Librascope/General Precision LGP-21 Hardware Maintenance
Manual
This is the
LGP-21 Hardware Maintenance and Training Manual supplied with the
machine, page-scanned at 150 dpi, 11.5" x 8.5" (U.S. A size). It
contains operation, theory of operation (including a complete
algebraic definition of all the machine logic), memory alignment
procedures and a complete set of logic diagrams, photographs and
schematics.
The original manual, borrowed from the Computer Museum
of America, was copied, then scanned on an ordinary flatbed
scanner. Each page image was saved to a disk file, named with the
original document's page number (eg. page 1-3 became disk file
1-3.tiff). A simple text file contains
these page-numbers, ordered, and notable pages have a title or
description separated from the page number by a tab character.
These pages were then created with a Perl script that takes a simple text-file list of
page number/filenames and descriptions, and creates all of the
HTML. This allows updating the entire dataset easily and
portably.
- Page cover, Front
cover
- Page i, Table of
Contents
- Page 1-1, Section I -
Introduction
- Page 2-1, Section II -
Operation
- Page 3-1, Section III -
Theory of Operation
- Page k-1, FLEXOWRITER FLOW
CHART, Figure 4-7, part 1
- Page 4-1, Section IV,
Maintenance
- Page 4-5A, 4.2.2
Program-controlled Carriage Return Operation
- Page 4-8, 4.3 Flexowriter
Relay Contact Information
- Page 4-14, 4.4 Flexowriter
Electrical Maintenance Specifications
- Page 4-15, FLEXOWRITER
FLOW CHART, Figure 4-7, part 2, AFU (rebuild)
- Page 4-16, FIGURE 4-8,
FLEXOWRITER TIMING CHART
- Page 4-19, 4.6 Disc and
Memory Head Maintenance Procedures
- Page 4-20, 4.6.1 Main
Memory Head Specifications
- Page 4-21, 4.6.2 Main
Memory Head Replacement and Adjustment Procedure
- Page 4-23, 4.6.4
Recirculating Register Head Adjustment Procedure
- Page 4-24, 4.7 Conversion
of Deciman Track-and-Sector Addresses to Hexadecimal
- Page 4-25, (Figure 4-16,
Main Memory Head Locations)
- Page 4-26, (Figure 4-17,
Typical Signals)
- Page 5-1, Section IV, Logic
Diagrams
- Page 5-2, Flexowriter
Functions
- Page 5-7, MEMORY CONTROL,
L121 COMPUTER [typo] LOGIC DIAGRAM
- Page 5-8, FIGURE 4-9, PHASE
CONTROL LOGIC DIAGRAM
- Page 5-9, FIGURE 5-7, LOGIC
DIAGRAM, P & Q REGISTER
- Page 5-9, FIGURE 5-8, LOGIC
DIAGRAM, ARITHMETIC, LGP-21 COMPUTER
- Page 5-11, FIGURE 5-9,
FLEX-TALLY I/O LOGIC DIAGRAM
- Page 5-12, FIGURE 5-10,
TALLY P AND R LOGIC DIAGRAM [orig typo corrected]
- Page 5-13, MEMORY CONTROL,
1 OF 3 SCHEMATIC
- Page 6-1, Section VI,
Schematics
- Page 6-4, FIGURE 6-2,
MEMORY CONTROL BOARD and SIGNAL REFERENCE LIST
- Page 6-5, MEMORY CONTROL, 2
OF 3 SCHEMATIC
- Page 6-6, FIGURE 6-3,
MEMORY CONTROL BOARD and SIGNAL REFERENCE LIST
- Page 6-7, MEMORY CONTROL, 3
OF 3 SCHEMATIC
- Page 6-8, FIGURE 6-4 PHASE
CONTROL BOARD and SIGNAL REFERENCE LIST
- Page 6-9, PHASE CONTROL, 1
OF 2 SCHEMATIC
- Page 6-10, FIGURE 6-5,
PHASE CONTROL BOARD and SIGNAL REFERENCE LIST
- Page 6-11, PHASE CONTROL,
2 OF 2 SCHEMATIC
- Page 6-12, FIGURE 6-6,
FLEX-TALLY I/O BOARD and SIGNAL REFERENCE LIST
- Page 6-13, FLEX-TALLY I/O,
1 OF 2 SCHEMATIC
- Page 6-14, FIGURE 6-7,
FLEX-TALLY I/O BOARD and SIGNAL REFERENCE LIST
- Page 6-15, FLEX-TALLY I/O
SCHEMATIC
- Page 6-16, FIGURE 6-8,
[TALLY] P AND R REGISTER BOARD and SIGNAL REFERENCE LIST
- Page 6-17, TALLY P & R
BOARD, 1 OF 2 SCHEMATIC
- Page 6-18, FIGURE 6-9,
[TALLY] P AND R REGISTER BOARD and SIGNAL REFERENCE LIST
- Page 6-19, TALLY P & R
BOARD, 2 OF 2 SCHEMATIC
- Page 6-20, FIGURE 6-10,
[TALLY] P AND R REGISTER BOARD and SIGNAL REFERENCE LIST
- Page 6-21, P & R
REGISTER, 1 OF 3 SCHEMATIC
- Page 6-22, FIGURE 6-11,
[TALLY] P AND R REGISTER BOARD and SIGNAL REFERENCE LIST
- Page 6-23, P & Q
REGISTER, 2 OF 3 SCHEMATIC
- Page 6-24, FIGURE 6-12, P
AND Q REGISTER BOARD and SIGNAL REFERENCE LIST
- Page 6-25, P & Q
REGISTER, 1 OF 3 SCHEMATIC
- Page 6-26, FIGURE 6-13,
ARITHMETIC BOARD and SIGNAL REFERENCE LIST
- Page 6-27, ARITHEMETIC, 1
OF 4 SCHEMATIC
- Page 6-28, FIGURE 6-14,
ARITHMETIC BOARD and SIGNAL REFERENCE LIST
- Page 6-29, ARITHMETIC
BOARD, 2 OF 4 SCHEMATIC
- Page 6-30, FIGURE 6-15,
ARITHMETIC BOARD and SIGNAL REFERENCE LIST
- Page 6-31, ARITHMETIC, 3
OF 4 SCHEMATIC
- Page 6-32, FIGURE 6-16,
ARITHMETIC BOARD and SIGNAL REFERENCE LIST
- Page 6-33, ARITHMETIC, 4
OF 4 SCHEMATIC
- Page 6-34, FIGURE 6-17,
DISTRIBUTION BOARD (S/N 21-40) and SIGNAL REFERENCE LIST
- Page 6-35, LOGIC DIAGRAM,
DISTRIBUTION
- Page 6-37, CONTROL
PANEL
- Page 6-38, REAR
PANEL
- Page 6-39, LGP-21 SYSTEM
ASS'Y CABLING DIAGRAM
- Page 6-40, INTERNAL TALLY
P & R BOARD TO TALLY PUNCH (Cable)
- Page 6-45, POWER SUPPLY,
L121 COMPUTER [not typo], ELECTRICAL SCHEMATIC DIAGRAM
- Page 6-46, SCHEMATIC POWER
SUPPLY
- Page 6-47, SCHEMATIC,
FLEXOWRITER, LGP-21, MODEL FIO
- Page 6-48, TAPE READER,
LGP-21 COMPUTER, SCHEMATIC DIAGRAM
- Page 6-49, SCHEMATIC
DIAGRAM, TAPE PUNCH, LGP-21 COMPUTER
- Page 6-50, SCHEMATIC
DIAGRAMS, BASIC LOGIC FUNCTIONS, LGP-21 COMPUTER [poor
original]
- Page 8-1, Section VIII,
Computer Parts List
- Page tpcover, Tape
Perforator, Tally model 420
- Page tpp1, Addendum
(sic)
- Page tpp2, Parts price
list
- Page tpw, Warrenty
- Page tpxw, Table of
Contents
- Page tpxx, List of
Illustrations
- Page tpxy, Identification
of parts
- Page tpxz,
Photograph
- Page tp1, 1.0
Introduction
- Page tp3, Figure 2,
partially exploded view
- Page tp4, Figure 3, capstan
drive
- Page tp6, 2.2 Perforator
mechanism
- Page tp7, Figures 4 and 5,
Perforator assembly
- Page tp8, Figure 6, Punch
drive, sheet 1
- Page tp9, Figure 6, Punch
drive, sheet 2
- Page tp12, 2.4 Punch head
assembly
- Page tp13, 3.3 Cycle
length limitations
- Page tp14, Figure 7,
Perforator timing diagram
- Page tp15, Figure 9,
Wiring diagram
- Page tp16, 4.0
Instructions for use
- Page tp17, Figure 11, Tape
guide adjustment
- Page tp18, Figure 13,
Lubrication points
- Page tp20, 5.2
Cleaning
- Page tp22, Table 5-1,
Capstan drive tolerances
- Page tp23, Figure 14,
Escapement adjustment
- Page tp24, Figure 15,
Switch accessories
- Page tp25, 6.0 Optional
accessories
- Page tp26, 6.2 Capstan
commutator
- Page tp27, Figure 16,
Capstan commutator
- Page tp28, Figure 17, Reel
drive mechanism
- Page tp30, Supplemental
parts list
- Page trcover, Tape
Reader Manual, Tally model 424
- Page triii, List of
illustrations
- Page trvi, Figure 5, Model
424PR plan view
- Page tr1, Table of
Contents
- Page tr2, 1.2
Description
- Page tr5, 2.2 Tape read
head
- Page tr6, 3.2 Switching
action
- Page tr7, Figure 8, Timing
diagram
- Page tr8, Figure 9, Wiring
diagram for 34-pin connector
- Page tr9, 4.0 Instructions
for use
- Page tr10, 5.0
Maintenance
- Page tr11, Figure 12,
Lubrication chart
- Page tr12, Figure 13, Tape
read head
- Page tr15, Table 5.3-1,
Capstan drive tolerances
- Page tr16, Figure 18,
Bidirectional tape splice
- Page tr17, 7.0 Special
accessories
- Page tr19, Figure 21,
Capstan commutator
- Page tr20, Figure 22,
Commutator timing
- Page tr21, 8.0 Parts
ordering and parts list
- Page tr23, Figure 23,
Model 424a parts list
- Page tr25, Figure 24,
Model 424c parts list
- Page tr34,
Warranty
- Page tr36,
Addendum