In English
	Publisher: Commodore Business Machines, Inc.
This book is available electronically at http://commodore.ca/manuals/pet_communication/com_pet.htm

Table of Contents

PET Interfaces and Lines	3
1. Connector Orientation	4
2. IEEE-488 Interfaces (Connector J1)	5
2.1 Receptables for the IEEE-Interface	6
2.2 IEEE-488 Connectors	6
3. Parallel User Port (Connector J2)	7
3.1 Versatile Interface Adapter	8
3.2 Programming the User Port	10
4. Second Cassette Interface (Connector J3)	10
5. Memory Expansion Connector (Connector J4)	12
Commands and Operations for Peripheral Devices	15
1. Additional BASIC Commands	17
2. Input/Output Command Parameters	17
2.1 Logical Files	17
2.2 Device Numbers	18
2.3 Secondary Addresses	19
2.4 File Names	20
3. Tape Cassette Operation for Files	20
3.1 File Recording Technique	21
3.2 File Headers	21
3.3 Tape Buffers	22
3.4 Multiple Files	22
4. Logical File I/O Operations: General	23
5. Opening Files	24
5.1 Examples of OPEN Statements	24
5.2 LOAD	25
5.3 VERIFY	26
5.4 SAVE	27
5.5 IEEE-488 Special Features	27
5.6 IEEE-488 OPEN Considerations	27
6. Tape File Operations Modes	28
6.1 OPEN for Write or Tape from PET	28
6.2 OPEN for Read from Tape to PET	28
7. Data Input: General	31
7.1 INPUT# - String and Variable Input	31
7.1.1 Example of INPUT# Statement	31
7.2 GET# - Character Transfers	32
7.3 Tape Input	32
7.4 IEE-488 Device Input Sequences	32
7.5 Input Buffer Limitations	32
8. Data Output: General	33
8.1 Print#	33
8.1.1 Examples of PRINT# Statement	35
8.2 IEEE-488 Bus Output	36
8.3 CMD Command	36
8.3.1 Examples of CMD Command	37
9. Closing Files	37
9.1 Example of CLOSE Statement	38
9.2 Tape File Closure	38
9.3 IEEE-488 Named Device Closure	38
10. Error Detection: General	38
10.1 Status Word (ST)	38
10.2 IEEE Device Errors	39
10.3 Tape Unit Errors	39
10.4 Examples of ST Use	40
11. Polling Techniques	41
12. Default Parameters	41
The IEEE-488 Bus - A Short Description	43
1. Introduction to the IEEE-488 Bus	44
1.1 Bus/Device Connection	44
1.2 The Data Bus	45
1.2.1 Data Transmission Modes	45
1.3 The Transfer Bus	45
1.3.1 The Handshake Procedure	46
1.3.2 PET/IEEE Bus Timing Constraints	49
1.4 The Management Bus	49
2. IEEE Signals and Definitions	49
2.1 Logic Level Convention	49
3. Status Word (ST)	51
4. IEEE-488 Register Addresses	51