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Internet Message Format | 1996-01-27 | 45.4 KB

To: Users From: The Author Subj: Simulator Usage, V2.2 Date: 27-Jan-96 This memorandum documents the PDP-8, PDP-11, PDP 18b, and Nova simulators. These simulators are freeware; commercial use is prohibited, and support is not available. The best way to fix problems or add features is to read and modify the sources yourself. Alternately, you can send Internet mail to dsmaint@pa.dec.com; but responses are NOT guaranteed. The simulators use a common command interface. The memorandum first describes the common features of the command interface and then provides information on each of the individual simulators. 1. Compiling And Running A Simulator The simulators have been tested on VAX VMS, Alpha VMS, Alpha UNIX, and Intel LINUX. Porting to other environments will require changes to the operating system dependent code in scp_tty.c. To compile the simulators on Alpha UNIX, use these commands (note that separate compilations are required for each of the 18b PDP's): % cc pdp8*.c scp*.c -lm -o pdp8 % cc pdp11*.c scp*.c -o pdp11 % cc nova*.c scp*.c -lm -o nova % cc -DPDP{4,7,9,15} pdp18b*.c scp*.c -lm -o pdp{4,7,9,15} To compile the simulators on LINUX, use these commands: % cc -DLINUX pdp8*.c scp*.c -lm -lbsd -o pdp8 % cc -DLINUX pdp11*.c scp*.c -lbsd -o pdp11 % cc -DLINUX nova*.c scp*.c -lm -lbsd -o nova % cc -DPDP{4,7,9,15} -DLINUX pdp18b*.c scp*.c -lm -o pdp{4,7,9,15} To start the simulator, simply type its name. The simulator takes one optional argument, a startup command file. If specified, this file should contain a series of non-interactive simulator commands, one per line. These command can be used to set up standard parameters, for example, disk sizes. % pdp8 <startup file>(cr) or % pdp11 <startup file>(cr) or % nova <startup file>(cr) or % pdp{4,7,9,15} <startup file>(cr) The simulator types out its name and version, executes the commands in the startup file, if any, and then prompts for input with sim> 2. Simulator Conventions A simulator consists of a series of devices, the first of which is always the CPU. A device consists of named registers and one or more numbered units. Registers correspond to device state, units to device address spaces. Thus, the CPU device might have registers like PC, ION, etc, and a unit corresponding to main memory; a disk device might have registers like BUSY, DONE, etc, and units corresponding to individual disk drives. Except for main memory, device address spaces are simulated as unstructured binary disk files in the host file system. (Thus, files with data widths greater than 8b are endian dependent.) The SHOW CONFIG command displays the simulator configuration. A simulator keeps time in terms of arbitrary units, usually one time unit per instruction executed. Simulated events (such as completion of I/O) are scheduled at some number of time units in the future. The simulator executes synchronously, invoking event processors when simulated events are scheduled to occur. Even asynchronous events, like keyboard input, are handled by polling at synchronous intervals. The SHOW QUEUE command displays the simulator event queue. 3. Commands 3.1 Loading Programs The LOAD command (abbreviation LO) loads a file in binary paper-tape loader format: sim> load <filename>(cr) 3.2 Saving and Restoring State The SAVE command (abbreviation SA) save the complete state of the simulator to a file. This includes the contents of main memory and all registers, and the I/O connections of devices: sim> save <filename>(cr) The RESTORE command (abbreviation REST, alternately GET) restores a previously saved simulator state: sim> restore <filename>(cr) Note: SAVE file format compresses zeroes to minimize file size. 3.3 Resetting Devices The RESET command (abbreviation RE) resets a device or the entire simulator to a predefined condition: sim> RESET(cr) -- reset all devices sim> RESET ALL(cr) -- reset all devices sim> RESET <device>(cr) -- reset specified device Typically, RESET stops any in-progress I/O operation, clears any interrupt request, and returns the device to a quiescent state. It does not clear main memory or affect I/O connections. 3.4 Connecting and Disconnecting Devices Except for main memory, simulated unit address spaces are simulated as unstructured binary disk files in the host file file system. Before using a simulated unit the user must specify the file to be used by a particular unit. The ATTACH (abbreviation AT) command associates a unit and a file: sim> ATTACH <device><unit number> <filename>(cr) If the file does not exist, it is created, and an appropriate message is printed. The DETACH (abbreviation DET) command breaks the association between a unit and a file and closes the file: sim> DETACH ALL(cr) -- detach all units sim> DETACH <device><unit number>(cr) -- detach specified unit The EXIT command performs an automatic DETACH ALL. 3.5 Examining and Changing State There are four commands to examine and change state: EXAMINE (abbreviated E) examines state DEPOSIT (abbreviated D) changes state IEXAMINE (interactive examine, abbreviated IE) examines state and allows the user to interactively change it IDEPOSIT (interactive deposit, abbreviated ID) allows the user to interactively change state All four commands take the form command {-switches} {<device>{<unit number>}} <state list> Deposit must also include a deposit value at the end of the command. The examine and deposit commands can work on the address space of any unit. If no device is specified, the CPU (main memory) is selected; if a device but no unit is specified, unit 0 of the specified device is selected. The "state list" consists of one or more of the following, separated by commas: register the specified register register1-register2 all the registers starting at register1 up to and including register2 address the specified location address1-address2 all locations starting at address1 up to and including address2 STATE all registers in the device ALL all locations in the unit Switches can be used to control the format of display information: -a display as ASCII -c display as character string -m display as instruction mnemonics The simulators typically accept symbolic input (see simulator sections). Examples: sim> ex 1000-1100 -- examine 1100:1100 sim> de PC 1040 -- set PC to 1040 sim> ie 40-50 -- interactively examine 40:50 sim> ex rx0 50060 -- examine 50060, RX unit 0 sim> de all 0 -- set main memory to 0 Note: to terminate an interactive command, simply type a bad value (eg, XXX) when input is requested. 3.6 Running Programs The RUN command (abbreviated RU) resets all devices, deposits its argument (if given) in the PC, and starts execution. If no argument is given, execution starts at the current PC. The GO command does NOT reset devices, deposits its argument (if given) in the PC, and starts execution. If no argument is given, execution starts at the current PC. The CONT command (abbreviated CO) does NOT reset devices and resumes execution at the current PC. The STEP command (abbreviated S) resumes execution at the current PC for the number of instructions given by its argument. If no argument is supplied, one instruction is executed. The BOOT command (abbreviated BO) bootstraps the device and unit given by its argument. If no unit is supplied, unit 0 is boostrapped. The specified unit must be attached to a file. 3.7 Stopping Programs Programs run until the simulator detects an error or stop condition, or until the user forces a stop condition. 3.7.1 Simulator Detected Stop Conditions These simulator-detected conditions stop simulation: o HALT instruction. If a HALT instruction is decoded, simulation stops. o Breakpoint. The IBKPT register provides a single virtual address breakpoint. If the PC matches the contents of the IBKPT register, simulation stops. The breakpoint is automatically disabled for the next instruction execution. o I/O error. If an I/O error occurs during simulation of an I/O operation, and the device stop-on-I/O-error flag is set, simulation usually stops. o Processor condition. Certain processor conditions can stop simulation; these are described with the individual simulators. 3.7.2 User Specified Stop Conditions Typing the interrupt character stops simulation. The interrupt character is defined by the WRU (where are you) register and is initially set to 005 (^E). 3.8 Setting Device Parameters The SET command (abbreviated SE) changes the status of a device parameter: sim> SET <unit> <parameter> The parameters are simulator and device specific. Disk drives, for example, can usually be set write ENABLED or write LOCKED; if a device supports multiple drive types, the SET command can be used to specify the drive type. 3.8 Displaying Parameters and Status The SHOW CONFIGURATION command shows the simulator configuration and the status of all simulated I/O devices. The SHOW <device> command shows the status of the named simulated I/O device. The SHOW QUEUE command shows the state of the simulator event queue. Times are in "simulation units", typically one unit per instruction execution, relative to the current simulation time. The SHOW TIME command shows the number of time units elapsed since the last RUN command. 3.9 Exiting The Simulator EXIT (synonyms QUIT and BYE) returns control to the operating system. 4. PDP-8 Features The PDP-8 simulator is configured as follows: device simulates name(s) CPU PDP-8/E CPU with 32KW of memory - KE8E extended arithmetic element (EAE) - KM8E memory management and timeshare control PTR,PTP PC8E paper tape reader/punch TTI,TTO KL8E console terminal LPT LE8E line printer CLK DK8E line frequency clock (also PDP-8/A compatible) RK RK8E/RK05 cartridge disk controller with four drives RF RF08/RS08 fixed head disk controller with four platters RX RX8E/RX01 floppy disk controller with two drives MT TM8E/TU10 magnetic tape controller with eight drives The PDP-8 simulator implements one unique stop condition: if an undefined instruction (unimplemented IOT or OPR) is decoded, and register STOP_INST is set, the simulator halts. 4.1 CPU The only CPU options are the presense of the EAE and the size of main memory; the memory extension and time-share control is always included, even if memory size is 4K. SET CPU EAE enable EAE SET CPU NOEAE disable EAE SET CPU 4K set memory size = 4K SET CPU 8K set memory size = 8K SET CPU 12K set memory size = 12K SET CPU 16K set memory size = 16K SET CPU 20K set memory size = 20K SET CPU 24K set memory size = 24K SET CPU 28K set memory size = 28K SET CPU 32K set memory size = 32K If memory size is being reduced, and the memory being truncated contains non-zero data, the simulator asks for confirmation. Data in the truncated portion of memory is lost. Initial memory size is 32K. CPU registers include the visible state of the processor as well as the control registers for the interrupt system. name size comments PC 15 program counter, including IF as high 3 bits AC 12 accumulator MQ 12 multiplier-quotient L 1 link SR 12 front panel switches IF 3 instruction field DF 3 data field IB 3 instruction field buffer SF 7 save field UF 1 user mode flag UB 1 user mode buffer SC 5 EAE shift counter GTF 1 EAE greater than flag EMODE 1 EAE mode (0 = A, 1 = B) ION 1 interrupt enable ION_DELAY 1 interrupt enable delay for ION CIF_DELAY 1 interrupt enable delay for CIF PWR_INT 1 power fail interrupt UF_INT 1 user mode violation interrupt INT 15 interrupt pending flags DONE 15 device done flags ENABLE 15 device interrupt enable flags OLDPC 15 PC prior to last JMP, JMS, or interrupt STOP_INST 1 stop on undefined instruction BREAK 16 breakpoint address (177777 to disable) WRU 8 interrupt character 4.2 Programmed I/O Devices (PTR, PTP, TTI, TTO, CLK, LPT) The paper tape reader (PTR), paper tape punch (PTP), and line printer (LPT) read data from or write data to disk files. The POS register specifies the number of the next data item to be read or written. Thus, by changing POS, the user can backspace or advance these devices. The programmed I/O devices typically implement these registers: name size comments BUF 8 last data item processed INT 1 interrupt pending flag DONE 1 device done flag ENABLE 1 interrupt enable flag TIME 24 time from I/O initiation to interrupt (for keyboard, polling interval) POS 32 position in the input or output file STOP_IOE 1 stop on I/O error For the serial devices, error handling is as follows: type error STOP_IOE processed as in,out not attached 1 report error and stop 0 out of tape or paper in end of file 1 report error and stop 0 out of tape or paper in,out OS I/O error x report error and stop 4.3 RK8E/RK05 RK8E options include the ability to place units online or offline, write enabled or write locked: SET RKn OFFLINE set unit n offline SET RKn ONLINE set unit n online SET RKn LOCKED set unit n write locked SET RKn ENABLED set unit n write enabled The RK8E implements these registers: name size comments STA 12 status DA 12 disk address MA 12 current memory address CMD 12 disk command BUSY 1 control busy flag INT 1 interrupt pending flag STIME 24 seek time, per cylinder RTIME 24 rotational delay STOP_IOE 1 stop on I/O error Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready end of file x assume rest of disk is zero OS I/O error x report error and stop 4.4 RX8E/RX01 RX8E options include the ability to set units write enabled or write locked: SET RXn LOCKED set unit n write locked SET RXn ENABLED set unit n write enabled The RX8E implements these registers: name size comments RXCS 12 status RXDB 12 data buffer RXES 8 error status RXTA 8 current track RXSA 8 current sector STAPTR 3 controller state BUFPTR 3 buffer pointer INT 1 interrupt pending flag DONE 1 device done flag ENABLE 1 interrupt enable flag TR 1 transfer ready flag ERR 1 error flag CTIME 24 command completion time STIME 24 seek time, per track XTIME 24 transfer ready delay STOP_IOE 1 stop on I/O error Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready RX01 data files are buffered in memory; therefore, end of file and OS I/O errors cannot occur. 4.5 RF08/RS08 The RF08 implements these registers: name size comments STA 12 status DA 20 current disk address MA 12 memory address (in memory) WC 12 word count (in memory) WLK 32 write lock switches INT 1 interrupt pending flag DONE 1 device done flag TIME 24 rotational delay, per word BURST 1 burst flag STOP_IOE 1 stop on I/O error The RF08 is a three-cycle data break device. If BURST = 0, word transfers are scheduled individually; if BURST = 1, the entire transfer occurs in a single data break. Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready RF08 data files are buffered in memory; therefore, end of file and OS I/O errors cannot occur. 4.6 Magnetic Tape (MT) Magnetic tape options include the ability to place units write enabled or or write locked. SET MTn LOCKED set unit n write locked SET MTn ENABLED set unit n write enabled The magnetic tape controller implements these registers: name size comments CMD 12 command FNC 12 function CA 12 memory address WC 12 word count DB 12 data buffer STA 12 main status STA2 6 secondary status DONE 1 device done flag INT 1 interrupt pending flag STOP_IOE 1 stop on I/O error TIME 24 record delay UST0..7 24 unit status, units 0..n Error handling is as follows: error processed as not attached tape not ready end of file (read or space) end of physical tape (write) ignored OS I/O error report error and stop 4.7 Symbolic Display and Input The PDP-8 simulator implements symbolic display and input. Display is controlled by command line switches: -a display as ASCII character -c display as (sixbit) character string -m display instruction mnemonics Input parsing is controlled by the first character typed in: ' ASCII character " two character sixbit string alphabetic instruction mnemonic numeric octal number Instruction input uses standard PDP-8 assembler syntax. There are four instruction classes: memory reference, IOT, field change, and operate. Memory reference instructions have the format memref {I} {T/Z} address where I signifies indirect, T a current page reference, and Z a zero page reference. The address is an octal number in the range 0 - 07777; if T or Z is specified, the address is a page offset in the range 0 - 177. Normally, T is not needed; the simulator figures out from the address what mode to use. However, when referencing memory outside the CPU (eg, disks), there is no valid PC, and T must be used to specify current page addressing. IOT instructions consist of single mnemonics, eg, KRB, TLS. IOT instructions may be or'd together iot iot iot... The simulator does not check the legality of the proposed combination. IOT's for which there is no opcode may be specified as IOT n, where n is an octal number in the range 0 - 0777. Field change instructions (CIF, CDF) have the format fldchg field where field is an octal number in the range 0 - 7. Field change instructions may be or'd together. Operate instructions have the format opr opr opr... The simulator does not check the legality of the proposed combination. EAE mode A and B mnemonics may be specified regardless of the EAE mode. The operands for MUY and DVI must be deposited explicitly. 5. PDP-11 Features The PDP-11 simulator is configured as follows: device simulates name(s) CPU J-11 CPU with 256KB of memory - FP11 floating point unit (FPA) PTR,PTP PC11 paper tape reader/punch TTI,TTO DL11 console terminal LPT LP11 line printer CLK line frequency clock RK RK11/RK05 cartridge disk controller with eight drives RL RLV12/RL01(2) cartridge disk controller with four drives RX RX11/RX01 floppy disk controller with two drives The PDP-11 simulator implements several unique stop conditions: - abort during exception vector fetch, and register STOP_VEC is set - abort during exception stack push, and register STOP_SPA is set - trap condition 'n' occurs, and register STOP_TRAP<n> is set - wait state entered, and no I/O operations outstanding (ie, no interrupt can ever occur) 5.1 CPU Memory size is a compile time parameter in pdp11_defs.h; the standard memory size is 248KB. These switches are recognized when examining or depositing in CPU memory: -v interpret address as virtual -d if mem mgt enabled, force data space -k if mem mgt enabled, force kernel mode -s if mem mgt enabled, force supervisor mode -u if mem mgt enabled, force user mode -p if mem mgt enabled, force previous mode CPU registers include the visible state of the processor as well as the control registers for the interrupt system. name size comments PC 16 program counter R0..R5 16 R0..R5, first register set R10..R15 16 R0..R5, second register set KSP 16 kernel stack pointer SSP 16 supervisor stack pointer USP 16 user stack pointer PSW 16 processor status word CM 2 current mode, PSW<15:14> PM 2 previous mode, PSW<13:12> RS 2 register set, PSW<11> IPL 3 interrupt priority level, PSW<7:5> T 1 trace bit, PSW<4> N 1 negative flag, PSW<3> Z 1 zero flag, PSW<2> V 1 overflow flag, PSW<1> C 1 carry flag, PSW<0> SR 16 front panel switches DR 16 front panel display MEMERR 16 memory error register CCR 16 cache control register MAINT 16 maintenance register HITMISS 16 hit/miss register CPUERR 16 CPU error register PIRQ 16 programmed interrupt requests FAC0H..FAC5H 32 FAC0..FAC5, high 32 bits FAC0L..FAC5L 32 FAC0..FAC5, low 32 bits FPS 16 floating point status FEA 16 floating exception address FEC 4 floating exception code MMR0..3 16 memory management registers 0..3 {K/S/U}{I/D}{PAR/PDR}{0..7} 16 memory management registers INT 32 interrupt pending flags TRAP 18 trap pending flags WAIT 0 wait state flag WAIT_ENABLE 0 wait state enable flag STOP_TRAPS 18 stop on trap flags STOP_VECA 1 stop on read abort in trap or interrupt STOP_SPA 1 stop on stack push abort in trap or interrupt OLDPC 16 PC prior to last JMP, JMS, or interrupt BREAK 16 breakpoint address (1 to disable) WRU 8 interrupt character 5.2 Programmed I/O Devices (PTR, PTP, TTI, TTO, CLK, LPT) The paper tape reader (PTR), paper tape punch (PTP), and line printer (LPT) read data from or write data to disk files. The POS register specifies the number of the next data item to be read or written. Thus, by changing POS, the user can backspace or advance these devices. The programmed I/O devices typically implement these registers: name size comments BUF 8 last data item processed CSR 16 control/status register INT 1 interrupt pending flag ERR 1 error flag (CSR<15>) DONE 1 device done flag (CSR<7>) IE 1 interrupt enable flag (CSR<6>) TIME 24 time from I/O initiation to interrupt (for keyboard, polling interval) POS 32 position in the input or output file STOP_IOE 1 stop on I/O error For the serial devices, error handling is as follows: type error STOP_IOE processed as in,out not attached 1 report error and stop 0 out of tape or paper in end of file 1 report error and stop 0 out of tape or paper in,out OS I/O error x report error and stop 5.3 RK11/RK05 RK11 options include the ability to place units online or offline, write enabled or write locked: SET RKn OFFLINE set unit n offline SET RKn ONLINE set unit n online SET RKn LOCKED set unit n write locked SET RKn ENABLED set unit n write enabled The RK11 implements these registers: name size comments RKCS 16 control/status RKDA 16 disk address RKBA 16 memory address RKWC 16 word count RKDS 16 drive status RKER 16 error status INTQ 9 interrupt queue DRVN 3 number of last selected drive INT 1 interrupt pending flag ERR 1 error flag (CSR<15>) DONE 1 device done flag (CSR<7>) IE 1 interrupt enable flag (CSR<6>) INT 1 interrupt pending flag STIME 24 seek time, per cylinder RTIME 24 rotational delay STOP_IOE 1 stop on I/O error Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready end of file x assume rest of disk is zero OS I/O error x report error and stop 5.4 RX11/RX01 RX11 options include the ability to make units write enabled or write locked: SET RXn LOCKED set unit n write locked SET RXn ENABLED set unit n write enabled The RX11 implements these registers: name size comments RXCS 12 status RXDB 8 data buffer RXES 8 error status RXERR 8 error code RXTA 8 current track RXSA 8 current sector STAPTR 3 controller state BUFPTR 3 buffer pointer INT 1 interrupt pending flag ERR 1 error flag (CSR<15>) TR 1 transfer ready flag (CSR<7>) IE 1 interrupt enable flag (CSR<6>) DONE 1 device done flag (CSR<5>) CTIME 24 command completion time STIME 24 seek time, per track XTIME 24 transfer ready delay STOP_IOE 1 stop on I/O error Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready RX01 data files are buffered in memory; therefore, end of file and OS I/O errors cannot occur. 5.5 RL11(V12)/RL01,RL02 RL11 options include the ability to set units write enabled or write locked, and to set the drive size to RL01, RL02, or autosize: SET RLn LOCKED set unit n write locked SET RLn ENABLED set unit n write enabled SET RLn RL01 set size to RL01 SET RLn RL02 set size to RL02 SET RLn AUTOSIZE set size based on file size at attach The size options can be used only when a unit is not attached to a file. The RL11 implements these registers: name size comments RLCS 16 control/status RLDA 16 disk address RLBA 16 memory address RLBAE 6 memory address extension (RLV12) RLMP..RLMP2 16 multipurpose register queue INT 1 interrupt pending flag ERR 1 error flag (CSR<15>) DONE 1 device done flag (CSR<7>) IE 1 interrupt enable flag (CSR<6>) INT 1 interrupt pending flag STIME 24 seek time, per cylinder RTIME 24 rotational delay STOP_IOE 1 stop on I/O error Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready end of file x assume rest of disk is zero OS I/O error x report error and stop 5.6 Symbolic Display and Input The PDP-11 simulator implements symbolic display and input. Display is controlled by command line switches: -a display as ASCII character -c display as two character ASCII string -m display instruction mnemonics Input parsing is controlled by the first character typed in: ' ASCII character " two character ASCII string alphabetic instruction mnemonic numeric octal number Instruction input uses standard PDP-11 assembler syntax. There are sixteen instruction classes: class operands examples comments no operands none HALT, RESET 3b literal literal, 0 - 7 SPL 6b literal literal, 0 - 077 MARK 8b literal literal, 0 - 0377 EMT, TRAP register register RTS sop specifier SWAB, CLR, ASL reg-sop register, specifier JSR, XOR, MUL fop flt specifier ABSf, NEGf ac-fop flt reg, flt specifier LDf, MULf ac-sop flt reg, specifier LDEXP, STEXP ac-moded sop flt reg, specifier LDCif, STCfi dop specifier, specifier MOV, ADD, BIC cond branch address BR, BCC, BNE sob register, address SOB cc clear cc clear instructions CLC, CLV, CLZ, CLN combinable cc set cc set instructions SEC, SEV, SEZ, SEN combinable For floating point opcodes, F and D variants, and I and L variants, may be specified regardless of the state of FPS. The syntax for specifiers is as follows: syntax specifier displacement comments Rn 0n - Fn 0n - only in flt reg classes (Rn) 1n - @(Rn) 7n 0 equivalent to @0(Rn) (Rn)+ 2n - @(Rn)+ 3n - -(Rn) 4n - @-(Rn) 5n - {+/-}d(Rn) 6n {+/-}d @{+/-}d(Rn) 7n {+/-}d #n 27 n @#n 37 n .+/-n 67 +/-n - 4 @.+/-n 77 +/-n - 4 {+/-}n 67 {+/-}n - PC - 4 if on disk, 37 and n @{+/-}n 77 {+/-}n - PC - 4 if on disk, invalid 6. Nova Features The Nova simulator is configured as follows: device simulates name(s) CPU Nova CPU with 32KW of memory - hardware multiply/divide PTR,PTP paper tape reader/punch TTI,TTO console terminal LPT line printer CLK real-time clock DK head-per-track disk controller DP moving head disk controller with four drives MT magnetic tape controller with eight drives The Nova simulator implements these unique stop conditions: - reference to undefined I/O device, and STOP_DEV is set - more than INDMAX indirect addresses are detected during an interrupt - more than INDMAX indirect addresses are detected during memory reference address decoding 6.1 CPU The only CPU options are the presense of the multiply/divide instructions and the size of main memory. SET CPU MDV enable multiply/divide SET CPU NOMDV disable multiply/divide SET CPU 4K set memory size = 4K SET CPU 8K set memory size = 8K SET CPU 12K set memory size = 12K SET CPU 16K set memory size = 16K SET CPU 20K set memory size = 20K SET CPU 24K set memory size = 24K SET CPU 28K set memory size = 28K SET CPU 32K set memory size = 32K If memory size is being reduced, and the memory being truncated contains non-zero data, the simulator asks for confirmation. Data in the truncated portion of memory is lost. Initial memory size is 32K. CPU registers include the visible state of the processor as well as the control registers for the interrupt system. name size comments PC 15 program counter AC0..AC3 16 accumulators 0..3 C 1 carry SR 16 front panel switches PI 16 priority interrupt mask ION 1 interrupt enable ION_DELAY 1 interrupt enable delay for ION PWR 1 power fail interrupt INT 15 interrupt pending flags BUSY 15 device busy flags DONE 15 device done flags DISABLE 15 device interrupt disable flags STOP_DEV 1 stop on undefined IOT INDMAX 15 maximum number of nested indirects OLDPC 15 PC prior to last JMP, JMS, or interrupt BREAK 16 breakpoint address (177777 to disable) WRU 8 interrupt character 6.2 Programmed I/O Devices (PTR, PTP, TTI, TTO, CLK, LPT) The paper tape reader (PTR), paper tape punch (PTP), and line printer (LPT) read data from or write data to disk files. The POS register specifies the number of the next data item to be read or written. Thus, by changing POS, the user can backspace or advance these devices. The programmed I/O devices typically implement these registers: name size comments BUF 8 last data item processed BUSY 1 device busy flag DONE 1 device done flag DISABLE 1 interrupt disable flag INT 1 interrupt pending flag TIME 24 time from I/O initiation to interrupt (for keyboard, polling interval) POS 32 position in the input or output file STOP_IOE 1 stop on I/O error For the serial devices, error handling is as follows: type error STOP_IOE processed as in,out not attached 1 report error and stop 0 out of tape or paper in end of file 1 report error and stop 0 out of tape or paper in,out OS I/O error x report error and stop Terminal options include the ability to set limited Dasher compatibility mode or normal mode: SET TTI ANSI normal mode SET TTI DASHER Dasher mode SET TTO ANSI normal mode SET TTO DASHER Dasher mode Setting either TTI or TTO changes both devices. In Dasher mode, carriage return is changed to newline on input, and ^X is changed to backspace. 6.3 Fixed Head Disk (DK) The fixed head disk controller implements these registers: name size comments STAT 16 status DA 16 disk address MA 16 memory address BUSY 1 device busy flag DONE 1 device done flag DISABLE 1 device disable flag INT 1 interrupt pending flag WLK 8 write lock switches TIME 24 rotational delay, per sector STOP_IOE 1 stop on I/O error Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready Fixed head disk data files are buffered in memory; therefore, end of file and OS I/O errors cannot occur. 6.4 Moving Head Disk (DP) Moving head disk options include the ability to place units online or offline, write enabled or write locked, and to select the type of drive: SET DPn OFFLINE set unit n offline SET DPn ONLINE set unit n online SET DPn LOCKED set unit n write locked SET DPn ENABLED set unit n write enabled SET DPn FLOPPY set unit n to floppy disk SET DPn D31 set unit n to Diablo 31 SET DPn D44 set unit n to Diablo 44 SET DPn C111 set unit n to Century 111 SET DPn C114 set unit n to Century 114 All drives have 256 16b words per sector. The other disk parameters are: drive cylinders surfaces sectors size (MW) DG models floppy 77 1 8 .158 6038 D31 203 2 12 1.247 4047, 4237, 4238 D44 408 4 12 5.014 4234, 6045 C111 203 10 6 3.118 4048 C114 203 20 12 12.472 4057, 2314 The moving head disk controller implements these registers: name size comments FCCY 16 flags, command, cylinder USSC 16 unit, surface, sector, count STAT 16 status MA 16 memory address BUSY 1 device busy flag DONE 1 device done flag DISABLE 1 interrupt disable flag INT 1 interrupt pending flag STIME 24 seek time, per cylinder RTIME 24 rotational delay Error handling is as follows: error processed as not attached disk not ready end of file assume rest of disk is zero OS I/O error report error and stop 6.5 Magnetic Tape (MT) Magnetic tape options include the ability to place units write enabled or or write locked. SET MTn LOCKED set unit n write locked SET MTn ENABLED set unit n write enabled The magnetic tape controller implements these registers: name size comments CU 16 command, unit MA 16 memory address WC 16 word count STA1 16 status word 1 STA2 16 status word 2 EP 1 extended polling mode (not supported) BUSY 1 device busy flag DONE 1 device done flag DISABLE 1 interrupt disable flag INT 1 interrupt pending flag STOP_IOE 1 stop on I/O error CTIME 24 controller delay RTIME 24 record delay UST0..7 32 unit status, units 0..n Error handling is as follows: error processed as not attached tape not ready end of file (read or space) end of physical tape (write) ignored OS I/O error report error and stop 6.6 Symbolic Display and Input The Nova simulator implements symbolic display and input. Display is controlled by command line switches: -a display as ASCII character -c display as two character ASCII string -m display instruction mnemonics Input parsing is controlled by the first character typed in: ' ASCII character " two character ASCII string alphabetic instruction mnemonic numeric octal number Instruction input uses standard Nova assembler syntax. There are three instruction classes: memory reference, IOT, and operate. Memory reference instructions have the format memref {ac,}{@}address{,index} LDA and STA require an initial register; ISZ, DSZ, JSR, and JMP do not. The syntax for addresses and indices is as follows: syntax mode displacement comments 0 <= n < 0400 0 n {+/-}n >= 0400 1 {+/-}n - PC must be in range [-200, 177] invalid on disk .+/-n 1 {+/-}n must be in range [-200, 177] {+/-}n,2 2 {+/-}n must be in range [-200, 177] {+/-}n,3 3 {+/-}n must be in range [-200, 177] IOT instructions have one of four formats syntax example iot HALT iot reg INTA iot device SKPDN iot reg,device DOAS Devices may be specified as mnemonics or as numbers in the range 0 - 077. Operate instructions have the format opcode{#} reg,reg{,skip} In all Nova instructions, blanks may be substituted for commas as field delimiters. 7. 18b PDP Features The four 18b PDP's (PDP-4, PDP-7, PDP-9, PDP-15) are very similar and are configured as follows: system device simulates name(s) PDP-4 CPU PDP-4 CPU with 8KW of memory PTR,PTP integral paper tape/Type 75 punch TTI,TTO KSR28 console terminal (Baudot code) LPT Type 62 line printer (Hollerith code) CLK integral real-time clock PDP-7 CPU PDP-7 CPU with 32KW of memory - Type 177 extended arithmetic element (EAE) - Type 148 memory extension PTR,PTP Type 444 paper tape reader/Type 75 punch TTI,TTO KSR 33 console terminal LPT Type 647 line printer CLK integral real-time clock DRM Type 24 serial drum PDP-9 CPU PDP-9 CPU with 32KW of memory - KE09A extended arithmetic element (EAE) - KG09B memory extension - KP09A power detection - KX09A memory protection PTR,PTP PC09A paper tape reader/punch TTI,TTO KSR 33 console terminal LPT Type 647E line printer CLK integral real-time clock RF RF09/RS09 fixed-head disk MT TC59/TU10 magnetic tape PDP-15 CPU PDP-15 CPU with 32KW of memory - KE15 extended arithmetic element (EAE) - KF15 power detection - KM15 memory protection PTR,PTP PC15 paper tape reader/punch TTI,TTO KSR 35 console terminal LPT LP15 line printer CLK integral real-time clock RP RP15/RP02 disk pack RF RF15/RS09 fixed-head disk MT TC59/TU10 magnetic tape The 18b PDP simulators implement one unique stop condition: if an undefined instruction (unimplemented OPR) is decoded, and register STOP_INST is set, the simulator halts. 7.1 CPU The only CPU options are the presense of the EAE and the size of main memory. SET CPU EAE enable EAE SET CPU NOEAE disable EAE SET CPU 4K set memory size = 4K SET CPU 8K set memory size = 8K SET CPU 12K set memory size = 12K SET CPU 16K set memory size = 16K SET CPU 20K set memory size = 20K SET CPU 24K set memory size = 24K SET CPU 28K set memory size = 28K SET CPU 32K set memory size = 32K SET CPU 48K set memory size = 48K SET CPU 64K set memory size = 64K SET CPU 80K set memory size = 80K SET CPU 96K set memory size = 96K SET CPU 112K set memory size = 112K SET CPU 128K set memory size = 128K Memory sizes greater than 8K are only available on the PDP-7, PDP-9, and PDP-15; memory sizes greater than 32KW are only available on the PDP-15. If memory size is being reduced, and the memory being truncated contains non-zero data, the simulator asks for confirmation. Data in the truncated portion of memory is lost. Initial memory size is 8K for the PDP-4, 32K for the PDP-7 and PDP-9, and 128K for the PDP-15. CPU registers include the visible state of the processor as well as the control registers for the interrupt system. system name size comments all PC addr program counter 7,9 PC 15 program counter 15 PC 17 program counter all AC 18 accumulator 7,9,15 MQ 18 multiplier-quotient 7,9,15 SC 6 shift counter 7,9,15 EAE_AC_SIGN 1 EAE AC sign all L 1 link 7,9 EXTM 1 extend mode 15 BANKM 1 bank mode 7 TRAPM 1 trap mode 9,15 USMD 1 user mode 9,15 USMDBUF 1 user mode buffer 9,15 BR addr memory protection bounds 7,9,15 TRAPP 1 trap pending 9,15 NEXM 1 non-existent memory violation 9,15 PRVN 1 privilege violation 7,9 EMIRP 1 EMIR instruction pending 9,15 RESTP 1 DBR or RES instruction pending 15 XR 18 index register 15 LR 18 limit register all SR 18 front panel switches all INT 32 interrupt requests all IORS 18 IORS register all ION 1 interrupt enable all ION_DELAY 2 interrupt enable delay all OLDPC addr PC prior to last transfer all STOP_INST 1 stop on undefined instruction all BREAK 18 breakpoint address (177777 to disable) all WRU 8 interrupt character "addr" signifies the address width of the system (13b for the PDP-4, 15b for the PDP-7 and PDP-9, 17b for the PDP-15). 7.2 Programmed I/O Devices (PTR, PTP, TTI, TTO, CLK, LPT) The paper tape reader (PTR), paper tape punch (PTP), and line printer (LPT) read data from or write data to disk files. The POS register specifies the number of the next data item to be read or written. Thus, by changing POS, the user can backspace or advance these devices. The programmed I/O devices typically implement these registers: name size comments BUF 8 last data item processed INT 1 interrupt pending flag DONE 1 device done flag TIME 24 time from I/O initiation to interrupt (for keyboard, polling interval) POS 32 position in the input or output file STOP_IOE 1 stop on I/O error For the serial devices, error handling is as follows: type error STOP_IOE processed as in,out not attached 1 report error and stop 0 out of tape or paper in end of file 1 report error and stop 0 out of tape or paper in,out OS I/O error x report error and stop 7.3 RP15/RP02 RP15 options include the ability to place units write enabled or write locked: SET RPn LOCKED set unit n write locked SET RPn ENABLED set unit n write enabled The RP15 implements these registers: name size comments STA 18 status A STB 18 status B DA 18 disk address MA 18 current memory address WC 18 word count INT 1 interrupt pending flag BUSY 1 control busy flag STIME 24 seek time, per cylinder RTIME 24 rotational delay STOP_IOE 1 stop on I/O error Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready end of file x assume rest of disk is zero OS I/O error x report error and stop 7.4 DRM The drum has no options. It implements these registers: name size comments DA 9 drum address (sector number) MA 15 current memory address INT 1 interrupt pending flag DONE 1 device done flag ERR 1 error flag WLK 32 write lock switches TIME 24 rotational latency, per word STOP_IOE 1 stop on I/O error Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready Drum data files are buffered in memory; therefore, end of file and OS I/O errors cannot occur. 7.5 RF09/RF15/RS09 The RF09/RF15 implements these registers: name size comments STA 18 status DA 21 current disk address MA 18 memory address (in memory) WC 18 word count (in memory) BUF 18 data buffer (diagnostic only) INT 1 interrupt pending flag WLK0..7 16 write lock switches for disks 0..7 TIME 24 rotational delay, per word BURST 1 burst flag STOP_IOE 1 stop on I/O error The RF15/RF09 is a three-cycle data break device. If BURST = 0, word transfers are scheduled individually; if BURST = 1, the entire transfer occurs in a single data break. Error handling is as follows: error STOP_IOE processed as not attached 1 report error and stop 0 disk not ready RF15/RF09 data files are buffered in memory; therefore, end of file and OS I/O errors cannot occur. 7.6 Magnetic Tape (MT) Magnetic tape options include the ability to place units write enabled or or write locked. SET MTn LOCKED set unit n write locked SET MTn ENABLED set unit n write enabled The magnetic tape controller implements these registers: name size comments CMD 18 command STA 18 main status MA 18 memory address (in memory) WC 18 word count (in memory) INT 1 interrupt pending flag STOP_IOE 1 stop on I/O error TIME 24 record delay UST0..7 24 unit status, units 0..n Error handling is as follows: error processed as not attached tape not ready end of file (read or space) end of physical tape (write) ignored OS I/O error report error and stop 7.7 Symbolic Display and Input The 18b PDP simulators implement symbolic display and input. Display is controlled by command line switches: -a display as ASCII character -c display as (sixbit) character string -m display instruction mnemonics The PDP-15 also recognizes an additional switch: -p display as packed ASCII (five 7b ASCII characters in two 18b words) Input parsing is controlled by the first character typed in: ' ASCII character " three character sixbit string alphabetic instruction mnemonic numeric octal number The PDP-15 also recognizes an additional input mode: # five character packed ASCII string in two 18b words Instruction input uses standard 18b PDP assembler syntax. There are six instruction classes: memory reference, EAE, index (PDP-15 only), IOT, operate, and LAW. Memory reference instructions have the format memref {I/@} address{,X} where I (PDP-4, PDP-7, PDP-9) /@ (PDP-15) signifies indirect reference, and X signifies indexing (PDP-15 in page mode only). The address is an octal number in the range 0 - 017777 (PDP-4, PDP-7, PDP-9, and PDP-15 in bank mode) or 0 - 07777 (PDP-15 in page mode). IOT instructions consist of single mnemonics, eg, KRB, TLS. IOT instructions may be or'd together iot iot iot... IOT's may also include the number 10, signifying clear the accumulator iot 10 The simulator does not check the legality of IOT combinations. IOT's for which there is no opcode may be specified as IOT n, where n is an octal number in the range 0 - 07777. EAE instructions have the format eae {+/- shift count} EAE instructions may be or'd together eae eae eae... The simulator does not check the legaility of EAE combinations. EAE's for which there is no opcode may be specified as EAE n, where n is an octal number in the range 0 - 037777. Index instructions (PDP-15 only) have the format index {immediate} The immediate, if allowed, must be in the range of -0400 to +0377. Operate instructions have the format opr opr opr... The simulator does not check the legality of the proposed combination. The operands for MUY and DVI must be deposited explicitly. Finally, the LAW instruction has the format LAW immediate where immediate is in the range of 0 to 017777. Appendix 1: Notes On File Representations 1. Disks Disks are represented as unstructured binary files of 16b data items. Thus, simulated disks are endian dependent. To share a disk file between versions of the simulator running on big and little endian systems, each 16b word must be byte swapped prior to use. 2. Magnetic tapes Magnetic tapes are represented as unstructured binary files of 16b data items. Each record consists of a 16b byte count n, followed by (n + 1)/2 16b words of data. If the byte count is odd, the last byte in the record is undefined. Magnetic tapes are endian dependent. To share a magnetic tape file between versions of the simulator running on big and little endian systems, each 16b word must be byte swapped prior to use. Note that the representation of magnetic tapes is only consistent within each simulator family. On a little endian system, a magnetic tape produced by the Nova simulator will appear to be "correct" for the PDP-11 simulator, even though on real hardware the results would be byte swapped. Interchange of tapes between simulators is not supported. Revision History (since Rev 1.1) Rev 2.2 Jan, 96 Added register buffers for save/restore Added 18b PDP's Guaranteed TTI, CLK times are non-zero Fixed breakpoint/RUN interaction bug Fixed magnetic tape backspace to EOF bug Fixed ISZ/DCA inversion in PDP-8 symbol table Fixed sixbit conversion in PDP-8 examine/deposit Fixed unit number calculation bug in SCP and in Nova, PDP-11, 18b PDP moving head disks Rev 2.1 Dec, 95 Fixed PTR bug (setting done on EOF) in PDP-8, Nova Fixed RX bug (setting error on INIT if drive 1 is not attached) in PDP-8, PDP-11 Fixed RF treatment of photocell flag in PDP-8 Fixed autosize bug (always chose smallest disk if new file) in PDP-11, Nova Fixed not attached bug (reported as not attachable) in most mass storage devices Fixed Nova boot ROMs Fixed bug in RESTORE (didn't requeue if delay = 0) Fixed bug in RESTORE (clobbered device position) Declared static constant arrays as static const Added PDP-8, Nova magnetic tape simulators Added Dasher mode to Nova terminal simulator Added LINUX support Rev 2.0 May, 95 Added symbolic assembly/disassembly