@ -16,12 +16,12 @@ fill.asm used to complete the track 0 build (see below)
Notes:
This adatation runs on a single RomWBW W HBIOS hard disk type device (CF
Cart , SD Card, IDE drive, etc.). The image built (psys.img) should be
copied to your disk media start at the first sector. You can then boot
by selecting the corresponding disk device unit number from the RomWBW
boot loader prompt. The p-System disk image (psys.img) is entirely
different from the RomWBW CP/M-style disk images.
This adap tation runs on a single RomWBW HBIOS hard disk type device (CF
Card , SD Card, IDE drive, etc.). The image built (psys.img) should be
copied to your disk media starting at the first sector. You can then
boot by selecting the corresponding disk device unit number from the
RomWBW boot loader prompt. The p-System disk image (psys.img) is
entirely different from the RomWBW CP/M-style disk images.
The boot device hard disk is broken up into 6 logical p-System
volumes. These are referred to as p-System slices. A single RomWBW
@ -91,4 +91,51 @@ There is currently no support for floppy drives.
Wayne Warthen
wwarthen@gmail.com
5:42 PM Sunday, January 15, 2023
5:42 PM Sunday, January 15, 2023
So, it turns out that the serial line support in p-System is seriously
deficient. It insists on polling all of the serial input devices
(console, remote, and printer) when the sytem is idle with the idea
that it will queue up any characters received. I guess the idea is
that this will help in scenarios where characters are coming in too
fast to be processed. However, the basic/default interpreter does not
support the queues! Strangely, it still polls the the devices and
literally discards anything received. This completely undermines the
ability of the underlying hardware which is doing it's own robust
interrupt or hardware based buffering and flow control.
I have relinked the interpreter (SYSTEM.INTERP) so that it now uses
the BIOS version that supports the queues (BIOS.CRP). This mostly
resolves the situation, but needlessly increases the size of the
interpreter. Additionally, I believe that if the p-System queue gets
full, it will still poll and discard any new characters received. I
have not seen any documentation indicating the size of the queues.
Seriously, what were they thinking.
One last thing in case anyone actually reads this. As indicated
above, this is an adaptation of p-System IV.0. It is well documented
that SofTech produced a IV.1 with some nice enhancements (like
subsidiary volumes and decent support for ANSI/VT-100 terminals). I
have been unable to track down the IV.1 distribution media despite
trying very hard. If anyone knows of a source for the media of the
Adapable p-System for Z80, I would love to get hold of it.
3:58 PM Tuesday, January 17, 2023
I forgot to discuss the terminal handling.
The p-System has a setup program (SETUP.CODE) that is used to define
terminal handling escape sequences. However, it is limited to a
single character to introduce the escape sequences. Since ANSI
and VT-100 escape sequences start with 2 characters, this is
problematic. The BIOS for RomWBW borrows a hack used by Udo Monk.
Specifically, whenever an outbound <esc> is seen, a '[' is added
in flight.
Likewise, it is problematic to define a way to interpret the
arrow keys transmitted by an ANSI/VT-100 terminal. In this case,
the setup program was used to define up/down/left/right like
WordStar does: ^E,^X,^S,^D.
5:48 PM Tuesday, January 17, 2023
Wayne Warthen
3 years ago