> Date: Wed, 14 Nov 2007 16:34:45 -0900
> From: Grant Stockly <grant at stockly.com>
> At 03:17 PM 11/14/2007, you wrote:
>> > The LAG is labeled "HAL16R8CN 8440 / 342-0251-A" so it does look like
>> a
>> > custom ("HAL") chip such as what Tony was mentioning. Guess that
>> would
>>I will try to find all my notes on the Mac+ (but not tonight!). I know I
>>never figured out the PAL equations, but I might have something of use.
>
> There are equations for the PALs on my website:
> http://www.stockly.com/forums/showthread.php?t=6
Wow, Grant, that's a really cool website. Where have you been hiding?
That is a very cool project. I keep my eyes open for other folks who
actually like to tinker with Mac hardware in a circuit board sense and
they are few and far between. Even the over-clocking enthusiasts try to
avoid soldering at every turn, for the most part.
Will you have to rewrite some of the firmware (ROM contents) in order to
change the timing of your project and gain the extra speed? Also, have
you looked at the Brainstorm accelerator at all--the one which simply
added a 16 MHz CPU on top of the original? It had a replacement BUG I
think and a small amount of firmware.
Jeff Walther
>
>Subject: Re: S100 Floppy Controller Question
> From: M H Stein <dm561 at torfree.net>
> Date: Thu, 15 Nov 2007 04:21:34 -0500
> To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org>
>
>---------Original Messages:
>Date: Tue, 13 Nov 2007 07:48:21 -0500
>From: Allison <ajp166 at bellatlantic.net>
>Subject: Re: S100 Floppy Controller Question
>>
>>Subject: Re: S100 Floppy Controller Question
>> From: M H Stein <dm561 at torfree.net>
>> Date: Tue, 13 Nov 2007 01:13:48 -0500
>> To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org>
>
><snip>
>>
>>I think you might have misunderstood, Allison; sounds like you thought I was
>>talking about replacing an FDC with one other than what the BIOS is configured
>>for; obviously that will require mods to the BIOS.
>
>Ok, then same fdc but sufficiently differnt drive requires new (modified) bios.
>
>Changes that affect a bios:
>
> Motor on/motor runs continiously.
>
> Step rate, head load delay, motor on delay
>
> Different on disk format (likely with 8 to 5")
>
>
>>What I was responding to was a previous post that suggested replacing an 8"
>>drive with a 5 1/4" HD drive might require mods to the BIOS, and I just wanted
>>to mention that this is not the case with a Cromemco 16/64FDC, to which a
>>TM848 and a JU475 appear identical as long as the jumpers on the 5 1/4 drive
>>are set correctly and it supplies /READY, and that this may also apply to some
>>other controllers. Also, if the controller has both 8" and 5 1/4 connectors and
>>they are effectively in parallel as they are on the Cromemco, you may not
>>even need a 50<>34 pin adapter cable.
>
>if the drive supplies ready _MAYBE_. If the Drive has the same step rate.
>
>-------------Reply:
>
>Well, I should know better than to argue (again ;-) with you of all people, but...
>
>Since we're talking about 'modern' 5 1/4" HD drives, Motor on and Ready
>are jumper selectable on all the drives I've run across, step rates etc. are
>faster than the 8" equivalent (except perhaps the PerScis), and with the
>same speed and data rate the disk formats are identical, no?
the drive used are a factor and many of the later designed systems
had what could be described as an adaptive, they have a bios written
to accomodate a wider variety of drives.
>In any case I'm only specifically talking about my Cromemco system and it
>seems to work fine for me. It gives me 1.1 MB on a 5 1/4HD diskette instead
>of 360KB and lets me deal with both 5 1/4 and 8" images conveniently in a
>single 5 1/4" FH bay box, without the complication of the 24V supply, 50 pin
>cable, unreliable old 8" drives etc. To initially read & convert my 8" disks I just
>temporarily plugged an external drive w/PS into the unused 50 pin connector.
>I haven't tried it yet, but it should also make recreating an 8" image on a PC
>easier, and it puts some 5 1/4HD drives & disks to a good use, which otherwise
>would end up on the shelf or in the trash since I don't use them on PCs.
Cromemco is one such example and much later than Altair/Tarbell.
>After installing the drive I happened to run across some old posts in the archives
>dealing with this very topic (on a Cromemco); apparently it was easy and worked
>fine for some and not for others. I just wanted to add my name to the former
>group in case it had relevance to someone else with a Cromemco FDC or
>_perhaps_ even with a different make of controller if it's similar, and especially
>mention to one of the original posters that it might not be necessary to kludge up a
>50<>34 pin adapter cable (which he was reluctant to make) if the two interfaces
>on his FDC are handled the same way as on the Cromemco FDC.
Same was the case for AmproLB, SB180, and Compupro. Generally most fo the
floppies are close to "setup, plug and play". However really old drives
for example SA800, SA400 it's fairly easy to get the signals right but things
like 40ms step rate (sa400) and 12ms step rate(sa800) have to be driven
by software. After about 1981/82 design had fewer problems and 5.25 floppies
started to look more alike than different electronically.
The gotchas still lurk out there.
Allison
>mike
> I had that a work once it was dust in the drives scaring the disks
> after one or two uses.
>
> Reaaon, PC suck air out of the box, where does it come in? Any ways it
> can and through the floppy was one path.
True enough. Actually, the first NeXT Cubes had their MO drives fail regularly due to the fan sucking dust in through the drive slot(s). When bringing the machine in for repair, the fan would be reversed to alleviate the problem. Later Cubes were manufactured with the fan blowing in as standard.
,xtG
tsooJ
---------Original Messages:
Date: Tue, 13 Nov 2007 07:48:21 -0500
From: Allison <ajp166 at bellatlantic.net>
Subject: Re: S100 Floppy Controller Question
>
>Subject: Re: S100 Floppy Controller Question
> From: M H Stein <dm561 at torfree.net>
> Date: Tue, 13 Nov 2007 01:13:48 -0500
> To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org>
<snip>
>
>I think you might have misunderstood, Allison; sounds like you thought I was
>talking about replacing an FDC with one other than what the BIOS is configured
>for; obviously that will require mods to the BIOS.
Ok, then same fdc but sufficiently differnt drive requires new (modified) bios.
Changes that affect a bios:
Motor on/motor runs continiously.
Step rate, head load delay, motor on delay
Different on disk format (likely with 8 to 5")
>What I was responding to was a previous post that suggested replacing an 8"
>drive with a 5 1/4" HD drive might require mods to the BIOS, and I just wanted
>to mention that this is not the case with a Cromemco 16/64FDC, to which a
>TM848 and a JU475 appear identical as long as the jumpers on the 5 1/4 drive
>are set correctly and it supplies /READY, and that this may also apply to some
>other controllers. Also, if the controller has both 8" and 5 1/4 connectors and
>they are effectively in parallel as they are on the Cromemco, you may not
>even need a 50<>34 pin adapter cable.
if the drive supplies ready _MAYBE_. If the Drive has the same step rate.
-------------Reply:
Well, I should know better than to argue (again ;-) with you of all people, but...
Since we're talking about 'modern' 5 1/4" HD drives, Motor on and Ready
are jumper selectable on all the drives I've run across, step rates etc. are
faster than the 8" equivalent (except perhaps the PerScis), and with the
same speed and data rate the disk formats are identical, no?
In any case I'm only specifically talking about my Cromemco system and it
seems to work fine for me. It gives me 1.1 MB on a 5 1/4HD diskette instead
of 360KB and lets me deal with both 5 1/4 and 8" images conveniently in a
single 5 1/4" FH bay box, without the complication of the 24V supply, 50 pin
cable, unreliable old 8" drives etc. To initially read & convert my 8" disks I just
temporarily plugged an external drive w/PS into the unused 50 pin connector.
I haven't tried it yet, but it should also make recreating an 8" image on a PC
easier, and it puts some 5 1/4HD drives & disks to a good use, which otherwise
would end up on the shelf or in the trash since I don't use them on PCs.
After installing the drive I happened to run across some old posts in the archives
dealing with this very topic (on a Cromemco); apparently it was easy and worked
fine for some and not for others. I just wanted to add my name to the former
group in case it had relevance to someone else with a Cromemco FDC or
_perhaps_ even with a different make of controller if it's similar, and especially
mention to one of the original posters that it might not be necessary to kludge up a
50<>34 pin adapter cable (which he was reluctant to make) if the two interfaces
on his FDC are handled the same way as on the Cromemco FDC.
mike
So I like early speech synthesis. I like DEC stuff. I've got a
couple forms of the DECTalk boxes (the portable, the ISA card.) I'd
like the DTC-01 unit, the one that sort of looks like a VX2000
terminal. They come up on ebay every other week or so and end up
selling for well over $100.
Who's buying these things? Are they popular with collectors? Or are
they still being used in the disability care industry?
>
>Subject: Re: Tarbell is making me insane
> From: Gordon JC Pearce <gordonjcp at gjcp.net>
> Date: Wed, 14 Nov 2007 08:26:55 +0000
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>
>On Tue, 2007-11-13 at 20:28 -0500, Allison wrote:
>
>> I use a stack (about 200) of written once disks, they have sales
>> promo and utility on them and never distributed. Good media
>> and easily erased.
>
>I bought a box of 500 DSDD floppies from a guy on eBay. They appear to
>be new. They seem to be pretty good quality too - the cases are a bit
>naff and plasticky but they actually work.
>
>I still don't understand how brand new 1.44M floppies fail after two or
>three uses, but the 20-year-old SSDD disks for my Ensoniq Mirage are
>still perfectly readable.
>
>Gordon
I had that a work once it was dust in the drives scaring the disks
after one or two uses.
Reaaon, PC suck air out of the box, where does it come in? Any ways it
can and through the floppy was one path.
Allison
Hello listmembers,
some days ago I stumbled across the remains of a parted-out Power Macintosh 9500 that I have no use for.
There are:
-3,5" floppy drive (Mitsubishi MF355F-2592MA)
-grey plastic mounting sled and 20-conductor ribbon cable for the above
-mainboard (P/N: 820-0563-B), bare (no DIMMs, no CPU, heck not even PRAM battery (but with power LED)).
Chances are I might go back and snatch case parts incase anybody wants me to; what I remember for sure is that there were no fans left and the back panel was missing too.
I couldn't test anything so it's assumed dead and offered for pickup or S&H (inside Europe only). I'm in Germany btw, and I could bring it to the VCFe in Munich next April.
Yours sincerely,
--
Arno Kletzander
Stud. Hilfskraft Informatik Sammlung Erlangen
www.iser.uni-erlangen.de
Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen!
Ideal f?r Modem und ISDN: http://www.gmx.net/de/go/smartsurfer
In among a whole bunch of audio tapes are these three "Teac CT-500H High
Density Magnetic Tape Cassette"s...
Instead of the usual tab that you can break out to prevent recording there's a
small red bit in one of the holes, which the bit of paper in there refers to
as a "write enable plug".
Two of the three are still sealed in their original plastic. I don't think
even the third one is used at all.
Feel free to contact me offlist if you have any use for these...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
The other day I picked up a Macintosh 512k with a broken monitor for $5
thinking that it'd be a fun project to hack on (yes, another thing to
add to my pile of things to hack on, just what I need :)).
The power/sweep board had a couple of obviously dead capacitors and a
few cracked solder joints, which I fixed up and lo and behold, the
screen came back to life and I did a little dance. There was still a
bit of jitter in the picture from time to time, and jiggling one of the
connectors revealed another dry joint so I powered it down and prepared
to fix the other joint. First point of business, I discharged the CRT.
To the main chassis. This, as I have now discovered, is not what you
are supposed to do to discharge the CRT unless you want to destroy the
logic board.
I now have a working monitor but a fried logic board; on powerup, the
normally short boot tone is long and drawn out, as if the machine were
running at a tiny fraction of its normal speed. Which I suppose is
actually what's going on. So I killed _something_ on the main PCB, but
I'm not sure what. Anyone out there experienced this failure mode? Any
obvious things to check?
Well, live and learn. At least it wasn't a 128K mac :).
Thanks,
Josh
I just won a TI 9980/180M evaluation board on eBay. I
was contacted by a losing bidder who apparently is in
need of a 9980 processor chip. Does anyone have one
for sale, or know an economical source for a single
unit?
--Bill
