<As far as OS/278 and WPS goes, the video/keyboard is the console. The
<console is run via a combination of hardware and slushware; the slushware
<provides terminal emulation services and the hardware provides the hooks
Slushware is the embedded system tracks that do terminal and keyboard work.
<needed by the terminal emulation services to appear as a normal console
<type serial device to OS/278 and WPS (which expect to talk directly to
<the console UART rather than via some sort of device driver).
If you were to reassemble os/278 it's possible to redirect it to a serial
port. Not a trivial task for a PDP-8 novice. It is doable as the sources
are on the net.
<If you are sufficiently technically equipped and inclined, it should be
<possible to switch the console port (on which the emulator runs) and
<the 9-pin serial port for the printer. The first thing done by the
<firmware (before it checksums the ROM and loads the slushware) is to
<program the I/O addresses of the various hardware ports. It is possible
<to switch a few instructions in the initialization sequence to swap the
<addresses of the printer and console ports. Although I've _thought_ about
<doing this and investigated far enough to determine that it ought to work,
<I've not actually _tried_ it, so I could be wrong.
No good. The control software is very port specific.
<There are a number of fun bits involved. The PDP-8 is a 12-bit machine.
<The ROMs are 8-bit parts (2716s). There are three ROMs, providing a
<4Kx12 memory image for the PDP-8. The ROMs are interleaved in a funny
<way; I figured it out once and Lasner was able to use the information to
<extract a ROM image and disassemble it, but that was a few years ago. I'd
<have to figure it out again.
I think I have that on line. The slushware is where all the interesting
stuff is.
Allison
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