3R Computers (Westboro, Mass.)

The 3R Avatar TC100 series was a dual-processor system used with a dumb terminal to give it full workstation capabilities. It used both a Z80 and 8088-2 CPUs so it could run both CP/M and MS-DOS applications. The TC 3278 is intended for use with only the IBM 3278 or 3178 terminals. The company is also known as RRR Computers.

Reader Brett Johnson added his experiences working for 3R on December 9,2010:

“I worked for 3R/Avatar back in the 1980s, writing the OS and other system software for these things.

An earlier version, the TC1, supported only a Z80A, and ran CP/M 2.2, but looked like the photo. In fact, that photo might be a TC1 (I can’t tell without looking at the back).

The TC100 line added the 8088 process, and ran CP/M and/or MS-DOS, so that existing CP/M applications could still be used. The TC100 would run CP/M in an emulated environment under MS-DOS: the apps and most of the CP/M OS ran at full-speed on the Z80, but had full access to the MS-DOS file system, and peripherals. The Z80 and the 8088 shared 64KB of RAM.

They were “Terminal Converters”, intended to be placed between a dumb terminal and minicomputer (or mainframe) in existing installations to provide local processing capability. File exchange software allowed files to moved between the local computer and the minicomputer, so that the user could edit the files locally using WordStar, CalcStar, etc. The goal was to offload heavy computational tasks from the minicomputer, while still “playing nice” with the centralized computing system.

The TC line supported a couple of dozen different host operating systems, and around 70 different dumb terminals. Early advertising slogans were “3R Computers – the cure for terminal dumbness.”

The device was quite successful early on, and 3R Computers eventually changed its name to Avatar Technologies Inc, reflecting the brand recognition of the product [as well as the departure of one of the founders (one of the ‘R’s)].

At first, we did software development for the machines using Onyx and Plexus Unix systems; cross compiling, then downloading the software.

Once we had MS-DOS 2.1 up an running on TC110s, we switched to native development; because a dedicated 8MHz 8088 beat the pants off of a timeshared Z8000 system. Our development machines were modified TC110s with 1MB of RAM and 20MB hard disks. The ROM was bank-switched, so the 8088 had access to the full 1MB (unlike the 640KB limit of IBM PCs of the era). The 8088 also ran at 8MHz (vs the 4.77MHz of the IBM PC).

Once we went native, our software development tools included a heavily modified version of Mince (an emacs clone for CP/M and MS-DOS), the Lattice C compiler (MS-DOS), BDS C compiler (CP/M), Z80 and x86 assemblers, Polytron PolyMake, Polytron Version Control System, and a handful of unix-like utilities (cat, ls, grep, etc) that I wrote for MS-DOS.

Of course, the IBM PC eventually won the MS-DOS desktop market, even though many other machines (like this one) ran nearly twice as fast, had 30% more memory, and double the disk space.

So Avatar took the daughter-board that allowed the TC100 to communicate with 3278 terminals and built a whole 3270 line of stand-alone boxes and plug-in cards (for the IBM PC). Avatar was eventually purchased by Digital Communications Associates, a competitor in the 3270 PC adapter marketplace.”

Model: 3R Avatar TC100 Universal Terminal Converter (1983, workstation)
Original Retail Price: $2,195
Base Configuration: Z80A and 8088-2 CPUs, 128K RAM (256K max), 2 RS-232C ports, 5.25-inch floppy disk drive, clock/calendar, 85W power supply
Size/Weight: 7.25H x 12.25W x 12.75D inches, 20 lbs.
Important Options: parallel interface; second floppy disk drive; 5MB, 10MB, or 20MB hard disk drive

Model: 3R Avatar TC110 Universal Terminal Converter (1983, workstation)
Original Retail Price: $4,795
Base Configuration: Z80A and 8088-2 CPUs, 128K RAM (256K max), 2 RS-232C ports and 1 parallel port, 5.25-inch floppy disk drive, 5MB hard disk drive, clock/calendar, 85W power supply
Size/Weight: 7.25H x 12.25W x 12.75D inches, 23 lbs.
Important Options: second floppy disk drive, 10MB or 20MB hard disk drive

3R Computers Avatar Series

Model: 3R Avatar TC3278 Universal Terminal Converter (1983, workstation)
Original Retail Price: $2,945
Base Configuration: Z80A CPU, 64K RAM, 2 RS-232C ports, 5.25-inch floppy disk drive, clock/calendar, 95W power supply
Size/Weight: 7.25H x 12.25W x 12.75D inches, 22 lbs.
Important Options: XChange Z80A processor board, parallel interface; second floppy disk drive; 5MB, 10MB, or 20MB hard disk drive

Literature:

1983 3r computers avatar terminal converter so you think you need a computer brochure
1983 3r computers avatar tc3278 systems brochure
1983 3r computers avatar tc3278 price list
1983 3r computers avatar tc110 systems terminal converter price list
1983 3r computers avatar tc100 systems terminal converter price list
1983 3r computers avatar tc100 systems terminal converter brochure

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