knudsen@ihwpt.ATT.COM (mike knudsen) (09/10/87)
I got my Sardis "no-halt" disk controller by UPS yesterday,
and it is Dead On Arrival. Maybe the controller portion works,
but I can't tell since the Coco can't even read the DOS ROM in it.
That's right, I tried to save $15 by ordering it without the stock
Tandy RSDOS 1.1 ROM (I have several of these, with 6ms step rate
patches).
Anyway, some ROMs at least let the Coco power up in Extended Basic.
Others keep it from coming up at all -- screen stays blank,
and cassette relay clicks after a few seconds.
I've tried both with MultiPak and direct into Coco, no difference.
I buzzed out the socket and it is powered and grounded only for
28-pin ROMs, which I have tried using. Pin 22 (Output Enable)
goes straight to the SCS- port lead, but pin 20 (or is it 18)
(Chip Select) is wired to the controller's logic somehow.
My only hope is the seven or so jumper areas surrounding the ROM
socket. There are no wires or jumpers installed.
Those of you with working controllers, could you please look
inside and tell me how big the ROM chip is, is it Tandy's stock
item (hard to be if 28 pins?), and are there any jumpers
installed?
Also mine has a test lead or some such thing soldered
to pin 11 (direction control) of a '245 chip.
Do you have that? What's it for? Thanks in advance....
OTHER COMMENTS
The board is very well made, with sockets for WD controller chip,
the 8Kx8 RAM, a 20-pin PAL, and the !@#$%^&* DOS ROM.
Metal case, gold contacts, easy to take apart and reassemble.
The software diskette includes a NEAT utility for re-configuring
boots. You tell it which modules to leave out and which new ones to
put in, and it writes a new bootfile.
Also included are Kevin Darling's DMOD utility and such SDISK
standbys as DESCGEN. You need these to convert your /d0, /d1,
etc. so they point to SDISK3 instead of CC3DISK (hmmm, should be
able to zap the strings in place...).
Another utility lets you change time delays for the disk motors
on and off, head settling, etc.
The installation process also has to zap the OS9 Kernel in a few
places -- sounds a little scary, will need to be updated for
future versions of Level 2.
Future software upgrades are promised, including
allowing other procs to share timeslices during disk accesses--
currently only keyboard and clock interrupts keep running.
Meanwhile, rumor on Delphi has it that Radio Shack may start
taking special orders for the competing DISTO unit.
But probably not without an RSDOS ROM....!
--
Mike J Knudsen ...ihnp4!ihwpt!knudsen Bell Labs(AT&T)
Delphi: RAGTIMER CIS: <memory failure, too many digits>
"Just say NO to MS-DOS!"knudsen@ihwpt.ATT.COM (mike knudsen) (09/11/87)
Last nite I figured out the problem with my Sardis controller ROM.
Using my ohm-beeper and some ROM mfgr's catalogs, I realized
that a 24-pin ROM should work if *right-justified* in the 28-pin socket,
just as shown in Sardis' ad photos (squint real close).
Tried a 24-pin EPROM RSDOS 1.1 with 6ms step rate, and it worked just
fine thru an evening of OS9 Level 2 (on the old driver software).
Mail from chinet!draco sez I should've got a hardware manual with
the beast, but all I got was the software docs (which are pretty
good). Also mad at self for forgetting the right-justify trick,
since six years ago I designed and debugged boards that could
use either size ROM. What threw me off was the two power pins,
tho that should have clued me in, but....this is what I deserve
for being over 40 I guess. Sorry for the bother.
BTW, draco (Kent), what else does that hardware manual have?
Addresses and bits for control registers? Schematic ;-) ?
--
Mike J Knudsen ...ihnp4!ihwpt!knudsen Bell Labs(AT&T)
Delphi: RAGTIMER CIS: <memory failure, too many digits>
"Just say NO to MS-DOS!"