IBM 5100
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IBM 5100 was the name of the first series of microcomputers that IBM introduced in 1975. This included both compact system units (for those times) and a selection of practical peripherals . The 5100s were the predecessors of the IBM PC (type 5150), but technically they are in no way similar. Despite the revolutionary concept that came in very handy, the series turned out to be a flop.
IBM SCAMP
The SCAMP ( S pecial C omputer, A PL M achine P ortable) introduced the prototype of the 5100 Portable Computer (see below). It consisted of a housing which the then usual desk calculator resembled. A small 5 ″ monitor, a complete keyboard with a number field and a tape drive were installed. A multi-chip solution called PALM, specially developed for this computer, served as the processor . Only the programming languages APL , BASIC or - selectable by switch - both were available as software or operating system .
IBM 5100 Portable Computer
The first freely available model was the IBM Portable Computer (type 5100), which came onto the market on September 9, 1975 with the PALM CPU. Only in the much later models did IBM also use microprocessors from third-party manufacturers, such as the Intel 8085 in the System / 23 .
The 5100 largely corresponded to the SCAMP (see above), but had a QIC tape drive for DC300 cartridges with a capacity of 204 kB. Depending on the configuration of the RAM and programming language, the 5100 struck between $ 9,000 and $ 20,000.
As an example, here is a code fragment for an Internal Machine Fix (IMF) for the IBM 5100:
; Patch file for the IBM 5100, not runnable on the 5110!
0200 1064 CTRL $0, #$64 ; display off
; Clear bottom half of screen (lines 8 to 15)
0202 D201 0400 LWI R2, #$0400
0206 D501 0100 LWI R5, #$0100
020A 2653 MOVE R6, $A6 ; constant 0
020C 5621 MOVE (R2)+, R6
020E F500 SUB R5, #$01
0210 C503 SZ R5
0212 F007 BRA -$08 ; → $020C
0214 015C MHL R1, R5
0216 C103 SZ R1
0218 F00D BRA -$0E ; → $020C
021A 2152 MOVE R1, $A4
021C B140 SET R1, #$40
021E 3152 MOVE $A4, R1 ; set RAMEXEC flag
0220 2161 MOVE R1, $C2 ; address of I/O supervisor entry
0222 3177 MOVE $EE, R1 ; address of ROS code to be executed
0224 D301 033A LWI R3, #$033A ; address of IOCB
0228 D101 0230 LWI R1, #$0230 ; address of RAM code to be executed (=return address)
022C 3174 MOVE $E8, R1
022E 2075 JMP ($00EA) ; jump to toggle return to ROS
IBM 5110 Portable Computer Model 1
In 1978 the improved version of the 5110 Model 1 came onto the market. Among other things, the new external floppy disk drives (see below) and the character code EBCDIC , which was otherwise in use at IBM at the time, were supported; the 5100 still used its own character code.
IBM 5110 Portable Computer Model 2
The 5110 Model 2 was the same as the Model 1, but did not include a tape drive or a connection for it.
IBM 5120 (5110 Model 3)
The 5110 Model 3 is the individually not available system unit of the 5120, a package consisting of the aforementioned computer and a suitable printer. A larger monitor and two 8 ″ floppy disk drives were integrated into the system unit. The keyboard was firmly attached in front of the device. With a weight of almost 50 kg, the 5110 Model 3 is probably the heaviest desk computer. The system / 23 was later developed from the 5110 Model 3, which has a very similar housing.
Periphery
Peripherals could be connected to the system units using a combination of three cables that represent the system bus . The devices could be cascaded. Example: System unit ← printer ← tape drive.
The matrix printer 5103 was available both individually and as part of the package 5120 in versions with 80 or 120 characters per second.
The floppy disk station was a voluminous tower case with two 8 "floppy disk drives. Among other things, it supported the IBM 3740 format (which has been retained in various computer systems to this day) and allowed storage of up to 1.1 MB per floppy disk. 3740 compatibility enabled exchanged data with other IBM computers and, together with the option - not available on the tape drive - of quick and targeted access to data, ensured that the 5100 computers were now also suitable for daily use in the office with several workstations.
The tape drive corresponds to that of the 5100 or 5110 Model 1, but in its own housing.
Furthermore, an IEEE-488 interface was available, which enabled a wide range of accessories already available for other computer systems and, above all, various devices from measurement technology for use on devices of the 5100 series. Together with the portability of the system units, this enables a large number of field applications.
Web links
- Technology of the IBM 5110 , Computer Museum of the University of Stuttgart
- The IBM 5100 . History Corner
- IBM 5110 emulator in JavaScript . IBM 5110 emulator in JavaScript by Norbert Kehrer