Cassette BASIC :
In 1981, when IBM released the IBM PC Model 5150, it included BASIC in ROM. In the 5150, it was contained on four 8KB chips, in later machines, it was included within the 32KB chips that included the BIOS. In every IBM PC model it occupies the space from F600:0000 to FDFF:0000.
Cassette BASIC, as its name implies, has commands for saving and loading only to a compact cassette. In order to save to or load a program from a cassette, the user needed to connect a cassette drive to his IBM PC with a special cable. On the back of the IBM PC Model 5150, there was a 5-pin DIN next to the keyboard DIN that this cable would plug into. At the other end of the cable there would be a 3.2mm audio jack for the auxillary or microphone input (to save/record data from a PC), a 3.2mm audio jack for the earphone output (to load/playback data to the PC), and a 2.5mm jack to control the tape recorder remotely. The PC had a relay circuit on the motherboard that would start and stop the motor so that the user would not have to.
IBM did not offer a cable for the 5150, but Tandy/Radio Shack TRS-80 and Color Computer tape recorders came with the correct cable. Most older tape recorders, including those Radio Shack sold for their non-PC compatibles, had four audio jacks, the EAR, REM, MIC and AUX. Current recorders ditch the AUX input and only have a MIC input. REM is the smaller jack that controls the cassette deck. There was a jumper on the system board to set the appropriate signal strength for a MIC input or an AUX input.
Cassette BASIC comes in three versions, C1.0, C1.1 and C1.2. C1.0 will only be found in the very first IBM PCs, typically those with a 16-64KB system board and a BIOS version dated 04/24/81 or 10/19/81. C1.1 generally should come with all IBM PC Model 5150s with a 64-256KB system board or those systems with a BIOS version dated 10/27/82 (the last). However, the BIOS in the IBM PC is contained in one chip, U33, and can be updated in an 16-64KB system board without updating BASIC.
All later IBM PCs, the XT, Portable, AT, XT/286 and Convertible, contain Cassette BASIC C1.1. The PCjr. (and probably the PC JX) uses Cassette BASIC C1.2 for reasons described below. All PS/2s released during the 1980s and early 90s, and the early IBM PS/1s, also contain Cassette BASIC C1.1 for compatibility reasons. No other PC Compatible system, unless an exact clone of one of these systems, included Cassette BASIC.
Unlike the disk-based versions of BASIC, Cassette BASIC does not require PC or MS-DOS to run. However, because the IBM PC and IBM PCjr. are the only PC-compatible systems known to come with circuitry to drive a cassette recorder, Cassette BASIC can only save or load programs on these two systems.
Disk BASIC, Advanced BASIC and GW-BASIC :
Disk BASIC and Advanced BASIC were included with PC-DOS v1.0 and every version thereafter, 1.1, 2.0, 2.1, 3.0, 3.1, 3.2, 3.3, 4.0 and 4.01. They were replaced by QBASIC in PC-DOS 5.0. The version number for Disk BASIC and Advanced BASIC correspond directly to the version of DOS they came with. This you will see D1.1 for the version of Disk BASIC accompanying PC-DOS 1.1 and A3.3 for the version of Advanced BASIC that came with PC-DOS 3.3. Disk BASIC is invoked by executing BASIC.COM in DOS, and Advanced BASIC by BASICA.COM in DOS.
The Disk BASIC-Advanced BASIC split was due to the low amounts of memory that came with early IBM PCs. You could buy an IBM PC with only 16KB of RAM, but with that amount of RAM, you could only run Cassette BASIC. Disk BASIC required 32KB of RAM, and Advanced BASIC 48KB of RAM. Disk BASIC could do everything that Cassette BASIC could do and added support for saving and loading programs to floppy disks and serial port access, keeping track of the date and time and supporting two additional printers. Advanced BASIC does all Disk BASIC does and more, such as support for more graphics and sound statements and event trapping.
PC BASIC does not support multiple memory segments, it runs everything within one 64KB segment. Thus, after PCs began shipping with 128KB of RAM or more, there was no further need to use Disk BASIC. In fact, as of DOS 3.3, BASIC.COM was just a small (1-2K) stub that called BASICA.COM and was only present for compatibility. DOS 1.0-3.2 had a functional BASIC.COM. PC BASIC would keep up with DOS features, like the added support for subdirectories in DOS 2.0 and the IOCTL calls in DOS 3.0.
With non-IBM machines, vendors and OEMs released system-specific versions of MS-DOS. With these operating systems, GW-BASIC was included. GW-BASIC did not require Cassette BASIC. In these systems, sometimes there is a large BASIC.EXE and a small BASICA.COM. BASICA.COM is the stub that executes BASIC.EXE. Sometimes there is also a BASIC.COM stub. In certain systems, the file was BASICA.EXE or GWBASIC.EXE.
Tandy's GW-BASIC for the Tandy 1000 series included the commands found in Cartridge BASIC to control its PCjr-derived advanced graphics and sound capabilities. The AT&T 6300's GW-BASIC included commands for the advanced graphics capabilities of that system, and the Hercules Graphics Card came with a utilities disk with HBASIC, which allowed the use of the 720x348 graphics mode these cards support. A generic GW-BASIC would not support these special features. Microsoft began releasing generic, non-OEM specific versions of MS-DOS starting with MS-DOS 3.2. A generic version of GW-BASIC can be found on them.
IBM also released Compiler BASIC which allowed users to compile their program into object code so it does not require a BASIC interpreter to run the program. Most companies that released games found it simpler to run their code through an interpreter, because every computer with a disk drive and DOS should have had one during the 1980s.
Cartridge BASIC :
The PCjr. included Cassette BASIC C1.2 in its system ROM. Due to the differences between the PC and PCjr., the BASIC code cannot be identical. However, to maintain compatibility with applications written for Cassette BASIC, all the functionality of PC Cassette BASIC is included in PCjr. Cassette BASIC, and nothing more. IBM released an official cassette cable that plugged into a unique male BERG-style port on the PCjr., but it requires a cassette recorder with an AUX input.
IBM released Cartridge BASIC with the PCjr., and the user had to buy it separately. It is a 32KB cartridge that plugs into either cartridge slot of the PCjr. Cartridge BASIC included commands to take advantage of the PCjr. video adapter and sound chip. Cartridge BASIC has only one version, J1.0. Disk BASIC and Advanced BASIC, when run on the PCjr., will show the version as J1.0, regardless of DOS version. Disk BASIC and Advanced BASIC will not run unless Cartridge BASIC is present.
Using Cartridge BASIC in a PCjr. with more than 128KB of RAM imposes special problems. Cartridge BASIC was not designed for more than 128KB, and programs run it may not run correctly or at all. However, the PCjr. will not recognize extra RAM unless a device driver is loaded in DOS. If DOS is loaded, either from a disk or a hard drive without a device driver loaded, then Cartridge BASIC should run normally. You will be limited to the first 128KB of RAM and the poor performance resulting by running BASIC code within it. The popular device driver JRCONFIG 3.1 included an unsupported /q command line switch where it will lie about the amount of memory available to BASIC, but it will warn you that anything contained in a RAM Disk or Print Spooler created by JRCONFIG will be in danger.
QBASIC :
In PC-DOS 5.0 and MS-DOS 5.0, Disk BASIC and Advanced BASIC were no longer included with the operating system. Instead, QBASIC version 1.0 was included. QBASIC was a cut down version of Microsoft QuickBASIC. QBASIC does not require line numbers and supports a mouse cursor, split windows, drop down menus and multiple colors in its text-based user interface. The MS-DOS EDIT.EXE program requires QBASIC.EXE, QBASIC.HLP and EDIT.HLP to work. QBASIC tends to be a poor performer on 8088-based XT-class and low speed 286-based AT-class machines.
I read that the original version of QBASIC in PC-DOS 5.0 still required Cassette BASIC in ROM, but it only used checked to see that it was there before loading QBASIC. This requirement was removed in the QBASIC that came with PC-DOS 5.02. QBASIC version 1.1 was included in MS-DOS 6.0 through Windows ME and NT 4.0.
BASIC Games :
The first game ever written for the IBM PC was Donkey. This simple game was included as the file DONKEY.BAS with several other demonstration programs included on the DOS disks. In fact, half the files included in PC-DOS 1.0 and 1.1 were BASIC demonstration programs. It is included with PC-DOS 1.0-3.2. With DOS 3.3, virtually all the demo programs were eliminated.
QBASIC in MS-DOS 5.0 and PC-DOS 5.0 came with two games, Gorillas and Nibbles. Their files are called GORILLA.BAS and NIBBLES.BAS. Nibbles is a text mode game that uses an 80x25 column mode, but appears as a 80x50 column mode by the use of a half-bar ASCII character (where the top half uses the foreground color and the bottom half uses the background color). It works with any video adapter. Gorillas uses either the 320x200x4 CGA Mode 04 or the 640x350x16 EGA Mode 0F. They are intended to be run on a low-end 386 or a high end 286. Both games would be gone by MS-DOS 6.22 and PC-DOS 6.1
Games Requiring BASIC :
Several games, usually early games, used Cassette/Disk/Advanced BASIC. Some were copy-protected DOS disks that directly accessed Cassette BASIC. They must be run on an IBM system. Nine games commercially released by IBM early in the life of its PC line require Cassette BASIC or Cartridge BASIC. They are
Adventures in Math
Arithmetic Games Set 1*
Arithmetic Games Set 2*
Bumble Games*
Bumble Plot*
Casino Games
Juggles Butterfly*
Monster Math
Strategy Games
* - Copy Protected (The Learning Company games) or probably Copy Protected (Science Research Associates, Inc.) IBM never seemed to copy protect the games it developed internally, but did with any game it released that was licensed from or developed by another company. Any game that is not copy protected, or has been cracked to run on a generic disk should be able to be run with GW-BASIC. Mobygames lists 75 games that require BASIC, and some are sophisticated commercial releases like Battle of the Bulge, some are old classics like Temple of Apshai and others are small single file games that just need a BASIC interpreter. There are many, many freeware games that run on QBASIC, and while Mobygames may not document every Cassette/Disk/Advanced BASIC game ever made, it does not really list any games that use QBASIC other than Gorillas an Nibbles. A good place to start to find QBASIC games is here :
http://www.qbasic.com/games/
http://www.petesqbsite.com/index.php
Showing posts with label Productivity Software. Show all posts
Showing posts with label Productivity Software. Show all posts
Friday, September 5, 2014
Monday, August 4, 2014
HomeWord - Sierra Online's Easy to Use Word Processor
Ken Williams, who founded what would become Sierra Online in 1979, was a programmer. He had worked service bureaus selling computing services to businesses. He programmed on mainframe computers, and bought an Apple II with a disk drive to develop a FORTRAN compiler. His wife Roberta loved playing computer text adventure games, and persuaded him to program her idea for a game on his Apple II. The result was Mystery House and the rest was history. Within a year of Mystery House's 1980 debut, Sierra had published a Word Processing program called ScreenWriter, but felt there was a market for a more family-friendly program.
The end result of Sierra's efforts was HomeWord, released for the Apple II and ported to the IBM PC and PCjr. Sierra's program was not going to compete with WordStar, WordPerfect or even Microsoft Word. In fact, it was marketed toward people who would have been too imtimidated by WordStar's command shortcuts or WordPerfect's brick-thick manuals. Many, many home-market friendly computer companies released word processors. Broderbund's Bank Street Writer was one of the products against which HomeWord would compete. Sierra would later release HomeWord II, which would have full hard drive support. HomeWord came with a tutorial cassette to walk the novice user through his first word processing session.
In this blog entry I am going to take a look at HomeWord for the IBM PCjr., released at the end of 1983. It was sold through IBM for $75.00. This version only ran on a PCjr., it will fail to load if it detects the presence of DMA, which would indicate a PC. It came with an overlay for the PCjr. chicklet keyboard that looked like this :
The disk was formatted for DOS 2.1, but was copy-protected. It required the user to save his files to a formatted floppy disk. It could exit to DOS and contained programs like FORMAT and DISKCOPY to allow the user to do that without needing his DOS disk. The program did not support hard drives. Hard drives were extremely expensive in 1983 and were not intended for the consumer PCjr.
When you boot the HomeWord disk, you will see the following :
then this :
After the title screen, the disk's AUTOEXEC.BAT file will automatically execute the DOS DATE and TIME commands, in order to remind you to set them. The PCjr. had no real-time clock, but even so, many people were probably too lazy to set the date and time. After the date and time prompts, the program would show you this screen :
The menu is using a tweaked 4-color graphics mode 04h, which requires less RAM than a 16-color mode but more flexibility than the PCjr. text modes.
HomeWord is pretty functional for a basic word processor, and the commands are easy to use. The program is will describe what you need to do, and you can see the results fairly quickly to make sure you have it right. The program will allow you access to most, if not all, of them via the menu. However, learning the shortcuts makes things easier (refer to the overlay in the image above). Instead of going through all its capabilities, let me allow the program to show some of them to you :
The program also supported 80-column "text", in reality graphics mode 06H :
The PCjr.'s graphics capabilities were not quite ready for WYSIWYG, but Sierra did try to give the user a good idea of what the document would look like before they used the print command. On the bottom right of the screen, there is a miniature version of the page, showing the text alignment as it was being typed. There is also a "show document" command that will display the whole document as it will appear on the printed page. The scrolling happens automatically, and you need to press the spacebar to pause it. Unfortunately, there is no obvious option to have it pause screen by screen.
The program supports custom margins, combining documents, headers and footers and page numbers. It does not support automatic footnotes, but that was a function of high-end Word Processors. The resulting files are very small and almost plain-text, so only the formatting would be lost. If you want to show off your mastery of printer escape codes, there is a function which would allow you to insert them into the document. You can also see the raw ASCII for the document.
Most keyboard functions are handled by the Control key, but the Alt key is sometimes required and the Fn key will also be frequently used. Since I don't have the manual, I am not aware of the function that will bring the cursor to the beginning or end of the line. Once you turn a function on, like Bold or Underline, the function will apply to all text until you use the Normal function to turn those attributes off. No support for italics, but that was not a common feature of the printers of the day.
Here is the end result as printed on my IBM Compact Printer. Although this program has explicit support for a serial printer, it refused to print anything more than two lines with that selection. It would stop printing, saying my printer wasn't ready. The hell it was! I believe it was confused because I had an Internal Modem and the Parallel Printer Attachment installed. Instead, I tricked it into thinking it was printing to a parallel printer via the DOS mode command. Using the MODE command found in DOS 2.1, I used the following commands to fool the program (you have to exit the program first, type the commands in DOS, then restart it):
mode lpt1:=com2:
mode com2: 1200,n,8,2,p
With that, the printer printed as well as the Compact Printer can, and here is a scan of the results :
This program was designed to run on a 128KB PCjr., and suffers from the performance limitations of that machine. Even so, the program is not as slow as you might expect. I do not know if the speed can be improved by loading it after using a device driver to allow it access to the fast memory contained on a PCjr. attachment, but I suspect it would.
The end result of Sierra's efforts was HomeWord, released for the Apple II and ported to the IBM PC and PCjr. Sierra's program was not going to compete with WordStar, WordPerfect or even Microsoft Word. In fact, it was marketed toward people who would have been too imtimidated by WordStar's command shortcuts or WordPerfect's brick-thick manuals. Many, many home-market friendly computer companies released word processors. Broderbund's Bank Street Writer was one of the products against which HomeWord would compete. Sierra would later release HomeWord II, which would have full hard drive support. HomeWord came with a tutorial cassette to walk the novice user through his first word processing session.
In this blog entry I am going to take a look at HomeWord for the IBM PCjr., released at the end of 1983. It was sold through IBM for $75.00. This version only ran on a PCjr., it will fail to load if it detects the presence of DMA, which would indicate a PC. It came with an overlay for the PCjr. chicklet keyboard that looked like this :
The disk was formatted for DOS 2.1, but was copy-protected. It required the user to save his files to a formatted floppy disk. It could exit to DOS and contained programs like FORMAT and DISKCOPY to allow the user to do that without needing his DOS disk. The program did not support hard drives. Hard drives were extremely expensive in 1983 and were not intended for the consumer PCjr.
When you boot the HomeWord disk, you will see the following :
 |
| Doesn't this look familiar... |
 |
| I sincerely doubt they sold nine hundred million copies |
The menu is using a tweaked 4-color graphics mode 04h, which requires less RAM than a 16-color mode but more flexibility than the PCjr. text modes.
HomeWord is pretty functional for a basic word processor, and the commands are easy to use. The program is will describe what you need to do, and you can see the results fairly quickly to make sure you have it right. The program will allow you access to most, if not all, of them via the menu. However, learning the shortcuts makes things easier (refer to the overlay in the image above). Instead of going through all its capabilities, let me allow the program to show some of them to you :
 |
| Beginning of the Document |
 |
| Menu Selections |
 |
| Scrolling Down is done by the Cursor Control (Arrow) keys |
 |
| 80-column mode, note the use of inverse text to identify functions |
The program supports custom margins, combining documents, headers and footers and page numbers. It does not support automatic footnotes, but that was a function of high-end Word Processors. The resulting files are very small and almost plain-text, so only the formatting would be lost. If you want to show off your mastery of printer escape codes, there is a function which would allow you to insert them into the document. You can also see the raw ASCII for the document.
Most keyboard functions are handled by the Control key, but the Alt key is sometimes required and the Fn key will also be frequently used. Since I don't have the manual, I am not aware of the function that will bring the cursor to the beginning or end of the line. Once you turn a function on, like Bold or Underline, the function will apply to all text until you use the Normal function to turn those attributes off. No support for italics, but that was not a common feature of the printers of the day.
Here is the end result as printed on my IBM Compact Printer. Although this program has explicit support for a serial printer, it refused to print anything more than two lines with that selection. It would stop printing, saying my printer wasn't ready. The hell it was! I believe it was confused because I had an Internal Modem and the Parallel Printer Attachment installed. Instead, I tricked it into thinking it was printing to a parallel printer via the DOS mode command. Using the MODE command found in DOS 2.1, I used the following commands to fool the program (you have to exit the program first, type the commands in DOS, then restart it):
mode lpt1:=com2:
mode com2: 1200,n,8,2,p
With that, the printer printed as well as the Compact Printer can, and here is a scan of the results :
 |
| To Boldly Go, or maybe Not |
Sunday, April 20, 2014
Tape Cassette Storage with the IBM PC and PCjr.
IBM include a 5-pin DIN cassette port in the IBM PC Model 5150. This was intended for systems sold without floppy disk drives, which were still very expensive in 1981. Until the PC was discontinued in 1987, you could still buy a 5150 from IBM without a floppy disk drive (Model 104).
The 5-pin DIN connector used a TRS-80 cassette cable to connect to a tape recorder deck. The Radio Shack CCR-81 and 82 came with the cables and had both Mic and Aux input jacks. IBM never made a cable for the PC, and the only software it ever supplied was IBM PC Diagnostics and Advanced Diagnostics. Otherwise, use of the cassette port was intended solely for users of Cassette BASIC. Cassette BASIC, built into the system, used its save and load commands to access the cassette drive. In this IBM followed other 8-bit microcomputers of the day, as Cassette storage was the cheapest form of storage available for home computing.
When IBM released the XT, it removed the cassette port circuitry but kept Cassette BASIC in ROM for compatibility with Disk BASIC, Advanced BASIC (BASICA) and programs which relied on any of the three. You could no longer save or load a program in Cassette BASIC. However, IBM also used the same cassette interface logic for the PCjr. This time, IBM released a cable to connect to the unique cassette port on the PCjr.
The IBM PC and PCjr. communicate with the cassette deck via Int 15. At the low level, the audio coming from the deck to the system is digitized and read serially on bit 4 of the 8255 Port C. Audio generated from the system to the deck is generated by 8253 Timer 2, which also controls the PC Speaker and then sent to the cassette. The motor is controlled by bit 3 (and bit 4 in the PCjr) of the 8255 Port B. The BIOS routine writes a 1 bit is with a tone of 1 millisecond (1000Hz), and a 0 bit with a tone of 0.5 millisecond (2000Hz).
To signal the beginning of a program to BASIC, there will be a "leader" of 256 bytes where all the bits are 1, followed by a 0-bit and then ASCII Hex 16. Then a 256-byte data block will be written, followed by a 2-byte Cyclic Redundancy Check, and then more data + CRC blocks until the whole program has been written. The maximum size that can be written is probably close to 64K, since that is the absolute maximum size of a BASIC program on the PC.
Typing SAVE"[program name] will save a BASIC program to the cassette. Typing LOAD"[program name] in Cassette BASIC will instruct BASIC to start the cassette and search for the file. It is up to the user to remember where the program is located. If the system cannot "hear" a program, it will eventually quit trying and give the "Device Timeout" error message. If there is some kind of problem with what it is trying to load, it will say "Device I/O Error." You should keep the volume as high as possible when recording and playing back.
By using the cassette cable, you can record the output of the IBM PC's Speaker without any other adapter hardware. You can of course plug the other end of the cable into a PC instead of a recording deck. It is better to use the audio jack of the PCjr. to record sounds from it, as that jack can record from the PC Speaker, the 3-voice sound chip, the PCjr. Speech Attachment or the audio coming from the cassette.
Using the cassette port is may be a good method to record PC speaker music from a PC, but note that unlike the internal Speaker, the PC will generate a solid tone from the time it signals a system ready beep until software takes control of the PC Speaker.
One program that specifically supports the cassette port is Electronic Arts Music Construction Set. This program has a setting to output 1 note PC Speaker or 4 note (tweaked) PC Speaker music, and has an option to output it to the internal PC Speaker or the cassette port. 4-voice output may sound better through a powered speaker than the internal speaker, but the basic sound will be the same.
One issue with the PC and PCjr. is that both support being connected to the Mic or Aux input of a tape deck. The PC does so via a jumper on the system board near the PC Speaker header. The jumper block is a 2x2 block. If the jumper is placed across the pins closest to the M silkscreened on the board, then the audio will be sent at a level appropriate for a Mic Input. If the jumper is placed across the pins closest to the A silkscreened on the board, then the audio will be sent at a level appropriate for a Line Input. The PCjr sends both the Mic and Aux input lines to the C connector, but the official cable only uses the Aux line. Some modern cassette recorders only come with a Mic Input.
The 5-pin DIN connector used a TRS-80 cassette cable to connect to a tape recorder deck. The Radio Shack CCR-81 and 82 came with the cables and had both Mic and Aux input jacks. IBM never made a cable for the PC, and the only software it ever supplied was IBM PC Diagnostics and Advanced Diagnostics. Otherwise, use of the cassette port was intended solely for users of Cassette BASIC. Cassette BASIC, built into the system, used its save and load commands to access the cassette drive. In this IBM followed other 8-bit microcomputers of the day, as Cassette storage was the cheapest form of storage available for home computing.
When IBM released the XT, it removed the cassette port circuitry but kept Cassette BASIC in ROM for compatibility with Disk BASIC, Advanced BASIC (BASICA) and programs which relied on any of the three. You could no longer save or load a program in Cassette BASIC. However, IBM also used the same cassette interface logic for the PCjr. This time, IBM released a cable to connect to the unique cassette port on the PCjr.
The IBM PC and PCjr. communicate with the cassette deck via Int 15. At the low level, the audio coming from the deck to the system is digitized and read serially on bit 4 of the 8255 Port C. Audio generated from the system to the deck is generated by 8253 Timer 2, which also controls the PC Speaker and then sent to the cassette. The motor is controlled by bit 3 (and bit 4 in the PCjr) of the 8255 Port B. The BIOS routine writes a 1 bit is with a tone of 1 millisecond (1000Hz), and a 0 bit with a tone of 0.5 millisecond (2000Hz).
To signal the beginning of a program to BASIC, there will be a "leader" of 256 bytes where all the bits are 1, followed by a 0-bit and then ASCII Hex 16. Then a 256-byte data block will be written, followed by a 2-byte Cyclic Redundancy Check, and then more data + CRC blocks until the whole program has been written. The maximum size that can be written is probably close to 64K, since that is the absolute maximum size of a BASIC program on the PC.
Typing SAVE"[program name] will save a BASIC program to the cassette. Typing LOAD"[program name] in Cassette BASIC will instruct BASIC to start the cassette and search for the file. It is up to the user to remember where the program is located. If the system cannot "hear" a program, it will eventually quit trying and give the "Device Timeout" error message. If there is some kind of problem with what it is trying to load, it will say "Device I/O Error." You should keep the volume as high as possible when recording and playing back.
By using the cassette cable, you can record the output of the IBM PC's Speaker without any other adapter hardware. You can of course plug the other end of the cable into a PC instead of a recording deck. It is better to use the audio jack of the PCjr. to record sounds from it, as that jack can record from the PC Speaker, the 3-voice sound chip, the PCjr. Speech Attachment or the audio coming from the cassette.
Using the cassette port is may be a good method to record PC speaker music from a PC, but note that unlike the internal Speaker, the PC will generate a solid tone from the time it signals a system ready beep until software takes control of the PC Speaker.
One program that specifically supports the cassette port is Electronic Arts Music Construction Set. This program has a setting to output 1 note PC Speaker or 4 note (tweaked) PC Speaker music, and has an option to output it to the internal PC Speaker or the cassette port. 4-voice output may sound better through a powered speaker than the internal speaker, but the basic sound will be the same.
One issue with the PC and PCjr. is that both support being connected to the Mic or Aux input of a tape deck. The PC does so via a jumper on the system board near the PC Speaker header. The jumper block is a 2x2 block. If the jumper is placed across the pins closest to the M silkscreened on the board, then the audio will be sent at a level appropriate for a Mic Input. If the jumper is placed across the pins closest to the A silkscreened on the board, then the audio will be sent at a level appropriate for a Line Input. The PCjr sends both the Mic and Aux input lines to the C connector, but the official cable only uses the Aux line. Some modern cassette recorders only come with a Mic Input.
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