removing the EPROM from its socket. Several programs can be saved into and read from one EPROM. The fast programming algorithm can be used for rapid program saving in 21V EPROMs. Serial I/O There are two RS232 serial ports. One is used for connection to the terminal - baud rates up to 9600 can be detected automatically at power-up, if required. The other port’s baud rate is set up with a couple of BASIC statements, and BASIC can use it to drive a printer. This port is for output only. 1/O can be redirected using assembly-language routines.

Parallel I/O

Parallel I/O is connected via the standard 50-way signal-conditioning connector. This connector is used on Arcom’s digital signal-conditioning boards, such as opto isolators, Darlington drivers and solid-state relays, and other manufacturers are adopting it as a standard. The ARC50 has 8 latched outputs and 8 buffered inputs at TTL levels, 4 counter/timer inputs, a programmable square-wave output and an MOS output line.

Real-time Clock

There are two real-time clocks on the ARC50. One is maintained inside the 8052 CPU, and is incremented every 5 milliseconds. BASIC statements can set, clear and generate interrupt jumps to other BASIC statements using this clock. The other real-time clock is a 146818 battery-backed clock/calendar which also has 50 bytes of internal battery-backed RAM and a power-fail protection circuit. The 146818 can interrupt at specified times, from seconds to 24 hours, can generate periodic interrupts, and has a 100-year calendar.

Power Requirements

Typically 5V at 1A, +12V at 100mA, -12V at 30mA and for programming EPROMs, 25V to 33V unregulated. Several Arcom power supplies are ideal.

How to Use the ARC50

You may find that the ARC50 has all the features you need on-board, so that no other boards are required. You then don’t require a backplane and you connect the power supply directly to the ARC50 using the 5-pin plug supplied. If you want to use other ARCbus boards as well, connect your power supply to an ARCbus backplane and plug the ARC50 into the backplane. If you wish to program EPROMs, connect the 25V supply directly to the ARC50 with the 2-pin plug supplied. Your RS232 terminal connects to 3 pins of a 10-pin connector on the ARC50. The printer may be wired to other pins on this connector. The ARC50 will cope with all the common baud rates on both terminal and printer. Once you’ve wired up the power supply and terminal, switch the power on and you are ready to start programming in BASIC. When you have entered a program, run and tested it, you can program it into an EPROM using BASIC commands, so that the ARC50 will autostart into your program on power-up. It’s as easy as that!