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A Technical History of ROCC Computers

This is intended as brief look at the technology that ROCC has developed and sold over the years compiled from Press Office records, sales brochures, and technical literature that has survived, as well as conversations with some of the people who were involved.

ROCC of course was Redifon Computers until 1981, then Rediffusion Computers, before becoming ROCC Computers in 1984, but this and the changes in ownership are covered in the company history.

Without any sales or revenue figures so it is difficult to know precisely how important the various products were to ROCC, any judgements on this or the reasons why certain developments occurred are largely speculative on my part.

It is also important to remember that many systems were on rental agreements for periods of up to five years rather than being sold outright, and along with the maintenance agreements, produced a regular income independent of short-term sales. On return from rental, systems were usually refurbished, up-dated and put out again for rental.

At the peak there were more than 800 UK customers, with as many again overseas, mainly in Eastern Europe, and up to 2000 systems installed. If the BCG serial numbers were an exclusive and contiguous range then more than 3200 systems were manufactured by 1992, although by the time the R-Range was launched in 1978 the numbers were already into the 2000’s indicating that the majority of systems were Seecheck ones sold during the 1970s. The later systems were a lot thinner on the ground as the market had become saturated and technology was moving on, although for the last 15 years or so nearly all the systems in the field were BSP/FBSP ones, split roughly 50/50 between 28x0 and 28x5 variants.

As this is a technical history I will mention the technologies involved and how they developed in the various products, rather than the more general development of the company itself.

Note that inter-relationship and nomenclature of the various product lines is quite complicated as this was driven more by marketing than the actual technology involved, so for instance when a new range was launched existing products would be renamed although not incorporating (at least initially) any new developments, and the standard specification of the systems would increase over the period they were current. Also names such as Seecheck have been re-used for totally unrelated products over the years.

Keycheck (1970)
This was the system that was originally derived from flight simulation technology circa 1969. The heart of the system was the R2000 computer upgraded in 1973 to the R2000A which had a 24-bit 650ns processor and could be supplied with up to 128K words of core store. Disk and tape storage were provided in separate cabinets, disc capacity being 7.2 MB with options allowing up to 40MB per system. The tape drives (maximum of three) used 2400’ tapes at 556/800bpi NRZ or 1600bpi PE.

The system could support up to 64 keystations, the original versions just having single line displays, later systems such as described above had 768 character VDU keystations.

There is very little information on these systems as they would have been superseded in the mid 1970s for all but the largest installations by the cheaper mini-based Seecheck systems.

Seecheck (1972)
The technology for the Seecheck system was developed with the Entrex company in the US, Redifon having the rights to sell it in the UK, and also developed a market in Eastern Europe and the Middle East. It was based around the Nova 16-bit mini computer produced by Data General, and set the basic architecture of all the systems developed down to the 2885 in 1990.

Seecheck Basic Control Groups (BCG) used a ‘Lowboy’ rack containing a 17 slot ‘DCC’ mini, tape drive, disk drives and necessary power supplies. The DCC mini computer had a 1200ns processor and 64KB of core store, and was also the only Nova based system supplied with programmers switches built in to the front panel, all subsequent systems having a detachable one for engineers’ use only.

One or two 2.5MB or 5MB DRI disc drives were supported, these utilising a single platter removable cartridge (although used as a fixed unit in Redifon systems) with a rack and pinion head actuator mechanism and optical sensor similar in principle to that subsequently used in floppy drives. The tape drive could be either a 7-track 556 bits per inch or a 9-track 800bpi.

Up to 32 Mk II terminals could theoretically be connected, each having its own I/F board in an auxiliary card cage, but eight was the normal limit. The terminals were normally the MK II type with the keyboard built in to the display unit, although the MK I was similar but with the base of the terminal integrated into the desk top. Both versions had a 480 character display. From the MK II onwards all Redifon terminals had a Cyrillic variant.

The Redicheck system was a cut-down version with only 48KB of core and a maximum of eight terminals.

The software was a pure key-to-disc application, although VDU orientated, and very flexible compared to the card or paper tape punching systems it was replacing. This software became known as ‘7’ series.

In 1974 Redifon signed a licensing agreement with Metronex/Meramat in Poland whereby Seecheck would be manufactured in Poland using Soviet-bloc hardware for sale in Soviet-bloc countries. Although peripherals were available in the Soviet-bloc there was not a suitable CPU so Redifon designed and developed a DG Nova compatible mini, called the P.1, for manufacture in Poland. This CPU complied with the then CoCom strategic embargo. Later Redifon would up-grade this design for the E.17 mini made in the UK.

R-Range (1978)
In 1978 Redifon’s product line was expanded by the launch of the R-Range systems developed from Seecheck, in fact Seecheck systems continued to be sold largely unchanged as the R50, while the R300, R400, and R550 introduced more memory, bigger, faster disks and 1600bpi tape drives housed in the new larger ‘Highboy’ rack. The DCC mini was also replaced by the in-house manufactured 1200ns ‘E17’ processor, and up to 128KB of core in a new 17 slot cage. The 5MB DRI discs were still offered, but there was now a ‘big disk’ option in the shape of Ampex 33MB or 66MB drives with removable disk packs, 4 disks or 66MB being the maximum. An 8” diskette option was also introduced with these systems.

The R300 supported 20 Mk II terminals, the R400 48, and the R550 30, and an OCR system, these systems all using a development of the Seecheck software referred to as ‘A’ load this being lean on features but optimised to achieve the maximum number of keystations. This software and an enhanced version of the R400 was still offered well into the 1980s for specialist keying operations.

At the same time another version of software was released, called ‘B’ load it added features to support data processing in an office environment and was the basis of all future developments, it also allowed a total of 264MB total disk capacity. To complement this software the R800/30 (8 terminals) and R800/50 (24 terminals), were launched at the same time as the keying systems. The R800s used ‘Highboy’ racks and much the same hardware as the other systems, but a new type of terminal, the MK III, with a detached keyboard (029 keypunch or typewriter layout) and a 480 or 1920 (24 x 80) character display was provided. An R800/50 system would probably have cost around £60,000 at the time.

The following year an enhanced E17 CPU with a 800ns cycle time and support for MOS memory was released in the R870 (R800/70) follow up to the R850. This CPU/memory could also be fitted in the R400 and R550. The replacement of core store by MOS memory was a major advance, but came at a price, as MOS is a volatile memory technology so required a Battery Backup Unit (BBU) to maintain its state while the system was powered off, or for intermittent power disruptions.

R1850 (1981)
Another major advance in CPU design followed soon afterwards with the introduction of the 400ns Bit Slice Processor (BSP) which supported 256KB or 1MB of MOS memory, the latter requiring three separate BBUs to be fitted. The term bit-slice comes from the technology used, each AMD 2901 chip providing a 4-bit wide ALU, the chips being designed such that by connecting them in parallel any word size which is a multiple of 4 can be implemented, in this case 4 x 4 = 16 bit. A single AMD 2910 microcode sequencer controlled the operation of the CPU. The flexibility of microcoding allowed the rigidly 16 bit instruction set of the original Nova to be enhanced by the introduction of some block move and byte orientated instructions among other things.

Some microprocessor based controllers were also introduced, initially Intel 8080 based, although later ones used the Z80.

To support these features new system software, ‘C’ load was introduced for the top of the range R1800/50, the R1800/30 and R1800/40 still using the E17 and ‘B’ load. The R1800/40 was an interesting (and very singular) system as it substituted the normal ‘Highboy’ rack with the smaller ‘Furnace Green’ rack (similar to the later ‘Smallboy’) and used a compact tape unit and an internal 8” 20MB BASF disk drive.

R1800 / R1850
R1800/50 in 1980 - Click to Enlarge

The major marketing drive for the R1800/50, apart from improved performance, was its capabilities as an advanced office system, with features for transaction processing, word processing, enhanced communications (IBM, ICL, Burroughs, Univac and other Redifon systems), Viewdata plus, and handwritten input using WRITAWAY terminals.

Viewdata used modified colour TVs as terminals, while the WRITAWAY terminal used a paper form with boxes for input overlaid on a pressure sensitive pad which detected the pen movements and interpreted them in similar way to OCR.

Videotex and Teleputer
In 1981 as the new R1800 range was opening up possibilities of Videotex systems, the Teleputer was launched as System Alpha (at this stage Teleputer was used to classify the device, not the actual marketing name). Systems Alpha 1 and 2 were Videotex terminals which could connect to both private systems such as an R1800/50 or Prestel. System Alpha 3 added the functionality of a CP/M based system with a Z80 CPU, 64KB of RAM and twin 5.25” floppy drives each giving 320KB of storage. The monitor was an adapted Rediffusion 14” portable colour TV. System 4 and 5 integrated a VCR or LaserDisc player into the system to allow video clips to be brought up on the screen.

During 1983 the systems were re-launched as Teleputers, with similar specifications/functionality, but with a different design of plinth and in a beige rather than dark colour scheme. The Teleputer 3 seems to have become the figurehead product, sold as a micro computer with a number of applications provided for standalone use i.e. STARTYPE – word processing, STARFILE – database management, STARCALC – spreadsheet, and STARDATA – formatted data entry. A BASIC interpreter was included with CP/M and STARTEL could be use to emulate a Videotex terminal. By this time RAM was 128KB with up to 16KB of video RAM allowing a 40/80 column by 24 line display or 240 x 240 pixels in seven colours. The built-in modem was a 1200/75 one although faster communications were available through the RS232 port.

2830 (1982)
The improvements continued at a rapid pace with the introduction of the Rediffusion 2830 which featured an improved rack, the ‘Tallboy’ and importantly Winchester disk technology. Two Fujitsu 8” disks (33MB or 66MB) were mounted internally along with their power supplies and being sealed units needed little maintenance and had greatly improved reliability – maintaining the Ampex drives had been one of the field service engineers’ more onerous tasks. Two more could be mounted in another rack to give the maximum supported by ‘C’ load 264MB, although some systems substituted the 8” drives with a Fujitsu 14” 132MB one.

The Ampex drives were still used though for the 2830EE (Easter European) variant (max 100MB), along with a 1000ns CPU and 256KB memory because of CoCom export restrictions to these countries at the time.

The standard tape drive was a Digidata 1740 800/1600 45ips unit which required some pretty solid steel bars in the base of the rack to counterbalance it when hinged out for maintenance.

A new 10 slot mini was fitted (some later systems had 20 slots) but the 400ns BSP and 1MB of extended memory was unchanged, although some new interface boards were produced, including the TM for supporting workstation clusters.

This was a new departure which allowed up to 64 workstations to be connected instead of 32 MK III terminals daisy-chained onto a scanner board. Each TM allowed 8 cluster controllers to be connected via links using HDLC protocol, each cluster controller being a Z80 based system supporting up to 4 workstations and two local printers. The workstations or ‘Ifield’ terminals had P31 high quality 15” screens and separate keyboards in 029, typewriter (several), and universal variants. All local character processing was done in the cluster controller, the Ifields being purely dumb I/O devices. In practice each TM could support a maximum of 12 workstations so at least 4 TMs were normally fitted.

The 2810 was a Highboy 1200ns E17 system with ‘B’ load, Ampex disks, and MK III terminals while the 2820 had an 800ns E17 CPU. The 2805 was an upgraded R400 running ‘A’ load for data entry.

2840 (1985)
The company, now ROCC extended the 2800 range in 1985 with the release of the 2840 and Videotex optimised 2850. These systems used the same architecture as the 2830, although with a 300ns BSP in a 20 slot mini and the option of a pair of Fujitsu 132MB 8” disks. The most noticeably change was the use of a Cipher M891 100ips tape streamer mounted horizontally in the rack which allowed the overall height to be reduced to around 4’. These Cipher streamers became the standard for all future ROCC systems, although the automatic loading process was not always very reliable, so many people preferred the Digitdata drives. The whole unit slide out of the rack on rails for maintenance or tape untangling, the lower part of the rack having a ‘decorative’ glass door.

The terminal count was still a maximum of 64 Ifields, or 32 plus 32 Videotex ports using ‘C’ load, whereas the 2850 could support 48 Videotex ports, and 16 Ifields, but this time using ‘V’ load which was optimised to improve Videotex performance. Eventually the 2895 appeared with 96 ports.

2800 Classic (1987)
In 1986/87 another major revision of the range and technology occurred with the low end 2825 and mid-range 2835 systems replacing the 2810, 2820, and 2830. The completely new and much smaller ‘Miniboy’ cabinet was used, made possible by the use of Fujitsu 5.25” SCSI disks and compact Farnell power supplies. The Cipher tape streamer could not slide out on rails because the rack was too small and light to counterbalance it, so the top of the cabinet was designed to hinge upwards with the assistance of a gas ram. The front of the cabinet encased all but the loading door on the Cipher, the tape controls being replicated on the cold start panel. The loading door was offset to the right which presented an interesting design problem to hide the asymmetry, the solution being to make a feature of it with the left side of the cabinet being mid-grey which extended to the front and lid on a ridged strip several inches wide. The rest of the cabinet was very pale grey.

The 2835 used a 10 slot mini (very early ones were 7), with a new CPU, the Fast BSP (FBSP), which was a redesign of the BSP with a single ALU chip instead of the four AMD2901s which allowed selectable speeds of 400ns, 300ns, 200ns, 150ns and up to 3MB of on-board memory, allowing two of the BBUs to be dispensed with. A SCSI board was also designed to interface to the two disks possible in the cabinet, 132MB ones being standard initially.

The 2835 could support up to 32 of the faster, improved workstations via similarly upgraded cluster controllers, while the second new system, the 2825 had a limit of 16. This BCG had a 7 slot mini, and normally one of the older BSP CPUs with 256KB of memory on a small board plugged directly onto the edge of the CPU. The tape streamer was the slow 25ips model, and some disks were only 33 or 66MB non SCSI so had a separate SCSI board to connect to the system.

Other systems in the Miniboy cabinet were the Videotex 2816 and the 2800 APS (Application Processing System) which supported 16 Wyse 50 serial terminals only for use with the local government applications etc, that ROCC was selling.

The high performance features of the ‘V’ load software were incorporated with support for the new hardware features into ‘D’ load operating system. This was eventually renamed Workstation Management System or WMS.

The following year the new technology was implemented for the high-end systems, the 2865, 2875, 2846, and 2896 replacing the 2840, 2850 and 2890. The ‘Bigboy’ cabinet was basically a Miniboy increased in height to accommodate a 20 slot mini, and four 5.25” SCSI disks. Typical configuration for a 2865 would have been 200ns/2MB and 150ns/3MB for the 2875, both supporting up to 64 workstations.

The ‘Classic’ name was probably first used about this time to differentiate the traditional systems from the new UNIX and PC based products being released.

2885 (1990)
Several new developments on the hardware side came to fruition in 1990 with the release of the 2885 and ROCCADDRESS systems.

The 2885 was based on the 2875 in a Bigboy cabinet with the new Advanced Custom Processor (ACP) consisting of a custom made ASIC chip working in conjunction with a 68020 to give the basic Nova functionality plus extra features for the future. This allowed the speed to be doubled to 75ns cycle time and on board memory increased to 4MB.

The other major developments concerned the introduction of SCSI tape devices which allowed the implementation of the ‘Quicksave’ feature on the accompanying WMS 5.1 release. The 2GB 8mm Exabyte drive was selected after an evaluation alongside 4mm DAT technology and was mounted below the Cipher streamer in an extra slot in the front cover. Some systems had the Cipher M995 6250bpi GCR streamer, the control panel of which required an extended cut-away in the front cover below the loading door.

WMS 5.1 allowed total disk capacity to increase to 1GB, and options of Fujitsu 300MB and 600MB drives were released about this time. Maximum workstation count was 96.

Another new system, the 2845 had the Exabyte option and larger disk in a Miniboy rack as an upgrade from the 2835, and soon most of these new features were offered as upgrades to users with existing 28x5 series systems, estimated at 100 plus at the time.

On a separate theme ROCCADDRESS was released, this was an add-on that used a database of UK postcodes generated from the Royal Mail’s Postal Address File (PAF) to allow fast entry of addresses. The hardware consisted of a SCSI disk controller with modified firmware connected to a 300MB disk and 150MB QIC tape drive in a slim-line tower cabinet. A ROCC (Wyse) 50 terminal was provided so operators could perform database maintenance and update operations. Every three months ROCC sent out a QIC 6150 tape generated from a simplified version of the latest PAF release so that customers could keep their systems current.

Finally the professional keyboard and workstation were released. These were promoted as a more ergonomic replacement for the Ifield Workstation, the keyboard being a slimline but heavy duty unit more like a PC one, while a VGA converter allowed a monochrome monitor to be connected to a cluster. These and the enhanced cluster, a single board in a much smaller and neater case than the standard unit were never widely used - by this time the market was starting to shrink as PCs took over general office functions, and keyboard data entry was replaced by more automated methods.

Hardware development probably finished in 1992, while WMS software was developed until 1995. Reconditioned systems continued to be supplied up to 1998, with software maintenance planned to finish in 2006.

The ROCC Classic series had a 36 year operational life, from the 1972 Seecheck to the last UK operational 2835 that was retired in 2008. It had a production life of twenty years, 1972-1992. Although it was marketed under many guises it was really only one system, a DG Nova style CPU with an integrated software environment known originally as ‘Loads’ and later as ‘Workstation Management System.’ All the systems were compatible.

ROCC seems to have seriously started investigating UNIX in the mid-1980s but the gestation was prolonged and the nomenclature confusing with at least three different designations for UNIX based systems. In 1986 ROCC’s Tripos strategy was announced, comprising the 2800 range, still targeted at bulk data entry, the 3800 UNIX based systems with the emphasis more on office and processing operations, and the 4800 multi-processor version of the 3800 which was intended as the ultimate upgrade path for both 2800 and 3800 users.

Until the advent of the Motorola 88000 based systems in the early 1990s ROCC’s UNIX technology was firmly based on Integrated Solutions Inc. (ISI) 68020/VMEbus systems running the ISI version of BSD 4.2 initially, progressing to BSD 4.3 with a SYS V dual universe option by the time of the production systems. These systems consisted of either the V8, 8 slot mini or the V16, 16 slot mini, the 68020 running at 16.7MHz in the initial systems, later increasing to 25MHz plus, with normally between 4MB and 12MB of RAM , 5.25” SCSI disks, and often an Ethernet interface, as well as 8 – 48 serial ports.

The 3800 range comprised the 3810, an 8-slot system with up to two disks and a QIC tape, which seems to have been a re-badged small ISI tower, the 3820 large ISI tower with 16 slots and four disks, and the 3830 a similar system in a Miniboy rack with a Cipher streamer. I think it unlikely that any of these systems were actually sold at this time.

Although ISI documentation suggests that multi-CPU systems should be possible, I have no evidence that the 4800 project proceeded whether for technical reasons or commercial ones.

The only software available initially was ROCC Integrated Office (RIO) which was a combined word processor/spreadsheet/ relational database, although work was already in progress on C-Check II, a programming/processing environment modelled on the WMS ‘Editor’ language and similarly used for data entry tasks. The third application was as a file server for PCs but other than C-Check II the major applications were the local government CCT ones based on the Unify/Accell RDBMS which were sold from 1988 onwards.

During 1987 the UNIX based 2895 was scheduled to be launched and was to be primarily a file server and communications gateway for up to 64 Ethernet connected PCs although it was to have the WMS/X operating system later standard on all ISI derived systems. WMS/X was BSD 4.3 modified by ROCC (they had a licence for the sources) to make routine tasks menu driven including access to RIO, C-Check II, and the Unify database, as well as enabling system shutdown in the event of a power failure.

ROCC’s UNIX systems were eventually released as the 28x8 series. The 2828 and 2838 were both in Miniboy cabinets, with V8 minis, 16.7MHz 68020s and Cipher streamers, the chief differentiation being number of serial ports (8 or 16), disk size (140MB or 324MB) and memory. One or two 5.25” disks could be fitted but half the lower cabinet was occupied by a third party UPS, and circuitry to detect a power failure. There was also a Czech export version of the 2838 with a 10MHz CPU. The 2848 was in a modified Bigboy cabinet, with enough space for a V16 mini and up to four 5.25” disks. The standard systems were quoted with a 150MB QIC tape (the drive was installed where the Cipher loading door would have been by means of a special bracket) but in practice most customers probably paid an extra £9000 for the Cipher unit.

The 1990 list price for an entry level 2828 with QIC tape, 4MB RAM, 140MB disk and 8 serial ports was £21,000 while a typical, but not fully spec’ed 2848 with a Cipher streamer, 12MB RAM, two 324MB disks and 32 serial ports was around £80,000.

These systems were never very numerous, at their height there were half a dozen 2828s, nine 2838s, two-thirds of which were the Czech variant, and eight 2848s, but nearly half of these ISI systems were actually used in-house by ROCC.

One final development of the ISI theme was the OpenKey system announced in 1990. This was meant to be a cheaper alternative to the 28x8 systems being an 8-slot system in the same tower cabinet as used for ROCCADDRESS, restricting systems to a single disk and QIC 150MB tape, although the front panel had four disk LEDs. This is another system that never seems to have made it into production, possibly being sidetracked by smaller more powerful Motorola systems.

In the early 1990s most customers were upgrading to 25MHz 88000 based Motorola 8220 or 8420 systems although there were a few who had the later M992 ‘stacking’ systems with 50MHz CPUs.

Software/Software Development
The Nova system used a 16-bit word addressed architecture which means only 128KB was visible at any one time, although later systems had up to 4MB available. From ‘C’ load onwards the memory was divided into a global area at the lower addresses containing common code, global variables etc that are in constant use by the system, and a number of ‘local’ banks in the remaining area, each one containing the data for a user session or task. If a 16KB bank size was used the lower 112KB of the address space would be the global area, with the bank of the current process visible as the remainder. When re-scheduling occurred the BSP hardware swapped the bank over before the next task resumed.

The task scheduling was not pre-emptive, the functioning of the system relying on the current process to relinquish control when it had used its allotted time, or started an I/O operation.

ACP Advanced Custom Processor - the last ROCC CPU developed
AFL Advanced File Load?
ALU Arithmetic Logic Unit
ASIC Application Specific Integrated Circuit
BBU Battery Backup Unit – maintains system memory during power interruptions
BCG Basic Control Group – the main system unit
BSP Bit Slice Processor – second generation CPU using AMD 2900 chips
E17 Redifon version of Nova CPU developed from P.1
FBSP Fast Bit Slice Processor – development of the BSP with different chipset
ISI Integrated Solutions Inc. – supplied ROCC with UNIX systems
NOVA Data General mini computer launched in 1969
P.1 Redifon version of the Nova CPU designed for Poland
PAF Postal Address File – Royal Mail postcode database
QIC Quarter Inch Cartridge tape
WARMS Warm Start

WMS Workstation Management System – the final name for the system software

Richard Hibbs
March 2011

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