VAX-11/780

VAX-11/780
Summary
Announcement date:	October 1977
Codename:	Star
OS support (VMS):	VMS V1.5
CPU Details
CPU name (VMS):	KA780
Number of processors:	1
CPU technology:	Bipolar Schottky
CPU cycle time:	200ns
Instruction-buffer:	8 bytes [1]
Translation-buffer:	128 entries [1]
Control store:	4K 99-bit words [1]
Gate delay:	3ns
User Writable Control Store:	2K 99-bit words [1]
Cache:	8KB [1]
Compatibility mode:	Yes [1]
Console processor:	LSI-11 [1]
Console device:	RX01 [1]
Memory
Minimum memory:	2MB
Maximum memory:	64MB
Physical address lines:	30
Memory checking:	8-bit ECC/longword [1]
I/O
Max I/O throughput:	5.0MB/s
MASSBUS:	4 @ 2.0MB/s
UNIBUS:	4 @ 1.5MB/s
LAN support:	optional
Performance
VUPs:	1.0

A 'typical' VAX-11/780 marketing image

The VAX-11/780 was the first member to ship of the VAX-11 family of larger computers. The VAX series was conceived as the successor to the successful PDP-11 series of minicomputers, and in order to make the VAX seem more PDP-11 friendly, they retained the -11 moniker for the first VAXen, hence the -11/780 designation.

It was announced on October 25^th, 1977 at Digital Equipment Corporation's Annual Meeting of Shareholders.[4]

One of the main design goals was to increase the address space available, in fact the VAX acronym originally stood for Virtual Address eXtension).[3]

The first VAX-11/780 systems shipped with one quarter of a megabyte of memory, built from 4Kb chips.[3]

The 11/780 didn't have normal firmware, instead it loaded its microcode from floppy. There was also the VAX-11/785, which was an upgraded version.

The VAX-11/780 was given the codename "Star" and its operating system, VAX/VMS, was codenamed "Starlet".[4] VAX/VMS Version V1.0 shipped in 1978, along with the first revenue-ship 11/780s.

Operating Systems

An actual VAX-11/780 system

The 11/780 was to ship with VMS 1.0.

• VMS 1.0 - ?.0
• 32v
• Ultrix
• BSD (CSRG flavor) version 3.0 - 4.3
• NetBSD
• OpenBSD

Emulation

SIMH is the only known emulator for the 11/780. SIMH can address up to 128MB of RAM emulating an 11/780. Also the following peripherals are emulated:

• CPU VAX-11/780 CPU
• TLB translation buffer
• SBI system bus controller
• MCTL0,MTCL1 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
• RX console RX01 floppy disk
• DZ DZ11 8-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 drives
• 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

More information about SIMH's VAX 11/780 emulation can be found here.

References

[1] VAX Hardware Handbook Volume 1 - 1986.

[2] Systems & Options Catalog. European Edition. Spring 1990.

[3] VAX Architecture Reference Manual. Timothy E. Leonard. 1987. EY-3459E-DP. ISBN 0-932376-86-X.

[4] Nothing Stops It! VAX Open VMS At 20.