I thought I'd try to fiddle with the Apple /// and see how it does its silentype. Man, the Apple /// is really an alien experience to someone who has only known DOS 3.3 and Applesoft.
There's a disk image of Apple3_Diskware_SilentypeIIIDriver_681-0009-a.dsk which has a basic demo program.
Doing a directory of floppy 2 you have to type "CAT .D2" or once you know the disk name is SITYPE, you can type "CAT /SITYPE".
Then to set the prefix, use the business basic prompt to
PREFIX$ = "/SITYPE/"
(CTRL+numpad 7 will pause/unpause listing) (good old CTRL+S and Q doesn't work)
at which point it freezes.
Business basic is sure different, with all of these commands like INVOKE and PERFORM which will load assembly language modules and execute routines in the modules.
I'm guessing the actual silentype driver is in BIG.DRIVER and SMALL.DRIVER.
Somewhere there exists a Silentype Manual for the Silentype ///. (I could only find a picture of it on worthpoint)
I was trying to experiment with the graphic commands from the basic command line with
and it would give ?SOS call error
would cause it to freeze up.
Trying the silentype demo program with only the OPEN #1,".silentype" gives a file not found error, so maybe the driver isn't there?
edit: ok, I was able to get some graphics operations working with Apple3BusBasic1.23.dsk
so how do you do a mixed text/graphics mode? It seems you have to switch back and forth with PERFORM grafixon and TEXT.