vax780_doc.md

VAX-11/780 Simulator User's Guide

Revision of 8-Aug-2021

Copyright Notice

The SIMH source code and documentation is made available under a X11-style open source license; the precise terms are available at:

https://github.com/open-simh/simh/blob/master/LICENSE.txt

Table of Contents

1 Simulator Files

2 VAX780 Features

2.1 CPU and System Devices

2.1.1 CPU

2.1.2 Translation Buffer (TLB)

2.1.3 SBI Controller (SBI)

2.1.4 Memory Controllers (MCTL0, MCTL1)

2.1.5 Time-Of-Day Clock (TODR)

2.1.6 Interval Timer (TMR)

2.1.7 Unibus Adapter (UBA)

2.1.8 Massbus Adapters (MBA0, MBA1)

2.2 I/O Device Addressing

2.3 Programmed I/O Devices

2.3.1 Console Input (TTI)

2.3.2 Console Output (TTO)

2.3.3 RX01 Console Floppy Disk (RXC)

2.3.4 Line Printer (LPT)

2.4 Disks

2.4.1 RP04/05/06/07, RM02/03/05/80 Disk Pack Drives (RP)

2.4.2 RL11/RL01/RL02 Cartridge Disk (RL)

2.4.3 RK611/RK06/RK07 Cartridge Disk (HK)

2.4.4 UDA50 MSCP Disk Controllers (RQ, RQB, RQC, RQD)

2.5 Tapes

2.5.1 TM03/TE16/TU45/TU77 Magnetic Tapes (TU)

2.5.2 TS11 Magnetic Tape (TS)

2.5.3 TUK50 TMSCP Tape Controller (TQ)

2.6 Communications Devices

2.6.1 DZ11 Terminal Multiplexer (DZ)

2.6.2 DHU11 Terminal Multiplexer (VH)

2.6.3 DELUA/DEUNA Unibus Ethernet Controllers (XU, XUB)

2.6.4 DMC11/DMR11 Unibus DDCMP Controllers

2.7 CR11 Card Reader (CR)

3 Symbolic Display and Input

This memorandum documents the DEC VAX-11/780 simulator.

Simulator Files

To compile the VAX-11/780, you must define VM_VAX, VAX780, and USE_INT64 as part of the compilation command line. To enable extended file support (files greater than 2GB), you must define USE_ADDR64 as part of the command line as well.

directory	file
sim/	scp.h
	sim_console.h
	sim_defs.h
	sim_disk.h
	sim_ether.h
	sim_fio.h
	sim_rev.h
	sim_serial.h
	sim_sock.h
	sim_tape.h
	sim_timer.h
	sim_tmxr.h
	scp.c
	sim_console.c
	sim_disk.c
	sim_ether.c
	sim_fio.c
	sim_serial.c
	sim_sock.c
	sim_tape.c
	sim_timer.c
	sim_tmxr.c
sim/vax/	vax_defs.h
	vax780_defs.h
	vax_vmb_exe.h
	vax_cis.c
	vax_cmode.c
	vax_cpu.c
	vax_cpu1.c
	vax_fpa.c
	vax_mmu.c
	vax_octa.c
	vax_sys.c
	vax_syscm.c
	vax7x0_mba.c
	vax780_mem.c
	vax780_sbi.c
	vax780_stddev.c
	vax780_syslist.c
	vax780_uba.c
sim/pdp11/	pdp11_cr_dat.h
	pdp11_mscp.h
	pdp11_uqssp.h
	pdp11_xu.h
	pdp11_cr.c
	pdp11_dmc.c
	pdp11_dz.c
	pdp11_hk.c
	pdp11_lp.c
	pdp11_rl.c
	pdp11_rp.c
	pdp11_rq.c
	pdp11_ry.c
	pdp11_tq.c
	pdp11_ts.c
	pdp11_tu.c
	pdp11_vh.c
	pdp11_xu.c

Additional files are:

directory	file	description
sim/vax/	vmb.exe	standard boot code

VAX780 Features

The VAX780 simulator is configured as follows:

device name(s)	simulates
CPU	VAX-11/780 CPU
TLB	translation buffer
SBI	system bus controller
MCTL0,MCTL1	memory controllers, MS780C with 4MB memory each, or MS780E with 8MB-64MB each
UBA	DW780 Unibus adapter
MBA0,MBA1	RH780 Massbus adapters
TODR	time-of-day clock
TMR	interval timer
TTI,TTO	console terminal
RXC	console RX01 floppy disk
DZ	DZ11 8-line terminal multiplexer (up to 32)
VH	DHU11 16-line terminal multiplexer (up to 4)
CR	CR11 card reader
LPT	LP11 line printer
RP	RP04/05/06/07, RM02/03/05/80 Massbus disks, up to eight
HK	RK611/RK06(7) cartridge disk controller with eight drives
RL	RL11/RL01(2) cartridge disk controller with four drives
RQ	UDA50 MSCP controller with four drives
RQB	second UDA50 MSCP controller with four drives
RQC	third UDA50 MSCP controller with four drives
RQD	fourth UDA50 MSCP controller with four drives
RY	RX211 floppy disk controller with two drives
TS	TS11 magnetic tape controller with one drive
TQ	TUK50 TMSCP magnetic tape controller with four drives
TU	TM03 tape formatter with eight TE16/TU45/TU77 drives
XU	DEUNA/DELUA Ethernet controller
XUB	second DEUNA/DELUA Ethernet controller
DMC	DMC11/DMR11 Synchronous network controller

The DZ, VH, LPT, RP, RL, RQ, RQB, RQC, RQD, RY, TS, TQ, TU, XU, XUB and DMC devices can be set DISABLED. RQB, RQC, RQD, VH, XU, XUB and DMC are disabled by default.

The VAX780 simulator implements several unique stop conditions:

• Change mode to interrupt stack
• Illegal vector (bits<1:0> = 2 or 3)
• Unexpected exception during interrupt or exception
• Process PTE in P0 or P1 space instead of system space
• Unknown IPL
• Infinite loop (BRB/W to self at IPL 1F)

The LOAD command supports a simple binary format, consisting of a stream of binary bytes without origin or checksum, for loading memory. The DUMP command is not implemented.

CPU and System Devices

CPU

CPU options include the size of main memory and the treatment of the HALT instruction.

SET CPU 8M	set memory size = 8MB
SET CPU 16M	set memory size = 16MB
SET CPU 32M	set memory size = 32MB
SET CPU 48M	set memory size = 48MB
SET CPU 64M	set memory size = 64MB
SET CPU 128M	set memory size = 128MB

The CPU also implements a command to display a virtual to physical address translation:

SHOW {-kesu} CPU VIRTUAL=n	show translation for address n in kernel/exec/supervisor/user mode

The CPU also implements the console AUTORESTART switch:

SET CPU CONHALT	enable AUTORESTART
SET CPU SIMHALT	disable AUTORESTART

Notes on memory size:

• The first version of the VAX-11/780 used MS780C controllers, which supported 1MB to 4MB of memory per controller. This is the only memory controller recognized by VMS V1. MS780E controllers supported 4MB to 64MB per controller.
• The controller type is set automatically based on memory size.

Initial memory size is 8MB.

Memory can be loaded with a binary byte stream using the LOAD command. The LOAD command recognizes three switches:

-o	origin argument follows file name
-r	load ROM in memory controller 0
-s	load ROM in memory controller 1

These switches are recognized when examining or depositing in CPU memory:

-b	examine/deposit bytes
-w	examine/deposit words
-l	examine/deposit longwords
-d	data radix is decimal
-o	data radix is octal
-h	data radix is hexadecimal
-m	examine (only) VAX instructions
-p	examine/deposit PDP-11 (compatibility mode) instructions
-r	examine (only) RADIX50 encoded data
-v	interpret address as virtual, current mode
-k	interpret address as virtual, kernel mode
-e	interpret address as virtual, executive mode
-s	interpret address as virtual, supervisor mode
-u	interpret address as virtual, user mode

CPU registers include the visible state of the processor as well as the control registers for the interrupt system.

name	size	comments
PC	32	program counter
R0…R14	32	R0 to R14
AP	32	alias for R12
FP	32	alias for R13
SP	32	alias for R14
PSL	32	processor status longword
CC	4	condition codes, PSL<3:0>
KSP	32	kernel stack pointer
ESP	32	executive stack pointer
SSP	32	supervisor stack pointer
USP	32	user stack pointer
IS	32	interrupt stack pointer
SCBB	32	system control block base
PCBB	32	process control block base
P0BR	32	P0 base register
P0LR	22	P0 length register
P1BR	32	P1 base register
P1LR	22	P1 length register
SBR	32	system base register
SLR	22	system length register
SISR	16	software interrupt summary register
ASTLVL	4	AST level register
MAPEN	1	memory management enable
PME	1	performance monitor enable
TRPIRQ	8	trap/interrupt pending
CRDERR	1	correctible read data error flag
MEMERR	1	memory error flag
PCQ[0:63]	32	PC prior to last PC change or interrupt; most recent PC change first
WRU	8	interrupt character

The CPU attempts to detect when the simulator is idle. When idle, the simulator does not use any resources on the host system. Idle detection is controlled by the SET IDLE and SET NOIDLE commands:

Enable idle detection:

SET CPU IDLE{=VMS|ULTRIX| ULTRIXOLD|ULTRIX-1.X|
              3BSD|4.0BSD|4.1BSD|4.2BSD|QUASIJARUS|
              NETBSD|NETBSDOLD|OPENBSD|OPENBSDOLD|32V|ELN}{:n}

Disable idle detection:

SET CPU NOIDLE

Idle detection is disabled by default. If idle detection is enabled with an incorrect operating system setting, simulator performance could be impacted. The default operating system setting is VMS. The value n, if present in the SET CPU IDLE={OS}:n command, indicates the number of seconds the simulator must run before idling starts.

The CPU can maintain a history of the most recently executed instructions. This is controlled by the SET CPU HISTORY and SHOW CPU HISTORY commands:

SET CPU HISTORY	clear history buffer
SET CPU HISTORY=0	disable history
SET CPU {-T} HISTORY=n{:file}	enable history, length = n
SHOW CPU HISTORY	print CPU history
SHOW CPU HISTORY=n	print first n entries of CPU history

The -T switch causes simulator time to be recorded (and displayed) with each history entry. When writing history to a file (SET CPU HISTORY=n:file), n specifies the buffer flush frequency. Warning: prodigious amounts of disk space may be consumed. The maximum length for the history is 250000 entries.

Translation Buffer (TLB)

The translation buffer consists of two units, representing the system and user translation buffers, respectively. It has no registers. Each translation buffer entry consists of two 32b words, as follows:

word n	tag
word n+1	cached PTE

An invalid entry is indicated by a tag of 0xFFFFFFFF.

SBI Controller (SBI)

The SBI is the VAX-11/780 system bus. The simulated SBI implements these registers:

name	size	comments
NREQ14	16	Nexus IPL14 interrupt requests
NREQ15	16	Nexus IPL15 interrupt requests
NREQ16	16	Nexus IPL16 interrupt requests
NREQ17	16	Nexus IPL17 interrupt requests
WCSA	16	writeable control store address
WCSD	32	writeable control store data
MBRK	13	microbreak register
SBIFS	32	SBI fault status
SBISC	32	SBI silo compare
SBIMT	32	SBI maintenance register
SBIER	32	SBI error status
SBITMO	32	SBI timeout address

Memory Controllers (MCTL0, MCTL1)

The memory controllers implement the registers for the MS780C (8MB memory) or MS780E (16MB or greater memory). Each controller implements these registers:

name	size	comments
CRA	32	control register A
CRB	32	control register B
CRC	32	control register C
CRD	32	control register D (MS780E only)
ROM[0:1023]	32	bootstrap ROM

ROM can be loaded from a file with the commands

LOAD -R <file>	load MCTL0 ROM
LOAD -S <file>	load MCTL1 ROM

Time-Of-Day Clock (TODR)

The TODR tracks time since an arbitrary start in 10 millisecond intervals. It has these registers:

name	size	comments
TODR	32	time-of-day register
TIME	24	delay between ticks

The TODR register autocalibrates against real-world time.

There are two modes of TODR operation.

1. Default VMS mode. Without initializing the TODR it returns the current time of year offset which VMS would set the clock to if VMS knew the correct time (i.e. by manual input). This is correct almost all the time unless a VMS disk hadn’t been booted from in the current year. This mode produces strange time results for non VMS OSes on each system boot.

2. OS Agnostic mode. This mode behaves precisely like the VAX 11/780 TODR and works correctly for all OSes. This mode is enabled by attaching the TODR to a battery backup state file for the TOY clock (i.e. ATTACH TODR TOY_CLOCK). When operating in OS Agnostic mode, the TODR will initially start counting from 0 and be adjusted differently when an OS specifically writes to the TODR. VMS determines if the TODR currently contains a valid time if the value it sees is less than about 1 month. If the time isn't valid VMS will prompt to set the time during the system boot. While prompting for the time it will wait for an answer to the prompt for up to the SYSGEN parameter TIMEPROMPTWAIT seconds. A value of 0 for TIMEPROMPTWAIT will disable the clock setting prompt.

Interval Timer (TMR)

The interval timer implements the VAX architectural timer, with 1 microsecond intervals. It has these registers:

name	size	comments
ICCS	32	interval timer control and status
ICR	32	interval count register
NICR	32	next interval count register
INT	1	interrupt request

For standard VMS intervals (10 milliseconds), the interval timer autocalibrates against real-world time.

Unibus Adapter (UBA)

The Unibus adapter (UBA) simulates the DW780. It recognizes these options:

SET UBA AUTOCONFIGURE	enable autoconfiguration
SET UBA NOAUTOCONFIGURE	disable autoconfiguration

and this SHOW command:

SHOW UBA IOSPACE	display IO address space assignments

The UBA also implements a command to display a Unibus address to physical address translation:

SHOW UBA VIRTUAL=n	show translation for Unibus address n

Finally, the UBA implements main memory examination and modification via the Unibus map. The data width is always 16b:

EX UBA 0/10	examine main memory words corresponding to Unibus addresses 0-10

The UBA has these registers:

name	size	comments
IPL14	32	Unibus IPL14 interrupt requests
IPL15	32	Unibus IPL15 interrupt requests
IPL16	32	Unibus IPL16 interrupt requests
IPL17	32	Unibus IPL17 interrupt requests
CNFR	32	configuration register
CR	32	control register
SR	32	status register
DR	32	diagnostic register
INT	1	internal UBA interrupt request
NEXINT	1	UBA Nexus interrupt request
AIIP	1	adapter initialization in progress flag
UIIP	1	Unibus initialization in progress flag
FMER	32	failing memory address
FUBAR	32	failing UBA map register
BRSVR0	32	spare register 0
BRSVR1	32	spare register 1
BRSVR2	32	spare register 2
BRSVR3	32	spare register 3
BRRVR4	32	vector register, IPL 14
BRRVR5	32	vector register, IPL 15
BRRVR6	32	vector register, IPL 16
BRRVR7	32	vector register, IPL 17
DPR[0:15]	32	data path registers 0 to 15
MAP[0:495]	32	map registers 0 to 495
AITIME	24	adapter initialization time
UITIME	24	Unibus initialization time

Massbus Adapters (MBA0, MBA1)

The Massbus adapters (MBA0, MBA1) simulate RH780's. MBA0 is assigned to the RP disk drives, MBA1 to the TU tape drives. Each MBA has these registers:

name	size	comments
CNFR	32	configuration register
CR	32	control register
SR	32	status register
VA	17	virtual address register
BC	32	byte count register
DR	32	diagnostic register
SMR	32	selected map register
MAP[0:255]	32	map registers
NEXINT	1	MBA Nexus interrupt request

I/O Device Addressing

Unibus I/O space is not large enough to allow all possible devices to be configured simultaneously at fixed addresses. Instead, many devices have floating addresses; that is, the assigned device address depends on the presence of other devices in the configuration:

DZ11	all instances have floating addresses
RL11	first instance has fixed address, rest floating
RX11/RX211	first instance has fixed address, rest floating
DEUNA/DELUA	first instance has fixed address, rest floating
MSCP	disk first instance has fixed address, rest floating
TMSCP	tape first instance has fixed address, rest floating

To maintain addressing consistency as the configuration changes, the simulator implements DEC's standard I/O address and vector autoconfiguration algorithms for all Unibus devices. This allows the user to enable or disable devices without needing to manage I/O addresses and vectors.

Autoconfiguration cannot solve address conflicts between devices with overlapping fixed addresses. For example, with default I/O page addressing, the PDP-11 can support either a TM11 or a TS11, but not both, since they use the same I/O addresses.

In addition to autoconfiguration, most devices support the SET <device> ADDRESS command, which allows the I/O page address of the device to be changed, and the SET <device> VECTOR command, which allows the vector of the device to be changed. Explicitly setting the I/O address or vector of a device DISABLES autoconfiguration for that device and for the entire system. As a consequence, the user may have to manually configure all other autoconfigured devices, because the autoconfiguration algorithm no longer recognizes the explicitly configured device. A device can be reset to autoconfigure with the SET <device> AUTOCONFIGURE command. Autoconfiguration can be restored for the entire system with the SET UBA AUTOCONFIGURE command.

The current I/O map can be displayed with the SHOW UBA IOSPACE command. Addresses that have set by autoconfiguration are marked with an asterisk (*).

All devices support the SHOW <device> ADDRESS and SHOW <device> VECTOR commands, which display the device address and vector, respectively.

Programmed I/O Devices

Console Input (TTI)

The terminal interfaces (TTI, TTO) can be set to one of three modes, 7P, 7B or 8B:

mode	input characters	output characters
7P	high-order bit cleared	high-order bit cleared, non-printing characters suppressed
7B	high-order bit cleared	high-order bit cleared
8B	no changes	no changes

The default mode is 8B.

When the console terminal is attached to a Telnet session, it recognizes BREAK. If BREAK is entered, and BDR<7> is set, control returns to the console firmware; otherwise, BREAK is treated as a normal terminal input condition.

The terminal input (TTI) polls the console keyboard for input. It implements 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>)
POS	32	number of characters input
TIME	24	input polling interval (if 0, the keyboard is polled synchronously with the TODR)

Console Output (TTO)

The terminal output (TTO) writes to the simulator console window. It implements 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>)
POS	32	number of characters input
TIME	24	time from I/O initiation to interrupt

RX01 Console Floppy Disk (RXC)

RX01 options include the ability to set units write enabled or write locked:

SET RXCn LOCKED	set unit n write locked
SET RXCn WRITEENABLED	set unit n write enabled

The RX01 implements a special command, FLOAD, for loading VAX executables from an RT11-formatted console floppy disk image:

FLOAD <file_name> {<origin>}

FLOAD searches the floppy disk image attached to the RX01 for the named file and then loads it into VAX-11/780 memory starting at the origin. If no origin is specified, the default origin is 200 (hex).

The RX01 implements these registers:

name	size	comments
FNC	8	function select
ES	8	error status
ECODE	8	error code
TA	8	track address
SA	8	sector address
STATE	4	protocol state
BPTR	7	data buffer pointer
CTIME	24	command initiation delay
STIME	24	seek time delay, per track
XTIME	24	transfer time delay, per byte
STOP_IOE	1	stop on I/O error
DBUF[0:127]	8	data buffer

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.

Line Printer (LPT)

The line printer (LPT) writes data to a disk file. The POS register specifies the number of the next data item to be written. Thus, by changing POS, the user can backspace or advance the printer.

The line printer implements 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>)
POS	32	position in the output file
TIME	24	time from I/O initiation to interrupt
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	out of paper
OS I/O error	x	report error and stop

Disks

All VAX-11/780 disks, and the TUK50 MSCP tape, support a special form of the boot command, with the following syntax:

BOOT <unit>{/R5:<value>}

For example,

BOOT RP0/R5:1

The optional switch, /R5, specifies that R5 is to be loaded with the specified value prior to booting. If the switch is omitted, R5 is loaded with 0.

RP04/05/06/07, RM02/03/05/80 Disk Pack Drives (RP)

The RP controller implements the Massbus family of large disk drives. RP options include the ability to set units write enabled or write locked, to set the drive type to one of six disk types, or autosize, and to write a DEC standard 144 compliant bad block table on the last track:

SET RPn LOCKED	set unit n write locked
SET RPn WRITEENABLED	set unit n write enabled
SET RPn RM03	set type to RM03
SET RPn RM05	set type to RM05
SET RPn RM80	set type to RM80
SET RPn RP04	set type to RP04
SET RPn RP05	set type to RP05
SET RPn RP06	set type to RP06
SET RPn RP07	set type to RP07
SET RPn AUTOSIZE	set type based on file size at attach
SET RPn BADBLOCK	write bad block table on last track

The type options can be used only when a unit is not attached to a file. The bad block option can be used only when a unit is attached to a file. Units can be set ENABLED or DISABLED. The RP controller supports the BOOT command.

The RP controller implements the registers listed below. Registers suffixed with [0:7] are replicated per drive.

name	size	comments
CS1[0:7]	16	current operation
DA[0:7]	16	desired surface, sector
DS[0:7]	16	drive status
ER1[0:7]	16	drive errors
OF[0:7]	16	offset
DC[0:7]	16	desired cylinder
ER2[0:7]	16	error status 2
ER3[0:7]	16	error status 3
EC1[0:7]	16	ECC syndrome 1
EC2[0:7]	16	ECC syndrome 2
MR[0:7]	16	maintenance register
MR2[0:7]	16	maintenance register 2 (RM only)
HR[0:7]	16	holding register (RM only)
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

RL11/RL01/RL02 Cartridge Disk (RL)

RL11 options include the ability to set units write enabled or write locked, to set the drive type to RL01, RL02, or autosize, and to write a DEC standard 144 compliant bad block table on the last track:

SET RLn LOCKED	set unit n write locked
SET RLn WRITEENABLED	set unit n write enabled
SET RLn RL01	set type to RL01
SET RLn RL02	set type to RL02
SET RLn AUTOSIZE	set type based on file size at attach
SET RLn BADBLOCK	write bad block table on last track

The type options can be used only when a unit is not attached to a file. The bad block option can be used only when a unit is attached to a file. Units can be set ENABLED or DISABLED. The RL11 supports the BOOT command.

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,RLMP1,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>)
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

RK611/RK06/RK07 Cartridge Disk (HK)

RK611 options include the ability to set units write enabled or write locked, to set the drive type to RK06, RK07, or autosize, and to write a DEC standard 144 compliant bad block table on the last track:

SET HKn LOCKED	set unit n write locked
SET HKn WRITEENABLED	set unit n write enabled
SET HKn RK06	set type to RK06
SET HKn RK07	set type to RK07
SET HKn AUTOSIZE	set type based on file size at attach
SET HKn BADBLOCK	write bad block table on last track

The type options can be used only when a unit is not attached to a file. The bad block option can be used only when a unit is attached to a file. Units can be set ENABLED or DISABLED. The RK611 supports the BOOT command.

The RK611 implements these registers:

name	size	comments
HKCS1	16	control/status 1
HKWC	16	word count
HKBA	16	bus address
HKDA	16	desired surface, sector
HKCS2	16	control/status 2
HKDS[0:7]	16	drive status, drives 0 to 7
HKER[0:7]	16	drive errors, drives 0 to 7
HKDB[0:2]	16	data buffer silo
HKDC	16	desired cylinder
HKOF	8	offset
HKMR	16	maintenance register
HKSPR	16	spare register
HKCI	1	controller interrupt flop
HKDI	1	drive interrupt flop
HKEI	1	error interrupt flop
INT	1	interrupt pending flag
ERR	1	error flag (CSR<15>)
DONE	1	device done flag (CSR1<7>)
IE	1	interrupt enable flag (CSR1<6>)
STIME	24	seek time, per cylinder
RTIME	24	rotational delay
MIN2TIME	24	minimum time between DONE and ATA
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

UDA50 MSCP Disk Controllers (RQ, RQB, RQC, RQD)

The simulator implements four MSCP disk controllers, RQ, RQB, RQC, RQD. Initially, RQB, RQC, and RQD are disabled. Each RQ controller simulates an UDA50 MSCP disk controller with four drives. RQ options include the ability to set units write enabled or write locked, and to set the drive type to one of many disk types:

SET RQn LOCKED	set unit n write locked
SET RQn WRITEENABLED	set unit n write enabled
SET RQn RX50	set type to RX50
SET RQn RX33	set type to RX33
SET RQn RD51	set type to RD51
SET RQn RD52	set type to RD52
SET RQn RD53	set type to RD53
SET RQn RD54	set type to RD54
SET RQn RD31	set type to RD31
SET RQn RA81	set type to RA81
SET RQn RA82	set type to RA82
SET RQn RA71	set type to RA71
SET RQn RA72	set type to RA72
SET RQn RA90	set type to RA90
SET RQn RA92	set type to RA92
SET RQn RRD40	set type to RRD40 (CD-ROM)
SET RQn RAUSER{=n}	set type to RA82 with n MB's
SET -L RQn RAUSER{=n}	set type to RA82 with n LBN's

The type options can be used only when a unit is not attached to a file. RAUSER is a "user specified" disk; the user can specify the size of the disk in either MB (1000000 bytes) or logical block numbers (LBNs, 512 bytes each). The minimum size is 5MB; the maximum size is 2GB without extended file support, 1TB with extended file support.

Units can be set ENABLED or DISABLED. The RQ controllers support the BOOT command.

Drive units have changeable unit numbers. Unit numbers can be changed with:

SET RQn UNIT=val	set unit plug value

Each device has 4 units which have unique MSCP unit numbers (0, 1, 2 and 3).

Each RQ controller implements the following special SHOW commands:

SHOW RQn TYPE	show drive type
SHOW RQ RINGS	show command and response rings
SHOW RQ FREEQ	show packet free queue
SHOW RQ RESPQ	show packet response queue
SHOW RQ UNITQ	show unit queues
SHOW RQ ALL	show all ring and queue state
SHOW RQn UNITQ	show unit queues for unit n
SHOW RQn UNIT	show unit plug value

Each RQ controller implements these registers:

name	size	comments
SA	16	status/address register
S1DAT	16	step 1 init host data
CQBA	22	command queue base address
CQLNT	8	command queue length
CQIDX	8	command queue index
RQBA	22	request queue base address
RQLNT	8	request queue length
RQIDX	8	request queue index
FREE	5	head of free packet list
RESP	5	head of response packet list
PBSY	5	number of busy packets
CFLGS	16	controller flags
CSTA	4	controller state
PERR	9	port error number
CRED	5	host credits
HAT	17	host available timer
HTMO	17	host timeout value
CPKT[0:3]	5	current packet, units 0 to 3
PKTQ[0:3]	5	packet queue, units 0 to 3
UFLG[0:3]	16	unit flags, units 0 to 3
PLUG[0:3]	16	unit plug values, units 0 to 3
INT	1	interrupt request
ITIME	1	response time for initialization steps (except for step 4)
QTIME	24	response time for 'immediate' packets
XTIME	24	response time for data transfers
PKTS[33*32]	16	packet buffers, 33W each, 32 entries

While VMS is not timing sensitive, most of the BSD-derived operating systems (NetBSD, OpenBSD, etc) are. The QTIME and XTIME parameters are set to values that allow these operating systems to run correctly.

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

Tapes

TM03/TE16/TU45/TU77 Magnetic Tapes (TU)

The TU controller implements the Massbus family of 800/1600bpi magnetic tape drives. TU options include the ability to set the drive type to one of three drives (TE16, TU45, or TU77), and to set the drives write enabled or write locked.

SET TUn TE16	set unit n drive type to TE16
SET TUn TU45	set unit n drive type to TU45
SET TUn TU77	set unit n drive type to TU77
SET Tun LOCKED	set unit n write locked
SET Tun WRITEENABLED	set unit n write enabled

Magnetic tape units can be set to a specific reel capacity in MB, or to unlimited capacity:

SET TUn CAPAC=m	set unit n capacity to m MB (0 = unlimited)
SHOW TUn CAPAC	show unit n capacity in MB

Units can be set ENABLED or DISABLED. The TU controller does not support the BOOT command.

The TU controller implements the following registers:

name	size	comments
CS1	6	current operation
FC	16	frame count
FS	16	formatter status
ER	16	formatter errors
CC	16	check character
MR	16	maintenance register
TC	16	tape control register
TIME	24	operation execution time
UST	17	unit status, drives 0 to 7
POS	32	position, drive 0 to 7
STOP_IOE	1	stop of I/O error

Error handling is as follows:

error	processed as
not attached	tape not ready; if STOP_IOE, stop
end of file	bad tape
OS I/O error	parity error; if STOP_IOE, stop

TS11 Magnetic Tape (TS)

TS options include the ability to make the unit write enabled or write locked.

SET TS LOCKED	set unit write locked
SET TS WRITEENABLED	set unit write enabled

The TS drive can be set to a specific reel capacity in MB, or to unlimited capacity:

SET TS0 CAPAC=m	set capacity to m MB (0 = unlimited)
SHOW TS0 CAPAC	show capacity in MB

The TS11 does not support the BOOT command.

The TS controller implements these registers:

name	size	comments
TSSR	16	status register
TSBA	16	bus address register
TSDBX	16	data buffer extension register
CHDR	16	command packet header
CADL	16	command packet low address or count
CADH	16	command packet high address
CLNT	16	command packet length
MHDR	16	message packet header
MRFC	16	message packet residual frame count
MXS0	16	message packet extended status 0
MXS1	16	message packet extended status 1
MXS2	16	message packet extended status 2
MXS3	16	message packet extended status 3
MXS4	16	message packet extended status 4
WADL	16	write char packet low address
WADH	16	write char packet high address
WLNT	16	write char packet length
WOPT	16	write char packet options
WXOPT	16	write char packet extended options
ATTN	1	attention message pending
BOOT	1	boot request pending
OWNC	1	if set, tape owns command buffer
OWNM	1	if set, tape owns message buffer
TIME	24	delay
POS	32	position

Error handling is as follows:

error	processed as
not attached	tape not ready
end of file	bad tape
OS I/O error	fatal tape error

TUK50 TMSCP Tape Controller (TQ)

The TQ controller simulates the TUK50 TMSCP tape controller. TQ options include the ability to set units write enabled or write locked, and to specify the controller type and tape length:

SET TQn LOCKED	set unit n write locked
SET TQn WRITEENABLED	set unit n write enabled
SET TQ TK50	set controller type to TK50
SET TQ TK70	set controller type to TK70
SET TQ TU81	set controller type to TU81
SET TQ TKUSER{=n}	set controller type to TK50 with tape capacity of n MB

User-specified capacity must be between 50 and 2000 MB. The TUK50 supports the BOOT command.

Regardless of the controller type, individual units can be set to a specific reel capacity in MB, or to unlimited capacity:

SET TQn CAPAC=m	set unit n capacity to m MB (0 = unlimited)
SHOW TQn CAPAC	show unit n capacity in MB

Drive units have changeable unit numbers. Unit numbers can be changed with:

SET TQn UNIT=val	set unit plug value

Device TQ has 4 units (TQ0, TQ1, TQ2 and TQ3) which have unique MSCP unit numbers (0, 1, 2 and 3).

The TQ controller implements the following special SHOW commands:

SHOW TQ TYPE	show controller type
SHOW TQ RINGS	show command and response rings
SHOW TQ FREEQ	show packet free queue
SHOW TQ RESPQ	show packet response queue
SHOW TQ UNITQ	show unit queues
SHOW TQ ALL	show all ring and queue state
SHOW TQn UNITQ	show unit queues for unit n
SHOW TQn UNIT	show unit plug value

The TQ controller implements these registers:

name	size	comments
SA	16	status/address register
S1DAT	16	step 1 init host data
CQBA	22	command queue base address
CQLNT	8	command queue length
CQIDX	8	command queue index
RQBA	22	request queue base address
RQLNT	8	request queue length
RQIDX	8	request queue index
FREE	5	head of free packet list
RESP	5	head of response packet list
PBSY	5	number of busy packets
CFLGS	16	controller flags
CSTA	4	controller state
PERR	9	port error number
CRED	5	host credits
HAT	17	host available timer
HTMO	17	host timeout value
CPKT[0:3]	5	current packet, units 0 to 3
PKTQ[0:3]	5	packet queue, units 0 to 3
UFLG[0:3]	16	unit flags, units 0 to 3
PLUG[0:3]	16	unit plug values, units 0 to 3
POS[0:3]	32	tape position, units 0 to 3
OBJP[0:3]	32	object position, units 0 to 3
INT	1	interrupt request
ITIME	1	response time for initialization steps (except for step 4)
QTIME	24	response time for 'immediate' packets
XTIME	24	response time for data transfers
PKTS[33*32]	16	packet buffers, 33W each, 32 entries

Error handling is as follows:

error	processed as
not attached	tape not ready
end of file	end of medium
OS I/O error	fatal tape error

Communications Devices

DZ11 Terminal Multiplexer (DZ)

The DZ11 is an 8-line terminal multiplexer. Up to 32 DZ11s (256 lines) are supported. The default number of lines is 32. The number of lines can be changed with the command

SET DZ LINES=n	set line count to n

The line count must be a multiple of 8, with a maximum of 256.

The DZ11 supports three character processing modes, 7P, 7B, and 8B:

mode	input characters	output characters
7P	high-order bit cleared	high-order bit cleared, non-printing characters suppressed
7B	high-order bit cleared	high-order bit cleared
8B	no changes	no changes

The default is 8B.

The DZ11 supports logging on a per-line basis. The command

SET DZ LOG=line=filename

enables logging for the specified line to the indicated file. The command

SET DZ NOLOG=line

disables logging for the specified line and closes any open log file. Finally, the command

SHOW DZ LOG

displays logging information for all DZ lines.

The terminal lines perform input and output through Telnet sessions connected to a user-specified port. The ATTACH command specifies the port to be used:

ATTACH {-am} DZ <port>	set up listening port

where port is a decimal number between 1 and 65535 that is not being used for other TCP/IP activities. The optional switch -m turns on the DZ11's modem controls; the optional switch -a turns on active disconnects (disconnect session if computer clears Data Terminal Ready). Without modem control, the DZ behaves as though terminals were directly connected; disconnecting the Telnet session does not cause any operating system-visible change in line status.

Once the DZ is attached and the simulator is running, the DZ will listen for connections on the specified port. It assumes that the incoming connections are Telnet connections. The connection remains open until disconnected by the simulated program, the Telnet client, a SET DZ DISCONNECT command, or a DETACH DZ command.

Other special DZ commands:

SHOW DZ CONNECTIONS	show current connections
SHOW DZ STATISTICS	show statistics for active connections
SET DZ DISCONNECT=linenumber	disconnects the specified line.

The DZ11 implements these registers:

name	size	comments
CSR[0:3]	16	control/status register, boards 0 to 3
RBUF[0:3]	16	receive buffer, boards 0 to 3
LPR[0:3]	16	line parameter register, boards 0 to 3
TCR[0:3]	16	transmission control register, boards 0 to 3
MSR[0:3]	16	modem status register, boards 0 to 3
TDR[0:3]	16	transmit data register, boards 0 to 3
SAENB[0:3]	1	silo alarm enabled, boards 0 to 3
RXINT	4	receive interrupts, boards 3 to 0
TXINT	4	transmit interrupts, boards 3 to 0
MDMTCL	1	modem control enabled
AUTODS	1	autodisconnect enabled

The DZ11 does not support save and restore. All open connections are lost when the simulator shuts down or the DZ is detached.

DHU11 Terminal Multiplexer (VH)

The DHU11 is an 16-line terminal multiplexer for Unibus systems. Up to 4 DHU11s are supported.

The number of active DHU11 devices is configured by setting the number of multiplexer lines desired. The number of DHU11 lines can be set as follows:

SET VH LINES=n	n must be a multiple of 16.

The DHU11 is a programmable asynchronous terminal multiplexer. The register sets are compatible with these devices. For transmission, the DHU11 can be used in either DMA or programmed I/O mode. For reception, there is a 256-entry FIFO for received characters, dataset status changes, and diagnostic information, and a programmable input interrupt timer. The device supports 16-, 18-, and 22-bit addressing. The DHU11 can be programmed to filter and/or handle XON/XOFF characters independently of the processor. The DHU11 supports programmable bit width (between 5 and 8) for the input and output of characters.

The VH controller may be adjusted on a per controller basis as follows:

SET VHn DHU	use the DHU programming mode and registers
SET VHn DHV	use the DHV programming mode and registers

DMA output is supported. In a real DHU11, DMA is not initiated immediately upon receipt of TX.DMA.START but is dependent upon some internal processes. The VH controller mimics this behavior by default. It may be desirable to alter this and start immediately, though this may not be compatible with all operating systems and diagnostics. You can change the behavior of the VH controller as follows:

SET VHn NORMAL	use normal DMA procedures
SET VHn FASTDMA	set DMA to initiate immediately

The terminal lines perform input and output through Telnet sessions connected to a user-specified port. The ATTACH command specifies the tcp listening port to be used:

ATTACH VH <port>	set up listening port

where port is a decimal number between 1 and 65535 that is not being used for other TCP/IP activities. This port is the point of entry for al lines on all VH controllers.

Modem and auto-disconnect support may be set on an individual controller basis. The SET MODEM command directs the controller to report modem status changes to the computer. The SET HANGUP command turns on active disconnects (disconnect session if computer clears Data Terminal Ready).

SET VHn [NO]MODEM	disable/enable modem control
SET VHn [NO]HANGUP	disable/enable disconnect on DTR drop

Once the VH is attached and the simulator is running, the VH will listen for connections on the specified port. It assumes that the incoming connections are Telnet connections. The connection remains open until disconnected by the simulated program, the Telnet client, a SET VH DISCONNECT command, or a DETACH VH command.

Other special VH commands:

SHOW VH CONNECTIONS	show current connections
SHOW VH STATISTICS	show statistics for active connections
SET VH DISCONNECT=linenumber	disconnects the specified line.

The DHU11 implements these registers, though not all can be examined from SCP:

name	size	comments
CSR[0:3]	16	control/status register, boards 0 to 3
RBUF[0:3]	16	receive buffer, boards 0 to 3
LPR[0:3]	16	line parameter register, boards 0 to 3
RXINT	4	receive interrupts, boards 3..0
TXINT	4	transmit interrupts, boards 3..0

The DHU11 partially supports save and restore. Restoring a saved configuration will reestablish the listening port configuration, however all active sessions will be lost. All open connections are lost when the simulator shuts down or the VH is detached.

DELUA/DEUNA Unibus Ethernet Controllers (XU, XUB)

The simulator implements two DELUA/DEUNA Unibus Ethernet controllers (XU, XUB). Initially, both XU and XUB are disabled. Options allow control of the MAC address, the controller mode, and the sanity timer.

SET XU MAC=<mac-address>                    ex. 08-00-2B-CC-DD-EE
SHOW XU MAC

These commands are used to change or display the MAC address. <mac-address> is a valid ethernet MAC, delimited by dashes or periods. The controller defaults to 08-00-2B-CC-DD-EE, which should be sufficient if there is only one SIMH controller on your LAN. Two cards with the same MAC address will see each other's packets, resulting in a serious mess.

SET XU TYPE={DEUNA|[DELUA]}
SHOW XU TYPE

These commands are used to change or display the controller mode. DELUA mode is better and faster but may not be usable by older or non-DEC OS's.

SHOW XU STATS

This command will display the accumulated statistics for the simulated Ethernet controller.

SHOW XU FILTERS

This command will display the MAC addresses which the controller will receive packets addressed to.

To access the network, the simulated Ethernet controller must be attached to a real Ethernet interface:

ATTACH XU {ethX|<device_name>}              ex. eth0 or /dev/era0
SHOW XU ETH

where X in ethX is the number of the Ethernet controller to attach, or the real device name. The X number is system dependent. If you only have one Ethernet controller, the number will probably be 0. To find out what your system thinks the Ethernet numbers are, use the SHOW XU ETH command. The device list can be quite cryptic, depending on the host system, but is probably better than guessing. If you do not attach the device, the controller will behave as though the Ethernet cable were unplugged.

One final note: because of its asynchronous nature, the XU controller is not limited to the ~1.5Mbit/sec of the real DEUNA/DELUA controllers, nor the 10Mbit/sec of a standard Ethernet. Attach it to a Fast Ethernet (100 Mbit/sec) card, and "Feel the Power!" 😄

DMC11/DMR11 Unibus DDCMP Controllers

The DMC11 is a communication subsystem which consists of a microprocessor based, intelligent synchronous communications controller which employs the DIGITAL Data Communications Message Protocol (DDCMP).

Hardware Description

The DMC11 consists of a microprocessor module and a synchronous line unit module.

Models

There were a number of microprocessor controlled DDCMP devices produced.

DMC11

The original KMC11 microprocessor board with DMC microcode and a sync line unit.

DMR11

The more advanced KMC11 microprocessor board with DMR microcode and a sync line unit.

DMP11

A newly designed Unibus board with a more complete programming interface and a sync line unit.

DMV11

A Qbus version of the DMP11 with some more advanced refinements and a sync line unit.

Registers

The DMC device implements these registers:

name	size	description
DMC RXINT	32	input interrupt summary
DMC TXINT	32	output interrupt summary
DMC POLL	32	connect poll interval
DMC SEL0[0:7]	16	Select 0 CSR
DMC SEL2[0:7]	16	Select 2 CSR
DMC SEL4[0:7]	16	Select 4 CSR
DMC SEL6[0:7]	16	Select 6 CSR
DMC SPEED[0:7]	32	line speed
DMC PEER[0:5119]	8	peer address:port
DMC PORT[0:5119]	8	listen port
DMC BASEADDR[0:7]	32	program set base address
DMC BASESIZE[0:7]	16	program set base size
DMC MODEM[0:7]	8	modem control bits

These registers contain the emulated state of the device. These values don't necessarily relate to any detail of the original device being emulated but are merely internal details of the emulation.

Configuration

A DMC device is configured with various SIMH SET and ATTACH commands.

SET commands

SET DMC LINES=N	Sets the number of DMC devices being emulated
SET DMC CONNECTPOLL=SECONDS	Sets the connection poll frequency
SET DMC ADDRESS=VAL	Bus address
SET DMC VECTOR=VAL	Interrupt vector
SET DMC ENABLE	ENABLES device DMC
SET DMC DISABLE	DISABLES device DMC
SET DMC DEBUG	ENABLES debugging for device DMC
SET DMC NODEBUG	DISABLES debugging for device DMC
SET DMC DEBUG=TRACE;WARN;REG;INTREG;INFO;DATA;DATASUM;MODEM;CONNECT;INT	Enables specific debugging for device DMC
SET DMC NODEBUG=TRACE;WARN;REG;INTREG;INFO;DATA;DATASUM;MODEM;CONNECT;INT	Disables specific debugging for device DMC
SET DMCn PEER=address:port
SET DMCn SPEED=bits/sec	speed 0=unrestricted
SET DMCn TYPE={DMR,DMC}
SET DMCn STATS	Display/Clear statistics

Lines

A maximum of 8 DMC11 devices can be emulated concurrently in the VAX 11/780 simulator. The number of simulated DMC11 devices or lines can be specified with command:

SET DMC0 LINES=n

Peer

To set the host and port to which data is to be transmitted use the following command:

SET DMC0 PEER=host:port

Connectpoll

The minimum interval between attempts to connect to the other side is set using the following command:

SET DMC0 CONNECTPOLL=n

Where n is the number of seconds. The default is 2 seconds.

Speed

If you want to experience the actual data rates of the physical hardware you can set the bit rate of the simulated line can be set using the following command:

SET DMC0 SPEED=n

Where n is the number of data bits per second that the simulated line runs at. In practice this is implemented as a delay while transmitting bytes to the socket. Use a value of zero to run at full speed with no artificial throttling.

Type

The type of device being emulated can be changed with the following command:

SET DMC0 TYPE={DMR,DMC}

A SET TYPE command should be entered before the device is attached to a listening port.

Attach

The device must be attached to a receive port, use the ATTACH command specifying the receive port number.

ATTACH DMC0 port

The Peer host:port value must be specified before the attach command.

Examples

To configure two simulators to talk to each other use the following example:

Machine 1:

SET DMC ENABLE
SET DMC0 PEER=LOCALHOST:2222
ATTACH DMC0 1111

Machine 2:

SET DMC ENABLE
SET DMC0 PEER=LOCALHOST:1111
ATTACH DMC0 2222

Monitoring

The DMC device and DMC0 line configuration and state can be displayed with one of the available show commands.

Show commands

SHOW DMC LINES	Display number of devices
SHOW DMC CONNECTPOLL	Display connection poll interval
SHOW DMC ADDRESS	Bus address
SHOW DMC VECTOR	Interrupt vector
SHOW DMC DEBUG	Displays debugging status for device DMC
SHOW DMCn PEER	Display destination/source
SHOW DMCn SPEED	Display rate limit
SHOW DMCn TYPE	Set/Display device type
SHOW DMCn STATS	Display/Clear statistics
SHOW DMCn QUEUES	Display Queue state
SHOW DMCn DDCMP	Display DDCMP state information

Restrictions

Real hardware synchronous connections could operate in Multi-Point mode. Multi-Point mode was a way of sharing a single wire with multiple destination systems or devices. Multi-Point mode is not currently emulated by this or other simulated synchronous devices.

In real hardware, the DMC11 spoke a version of DDCMP which peer devices needed to be aware of. The DMR11, DMP11, and DMV11 boards have configuration switches or programatic methods to indicate that the peer device was a DMC11. The emulated devices all speak the same level of DDCMP so no special remote device awareness need be considered.

Implementation

A real DMC11 transports data using DDCMP via a synchronous connection, the emulated device makes a TCP/IP connection to another emulated device which either speaks DDCMP over the TCP connection directly, or interfaces to a simulated computer where the operating system speaks the DDCMP protocol on the wire.

The DMC11 can be used for point-to-point DDCMP connections carrying DECnet and other types of networking, e.g. from ULTRIX or DSM.

Debugging

The simulator has a number of debug options, these are:

REG	Shows whenever a CSR is programatically read or written and the current value.
INTREG	Shows internal register value changes.
INFO	Shows higher-level tracing only.
WARN	Shows any warnings.
TRACE	Shows more detailed trace information.
DATASUM	Brief summary of each received and transmitted buffer. Ignored if DATA is set.
DATA	Shows the actual data sent and received.
MODEM	Shows modem signal transitions details.
CONNECT	Shows sockets connection activity.
INT	Shows Interrupt activity.

To get a full trace use

SET DMC DEBUG

However it is recommended to use the following when sending traces:

SET DMC DEBUG=REG;INFO;WARN

Related Devices

The DMC can facilitate communication with other SIMH simulators which have emulated synchronous network devices available. These include the following:

DUP11*	Unibus PDP11 simulators
DPV11*	Qbus PDP11 simulators
KDP11*	Unibus PDP11 simulators and PDP10 simulators
DMR11	Unibus PDP11 simulators and Unibus VAX simulators
DMC11	Unibus PDP11 simulators and Unibus VAX simulators
DMP11	Unibus PDP11 simulators and Unibus VAX simulators
DMV11	Qbus VAX simulators

* indicates systems which have OS provided DDCMP implementations.

The DMC11 is a synchronous serial point-to-point communications device. A real DMC11 transports data using DDCMP, the emulated device makes a TCP/IP connection to another emulated device and sends length-prefixed messages across the connection, each message representing a single buffer passed to the DMC11. The DMC11 can be used for point-to-point DDCMP connections carrying DECnet and other types of networking, e.g. from ULTRIX or DSM.

CR11 Card Reader (CR)

The card reader (CR) implements a single controller (the CR11) and card reader (e.g., Documation M200, GDI Model 100) by reading a file and presenting lines or cards to the simulator. Card decks may be represented by plain text ASCII files, card image files, or column binary files. The CR11 controller is also compatible with the CM11-F, CME11, and CMS11.

Card image files are a file format designed by Douglas W. Jones at the University of Iowa to support the interchange of card deck data. These files have a much richer information carrying capacity than plain ASCII files. Card Image files can contain such interchange information as card-stock color, corner cuts, special artwork, as well as the binary punch data representing all 12 columns. Complete details on the format, as well as sample code, are available at Prof. Jones's site: https://www.cs.uiowa.edu/~jones/cards/.

Examples of the CR11 include the M8290 and M8291 (CMS11). All card readers use a common vector at 0230 and CSR at 177160. Even though the CR11 is normally configured as a BR6 device, it is configured for BR4 in this simulation.

The card reader supports ASCII, card image, and column binary format card “decks.” When reading plain ASCII files, lines longer than 80 characters are silently truncated. Card image support is included for 80 column Hollerith, 82 column Hollerith (silently ignoring columns 0 and 81), and 40 column Hollerith (mark-sense) cards. Column binary supports 80 column card images only. All files are attached read-only (as if the -R switch were given).

ATTACH -A CR <file>	file is ASCII text
ATTACH -B CR <file>	file is column binary
ATTACH -I CR <file>	file is card image format

If no flags are given, the file extension is evaluated. If the filename ends in .TXT, the file is treated as ASCII text. If the filename ends in .CBN, the file is treated as column binary. Otherwise, the CR driver looks for a card image header. If a correct header is found the file is treated as card image format, otherwise it is treated as ASCII text.

The correct character translation MUST be set if a plain text file is to be used for card deck input. The correct translation SHOULD be set to allow correct ASCII debugging of a card image or column binary input deck. Depending upon the operating system in use, how it was generated, and how the card data will be read and used, the translation must be set correctly so that the proper character set is used by the driver. Use the following command to explicitly set the correct translation:

SET TRANSLATION={DEFAULT|026|026FTN|029|EBCDIC}

This command should be given after a deck is attached to the simulator. The mappings above are completely described at https://www.cs.uiowa.edu/~jones/cards/codes.html. Note that DEC typically used 029 or 026FTN mappings.

DEC operating systems used a variety of methods to determine the end of a deck (recognizing that 'hopper empty' does not necessarily mean the end of a deck. Below is a summary of the various operating system conventions for signaling end of deck:

OS	signal
RT-11	12-11-0-1-6-7-8-9 punch in column 1
RSTS/E	12-11-0-1 or 12-11-0-1-6-7-8-9 punch in column 1
RSX	12-11-0-1-6-7-8-9 punch
VMS	12-11-0-1-6-7-8-9 punch in first 8 columns
TOPS	12-11-0-1 or 12-11-0-1-6-7-8-9 punch in column 1

Using the AUTOEOF setting, the card reader can be set to automatically generate an EOF card consisting of the 12-11-0-1-6-7-8-9 punch in columns 1-8. When set to CD11 mode, this switch also enables automatic setting of the EOF bit in the controller after the EOF card has been processed. [The CR11 does not have a similar capability.] By default AUTOEOF is enabled.

SET CR AUTOEOF
SET CR NOAUTOEOF

The default card reader rate for the CR11 is 285 cpm. The reader rate can be set to its default value or to anywhere in the range 200 to 1200 cpm. This rate may be changed while the unit is attached.

SET CR RATE={DEFAULT|200 to 1200}

It is standard operating procedure for operators to load a card deck and press the momentary action RESET button to clear any error conditions and alert the processor that a deck is available to read. Use the following command to simulate pressing the card reader RESET button,

SET CR RESET

Another common control of physical card readers is the STOP button. An operator could use this button to finish the read operation for the current card and terminate reading a deck early. Use the following command to simulate pressing the card reader STOP button.

SET CR STOP

The simulator does not support the BOOT command. The simulator does not stop on file I/O errors. Instead the controller signals a reader check to the CPU.

The CR controller implements these registers:

name	size	comments
BUF	8	ASCII value of last column processed
CRS	16	CR11 status register
CRB1	16	CR11 12-bit Hollerith character
CRB2	16	CR11 8-bit compressed character
CRM	16	CR11 maintenance register
CDST	16	CD11 control/status register
CDCC	16	CD11 column count
CDBA	16	CD11 current bus address
CDDB	16	CD11 data buffer, 2nd status
BLOWER	2	blower state value
INT	1	interrupt pending flag
ERR	1	error flag (CRS<15>)
IE	1	interrupt enable flag (CRS<6>)
POS	32	file position - do not alter
TIME	24	delay time between columns

Symbolic Display and Input

The VAX simulator implements symbolic display and input. Display is controlled by command line switches:

-a,-c	display as ASCII data
-m	display instruction mnemonics
-p	display compatibility mode mnemonics
-r	display RADIX50 encoding

Input parsing is controlled by the first character typed in or by command line switches:

' or -a	ASCII characters (determined by length)
" or -c	ASCII string (maximum 60 characters)
-p	compatibility mode instruction mnemonic
alphabetic	instruction mnemonic
numeric	octal number

VAX instruction input uses standard VAX assembler syntax. Compatibility mode instruction input uses standard PDP-11 assembler syntax.

The syntax for VAX specifiers is as follows:

syntax	specifier	displacement	comments
#s^n, #n	0n	-	short literal, integer only
[Rn]	4n	-	indexed, second specifier follows
Rn	5n	-	PC illegal
(Rn)	6n	-	PC illegal
-(Rn)	7n	-	PC illegal
(Rn)+	8n	-
#i^n, #n	8F	n	immediate
@(Rn)+	9n	-
@#addr	9F	addr	absolute
{+/-}b^d(Rn)	An	{+/-}d	byte displacement
b^d	AF	d - PC	byte PC relative
@{+/-}b^d(Rn)	Bn	{+/-}d	byte displacement deferred
@b^d	BF	d - PC	byte PC relative deferred
{+/-}w^d(Rn)	Cn	{+/-}d	word displacement
w^d	CF	d - PC	word PC relative
@{+/-}w^d(Rn)	Dn	{+/-}d	word displacement deferred
@w^d	DF	d - PC	word PC relative deferred
{+/-}l^d(Rn)	En	{+/-}d	long displacement
l^d	EF	d - PC	long PC relative
@{+/-}l^d(Rn)	Fn	{+/-}d	long displacement deferred
@l^d	FF	d - PC	long PC relative deferred

If no override is given for a literal (s^ or i^) or for a displacement or PC relative address (b^, w^, or l^), the simulator chooses the mode automatically.