Editing IBM 5100 (section)

==Description==
The IBM 5100 is based on a 16-[[bit]] [[central processing unit|processor]] module called [[IBM PALM processor|PALM]] ('''P'''rogram '''A'''ll '''L'''ogic in '''M'''icrocode).<ref>{{cite journal |title=A Microprocessor-based portable computer: The IBM 5100 |journal=[[Proceedings of the IEEE]] |volume=64 |issue=6 |pages=994–999 |date=June 1976 |doi=10.1109/PROC.1976.10253 |last1=Roberson |first1=D.A. |s2cid=38243836 }}</ref>   The IBM 5100 Maintenance Information Manual also referred to the PALM module as the ''controller''.  The PALM could directly address {{val|64|ul=KB}} of memory.  Some configurations of the IBM 5100 had Executable ROS ([[read-only memory|ROM]]) and [[random-access memory|RAM]] memory totalling more than {{val|64|u=KB}}, so a simple [[bank switching]] scheme was used. The actual APL and BASIC interpreters were stored in a separate ''Language ROS'' address space which the PALM treats as a peripheral device. There were twelve models available: with BASIC, APL, or both. Memory could be {{val|16|ul=KB}}, {{val|32|u=KB}}, {{val|48|u=KB}} or {{val|64|u=KB}} of main
storage.<ref name=IBM5100.MoData75/> The 5100 sold for between {{US$|long=no|8975}} and {{US$|long=no|19975}} (between ${{formatnum:{{#expr:{{Inflation|US|8975|1975}} round-3}}}} and ${{formatnum:{{#expr:{{Inflation|US|19975|1975}} round-3}}}} in today's dollars).{{r|byte197512}}

Often described as being "approximately fifty pounds",<ref>{{cite web|url=https://www.ibm.com/ibm/history/exhibits/pc/pc_2.html|title=IBM Archives: IBM 5100 Portable Computer|website=[[IBM]] |date=January 23, 2003 }}</ref> its weight was closer to 55 pounds (25&nbsp;kg). In December 1975 ''[[BYTE]]'' stated "Welcome, IBM, to personal computing". Describing the 5100 as "a 50-lb package of interactive personal computing," the magazine said that with the company's announcement "personal computing gains an entry from the industry's production and service giant," albeit "at a premium price".<ref name="byte197512">{{cite magazine |magazine=[[Byte (magazine)|Byte]]|url=https://archive.org/stream/byte-magazine-1975-12/1975_12_BYTE_00-04_Assembling_an_Altair#page/n91/mode/2up|title=Welcome, IBM, to personal computing|date=December 1975 |access-date=March 19, 2016 |page=90}}</ref>

A single integrated unit provided the keyboard, five-inch [[CRT display]], [[tape drive]], [[IBM PALM processor|processor]], several hundred KB of [[read-only memory]] containing [[system software]], and up to {{val|64|ul=KB}} of RAM.<ref name="friedl198311">{{cite magazine|magazine=[[PC Magazine]]|url=https://books.google.com/books?id=q8fwTt09_MEC&pg=RA1-PA190|title=SCAMP: The Missing Link In The PC's Past?|volume=2|issue=6|date=November 1983 |access-date=January 8, 2015|author=Friedl, Paul J. |pages=190–197}}</ref> It was the size of a small suitcase, weighed about {{val|55|ul=lb}} ({{val|25|ul=kg}}), and could be transported in an optional carrying case, hence the "portable" designation.

In 1975, it was an amazing technical accomplishment to package a complete computer with a large amount of ROM and RAM, CRT display, and a tape drive into a machine that small.  Earlier desktop computers of approximately the same size, such as the [[HP 9830]], did not include a CRT nor nearly as much memory. The 5100 has an internal CRT (five-inch diagonal) and displays 16 lines of 64 characters. IBM provided an option switch to allow the user to display all 64 characters of each line, or only the left or right 32 characters (interspersed with spaces). Also there was a switch to display the first 512 bytes of main memory in hexadecimal for diagnostic purposes.

Two solutions existed for obtaining hardcopy output: printers such as the [[IBM 5103]], and attaching a typewriter via
an interface. The ''TYCOM 5100'' (from a company named ''Tycom Systems Corporation'') enabled controlling an [[IBM Selectric]] typewriter, printing at 15.5 CPS.<ref>{{cite magazine|url=http://www.bitsavers.org/magazines/Datamation/197605.pdf|department=Hardware|title=IBM 5100 peripheral|magazine=[[Datamation]]|volume=22|issue=5|page=212|quote=transferred at a maximum of 15.5 characters per second.|date=May 1976}}</ref>

Mass storage was provided by removable [[quarter-inch cartridge]] (QIC) [[magnetic tape]] drives that use standard [[DC300]] cartridges to store {{val|204|u=KB}}. One drive was installed in the machine and a second (Model 5106) could be added in an attached box.  The data format included several types and were written in 512 byte records. The introduction of a floppy option was not until the ''IBM 5110''.<ref>{{cite web|url=http://computermuseum.informatik.uni-stuttgart.de/dev_en/ibm_5110/index.html
|title=IBM 5110}}</ref>

At the same time IBM announced the IBM 5100, it also announced the IBM 5100 Communications Adapter, which allowed the 5100 to transmit data to and receive data from a remote system. It made the 5100 appear the same as an [[IBM 2741]] Communications [[Computer terminal|Terminal]] and was designed to be able to communicate with IBM 2741 compatible machines in start-stop mode using the ''EBCD'' ('''E'''xtended '''B'''inary '''C'''oded '''D'''ecimal) notation,<ref>{{cite book |url=http://www.bitsavers.org/pdf/ibm/5100/SA21-9215-0_IBM_5100_Communications_Reference_Manual_Sep1975.pdf |title=IBM 5100 Communications Reference Manual |edition=First |date=September 1975 |publisher=IBM |id=SA21-9215-0}}</ref> referred to as PTTC/EBCD in IBM 2741 documentation.<ref>{{cite book |url=http://www.bitsavers.org/pdf/ibm/2741/A27-3002-0_2741_Communication_Terminal_OEM_Information.pdf |title=2740/2741 Communication Terminal Original Equipment Manufacturer's Information |edition=First |pages=11–14 |publisher=IBM |id=A27-3002-0 |series=IBM Systems Reference Library}}</ref>  EBCD was similar to the more common IBM [[EBCDIC]] code, but not identical. A feature that does not appear in any advertisement for this computer is an optional Serial I/O Adapter.  In order to access the port extensions, they needed to be loaded from tape for the APL and BASIC programming languages.<ref>{{cite book |url=http://www.bitsavers.org/pdf/ibm/5100/SA21-9239-1_IBM_5100_Serial_IO_Adapter_Feature_Users_Manual_Jan1977.pdf |title=IBM 5100 Serial I/O Adapter User's Manual |edition=Second |date=January 1977 |publisher=IBM |id=SA21-9239-1}}</ref>   Unlike the Communications Adapter which could only be used to connect devices that supported the IBM 2741, this feature allowed users to connect and code for any device that used a standard serial I/O port, including devices not made by IBM.<ref>{{Cite book|title=IBM 5100 Communications/Serial I/O Maintenance Information Manual|page=1{{hyp}}1|url=http://www.bitsavers.org/pdf/ibm/5100/SY31-0429-2_IBM_5100_Communications_Serial_IO_Maintenance_Information_Manual_Oct1976.pdf|access-date=December 24, 2023|publisher=IBM|id=SY31-0429-2}}</ref>

One periodical described "an interesting standard feature"; that a 5100 could be connected to a television.<ref name=IBM5100.MoData75/> An external video monitor receiver could be connected to the IBM 5100 via a [[BNC connector]] on the back panel. While the 5100 had a front panel switch to select between ''white on black'' or ''black on white'' for the internal display, this switch did not affect the external monitor, which only offered white characters on a black background. The vertical scan rate was fixed at {{val|60|ul=Hz}}.