Computer Data Tables

This is my playground for experimenting with HTML tables. You need Netscape 1.1 or another viewer that knows about the <table> tag to see anything here.

SCSI Types

Reprinted without permission from Black Box's summer '96 catalog, pg. 16. See also the comp.periphs.scsi FAQ.
SCSI-1SCSI-2SCSI-3
The original SCSI standard was approved in 1986. It supports transfer rates of up to 5 MBps and 7 SCSI devices on an 8-bit bus. The most common connector for SCSI-1 is the Centronics 50. Approved in 1994, SCSI-2 introduced optional 16- and 32-bit bus "Wide SCSI." The transfer rate, normally 10 MBps, can go to 40 MBps when combined with Fast and Wide SCSI. SCSI-2 usually uses a MicroD 50-pin connector with thumbclips. Found in many high-end systems, SCSI-3 commonly uses a MicroD 68-pin connector with thumbscrews. The most common bus width for SCSI-3 is 16-bit, with transfer rates at 20 MBps. Serial-bus and fiber-channel protocols are in development.

My notes on the subject, mostly from reading the FAQ:

  1. Fast SCSI is anything above 5MB/sec, the SCSI-1 standard. There can be no Fast SCSI-1. What I have always called SCSI-2 is really Fast SCSI-2. 50-pins, 10MB/sec.

  2. Wide SCSI uses a 16- or 32-bit data path, instead of 8-bit. Wide SCSI-2 would actually use two cables - something that has never been marketed.

  3. Fast/Wide SCSI-2 is essentially SCSI-3. SCSI-3 has not actually been defined yet (7/2/96), but the industry has pushed forward. SCSI-3 uses a single 68-pin cable instead of the dual-cable Wide SCSI-2, and can reach 20MBps (16-bit) or 40MBps (32-bit).

  4. Plug and Play SCSI is basically a SCSI bus (of any kind, but probably SCSI-2 or 3) that allows you to add/remove devices without powering down the computer, and an OS that dynamically "does the thing" with these changes.

  5. Ultra SCSI - I can find no definition of this. I suspect it's a term the industry just coined, and is not a real standard. I'm guessing that it's 40MBps SCSI-3, a.k.a. 32-bit F/W SCSI-2.

4MM Tape Capacities

Format Length Native
Capacity 		Compressed
Capacity
DDS 60m 1.3 GB 2.6 GB
DDS 90m 2.0 GB 4.0 GB
DDS-2 120m 4.0 GB 8.0 GB

Data Rates
Interface Bits /
Second		 Bytes /
Second		 1 MB
Xfer
9600 modem 9.6K 1K 18 min
14.4 modem 14.4K 1.5K 12 min
28.8 modem 28.8K 3K 6 min
57.6 digital 56K 6K 3 min
Basic ISDN 64K 7K 2.5 min
Fractional T1 560K 50K 18 sec
T1 1.5M 150K 6 sec
Ethernet 10M 1M 1 sec
T3 45M 5M 0.2 sec
SCSI-1 50M 5M 0.2 sec
SCSI-2 100M 10M 0.1 sec
Fast Ethernet 100M 10M 0.1 sec
FDDI 100M 10M 0.1 sec
ATM 150M? 15M? 0.07 sec?
From: Mark Costlow
To: Paul Caskey
Subject: tables

One note: Fractional T1 is anything between 56k and T1. The way our CSU/DSU works is you can group together any number of 56k channels ... we're using 10, hence 560k. Common speeds are 256k, 384k, 512k. (Ours was called 512k, even though it's REALLY 560k).

Full T1 is 1.536 Mb (24 * 64k). I'm not sure how much gets shaved off for signalling (a 56k line is really a 64k channel with 8k used for control signals). 




mask (decimal) 	4th byte of mask (binary) 	#networks	#nodes
------------------------------------------------------------------------------
255.255.255.0	00000000			1		256 
255.255.255.128 10000000			2		128
255.255.255.192	11000000			4		 64
255.255.255.224 11100000			8		 32
255.255.255.240	11110000			16		 16
255.255.255.248 11111000			32		  8
...


SunOS	  =	Solaris
------------------------
4.1.3		1.1
4.1.3_U1	1.1.1
4.1.4		1.2
5.3		2.3
5.4		2.4

rrggbb Color
------------------------
000000 black
0000ff pure blue
00ff00 pure green
00ffff cyan
ff0000 pure red
ff00ff magenta
ffff00 pure yellow
ffffff white

000040 velvet
004000 army green
400000 blood red
000080 royal blue
008000 amity green
800000 brick red
0000c0 dark blue
00c000 green
c00000 red

004080 navy

444444 dark grey
888888 grey
cccccc light grey
c0c0c0 browser grey?

Graphic Formats
Bits Colors Notes Sample
1 2 Monochrome
2 4 4 shades of gray
4 16 16-entry colormap of 24-bit values
8 256 256-entry colormap of 24-bit values
15 32K 5 bits per r/g/b
16 64K Usually 5/6/5 r/g/b
24 16M 8 bits per r/g/b ('True Color')
32 16M Just faster than 24-bit
36 64G 12 bits per r/g/b (some scanners)

Screen Resolutions
Resolution
(HxV)		 Aspect
Ratio		 Commonly
Seen		 Video RAM Required
16-Color 256-Color True Color
320x200 8:5 CGA 32K 64K 192K
320x400 4:5 EGA 64K 128K 384K
640x400 8:5 VGA 128K 256K 768K
640x480 4:3 VGA 150K 300K 1M
800x600 4:3 SVGA 240K 480K 1.5M
1024x768 4:3 Real PCs 384K 768K 2.3M
1152x900 4:3 Suns 512K 1M 3M
1280x1024 5:4 Wow 640K 1.3M 4M
1600x1280 5:4 Ay Carumba 1M 2M 6M

Video Resolutions
Resolution
(HxV)		 Aspect
Ratio		 Video
Format		 Video RAM Required
16-Color 256-Color True Color
482x330 7:5 NTSC TV
482x250 2:1 NTSC VHS
482x400 6:5 NTSC SVHS
482x425 9:8 NTSC LD

Here's the full scoop from Bob Niland's FAQ on LDs:

The pulse-FM data structure on an LD (unlike ordinary VHS/Beta), is defined to hold all the information present in the composite video signal. Depending on source material and the transfer to disc, LD is above live TV broadcast quality: For NTSC, this is 425 TVL (luminance lines horizontally) and about 482 scan lines, compared to 330x482 for broadcast.

Compare this to 250x482 for typical VHS (recorded, pre-recorded is probably less). Only recently have Super-VHS and ED-Beta approached LD capability. Of course, pre-recorded material is not widely available in these VCR formats. Even using S-VHS/ED-Beta to tape off-air still only reaches the 330x482 of the broadcast signal. Compared to LD, all consumer tape formats also fall short in time-base stability, chroma resolution, video noise and audio fidelity. 



From pcaskey Fri Apr 26 14:51:52 -0600 1996
To: staff
Subject: line speeds

I got curious and looked this up in my class notes, and thought I'd
share.  Ignore at will.


OC == Optical Carrier
DS == Digital Signaling or Digital Service
T  == comes after "S"

DS-0 = one channel @ 8Khz = 64Kbps         /\
T-1 = 24 DS-0 = 24 * 64Kbps = 1.54Mbps     || COPPER
T-3 = 28 DS-1 = 28 * 1.54Mbps = 45Mbps     || 1 twisted pair half duplex
------------------------------------------------------------------------
OC-1 ~=    T-3    =   51.84 Mbps           ||
OC-3  =   3 OC-1  =  155.52 Mbps           || FIBER
OC-9  =   9 OC-1  =  466.56 Mbps           || 1 fiber strand half duplex
OC-12 =  12 OC-1  =  622.08 Mbps           ||
OC-18 =  18 OC-1  =  933.12 Mbps           ||
OC-24 =  24 OC-1  = 1244.16 Mbps           ||
OC-36 =  36 OC-1  =   1.866 Gbps           ||
OC-48 =  48 OC-1  =   2.488 Gbps           ||
OC-96 =  96 OC-1  =   4.976 Gbps           ||
OC-192 = 192 OC1  =   9.953 Gbps           \/


Then I have a note that says, "Bellcore getting up to 200 Gbps".


The OC ratings are much easier to remember because they make sense;
they're all scaled off a single base value.  Another nice version of
that table would be if it had rounded values, and was in html.  :)


Paul
See also: http://www.citilink.com/~kae/clink_faq/connecting/general/standards.html