4 Apr
2003
4 Apr
'03
8:16 a.m.
--- "Dr. Charles E. Morris" <c.morris(a)townsqr.com> wrote:
My "DF32x4" disk emulator is alive and
talking to my 8/L and appears to
be reading and writing blocks of data correctly.
Public congratulations!
---
My "DF32x4" disk emulator is alive and
talking to my 8/L and appears to
be
reading and writing blocks of data correctly. There are a few
instructions
that I did not implement (e.g. the "Maintenance" IOT's 6631-4 which the
manual says are only used in "diagnostic programming". - it
would
have taken quite a bit more logic to implement and there was no more room
on
the PC board; additionally the DEAL instruction would be used anyway,
which
combines the clear action with a load of these registers from the AC - so
the clear would be superfluous. The DEAL and DEAC load/read register
commands are, of course, implemented).
---
There are a few instructions that I did not
implement...
... the DCEA instruction does not clear the extended address and EA
registers... Ethan Dicks has pointed out that I should look at the
drivers in OS8 and TSS8 to see if this will be a compatibility problem.
Sorry I didn't get back you earlier, but over on David Gesswein's
searchable software archive...
RTS/8 DF-32 driver (probably will never matter, but good background info)
http://www.pdp8.net/pdp8cgi/os8_html/RF08.PA?act=file;fn=images/misc_dectap…
A code snippet from
http://www.pdp8.net/pdp8cgi/os8_html/DX.12?act=file;fn=linctape-images/os8l…
/ THE ROUTINE LINCDO CLEARS DF32 FLAGS TO ALLOW
/ A LINC DATA BREAK. IF A DIFFERENT DATA BREAK
/ DEVICE IS IN USE THE APPROPRIATE MODIFICATIONS
/ SHOULD BE MADE. (NOTE BY CLEARY)
LINCDO, 0 /EXECUTE A LINC PROGRAM
DCMA /CLEAR ANY DATA BREAK FLAGS
DCEA /THESE ARE FOR DF32
TAD (LINPRO)
ISSP /SET UP LINC PC
CLA
TAD (10)
ICON /SELECT LINC
TAD (2)
ICON /START LINC
NOP
TAD (-1)
ICON /DESELECT LINC
CLA
JMP I LINCDO
... shows the use of DMCA and DCEA to clear a disk, rather than DEAL.
Not exactly what you were looking for, but perhaps someone else has the
sources at their fingertips (I'm behind a restrictive firewall at the
moment, so my searching is somewhat limited).
As I mentioned earlier, I've only done some basic DF32 twiddling
from a PDP-8/i to prove that the interface mostly
worked (and to
diagnose my repairs of a smoked rotation sensor board). I've
never
had the joy of an 8K machine + DF32s, so I've never had an OS to
explore them.
-ethan