STD205
Description
The MICRO-LINK STD205 is a powerful, multi-function processor board based on the Z80A CPU and interfaced to the STD Bus. In addition to the Z80A CPU, the card features six sockets for EPROM or Static RAM and four programmable counter/timer channels. The STD Bus interface is buffered by bi-directional buffers which can be turned off and on through software to allow external masters to directly access the CPU memory.
General Operation
The STD205 utilizes a Z80A microprocessor which functions as the system controller by fetching, decoding and executing instructions in memory and by generating the required signals between the CPU and memory or I/O.
The card provides six sockets for RAM or EPROM. Each socket may be individually configured for the type and size of memory device. Flexible address decoding allows configuring the sockets on 2K boundaries in the STD-Z80 64K memory space. Memory mapping is performed by a firmware decoder which allows the user to select one of four standard maps. Alternatively, the user may program a different decoder PROM to assign the sockets to addresses as required by the application.
External Direct Memory Access (DMA) controllers can access on-board memory and I/O devices buy using the Z80A CPU control lines and providing the required bi-directional address, data and control buffers to the system bus.
The card supports extended addressing by decoding I/O port FFh as the STD Bus signal MCSYNC*. This allows multiplexing the data lines as eight additional address lines. In addition, the card supports MEMEX-controlled bank switching
The STD205 generates all address and control signals necessary to refresh system dynamic RAM. Refresh occurs automatically during each opcode fetch cycle and is transparent to the system.
A four channel counter/timer controller (CTC) allows for software controlled timing functions. A jumper set is provided to allow the user to cascade the CTC channels for extended timing functions.
Specifications
Physical Dimensions
- Meets STDbus Specifications
- 114.3mm (4.5") High x 165.1mm (6.5") Long
- 12.7mm (0.5")Maximum Profile Thickness
Power Requirements
- Vcc = +5VDC, ±5%, 625 mA typical, 1.05 A max.
Environmental
- Operating Temperature: 0 to 60°C
- Maximum Relative Humidity: 90% Non-condensing
Ordering Information
Product Number: STD205-001 with six unpopulated sockets, includes mating connector kit and operations manual.
Accessories:
- STD205-601 Monitor EPROM
- STD205-900 Mating Connector Kit contains one 26-pin connector
- S8000-205 Operations Manual