TOPS (file server)
TOPS (Transcendental OPerating System) is a
Early versions
TOPS was implemented in the 1980s, an era where each computer system featured its own
When TOPS was originally released in July 1985 there was no peer-to-peer file sharing solution on the Mac.
TOPS was initially a protocol using a custom set of
FlashTalk
Centram later[when?] introduced the "FlashTalk" networking system that used external clocking to improve LocalTalk performance. The Zilog SCC powering the serial ports on the Mac used an internal 3.6864 MHz clock that could then be divided down to provide different standard bit rates. The fastest rate available internally was 230.4 kbit/s, used by LocalTalk. However, the system also allowed the clock to be read from a pin in the serial port, giving rise to the possibility of faster speeds with the right external equipment.
FlashTalk combined a conventional LocalTalk-like dongle with a clocking source and an external power supply. Using these connectors, and the associated software, TOPS could run at 770 kbit/s. This was not only a fairly dramatic improvement over LocalTalk, but also relatively speedy overall in an era when 1 Mbit/s networks were still common.
TCP/IP Support
After the Sun purchase in April 1987, TOPS was given the problem of making a client that could also access Sun file shares using NFS.
Additionally, the majority of Macintosh systems used LocalTalk (or
One limitation of the TCP stack was that it did not support DNS, requiring users to type in IP addresses of the peers they wanted to communicate with. In a network of mostly Macs or Windows PCs this was not an issue, as DNS was not widely used with these systems at that time. KIP also reduced the need for DNS, as it allowed a Mac's existing Address Resolution Protocol (AARP) code within AppleTalk to look up the AppleTalk address of the remote peer, and then communicate with the TOPS stack on that machine to find the corresponding IP address.
TOPS also added the new "InBox Personal Connection"
Decline
TOPS' attractiveness was seriously eroded with the introduction of System 7 in 1991. TOPS had initially competed against the dedicated-server AppleShare, but System 7 included a file sharing server built-in, one that proved to be much faster than then-current versions of TOPS. TOPS sales dwindled and Sun spun off the division as Sitka,[7] before closing it entirely in 1993.[11]
See also
References
- ^ Ziff-Davis. p. 253-266. Retrieved 21 July 2019.
- ^ "Sun Microsystems Inc. / Centram Systems West". Venture Returns. June 1, 1988. Archived from the original on 17 July 2011.
- IDG. p. 68-72. Retrieved 21 July 2019.
- ^
- ^ John Battelle, "TOPS works hard to hold networking lead",[dead link] MacWEEK, 3 October 1989
- ^ a b Maroney, Tim. "File Servers versus Disk Servers". MacTech. Vol. 3, no. 4.
- ^ a b "TOPS peer-to-peer file sharing". Vintage Macworld. 16 October 2005. Archived from the original on 5 February 2013.
- ^ "Sitka Corp". Software Magazine. 1 March 1992. Archived from the original on 22 October 2012.
- ^ "TOPS Terminal". Vintage Macworld. Archived from the original on 5 February 2013.
- ^ "TOPS upgrades InBox PC client software", Archived 2009-01-13 at the Wayback Machine MacWEEK, 4 April 1989
- ^ Lisa Picarille, "SunSelect closes TOPS operation; cites companywide cost cutting",[dead link] MacWEEK, 12 July 1993