>drive work. I'm interested in the ones too small to bring even $10 at the
>flea market, i.e. the ones that are 10x what I need but only cost $6 or so.
Ok that ranges up to maybe 500mb now.
>It takes more than a latch, by the way, since you have to latch and hold
the
>low byte on writes, and the high byte on reads, in order not to screw up
the
>order of the bytes. Consequently, you need not only the two latches, but a
>bit of logic to effect the byte steering on reads and to perform the write
>after the CPU does the write, since the only time you can guarantee data
>valid is at the very end of the write strobe.
Limited logic, one latch. No rule said only one address for the data read
or write.
>The reason I'm whoring after the few drives with this feature included is
>that when this feature was available, if at all, the popular drives were of
>about the "right" capacity for the typical application of CP/M.
Of course when the IMSAI and Altair were around that would be casette tape,
8" floppy (SSSD 256k) or maybe minifloppy (80k).
Better find two as likely they will be so old that any reliability has been
run
out of them.
The nice part of a real 16bit interface is if it fails any drive make a good
replacement even if I dont choose to use all of it. that and despite the
claim that 8080 and cpm was slow they do run better with fast drives and
ramdisks proved that. So a fast drive (13-15ms or so, 4500rpm) with a
cache of say 32-256k does indeed improve perfomance.
Since IDE has been done for CPM (several articles in TCJ) and SCSI
even longer the idea of the right size is really a red herring to me. In the
CPM world the right size was literally whatever you had or could get
you hands on, the bigger the better. Even the deblocking example
in the CP/M-2.0 alteration guide they talk about how taking advantage
of it enabled a 35mb drive to be formatted using larger sectors to 57mb
with better perfomance. that was written in 1981. The concept was the
abiltiy to interface to almost any storage hardware via an extensable BIOS.
My current project is to take CP/M V2.2 and capitalize on P2DOS (suprbdos,
novados, Zrdos etal) clones and add a heirarchal directory to get past the
former flat structure (user areas helped only a little) and stay compatable
with apps that ran under V2.2. After all I want is better and not obsolete
perfectly good software.
Allison
----- Original Message -----
From: <sms(a)antinode.org>
To: <SIPKE(a)wxs.nl>
Sent: Saturday, April 08, 2000 6:27 PM
Subject: no chars on uVAX console
> Is that the speed selected by the rotary switch on the console
> bulkhead?
Yep
I've removed all boards save the memory boards (2*M7609)
and the CPU (M7606-AA)
Now I get characters (XON/OFF = on) and the bootprocess continues
until char 3
I've tried to put some of the boards back but I am not sure if I have a
missing
board.
Het boards were arranged as follows
slot 1 ----------------M 7606------------------
slot 2 ----------------M 7609------------------
slot 3 ----------------M 7609------------------
slot 4 -----M7516-------- (empty)
slot 5 -----M7555-------- ------M7546------
slot 6 (empty) ---Dilog sq703a---
The uVAX used to contain a Serial concentrator or something
like it but that was removed, propably from one of the
empty slot positions.
I've gathered that the first 4 slots are different from the rest of
the BA123, those beeing true Qbus 22 slots.
Should I rearrange the boards ? If so what do you suggest?
Sipke de Wal
-----Original Message-----
From: Peter Pachla <peter.pachla(a)wintermute.org.uk>
To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org>
Date: Monday, April 17, 2000 5:09 PM
Subject: Re: CPU upgrades, pt. II
>Hi,
>
> > Heres a PS2/50z question.
> >
> > Mine only has 1meg, looks like 72pin simm but none I have seem
> >work. All of them happen to be 8x32 (16chip).
>
>I don't really know too much about PS/2s yet, I'm only just starting to
>investigate these machines (I've got 3 - a Model 50, a Model 80 and a
Model
>95).
Ah, the model 95! The Ardent Tool of Capitalism itself! Makes a lovely file
server when running OS/2 or an old copy of NT 3.5. The machine is
indestructible, there's more than enough power and room for 3 or 4 modern
SCSI drives, and plenty of slots for a LANstreamer or two. If you don't
already have them, I'd suggest upgrading to a Type 4 (Pentium 60 or 66)
complex, and an IBM Fast/Wide SCSI controller. Alternatively, many of the
older complexes can take Evergreen or other upgrade CPUs, with the suitable
interposer.
The only downside of PS/2s these days is that 100 Meg Ethernet cards for
MCA are very hard to find.
You'll grow to love that Model 95 - I plan to have mine used as my
headstone when the time comes : v )
Cheers,
Mark
Does anyone have information on light bulbs for DEC front panels
circa 1968, in particular from a KA10 panel?
The bulbs in question have two metal pins. Some bear the legend
"OL-1", and others have two rows of info, "PL10161" on above "1209169".
There's temporarily a photo of one, next to a US penny for scale, at
http://www.36bit.org/dec/bulb.jpg
Would these be the same bulbs used on the PDP-8, PDP-8/I, or PDP-8/e?
I'd like to get a manufacturer and part number of a currently available
replacement. Or a source of old stock.
I've been told that there were also plug-compatible LED lamps in red and
green. These obviously must have contained a series current limiting
resistor. Any info?
Thanks!
Eric
>Does anyone have information on light bulbs for DEC front panels
>circa 1968, in particular from a KA10 panel?
>I've been told that there were also plug-compatible LED lamps in red and
>green. These obviously must have contained a series current limiting
>resistor. Any info?
If they're anything like the -8 front panels, there is also a "warming"
current through the bulb. The aftermarket LED "upgrades" either had you
snip the resistors that kept the prelight current flowing on the front
panel drivers, or (more classy) they had
divider networks in addition to current limiting to make sure the warming
current didn't appreciably light the LED.
It was about three years ago I posted an analysis of the divider method
to alt.sys.pdp8. I'd be glad to dredge up those calculations here if there
is any interest. The divider method is a little more complicated to
solder up, but it's easier to go back to real light bulbs if/when you decide
to go back to the "completely original" look.
Tim.
From: Richard Erlacher <edick(a)idcomm.com>
>I've never seen a CompuPro ANYTHING I liked. However, there's no
>accounting for taste.
Well the basic box with terminated mother board cant have ben that bad
since it was widely copied.
>You mustn't forget, BTW, that I'm not a collector, except in the sense that
>I haven't thrown some things away because I remember what they cost me.
I never said I was. Some of my sysstems are working systems because I
bought them 20+ years ago to do exactly that, work. Improving them is
reasonable in that context. The reast are collected because I wanted one
back when and could never afford it. Now I get to play with it.
>Of course, I have a real bunch of Multibus-1 stuff because it was always up
>to the mark.
I have MB1 and MBII systems as well plus boards made by my former (four
lifetimes ago) for MB as well. Nice stuff, big, sophisticated often very
fast
or very slow.
Allison
> "Has anyone got sufficient experience with the IDE in non-PC-compatible
>applications to say, unequivocally, whether the 8-bit operating mode
>described in section 6 of the standard for the ATA (IDE) interface, yes
>SPELLED OUT, actually exists in drives of the pre-1996 vintage?" It was
>dropped from the standard in 1996. There seem to be many folks with
>suggestions about how to implement this extremely elementary interface.
>There seem to be few who know whether the standard was every full
>implemented.
Why would they include that? NONE of the PC hardware they were intended
for wants to run as 8bit bus. Even the crippled SL/SLC run as 16bit busses.
>Allison seems to be the only one who's tried this, and, I fear, it may be
in
>a PC-compatible, where all bets are off as to what really happens.
Obviously visually impaired! I don't hack IO in PCs nor have I tried that
yet.
I may add why even bother, IDE works there as is.
ALL of the IDE work I've done was with 8085, z80s either stand alone
(bus less) or S100 Z80s. Further I'm currently working on a Z280 system
with IDE (Zbus 16bit). This is where I need interfaces and so I can replace
older MFM or non-existent hard disks. I currently have one S100 system
running a connor3044A (40mb) IDE that will be upgraded to a ST3250
(250mb) as it's a better drive.
The drives I've tried include:
Connor 2022
Connor 3044
WD2120
WD2420
St3096A
St3144A
St3250A
St3660
Fijitsu 528mb
Quantum LPS 80 and 120
Maxtor 124mb
and afew other sub 60mb WD, NEC, Seagate drives.
I now have two 2.5mb IDE in the 700-800mb region I may try one day.
I do have two WD PS/2m30 compatable 8bit IDE 20meg drives.
I think this is a good cross section
Allison
>
>Dick
>
>----- Original Message -----
>From: Mike Ford <mikeford(a)socal.rr.com>
>To: <classiccmp(a)classiccmp.org>
>Sent: Monday, April 17, 2000 7:22 PM
>Subject: Re: 8-bit IDE
>
>
>> I don't know a hoot about this, but I wonder if taking a look at the
>> Sequential Systems Focus card for the Apple II might be instuctive. Its a
>> controller and notebook IDE drive that all fits on a Apple II slot card.
>>
>>
>
Recently, as part of my effort on an S-100 "hard-card" using a 2-1/2 inch ide drive, I've been revisiting the 1994 standard for the ATA interface. There's a not-too-detailed mention of an 8-bit mode which is set up using a bit in register. This feature was apparently obsoleted as of 1996's standard.
Have any of you folks had contact with this feature as part of one or more of the standards? I know the original version of IDE as implemented on Compaq drives was 8-bits wide. However, once the ATA approach to HD interfacing became popular the 16-bit version won out.
Has anyone on this list dealt directly (not through the BIOS) with 8-bit IDE drives of 2-1/2" size? ... Any size at all?
Dick
--- "Merle K. Peirce" <at258(a)osfn.org> wrote:
>
> Actually, we got about 20 keyboards. It seems odd that the controller
> has a floppy drive. What was the purpose? Software upgrades?
Microcode, IIRC.
-ethan
=====
Even though my old e-mail address is no longer going to
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The original webpage address is still going away. The
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--- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote:
> Yes, but if you remove the entire head positioner (including the guide
> rails, etc) and put it back on _some_ drives you might have moved it
> sideways slightly. This will affect the index timing (since the relative
> position of head and index sensor have moved).
>
> Some drives have the guide rails fitting into V-grooves in the main
> casting, and those generally you can take apart and put back without
> problems.
I recently restored a Mac PowerBook 160 that was apparently dropped before
it made its way into my hands - the hard disk won't even spin up, several
of the screw mounts were sheared in the lower case and the floppy guide
rail had jumped its track entirely. The head was flopping around loose
inside the drive. It took a bit of fiddling, but I remounted the guide rail
and reassembled the drive - worked the first time. Now if only I had a
60-120Mb
2.5" SCSI drive to drop in this thing, I'd have a portable rig for dumping
my QuickTake 150 digital camera.
-ethan
=====
Even though my old e-mail address is no longer going to
vanish, please note my new public address: erd(a)iname.com
The original webpage address is still going away. The
permanent home is: http://penguincentral.com/
See http://ohio.voyager.net/ for details.
__________________________________________________
Do You Yahoo!?
Send online invitations with Yahoo! Invites.
http://invites.yahoo.com
