Bull and computer innovation.
In that page, we will go through a non-structured list of computer innovations and we will identify the reaction of Bull (and of its associated companies, particularly GE and Honeywell) engineers have reacted about or influenced them.
Electronic tubes
The original technology used in Bull's card machines was electro-mechanical relays. In the
1950's Bull started to adopt electronic vacuum tubes for calculator functions and solid
state diodes for logic functions.
Magnetic core logic
SEA pioneered that technology with CAB500 in late 1950s. That technology was obsoleted by
transistors for speed and by the emergence of integrated circuits for cost. It could be
noted that NEC used "parametrons" in an early computer, but, there also there
was no follow-on.
Solid-state circuits
Bull introduced the germanium diodes for its logic circuitry (in conjunction with
electromechanical relays) quite early in the industry.
Transistors
Transistors were initially (in the early 1950s) not reliable enough to replace electronic
tubes for sizeable computers. Their performances did neither obsolete tubes. So, the first
computer for which Bull relied on transistors was the Gamma 60. For that machine and for
the most part of the 1960s, computer manufacturers had to design all the logic circuits
from the elementary gates to the more complex multiplier using their own knowledge of the
performances of elementary transistors (both their specifications and the actual output of
the plant production). That lead to a sizeable team of electronics engineers who had to be
reused for other tasks when integrated circuits became available.
Integrated Circuits
Integrated Circuits were introduced by Fairchild and Texas Instruments in the early 1960s.
They became widely available around 1965. As both Bull-GE and CII rely at that time on
their American affiliates, it was only around 1970 that their own design was converted to
ICs. at that time the TTL technology from Texas was dominating the market that was
essentially made of the computer industry.
Bipolar (ECL) technology from Siemens was planned to be used in some aborted projects at
CII and Bull.
General Electric contemplated for a while to return to the semiconductor market by betting
on the CML version of bipolar technology. However, CML did not get a market inside
the Bull group until the 1980. Honeywell has bought the GE Colorado Springs laboratory in
1972 (?) and made a small production of CML. The technology was also acquired by NEC that
used it successfully in their ACOS product line.
Micropackaging
VLSI
From the beginning of the 1970s, it was obvious that MSI functional modules will
be eventually replaced by very large scale integrated circuits that will require a
complete change in the methodology of building a computer, replacing the workbench by a
virtual one in a computer. However, the size of Bull's main frame computers, starting
around 100,000 gates was too large for contemplating a single chip processor before the
late-1980s. So, an intermediary step was taken in the 1980s to design processor single
boards equipped with a handful of CMOS chips. Bull made its implementation of CMOS
versions of DPS-7 and DPS-8 at the same time or earlier than its major competitors.
Standard microprocessors
Although Honeywell and Bull designers have been briefed by Intel, National Semiconductors
and Motorola since the appearance of 4004, it was not before the early 1980s that use of
those microprocessors took a share in mainframe design.
The AMD bit-sliced 2900 processor was used in a Bull disk controller in the late 1970s.
But studies to use several of them for a proprietary processor failed
R2E, with the Micral 5, was the first in the world to offer a
commercially available computer system powered by a microprocessor (Intel 8008). The
Motorola 68000 family was adopted as the engine for SEMS UNIX system and took. It became
also a general purpose engine for the 1985 generation of peripheral controllers for DPS-7
and later for network processors.
As the Motorola 68000 line was essentially discontinued in 1990, Bull (courted and wac
courted by ) the companies trying to impose their RISC architecture and finally set for
the PowerPC of IBM and Motorola, before leaning for Intel in the late 90s.
Pipeline
The concept of designing a processor with several instructions being in execution inside a
single execution unit was relatively adopted by Bull that was not been addressing the
intensively computing market segment. The ADP project in the mid-70s in Phoenix, that gave
birth eventually to DPS-88, was the first pipelined design in the group, while the Auriga
design circa 1986 was the first true pipelined DPS-7.
Caches
After the first use of cache in the 360/85, Honeywell decided to add it on Level 66, but
the flushing had to be done by software, due to the reuse of the same multi-processor
synchronization mechanism as the no-cache version.
The P7G DPS-7 used the first "store-through" cache modeled by Amdahl. Complex
mechanisms were implemented to recover from a processor failure in a SMP system.
Magnetic Core Memory
DRAM
The first DRAM ever produced by Intel was to be used in the central memory of ACS, the
ill-fated Honeywell new product line, before the GE merger. Level 64 used for second
generation Intel 4K-bit DRAM instead of core memory, as did level 62. Level 66 followed
soon. Two generations of DRAM (e.g. 4Kb and 16Kb) were generally successively offered on a
mainframe processor, the memory controller was designed for that.
Bull and Honeywell did develop its own boards and mounted the chips on different boards,
initially using the same type of board as for logic. When processors came in one
board , memory was either on the processor board or in separate boards.
SRAM
SRAM was used initially for cache memory, and for control store in DPS-7 and later. On NEC
most powerful machines (Zeus) the main memory was implemented in SRAM.
Bubble memory
ASCII
While Bob Bemer at GE was one of the pre-eminent apostle of ASCII, the first system using
ASCII was Multics' 645 on a 9-bits byte. ASCII was later used in Large System first
in conjunction with BCD and was generalized on GCOS8. While also used on Level-61,
and terminals ASCII waited the generalization of networks and open systems to erode the
EBCDIC postion.
EBCDIC
Data compatibility with IBM S/360 was recognized as necessary for the business market in
the second half of the 1960s. Computers designed after that date for the business market
(GCOS 62 and GCOS64) used EBCDIC for that reason.
RISC processors
Jacques Stern, Bull's CEO in the early 1980s, and some Bul's scientists has been convinced
that RISC computers would revolution the computer industry as much and as definitively
as
S/360 had obsoleted the 1950s vintage computers. However, the hardware designers were busy
to reduce the cost of their proprietary GCOS systems by adopting the VLSI and MOS
technology and were not enthusiasts about a revolutionary change in the architecture,
even if HP and IBM were rumored to be interested. Product planners as well did not see
RISC computers to be able to exploit their market momentarily.
For Jacques Stern, RISC computers would take the essential part of the UNIX open systems
market (as they eventually did). he decided not to invest internally, but to outsource the
design, initially from a small Siilicon Valley company Ridge Computers. It was expected
that Ridge investments in architecture and compilers would be eventually benefit fro
Bull's CMOS technology design and operating system experience.
EPIC
Transferring to the compiler the responsibility of ordering the instructions is a
characteristic of the still recent IA-64 architecture. A remote predecessor of that
architecture could be traced up to the Gamma 60 that rely on the programmer the
synchronisation of arithmetic, logic and other operations. Unhappily, compilers able to
order object code were not yet available!
Microprogramming
Multiprocessor
Vector processing
Williams Tube
Magnetic Drum
Disc cache buffer
Discs
Removable discs
Tapes
Automated Tapes library
Data Cell drives
In the 1960s, the industry was in quest of very large random access memories to handle
files such as insurance and income tax. Discs were too small and too expensive, tapes
require batch processing. IBM and RCA produced magnetic strips devices. Bull naturally
adopted the RCA device and connected it to the GE-400 (naming it Bullrac). Bullrac was
somewhat more reliable as the IBM 2321, but the complexity of the mechanics caused this
type of device before the 1970s.
A revival of the automatic loading of magnetic media happened in the 1980s with IBM tape
cartridge library, followed by Masstor and StorageTek devices. Bull connected and
successfully market those devices to DPS-8 and to DPS-7.
Paper tape readers
Paper tape punch
Card reader
Card punch
Card sorter
Cassette
Diskette (floppy discs)
Check processing
Typewriters
CRT display terminals
Smart cards
Emulators
Dynamic partitioning of a SMP system
Virtual machines
Multiprogramming
Time sharing
Interactive processing
Real time processing
Networking
Languages
Data Bases
General Electric, as a major EDP user in the 1950s, was one of the first company to think
seriously about the organization of files stored on disks. Charlie Bachmann designed IDS
(integrated Data Store) in the early 1960s. IDS provided a data base organization that
seemed to address all the requirements of batch as well as direct access processing,
thanks to a mechanism of chained records, allowing hierarchical of structures as well. The
mechanism was then more expensive that indexed-sequential offered at the time by
IBM. Honeywell and Bull marketed IDS-2 -an evolved version, adopted by CODASYL)-
successfully in the 1970s and 1980s.
However, IDS-2 data bases reflected the structure of enterprises and were not easy to
restructure when the enterprises evolved. On the contrary, the relational model advocated
by Codd of IBM, while more expensive in terms of processing constraints, succeded to
dominate the world in the 1980s and later.
The strategy differed according the product lines of Honeywell and Bull. Multics and
GCOS-8 developed their own implementation of the relational model establishing links
with IDS data bases. GCOS-7 choose to port Oracle product as a server on their operating
system. The latter implementation opened the way for specialized processor(s) for running
the data base engine. Oracle's port was done by Bull's engineers but the contract with
Oracle prohibits any know-how transmission of the data base engine technology.
Macroprocessor
High level Implementation languages
Artificial Intelligence
Word processor
Automatic Translation
CAD Computer aided design
Revision : 27 juin 2001.