There were many manuals for the IBM 5100-series. For the IBM 5110, there are three main commonly available manuals:

MIM = Maintenance Information Manual
MAP = Maintenance Analysis Procedures
GIP = General Information and Physical Planning Manual

Then additional manuals for BASIC and APL. I do have hard copies of the following:

GA21-9383-0  1st ed. 1978       Operator's Guide
GA21-9383-1  2nd ed. 1979       Operator's Guide
SY31-0553-2  3rd ed. Jan. 1979  System Maintenance Analysis Procedures
GH30-0232-1  2nd ed. Sep. 1980  Computing Systems Bibliography
SY31-0550-2  3rd ed. Feb. 1979  Computer Maintenance Information Manual
SY31-0581-0  1st ed. Jan. 1978  Language Support MIM
S131-0627-2  3rd ed. Sep. 1978  Computer Parts Catalog
SA21-9306-0  1st ed. Jan. 1978  BASIC Introduction
SA21-9307-2  3rd ed. Apr. 1979  BASIC User Guide 
SA21-9308-2  3rd ed. Apr. 1979  BASIC Reference Manual
SR30-0310-0  1st ed. copy       Introduction to Programming IBM 5110 in BASIC
(also a small pamphlet "BASIC Technical Reference")

I also have the SLM (System Logic Manual) diagrams archived >>here<<

“The IBM 5100 Portable Computer” by Harry Katzan Jr, 1978

  • RND is the random number generator in BASIC, while APL uses “? n”
  • This book does not reference the diagnostic capability of the 5100 (i.e. it doesn’t describe machine language operation at all)

HERE is the maintenance manual that reads much like a detailed mechanics service manual for a car (like the HELMS manuals for major manufacturers like Honda) or an appliance like an air conditioning or refrigerator (that include details about sub-assemblies and pin-outs).

Within the MIM page 4-65, I came across the following interesting information about the use of the L32 and R32 switch combined with the SHOW REGISTERS switch: there are different sets of registers for each interrupt level.

Page 2-12 of the MIM has the following layout of what is essentially the motherboard of the system, simply called the “A1 board.”

Here is an overlay of the expansion components that I have:

Side by side comparison of the 5100 “CPU” and the 5110 “CPU.” They weren’t yet called CPUs, because the overall processing was really distributed across multiple boards. But the core “ALU” that would process PALM opcodes, and the corresponding clock rate, is located on these boards. The majority of part numbers is identical, with very few revisions between the two. But the mystery remains on how similar these were to the original 1973 SCAMP.

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