1985-06-28
by
Stan Sieler
This article evaluates seven terminal emulator packages for the HP 150 and the IBM PC:
An HP 150 can be used as a standalone terminal, but it offers only 2 pages of display memory and no access to disk storage. Thus, emulators like PC 2622 and enhancers like ADVANCELINK and ALLY/150 can greatly increase the usability of the HP 150.
Unlike the HP 150 (or other HP terminals), which has built-in displays, the IBM PC comes with a choice of two basic display types: monochrome (high quality text) or color (low-quality text). Unless otherwise noted, all of the programs reviewed here run on either a monochrome display adapter or a color display adapter. (Note: It is possible to run a color monitor with high quality text, but it costs about $1,000 and up. My Compaq does this with a Persyst BOB board and a Taxan 440 RGB color monitor.)
Because of hardware differences, it is not possible for a vanilla IBM PC to display all of HP's line-drawing character set, or any of the display-functions character set. The comparison tables show how each emulator copes with its hardware limitations.
For the IBM PC: PC 2622, PC-45, and VDTE were run on a Compaq Deskpro with 640KB RAM and a hard disk. PC2624B was run on an IBM PC with 320K RAM and a hard disk. (The Compaq Deskpro is compatible with an IBM PC, but defaults to running at 8 megahertz, rather than 4.77, just like an HP 150.)
For the HP 150: PC 2622, ALLY, and ADVANCELINK were run on an HP 150 with 640KB RAM, where 256K is reserved for a RAM disk.
Both the Compaq and the HP 150 were direct-connected to an HP 3000/40, and all timing tests were run with no other users on the HP 3000.
All the programs were tested over a one-month period and were subjected to a uniform testing process as well as random day-today testing. All performance results are in the comparison tables.
As I began the review I wondered if any one product would be so superior to the others that there would be essentially no choice in which are to purchase. On the contrary, each of the products reviewed provides something unique. See if your conclusions match mine.
Features
PC 2622 is a PC-DOS program that emulates an HP 2622 terminal. In addition, PC 2622 provides a number of powerful features, including type ahead, color enhancements, horizontal scrolling, a powerful command facility, and file transfer.
PC 2622 also provides an apparently complete emulation of three DEC terminals: VT52, VT102, and VT220.
Usability
PC 2622 is easy to learn and use. A new user need only remember one magic keystroke, ALT-H, which will display a help screen to remind him or her of how to enter any HP 2622 key that does not have an equivalent on the IBM PC keyboard (for example, the Clear Line key).
The file-transfer mechanism is a joy to use. It provides both a command-driven and a menu-driven interface. For example, if you want to download an ASCII file, FOO, from the HP 3000 to the IBM PC, use the following keystrokes:
Alt-Y (enters command mode) R FOOA grand total of seven keystrokes!(Receive file FOO from host)
If I forgot the syntax for the R command, I could enter:
Alt-Y HELP RSometimes it is easier to use a "fill-in-the-blanks" menu for a file transfer, which is easy too with the following sequence of keystrokes:
Alt-A (Pull up Aids softkey menu) F7 (enter File transfer menu) (fill in blanks)
The file transfer was the fastest, most comprehensive, and easiest to use of any of the packages tested.
Some of the choices for key substitutions, notably HOME and END, seem a bit odd. To home the cursor, CTRL-HOME must be used; CTRL-END will home-down. At first, I couldn't stand this feature, but I've found it has help break me of a nasty habit. I habitually press HOME and CLEAR, which really isn't necessary on modern terminals. And, with PC 2622 and its voluminous storage capacity, a HOME and CLEAR represents the loss of a lot of information! However, because PC 2622 forces me to do a CTRLHOME to move the cursor to the top of the screen, my unconscious use of HOME and CLEAR does not clear memory but, instead, clears the line the cursor is on.
If you are having problems with binary uploads, which can happen when you are connected to an ATP under MPE-V/E (or later), you can tell PC 2622 to use a nonbinary protocol by entering the CONFIG TRANSFER menu (Alt-A, F-7, F-2), and changing the HOST STARTUP SEQUENCE to: RUN PCLINK.PUB.SYS;PARM=1.
Reliability
I experienced no problems in testing PC 2622. I found it extremely reliable.
Documentation and Support
PC 2622 comes with an IBM-style 3-ring binder that contains a 123 page operations manual, a 201 page reference manual, and a combined index. The manual comes in a box, just like manuals from IBM. The manuals are somewhat difficult to read, and could be improved by adding white space between paragraphs.
The manual devotes several sections to trouble shooting.
I called Walker Richer & Quinn several times with questions. Usually, my questions were answered by a support person during the initial call. My more difficult questions necessitated follow-up a call from them. I was even able to get some technical assistance after 5:00 p.m. (PST).
Features
PC-45 is a low-cost program that allows an IBM PC (or compatible) to emulate most features of an HP 2645. Designed to run in conjunction with IMACS' DATA EXPRESS package, PC-45 provides enough features to be reviewed as a standalone terminal emulator.
In addition to providing a subset of an HP 2645, PC-45 also provides a simple ASCII file-transfer mechanism.
Usability
PC-45 is a very usable program. It provides many of the features of an HP 2645 terminal except some of the more esoteric ones, such as multipoint communication, data-field checking, insert/delete character with wraparound, binary read, monitor mode, and son on.
When you enter block mode, PC-45 automatically redefines the Return key to mean "enter." (The original meaning is obtained by pressing CTRL-Return.) This is a maddening feature, one that caused a lot of puzzlement and extra work for me. Many editors require the use of the Return key to move about the screen. Indeed, while typing this section of the review I was using PC-45 and a block-mode editor. I accidentally hit Return rather than CTRL-Return two out of five times.
Despite the missing HP 2645 esoteric functions, PC-45 satisfied all of my day-to-day uses. Its most severe limitation is the lack of a line-drawing character set and the automatic redefinition of the Return key.
Reliability
PC-45 "froze" twice during a week's worth of use, but no other problems surfaced. These freezes happened the first hour I was using PC-45, while I was still learning how to use it. I was unable to duplicate either freeze.
Documentation and Support
The manual is the size of normal IBM-PC manuals, and consists of 24 pages of text, a table of contents (no index), and is punched for a 3-hole binder (although, it does not come with a binder). It is typeset and easy to read. The manual does not include any trouble shooting information. An old version of the manual is included on the distribution disk. Having a version on disk is nice, because you can always exit PC-45 and then use PC-DOS or your favorite editor) to browse the manual.
I did not call IMACS with any problems during the evaluation period; but, rather, called for other reasons. Generally, I was able to contact the necessary individuals; if not, my calls were always promptly returned. Someone even answered the phone after 5:00 p.m.! They were not aware of any bugs that would cause a "freeze".
Features
VDTE is a PC-DOS program that allows an IBM PC (or compatible) to emulate most features of an HP 2624 or an HP 2648. It is the only emulator currently available that offers any form of HP graphics.
VDTE can be configured to respond as one of three different types of terminals: HP 2624, HP 2648, or DEC VT52. When setup as an HP 2648, it supports a subset of HP 2648 graphics that includes enter/exit graphics mode (ESC*dC, ESC*dD) and vector plotting (ESC*p...) with absolute, incremental, and relative coordinates.
VDTE's graphics differ from that of an HP 2648 in that it has no graphics cursor; no separate graphics memory (text and graphics are merged in memory; a "scroll" of text will also scroll the graphics); its resolution is 640 pixels by 200 pixels (the 2648 is 720 by 360); no pattern drawing; and no ZOOM.
Also note that VDTE's graphics requires a color-display adapter not a monochrome-display adapter.
Usability
Overall, VDTE is the "strangest" emulator tested. It doesn't "feel" like an HP terminal. For example, when a configuration menu presents three choices, it lists them in the middle of the screen like this:
VT52
HP2624
HP2648
An HP terminal, or any of the other emulators, would provide either 3 labelled function keys (F1, F2, F3) or a "fill-in-the blanks" menu. This is a minor quibble, but can be disconcerting when you try to use it. I think that emulators should "feel" as much like an HP terminal as possible ... particularly because some users will be switching between real terminals and emulated terminals, and they don't need unnecessary differences added to the unavoidable differences!
Some of the IBM PC keys work very strangely in VDTE. The two worst can cause a lot of work. (1) The END key erases from the cursor to the end of the screen. No other emulator uses this key in this manner; almost all use it to mean Home Down. (2) The usual IBM PC BREAK method (holding CTRL and hitting the Break key) causes VDTE to terminate immediately. I came up against this flaw at least a dozen times. What's worse is that it would have been easy for the programmer of VDTE to handle this key differently. Even now, I have to look in the manual to find that a Break is sent by hitting ALT-F10.
Block mode doesn't completely work. ENTRY was the only block mode program tested that ran fully, and that test is a very short one, with one simple field. FORMSPEC aborts or malfunctions after reading the form definition screen. QEDIT visual mode fails. It seems like VDTE goes out of its way to function in exactly the wrong manner: in the programs that failed, data typed onto the screen while in block mode does not appear on the screen but DOES get transmitted (as it is typed) directly to the host. (In block mode, the data is supposed to be local until the Enter key is pressed.)
Testing shows that the probable bug is associated with format mode. Any time the terminal is put into block mode without being put into format mode (for example, QEDIT, TDP, parts of FORMSPEC), VDTE forgets to put you into block mode and it still transmits characters to the HP 3000.
I tried two CSL games, SPACEWARE and VOYAGER, and several HP graphics programs on VDTE. None of them worked. SPACEWAR doesn't see VDTE as an HP 2648, and VOYAGER relies on some HP 2648 features that are not supplied by VDTE.
Reliability
VDTE crashed several times while I was using it, but I was unable to duplicate these. This, coupled with its block mode bugs, lead to give its low reliability score.
Documentation and Support
The manual consists of 49 text pages, a table of contents, and an index. It is roughly the same size as IBM PC manuals, and is punched for a 3-hole binder. However, it comes staple-bound, thus, does not need a binder. It is typeset and easy to read. The manual has a section on trouble shooting, but no summary of IBM-PC-to-HP-key sequences.
I had no technical questions for Inner Loop Software. However, in general when I called them prior to 5:00 p.m. (PST), they answered. An answering machine guaranteed a message reply mechanism. They were not aware of any bugs that could cause VDTE to crash, but were aware of problems with block mode.
Features
PC2624B is a combination PC-DOS program and hardware board that allows an IBM PC (or a DIRECT PC or other compatible) to emulate an HP 2624B. The emulation appears to be perfect: The line drawing character set and the display enhancements exactly match HP's.
To function, it requires that either a monochrome or color display adapter card already be in the IBM PC in addition to the PC2624B board. For testing, I installed the board into an IBM PC that had an IBM monochrome card and an IBM monochrome display.
Installing the board was straightforward (although I did have to pull another board out to make room for the PC2624B--all five of my PCs slots were full).
The secret to PC2624B is that the cable from the old display board (either flavor) runs from the board to the PC2624B board, and a new cable runs from the PC2624B board to the monitor. In effect, the PC2624B board has a "video switch" on it. This switch is set so that the video signal coming into the PC2624B board from the old PC board goes straight out to the monitor all the time unless the PC2624B emulator program is running. Then, the old PC card is ignored and only the PC2624B card is producing video output.
Thus, Direct appears to have built a card with all of the display hardware necessary for a 2624B terminal and found a slick way to add it to an existing PC without requiring the purchase of a second monitor.
Features
PC2624B does not stop at exact emulation, it also provides some impressive extensions: 80-or 132-column display; 27 display rows on an IBM monitor (25 is usual); double high/wide characters; smooth scrolling; optional down-loadable character set; and file transfer.
The display can be switched to 80-and 132-character mode with the push of a softkey or via an escape sequence. The text currently displayed is not lost by switching.
The time and date are displayed on the status line (line 27). The status line shows Insert Character mode, but not Caps Lock, Num Lock, or Scroll Lock.
The smooth scroll feature impressed me, especially considering I don't like smooth scroll. I always turn it off on those HP terminals that support it, but I was impressed at seeing my PC doing a smooth scroll. Then I turned it off.
PC2624B also provides a lot of display memory, although the amount can vary depending on available computer memory and average line length. (See the comparison tables).
Usability
PC2624B was easy to use. Setting parameters consisted of walking through a tree of softkeys, just like on an HP 2624. However, its choice of key sequences to simulate missing HP keys was poor. Almost every "extra" sequence was implemented as Alt and/or CTRL and/or Shift Fkey. For example, Clear Display was Alt-F8, Insert Line was Alt-F2. All of the other emulators at least tried to make the functions mnemonic (for example, Alt-I to insert a line, Alt-D to delete a line). This key-sequence design was certainly not made with the user (or programmer) in mind.
The Break key sequence has also changed, inexplicably since it already exists on the IBM PC keyboard. With PC2624B a BREAK is generated by hitting Alt-CTRL-BREAK.
I think that Direct should have chosen different default values for two of the configuration parameters: key click and baud rate. The first time I ran PC2624B, key click was on...and it makes a rather obnoxious sound, so I turned it off. Also, the baud rate was set to 2400 baud. The only users who would choose 2400 baud are those direct connected to an HP3000 Series III (or II). The majority of direct connected users would want 9600 baud. (Some would probably want 19200!) Users who plan to connect to an HP3000 via a modem would typically choose 1200 baud. Thus, 2400 baud is almost always the wrong choice.
The file-transfer program leads to a set of softkeys that do things like upload, download, and DOS commands. The file transfer program is easy to use, when it works. Upon entering file transfer, your screen is cleared, then the file-transfer status is displayed on the top third of the screen, with the bottom two-thirds reserved for further communication between you and the host computer. This is a nice feature. You can continue to type text to the HP 3000, and its responses will be shown in this window. At any time, you can press one of the softkeys to do functions such as Transfer from Host, Transfer to Host, Upload the Transfer Program, or you can ask for further software choices.
Unfortunately, when I tried to type to the HP 3000 while in this window, PC2624B froze at the first keystroke, usually requiring me to turn the computer off and on. I called Direct with this problem and was told that I had to have "enough memory" for the file-transfer program to work properly. The manual specifies that the packages requires "256K usable memory." My IBM PC has 320K, with over 256K being "usable," and it still encountered this problem. On the other hand, my Compaq, with 640K RAM, encountered no problems whatsoever. The moral: Make sure that you have a lot of memory when you run PC2624B. (Don't forget: RAM disks eat up memory too.)
The file-transfer program works with a "sister" program, called HPCLINK, on the HP 3000. (It comes on the distribution disk.) PC 2624B, just like PC 2622 and ADVANCELINK (HP 150), provides a method of uploading this program (via FCOPY). Like PC 2622, and unlike ADVANCELINK, this upload is accomplished from within the main emulator program, which is nice.
There are two severe limitations to the file-transfer program: 1) HPCLINK must reside in your logon group. Contrary to the manual's statement that it could reside in PUB.SYS, the file transfer protocol simply issues the command: RUN HPCLINK; 2) HPCLINK will allow you to download files only from your logon group.
The file-transfer program also has a minor drawback: If the target file exists when you're transferring files to the host, you are not asked to replace it. Instead, the old file is lost.
The file-transfer program offers a command mode similar to that of ADVANCELINK's and DSN/LINK's. PC2624B offers 13 of the 32 commands that DSN/LINK has, and adds two new ones: PAUSEUNTIL time, and RETRY n (to configure the number of transmission retries). These commands can be typed in directly or read from a file. They cannot be triggered from the HP 3000, nor is there a HOSTCOPY command to specify where HPCLINK resides.
One real nice feature is its ability to monitor the results of doing file transfers, and then send the output either to a printer or a file. Unfortunately, the disk file it created for me was always completely empty.
Be forewarned, PC2624B's hardware card may cause some computer freezes. Normally, a machine hang is nothing to worry about--a quick reboot will cure everything. With PC2624B, this isn't quite true. When PC2624B crashes, its card is left in control of the monitor. Thus, when the computer is rebooted, the display will continue to show whatever PC2624B was showing. The computer will run just fine, you just can't see your output.
There are three solutions to the "frozen display": 1) Turn the power off, wait a few seconds, and then turn it back on. At power-up, the PC2624B gives control to the old PC display card. 2) Reboot, and then carefully type the command to get PC2624B running again. (The program name is PC2624B, but I created a batch file called DIRECT to run it.) Type carefully because you can't see your input. (3) Reboot, and then carefully type RESETDEA. Assuming it is in your default directory, RESETDEA will run a program supplied by Direct. RESETDEA resets the PC 2624B and gives control back to the old PC card. This last mechanism can be incorporated into your AUTOEXEC.BAT file so that any reboot will unconditionally reset the PC2624B board.
The save configuration option of the configuration screens fooled me. If I made a change, like turning off key click, it was lost as soon as I exited the configuration screen unless I hit the Save Configuration softkey. (Perhaps a real HP 2624B works like this, perhaps the manual states that this happens. I am not in a position to vouch for either case.) There is only one Save Configuration file. Most of the other emulators ask Save Into which File?
Reliability
As I indicated earlier, on my IBM PC, PC2624B froze the computer every time I tried to send a character to the HP 3000 while in the file-transfer program. On the Compaq, it ran perfectly.
Documentation and Support
The manual consists of 90 pages of text, a table of contents, and an index. It is printed with a fixed-space font, but is easy to read. (The word processor used to format the manual has two problems: a dumb algorithm for right-edge justification, and but in the algorithm when handling the first line of a paragraph.) The appendix shows all of the IBM-PC-to-HP-key mappings. A list of error messages is also included, but there is no troubleshooting section.
The manual refers to Display Functions mode as Monitor Mode, which means something different to anyone familiar with HP 2645s. The file-transfer program manual explicitly says on page 4: "Check to be sure your menu displays Version A0. If you have a different version, contact your Direct representative for the correct instructions." Unfortunately, the software I received was version A1. I kept on going anyway, and discovered that the manual still covered the software adequately.
On the subject of version identification, the floppy disk says Rev A3, and the terminal configuration menu says Version 2.2.
Direct answered all of my calls promptly, except once (just before the long July 4th weekend!)
Features
PC 2622 for the IBM PC and the HP 150 differ only in keyboard utilization and display enhancements. Rather than present the same information twice, I refer you to the previous review of PC 2622 for the IBM PC (above).
PC 2622 allows the HP 150 to work like a real terminal, one with more than two pages of memory. In addition to providing over 100 pages of display memory, it also has a very powerful file transfer program (that's approximately 20 percent faster than ADVANCELINK), complete with a batch command-file mechanism, typeahead, and the ability to configure display enhancements (which allows you to make inverse-video display in italics).
PC 2622 can drive a printer (internal or external) in background printing mode with a user-configurable buffer. I typically set the buffer size to 10K, which means that when I press PRINT (or use the Copy Page softkey), I wait a fraction of a second, then continue working while the printer is printing.
PC 2622 does NOT use two features built into the HP 150: graphics and the touchscreen. (Only the softkeys may be touched, no other touch fields may be set up.)
Features
ALLY/150 is an MS-DOS program that extends the abilities of the 150. It comes on a single disk with a free chess game that is played via the touchscreen.
ALLY does not expand the amount of display memory available to the HP 150 (two pages), but works in tandem with it to add four major new functions: typeahead; dual port support; and background and foreground processing.
The typeahead buffer holds up to 500 characters, with input displayed on the status line. As the type-ahead input is sent to the HP 3000, one character at a time, the characters "slide" off the left end of the status line. This feature provides for confidence in typing ahead.
At a touch of a key, ALLY will switch from using COM1 to COM2. (COM1 is the MS-DOS name for the HP 150's Datacom Port 1, COM2 is Datacom Port 2.) When this happens, all of the display memory (all 48 lines!) and the entire state of the terminal is saved somewhere secret, and the prior display memory and state for COM2 is restored. This switch takes about one second, and effectively provides you with two separate terminals...providing you have both datacom ports connected to an HP3000 (either directly or via modems).
Usability
The dual port switch is very easy to use, even if one port is in a character-mode application and the other is in block mode.
The dual port switch does not affect the graphics display. In other words, if you are talking to COM1 and display a graph, and then press the softkey to switch to COM2, the graph will still be on the screen. If the graph is erased while you are talking to COM2, then it will be gone when you switch back to COM1.
Also, not all of the terminal state is preserved, some things seem to be global, like Remote mode. If you place COM1 in Local and then switch to COM2, it will be in Local mode too.
Both the load-background and load-foreground functions are easy to use, although the load-background process is of less use to most users. The background process allows a user to run a task, like a compile, "behind" ALLY. Any process that does not talk to the terminal is a good candidate for this process. For example, to start a background C compile, you might issue the command C SOURCE > C.OUT. The > C.OUT will redirect any output from the compiler to a disk file called C.OUT.
The foreground process lets you run a program while still in ALLY. From the documentation, it is not clear if ALLY is still alive and listening to the datacom line while the foreground process is running. No matter, this is still a feature not found on any other emulator. If you want to upload a WORDSTAR file and suddenly realize that you haven't yet stripped it of its control characters, you could use this mechanism to pop into DOS and run the contributed STRIP utility, then EXIT back to ALLY and transfer the file to the host.
Normal data transfer (for example, typing into QEDIT, doing a PSCREEN) from the HP 150 to the host computer is slowed to about one-fifth normal speed while running ALLY. This applies to both character-mode and block-mode data.
Reliability
With ALLY sometimes the entire machine freezes and sometimes the ALLY softkeys freeze and cannot be used, but the rest of the terminal functions normally. These freezes usually happened when I tried to hit a softkey, often just after doing graphics or block-mode things. I was not able to duplicate the freezes. No other bugs were found.
Support
I had a problem when making a backup of ALLY. I called Computing Capabilities, left a message, and received a quick call back with technical assistance. Although the installation instructions had a minor error (it failed to say: WRITE-ENABLE the ALLY master disk), the main problem had been caused by my penchant for immediately UNLOCKING all files on all disks I receive, which the copy-protection scheme objected to.
Features
ADVANCELINK is a file-transfer package for the HP 150 that provides both a menu-driven and a command-file interface. It also provides data-integrity checking for both ASCII and binary files.
ADVANCELINK has a simple block-mode editor designed for building auto-logon command files. It can also be used to create and/or edit files of up to 15 lines in length. It is not easy to pick out from the softkey labels so here's how to get into it: From the ADVLINK Main Menu, hit the COMMAND softkey (f3) and then AUTO LOGON softkey (f3).
Usability
ADVANCELINK is typically run only when you want to do a file transfer. While running, the HP 150 is still fully usable as a terminal. The drawback is that it's slow. Normal data transfer (for example, typing into QEDIT, doing a PSCREEN) from the HP 150 to the host computer is about one-fifth normal speed. This applies to both character-mode and block-mode data. It is interesting to note that DSN/LINK, the predecessor of ADVANCELINK, suffered from the same problem.
ADVANCELINK's file transfer generally requires that a sister program called MONITOR.PUB.SYS be available. If you are dialing into someone else's computer that does not have MONITOR.PUB.SYS, it's unlikely that you will be able to logon to MANAGER.SYS in order to upload MONITOR. ADVANCELINK makes it fairly easy to upload MONITOR to somewhere else (for example, your logon group), but making ADVANCELINK actually use that "somewhere else" later for file transfer is not that obvious. The following dialog will make ADVANCELINK look for FOO (in your logon group) instead of MONITOR.PUB.SYS: enter the command dialog of ADVANCELINK; hit the softkey to enter a direct command; type: &HOSTCOPY "RUN FOO."
Similarly, if you are having problems with binary uploads (for example, getting data parity errors with an ATP and MPE-V/E or later), you can ask ADVANCELINK to use a nonbinary protocol by entering the command &HEX ON.
The editor is simple-minded and easy to use.
Reliability
I found no bugs in ADVANCELINK.
For the IBM PC:
PC 2622 has a superior file-transfer package, speed, and the most display memory. It has the most complete emulation of all the software-only emulators, coming in second only to PC2624B. At present, it wins the "best all around" award.
PC-45 is a good emulator, and will handle most ordinary usages, both block mode and character mode. With its low price, it is definitely worth looking into.
VDTE will let you develop a simple graphic application (using only its subset of HP 2648 graphics) and use it without buying an HP 2648. If you do not need block mode, consider VDTE. Until I switched to a block-mode editor, the package would have met my day-to-day needs.
PC2624B offers complete HP26 24B emulation, plus extras. If your PC can handle an extra board, and you need exact emulation, this IS the only choice, but also you can be happy with. It would probably tie PC 2622 for the "best all-around" award.
For the HP 150:
PC 2622 is compatible with PC 2622 on the IBM PC, and is the only integrated emulator and error-checking file-transfer package for the HP 150.
ALLY/150's process handling (foreground/background) can be very useful. Additionally, its "visible type ahead" makes it easy to use.
ADVANCELINK provides a reasonably good file transfer package and is the only emulator that provides any kind of an editor. ADVANCELINK is sold and supported by HP. It should also be available at authorized dealers.