CER-203

CER-203: CPU testing

Block diagram

CER (Serbian: Цифарски Електронски Рачунар – Digital Electronic Computer) model 203 is an early digital computer developed by Mihajlo Pupin Institute (Serbia) in 1971. It was designed to process data of medium-sized businesses:

• In banks, for managing and processing of accounts, bookkeeping, foreign-currency and interest calculations, amortization plans and statistics
• In manufacturing, for production planning and management, market data processing and forecasting, inventory management, financial document management and process modelling
• In utilities, to calculate water and electricity consumption, to produce various reports and lists and for technical calculations and design
• In construction industry for network planning method design, financial management and bookkeeping
• In trading companies for payment processing, market analysis, inventory management and customer and partner relationship management

Specifications

Central Processing:

• Type: BMS-203
• Number of instructions: 32
• Performance:
  • one 16-cycle instruction: 20 μs
  • one single cycle instruction: 5 μs
  • addition and/or subtraction of two 15-digit numbers: 20 μs

Primary memory:

• Capacity: 8 kilowords
• Speed (cycle time): 1 μs
• Complete, autonomous memory error checking
• Parity control

Punched tape reader:

• Dielectric-based reading
• Speed: 500 to 1,000 characters per second
• Accepts 5, 7 and 8-channel tapes

Tape puncher:

• Speed: 75 characters per second

Parallel Line Printer 667:

• "On the fly" printing
• 128 characters per line
• Removable/replaceable printing cylinder
• Speed:
  • 500 lines per minute for a character set of 63 characters
  • 550 lines per minute for a character set of 50 characters
• Automatic paper feeder
• Two line spacing settings
• Programamtic tape for discontinuous paper movement
• Maximum number of carbon copies: 6

Independent Printer M 30:

• 132 characters per line
• Speed:
  • Prints 25 alphanumeric characters per second
  • Prints 33 numeric characters per second
  • Tabulation speed: 144 characters per second
  • Blank printing speed: 100 characters per second
• Maximum number of carbon copies: 6

Magnetic cassettes 4096:

• Capacity: 600,000 characters
• Variable record length
• Transfer rate: 857 characters per second
• Tape speed: 10 inches per second

Magnetic Tape Drives:

• Data format: 9-track ASCII with inter-record space of 0.6 inches (1.52 cm)
• Data density: 556/800 bits per inch
• Capacity per tape: c. 10,000,000 characters
• Tape speed: 24 inches/s, 150 inches/s fast-forward and rewind
• Transfer rate: 19.2 kHz
• Tape width: 1⁄2 inch (1.27 cm)
• Tape length: 2,400 ft (731.52 m)
• Working ambient temperature range: 5 °C to 40 °C
• Relative humidity: up to 80%
• Integrated circuit control logic
• Separate control panel for each drive
• Read/Write Capabilities:
  • Read and Write forward
  • Read forward
  • Read reverse

See also

• CER Computers
• Mihajlo Pupin Institute
• History of computer hardware in the SFRY

References

• M.Momcilovic, D.Hristovic, P.Vrbavac et al.:"Domaci cifarski el.racunari CER", Zbornik Savetovanja AOP u preduzecima, pp. 38–58, Nova Varos YU, May 22, 1969. (in Serbian);
• Miodrag Momcilovic, Miladin Dabic:"Domaci el. sistem za obradu podataka CER 203", Proc.of the VI yougoslav Symposium on AOP, Zagreb, 1972. (in Serbian).