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 http://archive.org/details/showandtellinter429read 
 
S/0. ^f 
 
 L£GAJ 'Report No. U29 
 
 ynu^ 
 
 SHOW-and-TELL 
 
 An Interactive Programming System 
 For Image Processing 
 
 System Specifications 
 
 by 
 
 John Read 
 
 COO-2118-0003 
 
 VHt^'^'^"' 
 
 ^r ir-ii. 
 
 cX- - ■ 
 
 February I8, 1971 
 
coo 2118-0003 
 
 Report No. U29 
 
 SHOW-AND-TELL 
 An, Interactive Programming System 
 Por Image Processing 
 
 System Specifications 
 by 
 John Read 
 
 February I8, 1971 
 
 Department of Computer Science 
 University of Illinois 
 Urbana, Illinois 618OI 
 
 Supported in part by Contract AT(ll-l)-21l8 with the U.S. Atomic 
 Energy Commission. 
 
TABLE OF CONTENTS 
 
 1. System Overview 
 
 2. System Commands 
 
 3. Show-and-Tell Language 
 h. Interactive PAX 
 
 5. Error Message Format 
 
 References 
 Appendix; Table of System Commands and S&T Language Instructions 
 
1. SYSTEM OVERVIEW . 
 
 1.1 System Objectives 
 
 The Show-and-Tell (S&T) progrannning system is a console- 
 oriented software package providing a facile method of using the 
 operational components of the Illiac III computer. 
 
 The system operates on the hardware depicted in figure 1. 
 An overall documentation of the Illiac III computer system is con- 
 tained in reference [3]. 
 
 S&T is designed to support two different types of programming 
 objectives corresponding to a well-known decomposition of image 
 processing into two phases: a preprocessing and feature-extraction 
 phase followed by an interpretation phase. 
 
 Some typical tasks included in the first phase are: 
 
 Cleaning up the digitized image to reduce noise introduced 
 
 by the transducer and by the digitization process. 
 
 Normalization of the digitized image to eliminate variations 
 
 inherent in the object being scanned. 
 
 Location of occurrences of primitive features such as edges 
 
 or lines . 
 
 Encoding of subsets of the image for input to phase 2 
 
 processing. 
 
 The second phase operates on the first phase output, which 
 is in a symbolic form, rather than as an array of gray-scale values. 
 It seems clear, however, that a data path must also lead from phase 2 back 
 to phase 1 to permit interpretation routines to direct the acquisition of 
 information from the original image. 
 
 Show-and-Tell 's design is oriented towards this model. On one 
 hand, it provides facilities for the manual control of scanning hardware 
 so that preprocessing routines can be tried out on a large number of 
 test images. On the other hand, a link is provided to the IBM 360/75 
 with its large amounts of storage and high-level programming languages 
 
 -1- 
 
DEC PDP-8/e SUBSYSTEM 
 
 IBM 360/75 SUBSYSTEM 
 
 r" 
 
 PATTERN 
 
 ARTICULATION 
 
 UNIT 
 
 ILLIAC _ 
 CORE MACHINE 
 
 I/O PROCESSOR 
 
 tmmxtsmviii^ arirMsuis^:, 
 
 
 
 SCANNER 
 -MONITOR 
 
 -VIDEO 
 CONTROLLER 
 
 
 
 
 
 
 
 
 STAGE a FOCUS 
 
 MOTOR 
 CONTROLLER 
 
 
 FLYING -SPOT 
 
 MICROSCOPE 
 
 SCANNER 
 
 
 
 
 
 
 
 
 
 46 MM 
 
 FILM 
 
 SCANNER 
 
 
 
 
 
 
 
 
 MONITOR 
 
 
 
 
 SCANNER 
 
 -MONITOR 
 
 -VIDEO 
 
 CONTROLLER 
 
 35 MM 
 
 FILM 
 
 SCANNER 
 
 70 MM 
 
 FILM 
 
 SCANNER 
 
 MONITOR 
 
 S-M-V 
 SUBSYSTEM 
 
 VIDEO SUBSYSTEM 
 
 VIDEO 
 SWITCHING 
 NETWORK 
 
 STAGE a FOCUS 
 
 MOTOR 
 
 CONTROLLER 
 
 AUTOMATED 
 
 VIDEO 
 MICROSCOPE 
 
 VIDEO 
 MONITOR 
 
 MANUAL 
 
 VIDEO 
 
 MICROSCOPE 
 
 VIDEO 
 MONITOR 
 
 LARGE FORMAT 
 
 VIDEO 
 
 CAMERA 
 
 DATA AND/OR CONTROL 
 CONTROL ONLr 
 
 FIGURE 1 
 
 HARDWARE 
 
 -2- 
 
 CONFIGURATION 
 
so that phase 2's interpretation routines caji be coded with a minimum of 
 wasted effort and time. Furthermore, this link is bidirectional, in 
 that interpretation programs written in a high-level language (currently 
 JORTEAN/PAX) cajn provide feedback to the acquisition and preprocessing 
 of phase 1. 
 
 Finally, due to the presently ill-defined requirements for 
 picture-processing software, it was deemed wise to implement a 
 minimal system at first, expecting that additions and changes would 
 naturally occur as work on applications progresses. To this end, the 
 system is fairly modular and includes provision for loading parts of 
 the system into the very restricted (8k) PDF 8 core as they are required 
 so as to reduce the need for tight or highly finished code. 
 
 1.2 System Elements 
 
 S&T is composed of the following subsystems: 
 
 Translator : Converts S&T language typed by the 
 operator into an interpretable list structure. Enough 
 information is contained in this internal coding to 
 reconstruct the source statements on demand for listing 
 and editing. 
 
 Interpreter : Operates on the aforementioned list structure 
 and on the Data Storage Lists. (see below). 
 Interpretable Code Area (ICA) : 
 
 Storage for the list structure produced by the Translator. 
 • Executable Code Area (ECA): 
 
 Storage for programs executed directly by the PDP-8 
 hardware; i.e., the output of the PAL assembler. 
 Interpretable Code Loader : Loads interpretable code into 
 the ICA. 
 
 ■3- 
 
F.xecutable Code Loader : Loads executable code into 
 
 the EGA. 
 
 Supervisor : Provides first-level interrupt handling and 
 
 controls loading of System Command Processors. 
 
 System Command Processors : Carry out system commands. 
 
 (see section 2). 
 
 Data Storage Lists; Provides dynamically allocated storage 
 
 for all operands. (see Section 3.2.2.5) 
 
 1.3 Use of the System 
 
 Figure 2 is a panorama of the Input/output room of the Illiac III 
 system, with the general location of some of the I/O devices indicated. 
 Figure 3 is a view of an operator station, showing a teletype for entering 
 instructions and a monitor console. On the monitor screen, the result 
 of executing a SCMM instruction can he seen. The SCAM4 instruction 
 enables an operator to select a small (128 x 128 picture elements) picture 
 segment for machine processing. The small, brightly-lighted square is 
 the segment. A low-resolution, reasonably flicker-free representation 
 of the entire picture is simultaneously available to give the operator a 
 general idea of the location of points of interest. 
 
 One of the input devices, a high-resolution (1500 lines) video 
 microscope is shown in figure U. A variety of other picture input 
 equipment, as shown schematically in figure 1, is also available or in 
 various stages of completion. 
 
 All of the I/O devices are operated by a common control device, 
 the Scanner-Monitor-Video Controller described in detail in reference [l]. 
 This device permits program control of a wide selection of processing 
 options, including a choice of raster size and location, sapling frequenc 
 spot size, number of gray levels detected and some others. 
 
 Pictures are converted to digital form by the input devices and 
 stored in a 128 K byte Fabritek core memory which can store 2 bits of 
 information. This capacity can be used in various ways, i.e., to store 
 
 -k- 
 
(U 
 •H 
 
one pict-ure of 512 x 512 picture elements (pixels) with four bits of 
 gray- level data per pixel, or sixteen 128 x 128 pictures, or 6h one-bit 
 X 128 X 128 planes, and so on. 
 
 The rest of this section contains a step-by-step description 
 of the use of Show-and-Tell to develop a simple application, the 
 counting of particles of a certain size and darkness. 
 
 In this sequence, the operator uses the XG (translate and go) 
 commajid to learn a few useful facts about the image he wants to process, 
 namely the size in pixels of a typical particle and a threshold value 
 he can use to discriminate between particles and background. As each 
 instruction is typed, it is translated and executed and the operator 
 observes the effect. Having obtained the threshold and size numbers, 
 the operator changes to translate mode (XL) and types a program to 
 detect and count particles. He then executes the program, makes a 
 change, re-executes it, and saves the program. 
 
 1. The operator identifies himself to S&T^ (DEMO), wakies 
 
 up the 360, (WK) , and indicates that he is using the h6mm 
 scanner (sU6). 
 
 >L0 1 
 
 > WK 
 
 3 60 p}-ADY 
 
 > DV 
 
 2. In order to measure some parameters of the image, the operator 
 puts the system into translate-and-go mode, where each in- 
 struction is translated and executed immediately after it is 
 typed (XG). He then selects a window and reads it into 
 memory (SCANM). While selecting the image, he determines that 
 
 less resolution is needed so he increases the x and y scanner 
 
 , , 1+ 
 
 sampling increment (P:++++ and Q:++++jto 2 in each case. The 
 
 next step is to find out the size in pixels of the particles 
 
 1 Underlined characters were typed by Show-and-Tell 
 
 -8- 
 
he wants to count, and also to establish a gray-scale 
 threshold which can be used to discriminate between 
 particles and background. To do this he executes a 
 TRACE command which displays the picture he just read 
 in with SCMM, and also a bright spot, or cursor, which 
 he can move around on the picture. He uses this to 
 point to a particle on the picture. S&T records the 
 coordinates of the particle. The next instruction, PNABE, 
 prints out the gray-scale values of those pixels in a 
 6x6 neighborhood of the point indicated, using a one- 
 character-per-pixel notation, (such that a gray-scale value 
 of ten is typed as an A). The operator notes that the 
 pixels in the area of the particle generally have gray-scale 
 value higher than four and that the particle has an area of 
 seven pixels. 
 
 >XG 
 
 SCANM p. 1 
 
 P ; ++++ 
 
 p : ++++ 
 ~ASC3N N. 1* 1 
 TRACE p. 1>C. 1>N. 1 
 PNABE p. 1*C. 1^6 
 
 9. 1 1^38 
 P 3 5671 
 
 1 57APg 
 
 2 12321 
 22211 1 
 2221 12 
 
 -9- 
 
3. Having obtained these facts, the operator puts the 
 
 system into translate mode (XL) and types in a program 
 vhich will send a picture to the 360, (PICIN) and cause 
 the PAX system on the 36O to put a one in picture P. 2 
 at each pixel whose corresponding P.l pixel had a gray- 
 scale vaJLue greater than 5 (SLICE) and find and count all 
 connected objects in P. 2 with an area between 3 and 10. 
 The count is then typed by the program. The program 
 assumes that picture P.l is already defined and has been 
 read into core and that pictures P,2 through P.U have been 
 defined as planes. 
 
 >XL 
 
 n 00 ASGN- N.2* 1 
 
 001 ASGN N. 1,0 
 
 OOP ASGN I.l,(C-l,-l),C-l,0),Cl,-l),(l,n)) 
 
 03 CALL PAX> 'PICIlx; ',?. 1 ,-i^ 
 
 0/j CALL FAX, 'SLICE %P.2,P. 1,^, 5>5 
 
 n05 LOOP: CALL PAX, ' XLI SIX ' ,P . P, C . 1 , X .^ 
 
 006 CALL PAX, 'CLt AP',p.3,n 
 
 ncP^ CALL PAX, •XWRITC',P.3,C. 1 
 
 OOH CALL PAX, 'XCGK'NE ', I . l,P.^,P.p,P.3,\.2 
 
 09 CALL PAX, •ARfc,A',P. A,0,0,N.2 
 
 10 CALL PAX, 'AND', P. 2, P.?, P. -a, 1 
 
 ■ 1 1 IFGO N.2, .GT, 10, WRGSIZ 
 
 12 IFGO N.2, .LT,3, WRGSIZ 
 
 13 IvMCR N. 1, 1 
 
 1^ WRGSIZ: CALL PAX, ' NULL ' , P . 2, N . 3 
 
 15 IFGO i\.3, .EO, l,FIi\ISH 
 
 16 GOTO LOOP 
 
 17 FINISH: ASGi\ T.l,N.l 
 
 .Q,L^ TEXTO 'PARTICLf CUUM=' 
 
 0'l9 TFXTO T.l 
 
 20 I-XIT 
 
 -^lO- 
 
k. The program is then tested (GO), using the pic- 
 ture currently in Illiac III core. An answer 
 is typed (PARTICLE COUNT =5) which is unsatis- 
 factory. The operator decides to change (CH) the 
 rei-Ltion code in the SLICE instruction from a 5 
 to a U, meaning a change from 'greater than' to 
 'greater than or equal to'. The program is re- 
 executed, this time with hetter results. 
 
 > GO 
 
 P ARTICLE C0Ui\T=5 
 >CH 
 
 00^ CALL PAX^ VSLICF'^P.P*?. 1,-^,^, 5 
 
 > GO 
 
 PARX-tCLE C0Ui\'T=13 
 
 5. The corrected program is saved on the system 
 
 device (SV) and given a file name of PCNT. The 
 
 companion 360 program is terminated (KL) and the 
 operator Logs off. 
 
 >SV 
 
 ^OUT-S ;PCNT 
 
 >KL 
 
 >LF 
 
 -11- 
 
. 2. SYSTEM COMMANDS 
 
 2.1 Entering System Commands 
 
 Execution of system programs such as the translator or the 
 interpreter is controlled by typing system commands. S8sT signals 
 that it is ready to receive a system command by typing a 'greater 
 than' symbol (>). S&T can be put into system command mode at any 
 time by typing CTLE, i.e., holding down the CTL key on the teletype 
 and pressing E. S&T will then type >. 
 
 2.2 Docijmentation of System Commands 
 
 In this section, underlined statements are those typed by the 
 S&T system. 
 
 The syntax notation used in this report is almost the same 
 as the standard IBM notation described in the front of, for example, 
 the PL/1 Language Specifications Manual, reference [6]. The only 
 differences are (l) for emphasis, BNF-type brackets are placed 
 around "notation variables" as in <integer> and (2) BNF- format rewrite 
 rules are used where this presentation seems clearer. 
 
 -12- 
 
•Command: CH 
 
 Purpose: To change statements in a program already in the 
 
 Interpretable Code Area. 
 Execution: This command has the effect of a DL followed by an Hi. 
 
 A colon is typed. The operator responds with: 
 
 <statement number 1> [, <statement number 2> ] 
 
 (see DL command). Statements entered are then 
 
 translated and inserted in place of the ones just 
 
 deleted. (See IN command). 
 
 Command ; DL 
 
 Purpose: To delete code from the Interpretable Code Area. 
 
 Execution: A colon is typed. The operator's response is of the form; 
 <statement number 1> [, <statement number 2> ] 
 If <statement niimber 2> is present, all statements 
 between and including <statement niomber 1> and <statement 
 number 2> are deleted. Otherwise, only the statement at 
 <statement number 1> is deleted. If a labeled statement is 
 deleted, the label must be placed on some other statement 
 in the program. If this is not done, execution of the 
 program will terminate if a GOTO, IFGO or CALL to that 
 label is attempted. 
 
 -13- 
 
Command: DV 
 
 Purpose: To identify which scanning device is to "be used. 
 
 Execution: A request for a device code is typed: 
 CODE; 
 
 The operator selects the code from the following list and enters it, 
 Sl+6 - i;6 mm film scanner 
 SMS - Scanning microscope 
 VMS - Video microscope 
 VLF - Large format video 
 S70 _ 70 mm film scanner 
 235 - 35 mm film scanner 
 
 Command: GO 
 
 Purpose: To execute S8eT code which has been loaded into the Interpretable 
 Code Area "by the Loader or the Translator, 
 
 Execution: The interpreter is invoked. Execution begins with the first 
 location of the ICA. If the ICA is empty, an error message is 
 typed and control returns to the System Command Processor. 
 
 -lU- 
 
Command: IN 
 
 Purpose: To insert code into a program already in the Interpretable 
 Code Area. 
 
 Execution: A Colon is typed. The operator responds with the number 
 
 of the statement before vhich the code is to be inserted. The 
 Translator is then invoked and types a carriage return and 
 line feed. All statements entered are translated and inserted, 
 A CTLE statement terminates the command. 
 
 Command: KL 
 
 Purpose: To delete the PAXDRIVR task (see section U, 'Interactive PAX' 
 
 Execution: A command is sent to PAXDRIVR which causes it to terminate. 
 
 -15- 
 
Command: LS 
 
 Purpose: To print contents of Data Storage Lists currently at the top 
 of the stack or the Interpretable Code Area. 
 
 Execution: A colon(:) is typed. The operator enters parameters 
 describing the item to be listed: 
 
 <lower limit> [ ,<upper limit>] 
 Each limit is of the form 
 
 <data code> [.<integer>] 
 where<data code>is one of the Data Storage List Codes (except 
 P), or is an S, meaning that the program in the ICA is to be 
 printed. If .<integer> is omitted, the entire Data List or ICA 
 is to be printed. <integer> for the ICA refers to a statement 
 number. 
 
 Example: Typing N.3, N.IO causes the contents of counters 
 three through ten to be printed. Another example: typing S.39 
 causes the 39th instruction in the ICA to be printed. 
 
 Command: LD 
 
 Purpose: To load previously translated and saved S&T code into the Inter- 
 pretable Code Area. 
 
 Execution: The Loader is invoked. The PDP8 Disk Monitor is used to get 
 the file Name from the Operator: * IN - 
 
 The operator types the device code and file name of the file 
 containing the saved program. (See reference [^]). Note that 
 since the interpreter alvays begins execution at the first 
 location of the ICA, the main-line program must be loaded 
 before subroutines. 
 
 -16- 
 
.Command: LF 
 
 Purpose: Updates acco\mting data. 
 
 Execution: Usage data is computed aoid entered into accounting tables. 
 
 Command: L0 
 
 Purpose: Obtains a code from the operator to be used for accounting 
 
 purposes. 
 Execution: Command is automatically typed when S&T is first entered: 
 
 >L0 
 
 Code : 
 
 No other commands are accepted until the operator types a 
 
 valid operator code. 
 
 -IT- 
 
Command: SV 
 
 Purpose: To save the contents of the Interpretable Code Area 
 
 Execution: The PDP8 Disk Monitor is used to get a file and device 
 
 name from the operator: *OUT- 
 
 The operator types descriptors for the file to contain the ICA, 
 
 (see reference [U]). 
 
 Command: WK 
 
 Purpose: To determine whether PAXDRIVR is active on the 360/75. (see 
 
 section 5» "Interactive PAX'). 
 Execution: If PAXDRIVR has not started, the message 'WAITING FOR 36O' 
 
 is typed, and a WAIT loop is entered. When PAXDRIVR responds, 
 
 '360 READY' is typed. 
 
 -18- 
 
-Command: XG 
 
 Purpose: Invokes the S&T Translator to translate one statement, 
 
 then invokes the Interpreter to execute the instruction. 
 
 Execution: When the translator is ready, it types a carriage 
 
 return-line feed. The statement is entered by the operator, 
 translated and interpreted. As each instruction is trans- 
 lated, it overlays the previous one. Typing a CTLE 
 returns control to the system command processor. 
 
 Command: XL 
 
 Purpose: To invoke the S8eT Translator 
 
 Execution: When the S&T Trsmslator is ready, it types a carriage 
 return followed by a line feed. Statements may then be 
 entered for translation. The Translator Continues to 
 accept statements until a CTLE is typed. Line numbers 
 are automatically generated. 
 
 -19- 
 
3. S&T LANGUAGE " 
 
 3.1 Introduction 
 
 An interactive, incremental translator is provided for 
 SHOW-AND-TELL , a language for processing pictures using the S-M-V 
 and PAU subsystems of the Illiac III. The translator is inter- 
 active in that programs can he composed and debugged from a console 
 typewriter and is incremental in that each statement is translated 
 as it is entered and may be immediately executed, at the programmer's 
 option. Alternatively, blocks of code may be translated an masse , 
 saved, and called by the operator or by other programs. 
 
 The operations in the language are classified: PAU instructions, 
 sequence control instructions, data-manipulating instructions and 
 input-output instructions. PAU instructions are those to be executed 
 by the Pattern Articulation Unit of the Illiac III. 
 
 To simplify the system, any operand to be processed is stored 
 in one of eight predefined lists (see Sec. 3.2,2.5), vith each list 
 dedicated to a single type of data. 
 
 3.2 Language Elements 
 
 3.2.1 Statement Syntax 
 
 [ <label>: ] <instruction> CR 
 where CR is a carriage return. Statements may be continued 
 t>y typing LF (line feed) instead of CR and continuing in the first 
 col\imn of the next line. 
 
 3.2.2 Instructions 
 
 Documentation of instructions is classified by instruction 
 type. Operands are documented separately in section 3.2.3. At 
 various places in the syntax, a symbol< * n *> appears, where n 
 is a positive integer. These refer to notes which modify or clarify 
 certain aspects of the syntax. The notes corresponding to the 
 integers are in section 3. 2.U. 
 
 -20- 
 
.3.2.2.1 PAU Instructions 
 
 References [3] and [5] describe the operation and pro- 
 gramming of the PAU in depth; the documentation which follows 
 describes syntax to use in writing instructions and does not 
 repeat any of that information. 
 
 A few changes have been made in some of the instructions. 
 STOREB and LOADS have been replaced by STOREW and LOADW. These 
 instructions cause a 32 x 32 window with "upper left" corner at 
 < coordinate > within picture P. <index> to be loaded ijn or stored 
 from the lA, where "upper left" is used with reference 
 to a coordinate system like: 
 
 X. 
 
 128 
 
 -H 
 
 128 _i 
 
 <coordir 
 
 iate> 
 
 
 picture 
 
 window 
 
 If the edge of picture P. <index> falls within the window, 
 then the window is truncated and the lA is filled out with zeroes. 
 For example, if 
 
 <coordinate> = (100,100), 
 then the following situation obtains for a 128 x 128 picture: 
 
 
 
 128 f 
 
 128 
 
 (100,100) 
 
 n 
 
 ^ 
 
 
 ^ 
 
 picture 
 
 filled 
 
 window 
 -21- 
 
 J 
 
 with zeros 
 
PAU Instruction Syntax: 
 
 BOOLE <bit-string reference> , <function reference> <*S1*> 
 
 CLEARP [<bit-string reference>], <plane reference> <*S2*> 
 
 CONNEC <plane reference> , <plane reference> , 
 
 <plane reference>, <bit-string reference> <*S3*> 
 
 LIST <plane ref erence> , N. <index> , C. <index> 
 
 COPY <plane referenco , <plane reference> 
 
 COPYC <plane reference> , <plane ref erence> 
 
 TALLY [<plajae referenco] [ ,<bit-string reference>] <*S3*> <*SU*> 
 
 TALLYH [<plane reference>] [ ,<bit-string reference>] <*S3*> <*Si+*> 
 
 SHIFT <plane reference>, <d.isplacement> 
 
 SETP <plane reference> ,[ <bit-string reference>] <*S2*> 
 
 -22- 
 
PLMD <plane reference> , <plane reference> 
 
 PLOR <plane reference> , <plane reference> 
 
 PLEXOR <plaxie reference>, <plane reference> 
 
 LOADW <picture reference>, <coordinate> 
 
 STOREW <picture reference>, <coordinate> 
 
 AREA <plane reference>, N. <index> 
 
 -23- 
 
3.2,2,2 Sequence Control Instructions 
 GOTO «label> 
 
 unconditional jxomp to statement <label> 
 
 IFGO N. <index> , <relation>, <number reference>, <laTDel> 
 
 A conditional jump to <label> , taJcen if N. <index> 
 <relation><number reference> is true. 
 
 CALL label [ { , <operand> } . . . ] 
 
 A jump to subroutine with an optional 
 argument list. Several actions occur as 
 a result of executing this instruction: 
 
 1. All data lists except P are pushed 
 into stacks. 
 
 2. The contents of RETADD (the return 
 address) are pushed into the RETADD 
 stack. 
 
 3. A sequence of implicit ASGN statements 
 is executed, e.g. 
 
 ASGN A.l,<operajad 1> 
 
 ASGN A.2,<operand 2> 
 
 etc. 
 h. Control is given to the subroutine 
 identified by <label>. 
 
 -21;. 
 
ViAIT <number reference> 
 
 <number reference>is a count of the number 
 of timer intervals to wait. If the operator 
 strikes the CTL E key, control is returned 
 immediately. 
 
 EXIT 1. All data lists except P are popped. 
 
 2. RETADD is saved for step h, 
 
 3. RETADD is popped. 
 
 k. Control is returned to the statement 
 at the location saved in step 2. 
 
 -25- 
 
3.2.2.3 Data-Manipulating Instructions 
 INCR 
 
 N. <index>, <nuinber reference> 
 
 N, <index> is incremented by <n'umber reference> 
 
 DECR N. <index> , <nuiiiber reference> 
 
 N. <index> is decremented by <number reference> 
 
 ASGN <operand> , <operand> <*S12*> 
 
 The second <operand> is copied into the 
 first <operand> . 
 
 RPIXEL N. <index> , <picture ref erence> , <coordinates> 
 The gray-scale value of the pixel at location 
 <coordinates> in <picture reference> is loaded 
 into N. <index>. 
 
 WPIXEL N. <index>, <picture ref erence> , <coordinates> 
 
 The integer in N. <index> is stored at <coordinates> 
 in <picture reference> as a gray-scale value. If the 
 binary representation of the value of N. <index> 
 has more significant bits than the number specified 
 in the DEFPIC for <picture ref erence> , low order bits 
 are truncated. 
 
 -26- 
 
3.2.2.U Input-Output Instructions 
 
 SHOW <picture reference> 
 
 <picture referenco is displayed on the 
 monitor. The display remains on the 
 monitor until another picture I/O operation 
 is executed. Control returns immediately 
 to the program. 
 
 SHOWTL <picture reference>[ ,<picture reference>] 
 The pictures denoted "by the operands are 
 displayed on alternate scans on the monitor. 
 A cursor is also displayed, which can "be 
 moved around on the display of the first 
 <picture reference> , setting points to zero 
 or all ones by pressing D or A, respectively. 
 CTL I terminates execution of the instruction. 
 
 LOOK <picture reference> , <coordinates> 
 
 [ ,<num'ber reference> ] 
 This instruction may be used to cause a 
 scanning device to display a picture on the 
 monitor without reading the picture into core. 
 Only the picture descriptor at <picture reference> 
 is used; no core storage is used. In this way 
 rasters larger than 128 x 128 pixels may be 
 generated. The display remains on the monitor 
 for <number reference> timer intervals. If the 
 raster would fall outside the virtual raster for 
 the scanning device, an error message is printed. 
 
 -27- 
 
If the value of <nuinber reference> is 
 zero, one sweep of the raster only occiirs. 
 If <nujii'ber reference> is omitted, the 
 display is maintained until the operator 
 types CTL R. 
 
 SCMM <pict\rre reference>, <coordinates> 
 
 A LOOK instruction is executed twice using the 
 operands : 
 
 pictiire reference , coordinates 
 Then a magnified 128 x 128 pixel window is 
 superimposed on the previous display for one 
 scan. These two displays alternate, generating 
 a composite image of a high-resolution 
 "magnifying glass" on a large, low resolution 
 display. The "magnifying glass" may be moved 
 over the large picture by typing T (up), 
 F (left), H (right), space (down). The distance 
 the "magnifying glass" moves in the X or Y 
 direction at each step can be changed by typing 
 X or Y respectively. The operator can then 
 enter plus or minus signs. A plus sign doubles 
 the previous movement distance and a minus 
 halves it. Similarly, the scanner's sampling 
 resolution in the X or Y direction and, hence 
 the scope of the window can be changed by 
 typing P or Q respectively. This is done by typing 
 a plus or minus sign where plus doubles and a 
 minus halves the sampling increment. 
 When the operator types CTL R , a final scan of 
 the "magnifying glass" is made, and the window 
 is read into core using a picture descriptor 
 
 -28- 
 
and coordinates developed from parameters 
 entered by the operator during processing oX 
 SCANM. The values of the parameters 
 <picture reference> and <coordinate s> 
 are then changed to agree with the attributes 
 of the window just read in. 
 
 SCAN <picture reference> , <coordinates> 
 
 The picture descriptor at <picture reference> 
 is used to scan a window at location 
 <coordinateB> within a virtual raster 
 of the current scanning device. If 
 <picture reference> describes a window with 
 either dimension larger than 128 pixels, that 
 dimension is truncated to 128 pixels, and 
 <picture reference> is changed to match. If 
 a window is smaller than 128 x 128 pixels, it 
 is stored as specified; i.e., variable size 
 windows are accommodated. 
 
 PNABE <picture reference>, <coordinates> , <number reference 
 The gray-scale values of the pixels in a square 
 neighborhood of side <number reference> centered at 
 <coordinates> in <picture reference> are printed on 
 the teletype. <n\amber reference> must have a 
 positive value less than 73. 
 
 -29- 
 
DEFir^C <picture reference>,< niomber reference i>, 
 
 <number reference2>, <niiiiiber reference3>, 
 <number referencei+>, <nuiiiber reference5>, 
 <;number reference6> 
 Defines a picture descriptor. 
 
 A DEFPIC must be executed before any reference 
 is made to the operand < picture reference >. 
 
 Operands : 
 
 <number reference|> is the size in pixels 
 of the window in the X direction. 
 
 <number reference2> is the size in pixels 
 of the window in the Y direction. 
 
 <number reference3> is the scanner X step 
 size (P). Must be non-negative and less than Sio- 
 
 <number referenceit> is the scanner Y step 
 size (Q). Must be non-negative and less than 8io« 
 
 <number reference 5> is the magnification factor (H) 
 to be used when displayingthe pictiire. Must be 
 non-negative and less than 8]_q. 
 
 <number reference5> is the number of bits used 
 to store the gray-scale value for each pixel. 
 
 RELPC 
 
 <picture reference> 
 
 Releases all storage associated with 
 
 <picture reference>. 
 
 1 When storing data into a picture, a reference can be made to an 
 undefined picture. In this case, a definition is assumed: 
 
 DEFPIC <picture reference> , 128,128,0,0 ,0,U 
 Also if any of the operands are omitted in Miy DEFPIC, they are assumed 
 to take the above values, unless the picture was previously defined, 
 in which case the old values are retained. 
 
 -30- 
 
TRACE <picture reference>, C. <index>, N. <integer> 
 
 [ ,<increment reference> ] 
 
 The -value of N. <integer> is se^yed, and N. "^integer^ 
 is s-et to one. A one-scan SHOW is executed using 
 operand <picture reference>, alternating with a 
 display of a small, bright point which acts as 
 CUTS or. The cursor is moved around using 
 commands similar to those for the SCANM command. 
 Whenever S is typed, the coordinates of the cursor 
 are placed in C. <index> and N. <integer> is in- 
 cremented by one. In addition, if' < increment 
 reference> is present, the coordinates and gray-scale 
 values of the neighbors of each sample point as 
 indicated by increment reference are recorded on 
 LINC tape. CTLI ends processing of the instruction, 
 as does attempting to move the cursor off the picture. 
 In addition, if N. <integer> exceeds the original ^ 
 value of the argument N. <integer>, processing ends. 
 
 SAVEPC <picture reference> 
 
 <picture reference> is written on LINC tape in 
 a standard format. 
 
 LOADPC <picture reference> 
 
 A previously-saved picture is read from LINC 
 tape and stored in <picture reference>. The 
 descriptor for the saved picture is also loaded, 
 performing an implicit DEFPIC. 
 
 -31- 
 
 J 
 
TEXTI T. <index> 
 
 Characters typed on the console typewriter 
 are stored in T. <index> 
 
 TEXTO <text reference> 
 
 Characters in <text reference> are typed on 
 the console typewriter. 
 
 3,2.2,5 Data Storage Lists 
 
 All variahles used as operands in S&T instructions are 
 pre-declared and are stored in lists. Table 1 shows the eight 
 different list types and the codes used to refer to them. 
 A variable in a list is accessed by means of 
 an <index> , as in 
 
 SHOW P. 3 
 which refers to the third picture descriptor. The following sequence 
 could also be used to accomplish the same thing: 
 
 ASGN N.1,3 
 SHOW P.N. 1 
 The elements of two lists are themselves lists. Sublists 
 of the C and I lists can be accessed as entities, or elements of 
 the sublists can be accessed. The following statements assign a 
 list of coordinates to the 5th sublist of list C, then changes the 
 second coordinate pair of the list of coordinates just assigned. 
 
 ASGN C.5j: (19,3), (lU,2), (6,25)) 
 ASGN C.5.2, (2, 111) 
 Sublists can be of variable length, as can the elements of 
 lists B, F, and T. Coordinates and increments are stored as 
 signed double-precision (23 bits and sign bit) integers, although 
 there may be semantic restrictions on the magnitudes, (see section 3.2.i+) 
 Storage allocation and de-allocation is handled by the system, so 
 sublists can have new values of different length assigned. 
 
 -32- 
 
Each list can have only certain data types assigned 
 to it. Assignands can be either lists or literals of the 
 proper type, e.g.; 
 
 ASGN B.l, #101101 
 
 ASGN B.2, B.l 
 
 ASGN T.l, B.2 
 
 TEXTC T.l 
 
 ASGN T.l, #1011100 
 
 TEXTO T.l 
 
 The sequence above demonstrates the use of ASGN to print 
 some bit strings on the teletype. Data type conversions are per- 
 formed where necessary. Table 1 shows which combinations of 
 assignee and assignand data types are legal. { In the first state- 
 ment in the previous example, B.l is the assignee and #101101 is 
 the assignand. 
 
 A special <picture reference>, P.O, is used by PAXDRIVR 
 to store pictures for use by PAX routines. A built-in DEFPIC, i.e., 
 
 DEFPIC P.O, 128,128,,,U,U 
 is in effect for this picture whenever PAX is in use. 
 
 -33- 
 
tTABLE 1 DATA STORAGE LISTS 
 
 CODE 
 
 B 
 
 N 
 
 LEGAL ASSIGNANDS 
 Any 
 
 A, T, B 
 A, T, C 
 A, T, F 
 
 A, T, I 
 A, T, N 
 
 A, P 
 
 Any except P 
 
 DESCRIPTION 
 
 List of argToments used in 
 call statement 
 
 List of bit-strings 
 
 List of coordinate lists 
 
 List of Polish post -fix 
 Boolean functions 
 
 List of increment lists 
 
 List of double-precision 
 integer storage cells 
 
 List of picture descriptors 
 
 List of text strings 
 
 -3i+- 
 
3.2.3 Operand Syntax 
 
 <bit-atring reference> ::= B, <index> | <bit-string literal> 
 
 <direction reference> ::= <'bit-string reference> <*S3*> 
 
 <plane reference> : : = <signed integer> <*S5*> 
 
 <picture reference> :: = P, <index> 
 
 <function reference> : : = F. <index> | <f\inction literal> 
 
 <increment reference> :: = I. <index> | < increment literal>l 
 
 I. <index> , <index> 
 <coordinate reference> : : = C. <index> |<coordinate literal>| 
 
 C. <index> , <index> 
 
 <text reference> :: = T. <index> | <text liter al> 
 
 <nuiaber reference> :: = N. <index> | <signed integer> <S*11*> 
 
 <tiit-string literal> :: = 0{1\q}.,, 
 
 <function literal> : : = <term string> <plane reference> 
 
 <term string >:: ={< elementary function> [{&|*| *}..,];},. , 
 
 <elementary function> :: = ^ <variable> [ <operator> <variable>]i 
 
 <variable> : : = [ ' J <plane ref erence> <direction number> <^*S7*> 
 
 <direction niamber> : : = <integer> <*S6*> 
 
 <operator> :: = &|+ 
 
 1 The lines under the brackets in this production indicate that these 
 particular brackets are not metasymbols but that an elementary function is 
 a string of variables and operators all enclosed in brackets, 
 
 -35- 
 
'■<text literal> :: = ' <character >...' 
 
 <coordinate literal> :: = (<coordinates> [{, <coord.inates>}. . . ] ) 
 
 <coordinates> :: =(<nuinber reference>, <nuiiiber reference>) <*S8*> 
 
 <increment literal> :: = (<displacement> [{, <displacement>i. . . ] ) 
 
 <displacement >:: = (<nuiiiber reference>, <n\amber reference>)<*S9*> 
 
 <signed integer> :: = [{+|-}] <integer> 
 
 <integer> :: = <digit>,., 
 
 <digit> :: = o| l| 2| 3| i+| 5| 6| t| 8| 9 
 
 <relation> :: = .GT| .LT| .EQ| .NE| .GE| .LE 
 
 <label> :: = <alphabetic> [<alphanumeric>, . . ] <*S10*> 
 
 <alphabetic> :: = a|b| c|d|e|f| g|h| I | j|k| l|m|n| 0|p| q|r| 
 
 s|t|u|v|w|x|y|z 
 
 <alphanuineric> :: = <alphabetic> | <digit> 
 
 <character> :: = <any character on a teletype keyboard 
 except quote ( ' )> 
 
 -36- 
 
<operand> : : = <picture reference> 
 <f\inction reference> 
 <increment reference> 
 <coordinate reference> 
 ■^text reference> 
 <number reference> 
 <bit-string reference> 
 < argument reference> 
 
 <index> 
 
 = <integer> I N. <integer> 
 
 -37- 
 
3.2.i| Not 
 
 es 
 
 <*S1*> <Bit-string reference> generates the availability 
 list. Length must be 9. 
 
 <*S2*> <Bit-string reference> generates the ID bjrte. 
 If present, length must be 9. If omitted, 
 assumed value is #100000000. 
 
 <*S3*> <Bit-string reference> generates the direction 
 list. Length must be 9. 
 
 <*Si+*> If <plane reference> is omitted, it is assumed that 
 the M-plane (plane number-l) has already been loaded 
 with the operand plane. 
 
 <*S5*> <signed integer> must take one one of the 
 values -1, 0, 1, ..., 7. 
 
 <*S6*> <integer> must take on one of the values 0, 1, 2, . . . ,8 
 
 <*S7*> Either: all of the <plane reference>s In an 
 
 <elementary function> must be the same or all of the 
 
 <direction number> s must be zero. Also, all 
 
 <operator>s must be the same. (see reference 5 for 
 
 explanation). 
 
 <*S8^ Each <number reference> must have a value 
 
 23 
 such that <- value <2 '"-'-• 
 
 ■^S9^ Each <number reference> must have a value 
 such that -7 < value <7. 
 
 -38- 
 
<*S10*> <label> must have length no greater than six. 
 
 <*S11**> All <num'ber references> must have a value such that 
 -2^^ <yalue <2^^. 
 
 <*S12*> See section 3.2.2.5 for restrictions on the values 
 of ^operandF*. 
 
 -39- 
 
k. INTERACTIVE PAX 
 
 U . 1 Introduction 
 
 PAX II is a set of Fortran-callable subroutines which 
 perforin picture-processing operations on the elements of digitized 
 images . (pixels ) 
 
 The PAX II System is derived from a system developed at the 
 University of Illinois to simulate the operations of the Illiac Ill's 
 Pattern Articulation Unit, 
 
 An example of a PAX operation which is available is 
 SLICE which identifies the pixels which have gray-scale values for 
 which some condition, e.g., "greater than 8" is true. PAX operations 
 can be used to remove noise from the picture, find edges and objects, 
 and in general perform the pre-processing and feature extraction phases 
 of the image processing task. For further details, the user is referred 
 to the PAX II Programming Manual, reference [2]. 
 
 PAX was intended to be used in a batch or off-line mode 
 where pictures are stored on tape or disk, processed, and results 
 printed, with no opportunity to monitor the process as it occurs. 
 The S&T system extends PAX to include facilities which make it 
 possible to use PAX interactively. That is, pictures can be selected, 
 PAX routines called to process them, resvilts examined on a video display, 
 changes made in the sequence of execution of the PAX procedure and so 
 forth, all from a console on-line to the computer. 
 
 Conversely, and in line with the two-part nature of the 
 overall system objective (see section 1 ) , special subroutines 
 have been implemented which permit a PAX program running on the IBM 360 
 to control the acquisition of pictures directly. 
 
 -1+0- 
 
k.2 Using Interactive PAX 
 
 All use of PAX from S&T is initiated via the S&T CALL 
 instruction. Calls to PAX subroutines are of the form 
 CALL PAX, '<subroutine name> ' , <argument list> 
 where <subroutine name) can be any of the subroutines ciirrently 
 implemented. The operand, <argument list>, follows the argument 
 list described for the PAX routine being called, with a few 
 restrictions: 
 
 all references to pictures or planes must be of the form 
 P. <index> , where P. <index> was the operand of a DEFPIC 
 instruction executed previously. 
 
 Calls to PAX subroutines which include windows as arguments 
 are replaced by calls to special versions of those routines 
 which do not require window arguments. The names of these 
 routines are the same as the standard PAX routines, except 
 that an X precedes the subroutine name. If the addition of 
 the X causes the name to be 7 characters long, the new name has 
 the right hand character dropped. Thus CARDS becomes XCAKDS 
 and RANPIC becomes XRANPI. The new subroutines apply to the 
 entire 128 x 128 picture instead of to a window. 
 Execution of CALL PAX, etc. causes the following to occur: 
 
 Control is passed to the S&T built-in subroutine PAX 
 (hereafter referred to as PAXo), which acts as an interface 
 between S&T and the 360 program PAXDRIVR. (See WK system 
 command, section 3.2), 
 
 PAXq moves the argument string from the CALL instruction to 
 its buffer and sends it to the 360. 1 
 
 PAXDRIVR reads the argument string, which includes the name of 
 the subroutine to be called. The subroutine name is converted 
 to EBCDIC and saved. 
 
 -1+1- 
 
All of the arguments are converted to the form which the 
 PAX subroutine being called expects, i.e., integers are 
 converted to f ullwords , etc. Pointers are set up to each 
 converted argiiment and saved in an arguments string to be 
 passed in Register 1 to the PAX subroutine. Picture 
 references point to arrays of PAX plane indices (stored in 
 PAXDRIVR) which are initialized by DEFPIC instructions. 
 When the argument string has been completed, the name of 
 the subroutine to be called is used to enter a table of 
 addresses. The address of the entry point of the sub- 
 routine is retrieved, register 1 is loaded with the address 
 of the parameter list just constructed and control is 
 transferred to the PAX subroutine. If the subroutine name 
 is not found in the table, a 'command reject 'reply is 
 returned to S&T. 
 
 if the PAX subroutines completes execution normally, a 
 ' commaad completed OK' reply is sent to the 360, and 
 PAXDRIVR lapses into the wait state until the next interrupt 
 from the PDP8. 
 
 As it is being executed, the PAX subroutine may require 
 pictvires or other data to be transferred to or from the 
 PDP8/SMV. PAXDRIVR contains several subroutines which can 
 be called from the PAX program for this purpose. Those 
 subroutines are documented in section U.3. The important 
 point to know is that until a 'command completed OK' reply 
 is sent to the PDP8, the PDPB is enslaved to the 36O, and 
 may be called upon to perform various functions. Control 
 is not returned to the S&T interpreter from PAXg until a 
 'command completed OK' reply is received. 
 
 -h2- 
 
• 1+.3 Special PAX Subroutines 
 
 1+,3.1 Introduction 
 
 A number of subprograms are provided as extensions to 
 
 PAX for use with the S8eT system. These routines are not avail- 
 able in the standard batch PAX, since SScT and the S-M-V may not 
 be on-line when a batch Job is run. However, these subroutines 
 may be called from PAX programs , provided that such programs are 
 executed only via S&T. 
 
 For example, to write a PAX program which performs a fairly 
 large task semi -autonomously, the program can be coded in FORTRAN IV 
 using PAX subroutines, e.g.. Figure 5. This program can then be 
 added to the library of PAX programs callable from S&T and to the 
 subroutine name table in PAXDRIVR. It can then be invoked with an 
 S&T statement (i.e., CALL PAX, 'SMART') and its progress can be 
 observed on the monitor screen. 
 
 -ii3- 
 
SUBROUTINE SMART 
 DIMENSION, Etc. 
 
 RETURN 
 
 END 
 
 <set IXCOR, IXSS, lYCOR, lYSS to scan large portion of 
 the subject at low resolution>. 
 
 CALL SCAN (IXCOR, IXSS, lYCOR, lYSS) 
 
 <interpret low-resolution image, compute coarse internal 
 model of scene to direct further processing>, 
 
 <scan smaller portions at higher resolution, update internal 
 model of scene>. 
 
 <display interpretation of scene for operator's evaluation>. 
 
 Pig. 5 PAX PROGRAM: EXAMPLE OF AN AUTONOMOUS 
 
 SUBROUTINE 
 
 -hk- 
 
i|.3o2 Documentation of SpecieLl PAX Subroutines 
 
 'h5- 
 
Subroutine: PICIN 
 
 Piirpos e : 
 
 To transfer a picture from Illiac III core to a stack of PAX 
 planes. 
 
 Usage: 
 
 CALL PICIN (ipo, m>) 
 
 Parameters : 
 
 IPO - Array of indices of planes into which picture is to be 
 
 transferred. 
 NP - Number of planes in IPO. 
 
 Execution: 
 
 PICIN calls RDPIC to get a scan line from Illiac III core, 
 then calls INROW to store it in IPO. This sequence occurs 128 times. 
 
 -r-ke- 
 
Subroutine: PICOUT 
 
 Purpose: 
 
 To transfer a pict\ire from a stack of PAX planes to Illiac III 
 core. 
 
 Us age : 
 
 CALL PICOUT (IPI, NP) 
 
 Parameters : 
 
 IPI - Array of indices of planes from which picture is to 
 
 "be transferred. 
 NP - Nvunber of planes in IPI 
 
 Execution: 
 
 PICOUT calls OUTROW to get a row of IPI and then calls 
 WRTPIC to transfer it to Illiac III core. This sequence occurs 128 times, 
 
 -UT- 
 
Subroutine RDPIC 
 
 Purpose: 
 
 To transfer one 128-element row of a 128 x 128 x i+-"bit 
 picture frojn the Illiac III core to an integer array. 
 
 Usage; 
 
 CALL RDPIC (WAERAY, & N). 
 
 Parameters : 
 
 NARRAY - 128-eleinent , one-dimensional integer array. 
 
 Must be of type INTEGER *1+. 
 &W - N is statement number to which control is to be 
 
 given when all 128 rows have been transferred. 
 
 Execution; 
 
 Each time RDPIC is called, one 128-element scan line of the 
 picture currently in picture P.O. in Illiac III core is transferred to 
 the 360 and stored in NARRAY. 
 
 On the 129th call, RDPIC returns control to statement N with- 
 out transferring any data. 
 
 The next call to RDPIC reads the first scan line from the 
 Illiac III, etc. 
 
 -U8- 
 
Subroutine : SCAN 
 
 Purpose: 
 
 To cause the Illiac III S-M-V system to read a picture 
 
 into Illiac III core. 
 
 Us age : 
 
 SCM (IXCOR, lYCOR, IXSS. iySS,&N) 
 
 Parameter: 
 
 IXCOR - X coordinate of first point in window to be scanned. 
 Must be of type INTEGER *U, and such that 0<IXCOR 
 
 1 2 -1. 
 IXSS - X step size. Determines the sampling frequency along 
 
 a scan line. Must be such that 0<IXSS <5 
 lYCOR - Analogous to IXCOR 
 lYSS - Analogous to lYSS 
 N - Statement number to which control is to be returned if 
 
 the desired window could not be scanned (see below). 
 
 Execution: 
 
 The arguments IXCOR, lYCOR, IXSS and lYSS are sent to the PDP-8 
 where they used to compute values for the S-M-V s parameter and coordinate 
 words. For a complete discussion of the S-M-V, see reference [l]. 
 A 128 X 128 X k - bit window is scanned into picture P.O in 
 Illiac III core, provided that the window falls wholly within the raster 
 area of the device currently in use. If the window to be scanned 
 would fall outside the raster area, one of two things occurs, depending 
 on device type. If the device has a means of moving the object being 
 scanned, as in the case of a program- controlled microscope stage, the 
 object is shifted so that the desired window falls within the raster 
 area. In this way, the entire ^o^bject area is treated as a virtual 
 raster, so that a maximum of 2 '^ location are addressable in each 
 direction. Note, however, that injudicious use of this facility can 
 result in long wait times while mechanical motion is effected. 
 
 -U9- 
 
The parameters IXSS and lYSS are inserted into the 
 sampling increment slots (P and Q) of the S-M-V Parameter word. 
 These parameters determine how frequently the scanner will meas\ire the 
 gray-scale value of the image. For example, if IXSS=3, then of the 
 locations along the scan line where the scanner is capable of making 
 a measurement, only one in eight (2 ) will actually be made. The 
 effect is to control the coarseness of the digitized image. Since the 
 number of sample points is fixed at 128 per scan line for this sub- 
 routine, the effect is also to control the size of the image area 
 being read in. The S-M-V hardware requires that the locations of all 
 the points be integral multiples of the sample spacing. This means 
 that if IXCOR and lYCOR are not integral multiples of 2**IXSS and 
 2**IYSS, respectively, then their binary representation will be 
 truncated so that they are. For example, if IXSS=2 and IXC0R=15U, 
 then IXCOR becomes 152. 
 
 -50- 
 
Subroutine : WRTPIC 
 
 Pxorpose: 
 
 To transfer one 128-element row of a 128 x 128 x U-bit picture 
 from an integer array to Illiac III core. 
 
 Usage: 
 
 CALL WRTPIC (NARRAY, &N) 
 
 Parameters: 
 
 NARRAY -128- element , one-dimensional integer array. Must be 
 
 of type INTEGER * k, 
 N - N is statement number to which control is to be given 
 
 when 128 rows have been transferred. 
 
 Execution: 
 
 Each time WRTPIC is called, the 128 elements of NARRAY are 
 transferred to Illiac III core and stored in picture P.O. 
 
 Successive calls to WRTPIC transfer successive scan lines to the 
 Illiac III. On the 129th call, WRTPIC returns control to 
 statement niimber N without transferring any data. The next call transfers 
 NARRAY to the first scan line in P.O., etc. 
 
 -51- 
 
6o Error Message Format 
 
 Error messages are oX the Xann 
 
 * E <integer> I <text> ] 
 
 To interpret the eorror message, use '>integer> as an index to a 
 table of error messages o Entries in the table explain the cause of the 
 error condition and recommend remedial actiono The optional<text> entry 
 provides detailed information ahout the error condition to aid in 
 debugging. 
 
 -52- 
 
REFERENCE 
 
 [l] Dunn,L, ,et.al; "Parametric Description of a Scan-display 
 
 System," Proc. I969 Spring Joint Computer Conference pp,l87-206 
 
 [2] Borovec, R. , "The PAX II Picture Processing System-Programming 
 
 Manual," University of Illinois, Dept. of Computer Science 
 
 Report No. 31^+ , March I969 
 [3] McCormick, B. , et.al; "llliac III Programming Manual," 
 
 University of Illinois, Dept. of Computer Science. 
 [k] Digital Equipment Corporation "PDP-8 Disk Monitor Manual." 
 
 I5] McCormick, B. , et.al.; "The Pattern Articulation Unit of the 
 
 llliac III : Hanogeneous Boolean Functions in the Iterative 
 
 Array." University of Illinois, Dept. of Computer Science 
 
 Report No. 253. 
 [6] International Business Machines Corp. "PL/l Language 
 
 Specifications," IBM Systems Reference Library, Form C28-65T1 
 
 -53- 
 
APPENDIX: 
 Table of System Commmands and Show-and-Tell Language Statements 
 
 System Commands 
 
 Code 
 
 CH 
 DL 
 BY 
 GO 
 IN 
 KL 
 LD 
 LT 
 L0 
 LS 
 
 sy 
 w. 
 
 XG 
 XL 
 
 Function 
 
 Change program statements 
 
 Delete program statements 
 
 Define scanning device 
 
 Execute program in the ICA 
 
 Insert program statements 
 
 Kill PAXDRIVR 
 
 Load a previously-translated program 
 
 Log off 
 
 Log on 
 
 List storage 
 
 Save ICA 
 
 Test for 36o awake 
 
 Translate and go 
 
 Translate 
 
 Show-and-Tell Language Statements 
 PAU Instructions 
 
 Code 
 
 AREA 
 
 BOOLE 
 
 CLEARP 
 
 CONNEC 
 
 copi 
 copyc 
 
 LIST 
 
 LOADW 
 
 PLAND 
 
 Function 
 
 Count ones in a plane 
 
 Evaluate homogeneous Boolean Function 
 
 Set plane to zeros 
 
 Determine graph connectivity 
 
 Copy plane 
 
 Complement plane and copy 
 
 Scan plane and store coordinates of ones 
 
 Load window into Iterative Array 
 
 Perform logical AND between two planes 
 
 -5ii 
 
PLEXOR 
 
 PLOR 
 
 SETP 
 
 SHIFT 
 
 STOREW 
 
 TALLY' 
 
 TALLYH 
 
 Perform logical EXCLUSIVE OR between tvo planes 
 Perform logical OR between two planes 
 Set planes to ones 
 Shift plane 
 
 Store window from Iterative Ar ray- 
 Base -1 count up 
 Base-1 count down 
 
 Sequence Control Instruction 
 
 Code Junction 
 
 CALL 
 EXIT 
 GOTO 
 IJGO 
 
 mm 
 
 Subroutine call 
 
 Return from subroutine 
 
 Unconditional jump 
 
 Conditional jump 
 
 Wait for operator response or timeout 
 
 Data-manipulating Instructions 
 Code Function 
 
 ASGN 
 
 DECR 
 
 INCR 
 
 J^IXEL 
 
 WIXEL 
 
 Assign a value to a data item 
 Decrement a counter 
 Increment a counter 
 Read picture element 
 Write picture element 
 
 Input-Output Instructions 
 
 Code Function 
 
 DEFPC 
 
 LOADPC 
 
 LOOK 
 
 PNABE 
 
 RELPC 
 
 SAVEPC 
 
 Define picture 
 
 Read picture from LINC tape 
 
 Scan picture without input to core 
 
 Type gray-scale values of a small region 
 
 Release picture storage 
 
 Write picture on LINC tape 
 
 -55- 
 
SCAN Select picture and read into core (program control) 
 
 SCANM Select picture and read into core (operator control) 
 
 SHOW Display picture on monitor 
 
 SHOWTL Display picture with operator feedback 
 
 TEXTI Read text from teletype 
 
 TEXT0 Write text on teletype 
 
 TRACE Record cursor movement and sample neighborhoods 
 
 -56- 
 
orm AEC-427 
 
 (6/68) 
 AECM 3201 
 
 U.S. ATOMIC ENERGY COMMISSION 
 
 UNIVERSITY-TYPE CONTRACTOR'S RECOMMENDATION FOR 
 
 DISPOSITION OF SCIENTIFIC AND TECHNICAL DOCUMENT 
 
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 AEC REPORT NO. i|29 
 
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 2. TITLE 
 
 SHOW-AIJD-TELL 
 
 An Interactive Programming System For Image 
 
 Processing _^_ 
 
 3. TYPE OF DOCUMENT (Ch«ckon«): 
 
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 University of Illinois 
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 Date 
 
 February I8, 1971 
 
 FOR AEC USE ONLY 
 
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