"Advanced Computer Typography"

Contents

1. Overview
2. Display Methods
3. Hardware

1 - Overview

In this paper, written while a Research Affiliate at the Naval Postgraduate School, Monterey, CA, Dr. Hershey describes the "HERA" cartographic and typographic system of the Naval Surface Weapons Center. He notes that this system has "replaced" his earlier FORTRAN-based system there.

This report discusses some of the implementation issues in the HERA system, but does not include the actual source code.

2 - Display Methods

From the point of view of the history of computer typesetting, perhaps the most interesting paragraph of the report is this:

There are three methods for displaying characters. In the HERA method the characters are polygonalized by eye to achieve optimum simulation. Each character is displayed by a series of strokes which are confined to the black area of the character. In the Mergenthaler⁷ method each type is scanned on parallel lines to determine the coordinates of the edges of the type. Each character is displayed in a series of scans by a beam which is off over the white area and on over the black area. In the TEX method the coordinates of the cetner of a pen are expressed by cubic parametric equations. Each character is displayed as a pattern of pixels whose centers are crossed by an elliptical pen. (1)

[These are the original bibliographic notes.]
{7} Omnitech/2000. (Mergenthaler Linotype Company, Melville, NY, February 1980)
{8}TEX and METAFONT. New Directions in Typesetting. D. E. Knuth. (American Mathematical Society and Digital Press, Bedford, MA 1979)

What I find interesting in this is Dr. Hershey's clear distinction between his method of polygonalization and other methods, together with his emphasis on aesthetic judgment.

1 - Hardware

Dr. Hershey describes the hardware setup for HERA at Dahlgren in this way:

In the current installation the IBM 3033 computer has an MSS or Mass Storage System, and MVS or Multiple Virtual System, and a CMS or Conversational Monitor Sytem. The CMS cannot communicate with the MSS or with the Versatec, but it can submit data and programs to the MVS. Therefore the CMS is used in the present system as a replacement for the keypunch and the card reader in the old system. (8)

Dr. Hershey's comments may require a bit of sorting out. The IBM 3033 was a computer, employing the IBM System/370 machine architecture (earlier in this report, Dr. Hershey refers to the IBM System/360 computer; it isn't clear if he's referring to a predecessor of the 3033 or to the 3033 itself). The MSS was an extremely complex tape storage device. MVS, on the other hand, was an operating system: more fully, OS VS2 MVS (Operating System / Virtual Storage 2 Multiple Virtual Storage). It was the then-current release of IBM's flagship mainframe operating system (still in production as "z/OS" today). Dr. Hershey does not mention another of IBM's mainframe operating systems, VM (Virtual Machine), but it is implicit in his description. VM is an operating system which virtualizes a single computer into what appear to be many (virtual) computers. Multiple ordinary computer operating systems, such as MVS, can run as "guest" operating systems under VM more or less as if they were running directly on physical hardware. CMS is a single-user operating system commonly run with VM as a convenient user environment. Thus, MSS is a hardware device, but MVS and [VM/]CMS are operating systems. From the description above, I would guess that the 3033 was running VM, and that both MVS and CMS were running as guests under VM.

Dr. Hershey also indicates that a version of HERA was available, written in BASIC, for the HP85 computer. For more on this see "Cartography and Typography with True BASIC" [Hershey 1995].