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1) Depress RUN to run the bootstrap loader. If the loader was entered cor-
rectly, address lights A10-A9, and A4-A0 should be on.
2) Use the “File->Send File” menu option in the cassette TeraTerm window
to transmit the cassette tape image to the Altair. Browse to and select
the file “8K Basic Ver 4-0.tap” which is located in the “Paper Tape and
Cassette” folder inside the “BASIC” folder. Be sure the “binary” check-
box at the bottom of the send file dialog is checked.
3) Loading BASIC will only take about eight seconds at 9600 baud (instead
of about four minutes at 300 baud!). Once loaded, BASIC initializes and
prompts the user for memory size.
4) Turn on “Caps Lock” on the keyboard.
5) In response to the “MEMORY SIZE” prompt, press RETURN to let BASIC de-
termine the amount of RAM present.
6) In response to the “TERMINAL WIDTH” prompt, press RETURN.
7) In response to the “WANT SIN?” prompt, key in “Y” and press return.
At this point, 8K BASIC is up and running! You can type an immediate command
like “PRINT 2+2” and press RETURN. BASIC will display the answer, 4. You can
also type in a program and run it. Note that in these early versions of BA-
SIC, the underscore character “_” is used as the delete key. The underscore
does not cause a visible delete or backspace. The underscore character is
echoed, but it’s up to you to figure out how many characters you have deleted
as you type underscores. Here is a simple program you can key in and “RUN”:
10 FOR I=1 TO 20
20 PRINT “LOOP”;I
30 NEXT I
Loading a BASIC Program from Cassette Tape
In 8K BASIC, the “CLOAD” and “CSAVE” commands can be used to load and save
programs from cassette. The CSAVE command writes an image of the program as
it exists in RAM to the tape. Since the program in RAM is already pre-
processed and encoded to run, this format loads and saves more quickly than a
printable listing of the program. However, this means the CLOAD command can-
not be used to load a program in printable (ASCII) format – only programs
previously saved with a CSAVE command. Also, since “Extended BASIC” encodes
programs differently in memory than 8K BASIC, files saved to cassette are not
compatible between these two versions of BASIC.
The file “BASIC\BASIC Programs\8K BASIC\cassetteDemo.tap" is an image of a
cassette tape created by saving programs from 8K BASIC using the CSAVE com-
mand. The tape contains two BASIC games, hangman and lunar lander.
To load the hangman program type: CLOAD "H"
or...
To load the lunar lander program type: CLOAD "L"
After typing the desired load command and pressing return, use the “File-
>Send File" menu option in the cassette TeraTerm window to send the file
"cassetteDemo.tap" to the Altair. BASIC scans the data coming in from the
cassette looking for the one character file name specified in the CLOAD com-
mand ("H" or "L"), then loads that program.
You’ll find that even at 9600 baud, the CLOAD command can keep up without re-
quiring transmit delays in the file transfer. Since the program was saved to
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