Control system employing microprogram discrete logic control routines

Claim 2

A control system using microprogram selection of discrete logic control routines for a character reader, comprising: a local store for storing microprograms, tables, and intermediate computation results; a sequence control unit connected to said local store for receiving microinstructions therefrom, said sequence control containing discrete logic control routines including a discrete logic trap control routine comprising decoder means for decoding an instruction received from a computer to provide a microprogram start address, and comprising microinstruction addressing means connected to said decoder means and to said local store for receiving said start address and for addressing storage locations within said local store, and further comprising incrementing logic having inputs connected to outputs from said discrete logic control routines and to outputs of said local store for incrementing an address within said microinstruction addressing means; an arithmetic logic unit connected to said local store and to said sequence control unit for performing computations under the control of said sequence control unit, said arithmetic logic unit further comprising a profile generator for accumulating a vertical profile of a character thereby indicating the height and vertical position of said character, and an accumulator for counting under control of said discrete logic control routines; and a controlled character reader connected to said sequence control unit and receiving direct control therefrom, connected to said local store and receiving operating parameter information therefrom, and connected to said arithmetic logic unit for providing feedback information thereto.

Claim 3

A control system as in claim 1 wherein said sequence control includes discrete prescan control logic comprising: prescan micro-order storage means for storing a prescan micro-order; prescan modifier micro-order storage means for storing base scan rate and direction micro-orders, the outputs of said prescan modifier micro-order storage means being connected to said character reader to provide raster size and scan direction control; a plurality of sequencing gates each having a first input connected to said prescan micro-order storage means, a second input connected to said character reader, a third input connected to said system timing, and an output connected to said arithmetic logic unit, a first of said sequencing gates controlling said profile generator to accumulate said vertical profile, and others of said sequencing gates controlling said accumulator for generating a prescan width count of a character.

Claim 4

A control system as in claim 2 wherein said sequence control includes discrete compute control logic comprising: compute micro-order storage means for storing a compute micro-order; compute modifier micro-order storage means for storing character type micro-orders, the outputs of said compute modifier micro-order storage means being connected to said arithmetic logic unit through logic gates for modifying table addresses being generated in said arithmetic logic unit thereby generating different table addresses for different character types having the same size; normalize width latch having set inputs connected to said compute storage means and to said system timing, the output of said normalize width latch operating through logic gates seQuenced by said system timing to address a table entry in said local store, utilizing said prescan width count as an incremental address and output from said compute modifier storage means as a base address, and to transfer a horizontal scan rate stored at said addressed table entry to said character reader; normalize height latch having set inputs connected to said compute storage means and to said system timing, the output of said normalize height latch operating through logic gates sequenced by said system timing to address a table entry in said local store, utilizing a prescan profile height count as an incremental address and output from said compute modifier storage means as a base address, and to transfer the vertical scan rate and the normalization center adjustment stored at said addressed table entry to said character reader and to said arithmetic logic unit respectively; center adjust latch having set input connected to said compute storage means and to said system timging, the output of said center adjust latch operating through logic gates sequenced by said system timing to add a prescan center adjustment to said normalization center adjustment for adjusting the vertical position of the normalized vertical scans by a move distance to coincide with the location of a character; sequencing gates for storing said move distance in said memory;

Claim 5

A control system as in claim 3 wherein said sequence control includes move horizontal control logic comprising: move horizontal micro-order storage means for storing a move horizontal micro-order; horizontal modifier micro-order storage means for storing move rate and direction micro-orders, the output of said horizontal modifier micro-order storage means being connected to said character reader to provide rate of position change and direction control; move distance retrieval gates connected to the output of said move horizontal micro-order storage means for retrieving a move distance from memory and loading it into said accumulators; sequencing gates each having a first input controlled by said move horizontal micro-order storage means and a second input connected to said system timing for sequentially incrementing said accumulator whenever predetermined intervals of time have passed.

Claim 6

A control as in claim 3 wherein said sequence control includes move vertical control logic comprising: move vertical micro-order storage means for storing a move vertical micro-order; vertical modifier micro-order storage means for storing move rate and direction micro-orders, the output of said horizontal modifier micro-order storage means being connected to said character reader to provide rate of position change and direction control; move distance retrieval gates connected to the output of said move vertical micro-order storage means for retrieving a move distance from memory and loading it into said accumulator; sequencing gates each having a first input controlled by said move vertical micro-order storage means and a second input connected to said system timing for sequentially incrementing said accumulator whenever a predetermined interval of time has passed.

Claim 7

The control system of claim 1 wherein said profile generator further comprises: a center directed profile shift register; recirculation gates having inputs connected to outputs of center most stages of said profile register and having outputs connected to inputs of end stages of said profile register; a shift input, receiving a shift signal for recirculating data within said profile register in two circular paths from each end toward the center of said profile register.

Claim 8

The control system of claim 6 wherein said profile generator further comprises: an auxiliary register having an input for receiving data from said character reader representing a scan of a character; gating means having inputs connected to outputs of each stage of said auxiliary register, and having outputs connectEd to set inputs of corresponding stages of said profile register for accumulating a profile of said character by superimposing data from each scan of said character in said profile register.

Claim 9

The control system of claim 6 wherein said arithmetic unit includes compute logic having inputs connected to said profile register and outputs connected to said accumulator.

Claim 10

The control system of claim 8 wherein said compute logic further comprises: character height compute logic controlled by said height latch of said discrete compute control logic for counting the number of dark bits within said vertical profile of a first character located closest to the center of said profile register and rejecting dark bits from adjacent characters, said adjacent characters being located farther from said center line than said first character, said number of dark bits being said prescan profile height count, and; center adjust compute logic controlled by said center adjust latch of said discrete compute control logic for counting the number of bit positions from the center of said vertical profile of said first character to the center of said profile register; thereby generating said prescan center adjustment, said prescan center adjustment being counted into said accumulator on top of said normalization center adjustment thereby adding said prescan center adjustment to said normalization center adjustment to provide said move distance.