Emu72

A real emulator of the virtual HP-72S and HP-74S

Warning: The HP-72S and HP-74S have never been released by HP,
and - to the author's knowledge - no such project ever existed in HP.
All the information about the hypothetical HP-72S and HP-74S below are pure speculations.

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HP-72S and HP-74S presentation

The HP-72S and HP-74S are hypothetical HP BASIC handhelds that would have been the successors of the HP-71B.

The documents below are early attempts to define the hardware specifications of these machines:

Summary of the enhanced functionalities of the HP-72S:

Enhancements related to the new display:

- 2-line display forming a single 44-character user line,

- WINDOW statement expanded to manage the 44 display positions,

- GDISP statement acting on the full 44-character line for full graphic capabilities.

Built-in additional keywords:

- equivalent to the HP-71B CUSTUTIL & STRINGLX LEX files,

- most common and useful HP-71B extension functions such as:
KEYWAIT$, STD$, MSG$, RPT$, REV$, TRIM$, LWRC$ and more.

Other enhancements:

- faster key repeat rate,

- non-rolling command stack for better use of HP-IL displays,

- ports 6 and 7 now accessible, e.g. CAT :PORT(6.01),

- MOD modulo function usable as an operator, e.g. 1024 MOD 7,

- RENUMBER keyword can be shorted to RENUM or just REN,

- new more legible SHOW PORT format,

- new keystrokes to get the missing \ | _ ~ and ` characters,

Emu72 for Windows - Beta version 0.92 - May 2021

Emu72 is based on Christoph Giesselink's great Emu71 emulator.

Supported machines:

Emu72 supports the following virtual machines:

- HP-71B+ : a (also hypothetical) slightly redesigned HP-71B based on the same 72S/74S hardware architecture.
Differences vs the HP-71B are: one 32K RAM device in port 0 instead of the old 4 x 4K ports,
HP-IL in port 6 (instead of end of port 0), CPU speed increased to 1MHz,

- HP-72S : fully functional, according to the documentation above,

- HP-74S : this prototype version uses the HP-72S ROM for the same functionalities,
so only the bottom line of the multiline display is managed.

Installation:

This preliminary emu72 version doesn't provide an automated installation procedure.

The procedure for installation is:

- install the latest version of Christoph's Emu71,

- copy the content of the emu72 and rom72 zip files (see below) into the folder where the emu71 executable
is located, usually "C:\Program Files (x86)\HP-Emulators\Emu71",

- optionally, create a short-cut to emu72.exe on your desktop.

Opening a new HP-71B+, HP-72S or HP-74S in emu72 creates a simple core machine with 32K RAM without HP-IL.

To properly emulate the target machine, do the additional manual steps:

- HP-72S: add one more 32K RAM device in port 0, providing a total of 64K RAM,

- HP-74S: add three more 32K RAM devices in port 0, providing a total of 128K RAM,

- all machines: add the HP-IL ROM in port 6.

You can then add more RAM or ROM modules such as the Math ROM, JPC ROM or FORTH/Assembler in any of the ports 1 to 5.

In this hypothetical HP72S/74S hardware platform, port 6 is assumed to be dedicated to the HP-IL module slot (although other ROM/RAMs can be plugged in that port in emu72), and port 7 is assumed to be an extra internal port for installing dedicated custom ROM (again any ROM/RAMs can be plugged in that port in the emulator).

Note: all machines are using state files with extension e72 including the HP-71B+. State files for the HP-71B+ are not compatible with the regular emu71 state files e71.

Examples:

Below are a few screenshots demonstrating the new display capabilities of the HP-72S:

Full CAT display

AT LAST full display of a complex number !

New SHOW PORT display format

OF COURSE a much much more comfortable view of program code

File download:

emu72_092.zip : Emu72 beta version 0.92

Files to be installed in the emu71 execution folder. Content:

emu72.exe : HP-72S emulator

real72sm.kml : KML script for the HP-72S medium skin

real72sl.kml : KML script for the HP-72S large skin

real74sl.kml : KML script for the HP-74S large skin

real72sm.bmp : HP-72S medium skin for 800x600

real72sl.bmp : HP-72S large skin for 1024x768

real74sl.bmp : HP-74S large skin for 1024x768

rom72s_3e7.zip : HP-72S ROM file

prototype version 3eeee (revision 7)

emu72pat092.zip : patched source files for emu72, to be used with the emu71v114 source files.

Contact

If you have more information on any projects related to HP-71B developments, or if you have bug reports or suggestions for improvement, please contact me:

J-F Garnier, 2021