Editing IBM 5110

{{Infobox computer
| name          = IBM 5110 Computing System
| image         = [[File:IBM 5110 Ridai Museum.jpg|260px]]
| caption       = IBM 5110 Computing System at the Ridai Museum of Modern Science, Tokyo
| developer     = IBM General Systems Division; designed at IBM Rochester, Minnesota; project led by Bill Sydnes
| manufacturer  = IBM
| type          = Desktop business computer
| release date  = January 1978 (announced); first customer shipment 2 February 1978 to Punxsutawney Electric Repair
| discontinued  = 31 March 1982 (Models 1 and 2); Model 3 (= [[IBM 5120]]) withdrawn 10 December 1982
| cpu           = IBM '''PALM''' (Put All Logic in Microcode) — 16-bit board-level processor (same as [[IBM 5100]]). 1.9 MHz, 530 ns 2-byte cycle. 13 bipolar gate arrays
| memory        = '''RWS (RAM)''' 16 / 32 / 48 / 64 KB in 16 KB increments. '''Executable ROS''' + '''Language ROS''' (APL / BASIC); sized for the larger EBCDIC character set support
| storage       = '''Model 1''': 1 × DC300 1/4-inch cartridge tape drive built-in. '''Model 2''': no internal tape; diskette only via external 5114. '''Model 3 (= 5120)''': 2 × 8-inch floppy drives built-in. External IBM 5114 Diskette Unit (1 or 2 × 8-inch floppy drives, 1.2 MB each, up to two 5114 units for 4 drives × 1.2 MB total)
| display       = Integrated 5-inch CRT (same as 5100), 1024 characters (16 × 64) addressable
| sound         = None
| dimensions    = ~610 mm wide × ~440 mm deep × ~240 mm high (same shell as 5100)
| weight        = ~25 kg
| os            = APL and / or BASIC interpreter as operating environment. EBCDIC character set throughout (different from 5100's 5100-specific code). PALM microcode includes the same System/370 and System/3 instruction-subset emulators as the [[IBM 5100]]
| predecessor   = [[IBM 5100]] (1975)
| successor     = [[IBM 5120]] (1980, also designated 5110 Model 3)
| model         = 5110
}}

The '''IBM 5110 Computing System''' is a desktop business computer announced by IBM General Systems Division in '''January 1978''' and first shipped on '''2 February 1978''' to Punxsutawney Electric Repair — whose vice-president Jeff Grube said "If you can type and use a hand-held calculator, you have all the skills necessary to operate a 5110."<ref name="wp5110">Wikipedia, "IBM 5110". Tertiary; used for the marketing chronology, the first-customer-shipment story and the withdrawal dates. Those dates are sourced there to the IBM Hursley Museum's ''Hardware Announcements to 1987'' list, whose URL no longer serves the PDF (it redirects to the museum home page), so they could not be confirmed against the underlying document during verification.</ref> Models 1 and 2 were withdrawn on 31 March 1982; Model 3 (= the [[IBM 5120]]) was withdrawn on 10 December 1982.<ref name="wp5110" />

The 5110 was designed at IBM Rochester, Minnesota; the project was led by '''Bill Sydnes''' in a reportedly 90-day concept-to-production effort. Sydnes later joined Bill Lowe's task force that produced the [[IBM PC (5150)]] — making the 5110 a direct ancestor in personnel as well as architecture.<ref name="ibm100">IBM, "IBM 100 &mdash; The Personal Computer: the team", at <code>ibm.com/ibm100/us/en/icons/personalcomputer/team/</code>. Supports Bill Sydnes's presence on both programmes.</ref>

== Relationship to the IBM 5100 ==

The 5110 is the successor to the [[IBM 5100]] Portable Computer, sharing:

* Same '''PALM''' board-level processor.
* Same '''5-inch CRT''' housing and shell.
* Same '''APL and BASIC''' language environments.

The 5110 adds:

* '''A different internal character code.''' The 5100 uses a 5100-specific internal code (the code chart is in section 6 of its maintenance manual); 5110 data is not byte-compatible with it. The widely repeated claim that the 5110 "uses EBCDIC throughout" could not be confirmed: '''the word EBCDIC does not appear anywhere in the 5110 maintenance manual''', and what the manual does document is a keyboard code-translation stage and a Katakana check jumper.<ref name="mim5110">IBM, ''IBM 5110 Computer Maintenance Information Manual'', SY31-0550-2, February 1979 &mdash; hosted on this wiki as [[IBM 5110 Maintenance Information Manual]]. Section 3 "Theory": Functional Units and the A1 board block diagram (which names every card by slot &mdash; processor J2, base I/O H2, executable ROS L2, feature ROS K4, common and language ROS F2, APL ROS E4, read/write storage M2/M4/N2/N4, display adapter G2, parallel I/O K2, I/O cable driver A2); the 5110 processor data flow; the I/O Control Block table giving the device addresses; the interrupt priority rule; the power chapter describing the supply as a transistor switching regulator and giving the trip points and the five-second restart rule. Section 2 item 272 (Y1 socket pin assignments and DC rail tolerances) and item 280 (I/O interface cable pin assignments, which show +5, +8.5, +12, &minus;12 and &minus;5 Vdc on the power connector). Section 4 "Diagnostic Aids": the bring-up diagnostic and its halt codes, the Diagnostic Control Program, the error-code and device-address summary, and the status-byte descriptions. Appendix A, 5110 specifications.</ref> Treat the incompatibility as real and the name "EBCDIC" for it as unverified.
* '''An IEEE bus''' on a 24-pin '''parallel I/O''' connector. IBM's logic manual labels it "IEEE Bus (bi-directional)" on sheet 445 and shows the ATTN, IFC and EOI lines of the IEEE-488 / GP-IB protocol, driven from the parallel I/O card in slot '''K2''' through external connector '''Y3'''; pin 12 is the protective ground, bonded to the frame. IBM also supplies a '''parallel I/O wrap connector''' for testing the port without an instrument attached.<ref name="logic5110">IBM, ''IBM 5110 System Logic Manual'', SY31-0552-3, February 1979 &mdash; hosted on this wiki as [[IBM 5110 System Logic Manual]]. Sheet 445 "Parallel I/O", which draws the parallel I/O card (A1K2), its internal and external cables, the bi-directional drivers and receivers, the ATTN, IFC, EOI and DIO control lines, and the 24-pin external connector Y3, labelling the bus as the "IEEE Bus (bi-directional)". Sheet 480, "5110/5114 D.C. Power Distribution".</ref> This is the 5110's most distinctive interface and it has no 5100 equivalent.
* '''Asynchronous communications and serial I/O''' on device address 8, and a '''BSCA''' (binary synchronous) adapter on device address 6.<ref name="mim5110" />
* '''External diskette support''' via the IBM 5114 Diskette Unit.

== Models ==

{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+'''IBM 5110 models'''
! Model !! Storage !! Notes
|-
| '''Model 1''' || Built-in DC300 1/4-inch tape drive (204 KB / cartridge) + optional external 5114 || Direct equivalent of the 5100 form factor
|-
| '''Model 2''' || No internal tape; diskette only via external 5114 || Diskette-first configuration
|-
| '''Model 3''' || No internal tape; 2 × built-in 8-inch 1.2 MB floppy drives; 9-inch CRT; detached keyboard || Marketed separately as the '''[[IBM 5120]]''' from 1980
|}

== Architecture ==

The 5110 uses the same processor as the [[IBM 5100]], on the same 15.1 MHz oscillator producing 66.2 ns clock pulses.<ref name="mim5110" /> On the 5110 it sits in '''slot J2''' &mdash; not G2 as on the 5100, where J2 is the display card. Get this the wrong way round and the bring-up halt codes point you at the wrong card.<ref name="mim5110" />

IBM's name for it is the ''processor'' or ''controller''; the internal name '''[[IBM PALM processor|PALM]]''' appears nowhere in the 5110 manual. Memory architecture matches the 5100:

* '''Executable ROS''' — microcode + monitor in PALM's directly addressable 64 KB.
* '''Language ROS''' — APL and / or BASIC interpreters in a separate ROS address space; PALM accesses it as a peripheral.
* '''RWS (RAM)''' — 16, 32, 48 or 64 KB. Cards M2, M4, N2 and N4.<ref name="mim5110" />

The PALM microcode includes the same System/370 and System/3 instruction-subset emulators as the 5100, used to run the unmodified APLSV and System/3 BASIC interpreters in their original object code.

== Form Factor ==

* Same shell as the 5100, with a different cosmetic colour scheme.
* '''Integrated 5-inch CRT''' — 1024 characters (16 lines × 64) addressable.
* '''Integrated keyboard''' with APL, BASIC, or dual-language keytops (toggle on dual-language units).
* '''Front-panel storage''' — DC300 cartridge tape (Model 1) or floppy port (Model 2 connects to external 5114).
* Weight and dimensions match the 5100 — approximately 25 kg.

== Storage ==

* '''DC300 cartridge tape''' (Model 1 only) — 204 KB per cartridge, same drive as the [[IBM 5100]].
* '''IBM 5114 Diskette Unit''' (external) — 1 or 2 × 8-inch floppy drives; up to '''two 5114 units''' attachable to a Model 1 or Model 2, giving '''four drives × 1.2 MB = 4.8 MB total online''' (Model 3 limited to one external 5114).
* '''Diskette formats''' — single-sided "Diskette 1" (~250 KB) vs '''Diskette 2D''' (double-sided double-density, 1.2 MB). The 5114 writes Diskette 2D format.
* '''IBM 5106 Auxiliary Tape Unit''' — external second DC300 drive (Model 1 only).

== I/O and Peripherals ==

* '''IBM 5103 Printer''' — matrix printer carried over from the 5100.
* '''IBM 5106 Auxiliary Tape Unit''' — external DC300 second drive (Model 1).
* '''IBM 5114 Diskette Unit''' — defining peripheral of the 5110.
* '''5110 Async Communications Feature''' (SY31-0557) — start-stop over RS-232.
* '''Parallel I/O (IEEE bus)''' — card K2, connector Y3, 24 pins.<ref name="logic5110" />
* '''Communications Adapter''' — IBM 2741 terminal emulation for host connectivity.

== Languages: APL and BASIC ==

The 5110 supports APL and BASIC, the same as the 5100. The language semantics are identical but the internal character coding is not, so 5100 data is not byte-compatible with 5110 data. APL is APLSV, retargeted from System/370; BASIC is the System/3 port. Which language a machine will come up in is set by a '''basic language jumper''' on the A1 board, and there is a separate '''Katakana check jumper''' — both are documented under Service Aids, and both have been found in the wrong position on machines that "won't boot the right language".<ref name="mim5110" />

== Service Documents ==

Four of these are hosted on this wiki; the rest are at [http://bitsavers.org/pdf/ibm/5110/ Bitsavers].

* '''GA21-9300-0''' — IBM 5110 General Information Manual, December 1977.
* '''GH30-0232-1''' — IBM 5110 / 5120 Computing Systems Bibliography, September 1980 — the master reference list.
* '''SY31-0550-2''' — IBM 5110 Computer Maintenance Information Manual (MIM), February 1979 — the CE service manual. '''Hosted here''': [[IBM 5110 Maintenance Information Manual]].<ref name="mim5110" />
* '''SY31-0552-3''' — IBM 5110 System Logic Manual, February 1979 — the fold-out logic sheets. '''Hosted here''': [[IBM 5110 System Logic Manual]].<ref name="logic5110" />
* '''SY31-0553-2''' — IBM 5110 System Maintenance Analysis Procedures (MAP), January 1979.
* '''SY31-0551-1''' — IBM 5114 Diskette Unit Maintenance, January 1979. '''Hosted here''': [[IBM 5114 Diskette Unit Maintenance Information]].
* '''S131-0626-1''' — IBM 5114 Diskette Unit Parts Catalog, September 1978. '''Hosted here''': [[IBM 5114 Diskette Unit Parts Catalog]].
* '''SY31-0557-0''' — IBM 5110 Async Communications, January 1978.
* '''SA21-9301-0 / -9302-1 / -9303-0''' — APL Introduction / Users Guide / Reference.
* '''SA21-9306-0 / -9307-2 / -9308-2''' — BASIC Introduction / Users Guide / Reference (April 1979 revisions are most complete).
* '''SA21-9311-1''' — Customer Support Functions, October 1978.

== Common Faults ==

* '''Processor card (J2)''' — same unobtainable gate arrays as the 5100's G2 card. Reseat before condemning. IBM's bring-up diagnostic halt codes point at specific cards, and the summary chart in the Diagnostic Aids section is the fastest way to narrow a dead machine down: the very first tests implicate H2, J2 and L2, and the ROS content and CRC test implicates E4 and F2.<ref name="mim5110" />
* '''ROS cards''' — executable ROS on '''L2''', feature ROS on '''K4''', common and language ROS on '''F2''', APL ROS on '''E4'''. IBM's own error-cause list maps the codes directly: error 001 or 005 is the common and language ROS card (F2); 002 and 014 are executable ROS (L2), the processor (J2) or read/write storage (M2); 007 is a CRC error; 008 a module ID error.<ref name="mim5110" />
* '''5114 8-inch diskette drive''' — belt ageing, head-load solenoid fatigue, spindle motor brush wear, and oxide shedding from period media. IBM error '''045 "No Index"''' means no index pulse was sensed for 333 ms: either no diskette was mounted, or it was mounted backwards. Check that before suspecting the drive.<ref name="mim5110" />
* '''Tape drive''' (Model 1) — belt and capstan, same as the 5100. The tape status byte lives at read/write storage address '''hex 8F''' and its eight bits are documented individually, so a tape fault can be narrowed down without a scope.<ref name="mim5110" />
* '''CRT''' — same risks as the 5100.
* '''Power supply''' — '''not a linear supply.''' IBM describes it, as on the 5100, as a transistor switching regulator, with the same five rails (+5, &minus;5, '''+8.5''', +12, &minus;12 V), the same protection behaviour and the same '''five-second''' restart rule after an automatic shutdown.<ref name="mim5110" /> The '''5114 Diskette Unit is different''' — its supply is '''ferroresonant''', not a switcher, and it has its own AC box. Both are covered on the [[IBM 5110 Capacitor Replacement Guide]].

== Software ==

The 5110 was aimed at IBM General Systems Division's small-business accounting market; IBM offered a basic accounting software bundle. '''Core International''' (Hal Prewitt) developed an extensive third-party application catalogue and, in 1981, a '''hard-disk subsystem''' and a '''CoreNet LAN''' add-on for the 5110 and 5120.<ref name="core81">Core International, ''1981 5110 Disk brochure''. The publisher's own site is long gone; the brochure survives only in the Internet Archive's Wayback Machine, which is not reachable from this wiki's verification tooling, so the brochure's contents could not be checked directly. The claim is therefore recorded as attributed, not verified.</ref>

== John Titor Connection ==

The 5110 is the machine '''originally''' named in the John Titor IRC log of 14 October 2000 — the poster mentioned the 5110 four times before quietly switching to "5100" on the public forums in November 2000. Pamela Moore, a Titor correspondent, received a physical fragment of a 5110 label by post with an Orlando postmark, consistent with the IRC claim.<ref name="titor">Wikipedia, "John Titor". Tertiary; used only for the chronology of the hoax and the 5110-before-5100 discrepancy in the IRC logs.</ref> See the [[IBM 5100]] page for full coverage of the Titor story and the System/370 emulator claim.

== Gallery ==

<gallery widths="220" heights="160" mode="packed">
File:IBM 5110 Ridai Museum.jpg|IBM 5110 at the Ridai Museum of Modern Science, Tokyo
</gallery>

== Related Pages ==

* [[IBM 5110 Maintenance Guide]]
* [[IBM 5110 Troubleshooting Guide]]
* [[IBM 5110 Capacitor Replacement Guide]]
* [[IBM 5100]] — 1975 predecessor
* [[IBM 5120]] — 1980 desktop sibling (5110 Model 3)
* [[IBM 5114 Diskette Unit]] — external 8-inch floppy enclosure

== References ==

<references />

=== Further reading ===

* [https://computermuseum.informatik.uni-stuttgart.de/dev_en/ibm_5110/ibm_5110.html Stuttgart Computermuseum — IBM 5110] — Christian Corti's reverse-engineering of the processor card, the ROS extraction work and the backplane pinouts.
* [http://bitsavers.org/pdf/ibm/5110/ Bitsavers — IBM 5110 documents] — the MAPs (SY31-0553) and the language manuals, which are not hosted here.

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