INTERNATIONAL COMPUTERS LIMITED
MLADOST ZAGREB, CROATIA, (YUGOSLAVIA)Rudolf Bosnjak History With Computers
I worked on the ICL 1902 series machines as Hardware Engineer for area of Bosnia and Herzegovina. We serve ELECTRONIC CENTERS in Electro Technical Faculty in Lukavica, Sarajevo, Metallurgy Institute in Zenica, and Furniture Factory in Zavidovici and company Radoje Dakic, Titograd, Monte Negro other sites in Yugoslavia.
The ICL 1900 was a word machine with 24-bit words, containing 4 * 6-bit characters. Instructions were whole words, and a word could be addressed in both 'word' or 'character mode depending on the type of data it held and IMHO a nice instruction set for commercial DP.
Likewise all peripherals were available in a general pool and allocated to a program when requested and then released back to the pool when finished with. Every program started at address zero wherever it was located in physical memory, hardware 'datum' and 'limit' registers provided the translation/protection for user programs, which could be moved in memory as other programs altered their size or were deleted.
The memory size (core store or later ECL electronic) was typically 32K, 48K for smaller machines, 64K, 128K, 192K or 256K for larger machines. The biggest that I heard of was 512K and I think that was a University machine.
1900 Mainframe series
The 1900 Series was announced in September 1964, only six months after IBM launched System/360 and some 1900 models were delivered earlier than their IBM equivalents. The FP6000 was based on logic cards developed in Ferranti Wythenshawe for Orion 2. Some major changes had to be made to the architecture to turn it into a range. The order code had to be altered to allow the memory size to be greater than 128K 6-bit characters.
There were five series of 1900 processors, each series being an improvement on technology and speed from the previous. The initial series were a number without any letter suffix, the next series had the E & F suffixes, the third series had an A suffix, the fourth series had an S suffix and the final series a T suffix. The FP6000, from which the series originated, became the 1904.
ICL 1900 SYSTEM MEMORY CARD
Teletype terminal was connected to the ICL 1900 system.
1916 1,000 ch/sec Paper Tape Reader
FAULT FINDING PROCEDURE FOR CE 32 BOARDS
CLICK ON IMAGE TO SEE MY CE 32 BOARD TESTER
2 deck cluster - 1973 7-track Magnetic Tape
On a 1900 series machine, all peripheral
transfers were initiated by a PERI instruction referencing a control block, which was an
'extracode' handled by the EXECutive. This meant that programs could handle transfers on
all types of peripherals in a similar manner, with specific device driver code in the
EXECutive for the type/model concerned and programmers need not worry about differences
between say a 7-track tape unit and 9-track tape unit.
I worked on the ICL DRS 25 series machines as Hardware Engineer for area of Bosnia and Herzegovina and Serbia (now SCG), in Former Yugoslavia from Service Center in Belgrade. We serve company Robne Kuce Beograd, in more than 30 Department Stores in Yugoslavia.
In the early 70s, the British government whished an English computer company could compete with the world major manufacturers. Some years later, the ICL company became one of the larger manufacturer of computers in Europe and did really compete with U.S. companies.
In 1980, before the ICL Personal Computer was born, the company met serious financial problems, the English government paid several million pounds and ICL asked the British RAIR CIE to provide the ICL-PC hardware.
This ICL Personal Computer system using a serial video terminal as video display,
and CP/M (single user) or MP/M (multi-user) operating systems.
Several models were available, all based on the Intel 8085 processor. Among them:
Model 15 - 64 KB RAM, 2 x 5.25" FDD, CP/M O.S.
Model 25 with a 5 MB hard disc, CP/M O.S.
Model 26 64 KB RAM, three users, 5 MB hard disc, MP/M O.S.
Model 35 256 KB RAM, three users, 10 MB hard disc, MP/M O.S.
KOMENTARI MOJIH RADNIH KOLEGA NA OVOM POSLU KOJI SU SE SVI OSAMOSTALILI...
Budimir Raketic ima firmu http://www.melcobuda.co.yu
ovo Ti je super ideja za ICL, samo Mi se slabo slikasmo onda, vise smo uzivali u radu i zaradi kao trosenju para...
Mr. Sherif Bacevina work with me on ICL 1900 Mainframe computers in in Electro Technical Faculty in Lukavica, Sarajevo, Metallurgy Institute in Zenica, and Furniture Factory in Zavidovici and company Radoje Dakic, Titograd (Podgovrica now) in Monte Negro and some other sites in Yugoslavia. This image is somewhere from his work in Canada.
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