> -----Original Message-----
> From: Roger Merchberger [mailto:zmerch@30below.com]
> If you actually put sockets on the board and insert the fuses
> into that,
> you could simulate an EPROM/Flash[like] part. ;-) It'd take a while to
> "erase & re-write", but hey... ;-)
Exactly what I wanted to do. I thought about setting them flat against
a board and using the small (half-inch long) "glass tube" inline fuses.
If I can get those to smoke the glass dramatically enough when they blow,
it would be easy to replace the blown parts with fresh fuses for a new
program. Not to mention that it may be fun to be able to re-arrange the
fuses ;)
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'
I've used a plextor plexwriter, toshiba 2x, some noname
($29.95 new!) scsi successfully. The cdrom,(hobbiest)
does however not boot on any of them, though the standalone
backup does and that is used to copy the images to a small
RZ25 for actual running.
Allison
-----Original Message-----
From: Alexander Schreiber <als(a)thangorodrim.de>
To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org>
Date: Wednesday, April 10, 2002 10:17 PM
Subject: Re: Half on, half off -- New CD-R drive and 512-byte blocks
>On Tue, Apr 09, 2002 at 04:27:50PM -0500, Dan Wright wrote:
>> I do know, from experience, that any SCSI Plextor CDROM/CD-R/CD-RW
will boot
>> basically anything -- Sparc, SGI, RS/6000, HP,.... I've tried
plextors of
>> varying ages (old 8plex caddy-loader up to a 12/4/32 CD-RW that's
about 1 year
>> old) and they all work great...
>
>In this case, I've got bad news or you. You might be out of luck trying
>this with a VAXstation 3100. My VAXstation 3100 started to boot the VMS
7.1
>install CD, but barfed halfway through loading the kernel. I was not
>happy with either the 4x, the 8x or the 12 SCSI Plextor, nor with the
>Toshiba drive (all set to 512 byte/sector). Ripping a DEC RRD42 out of
>one of my DECstations finally did the trick. Seems like this machines
>are rather ... touchy about what they boot from.
>
>Regards,
> Alex.
>--
>We're gonna be body guards for teen rock-stars. Wouldn't the cause of
freedom
>be better served if we killed them instead?
> -- Schlock from the ''Schlock Mercenary'' comic
strip
>
Hi everybody. This isn't strictly on topic, but I think the intent
of the question makes it close enough.
I just bought a new CD-RW drive -- a Sony CRX145s -- and am curious
about whether it may read the 512-byte blocks necessary for using it
as a backup boot device on my VAXen, Sparc, SGI, etc.
Does anyone know whether this, or just for information, some other
CD-RW unit, will do such a thing?
Note that I do know that discs are written in 2048 byte blocks, and
the answer won't affect its performance in writing disks on these
systems. I am also aware that doing this for the long term may
needlessly shorten the life of the drive. As I said above, it is
more for curiosity, and eventually I would like to know that in case
my RRD42 dies, I have a backup. :)
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'
Thilo Schmidt wrote:
> The Address of the ROM is the current-state (lets say the line-number
> of the programm). Every line of Code consists only of the "outputs" and
> one or more "next states". The "inputs" select which "line" comes
> next: Either the next "line" of Code (that's what the counter is for),
> or one of the "next states". I made a mistake there, the Microcoded Machine
> has to look like that:
>
> |---|---> OUT
> address | R |--->
> |-->| O |---> |--[Counter]
> | | M |----| |
> | |___| \MUX/<--- IN
> | |
> |-[StateReg]<--
Actually, there are a grundle of ways to do this. Here's a scheme that
doesn't require a counter, but requires wider microcode:
> |---|---> OUT
> address | R |--->
> |-->| O |--->
> | | M |------|
> | | |----| |
> | |___| \MUX/<--- IN
> | |
> |-[StateReg]<--
In this case, each microcode word contains two addresses: one for when
the input is true and one for when the input is false. If you want to
go to the "next" word, the appropriate field in the microcode contains
the current address +1.
And then there's:
> |---|---> OUT
> IN ---->| |--->
> address | R |--->
> |-->| O |--->
> | | M |-----|
> | |___| |
> | |
> |-[StateReg]<--
This does away with the mux by using the input as one of the address
bits. It doesn't get more simple than this. You used to be able to
get registered EPROMs; using those, the state and output registers
are built into the EPROM and all you have to do is wire it up. And
write a grundle of microcode, of course...
The Firefox QBUS Adapter was implemented this way. Some of the outputs
ran back around to control a mux to select which input was being
examined by the microcode for a given state. Hmm, I'm going to have
to turn your drawing sideways, I think:
> INPUTS
> |||
> |||
> VVV
> +----------->\MUX/
> |+-------+ |
> || | |
> || V V
> || +--------------+
> || | ROM |
> || +--------------+
> || | |||
> || V VVV
> || [State and Output reg]
> || | |||
> |+--------+ |||
> +----------------+||
> ||
> VV
> OUTPUTS
Since this was done using registered PROMs, the only parts are ROMs
and the mux. And a synchro register for inputs; I don't recall whether
I synchronized the inputs before or after the mux.
Am I the only person who sees registered SRAMs intended for cache
and things "Hey! A huge microcode store that can run really fast!"?
Some of them even have JTAG inputs you could use to load the microcode.
Fundamentally, a state machine consists of inputs, outputs, a state
register, and a next state decoder. A microcoded system just uses a
ROM for the next state decoder.
Roger Ivie
ivie(a)cc.usu.edu
I'm quite tickled. Also inordinately proud of myself (for figuring
out the BA23's slightly different connections & stuff and not letting
loose any Magic Smoke).
First thing:
Thanks, Terry! I really like it.
Terry's rackmount MicroVAX II has been condensed into a single
BA23. For the nonce, I'm running a single RD54 and a TK50 on their
respective controllers, and a DELQA ethernet board. The KA655-A with
32M is a LOT faster than the KA630 with 13M. The TK50 is slow as
ever....
I was hoping the BA23 would be quieter than the BA123. It's not.
Questions:
Does the KA655 CPU make this a MV-3800, a MV-III, or a MV-II with a
KA655?
Terry, looks like you were right:
The memory board, which is a DataRAM 63016 C0. Listed online as a 16M
board some places and 32M others. The system sees it as 2 16M boards.
Is this kosher?
The 3-position CPU-RAM ribbon cable is plugged at one end and at the
middle connector. Does it matter?
I'd _really_ like to run the RX50 instead of the TK50. Unfortunately,
I don't have a cable. Can a PC floppy cable be modified to work? It
looks like, from reading past posts, connecting on the "B" connector -
i.e. no twist - ought to do the trick. Not quite brave enough to just
plug it in and see.
Last (not really applicable in the BA23), I see references to
terminating the last RD5x on an RQDX3. Is that termination effected at
the distribution board (M9058 in the BA123) or on the drive? Drive 1
and Drive 2 don't look any different. Which may be why they're, um,
terminally off-line.
Doc
P.S. - I've always wanted to say "For the nonce"....
>Hello all, I would be extremely grateful if those of you with VAX
>11/750s out there could either take pictures or draw diagrams of
how the
>PSU blocks are connected in this wonderful system.
You have the printsets. You'll find that in addition
to the schematics, they also include (almost)
enough information to build the PSU from
scratch.
If you have The Installation Manual (there are
several, two of which you can find at
http://208.190.133.204/decimages/moremanuals.htm
... except it's still down...) specifically EK-SI75F-IN-001
has some pictures on pp1-18, 2-1
The printset is probably a better guide!
>I have (finally) received my first piece of Big Iron but it has
death of
>the 2.5v PSU, and all the PSU bricks were removed and handed to me
>before I could note their positions.
Oddly enough, the last one I saw had
exactly the same problem. The 2.5V
PSU was not regulating properly.
>Also, if any of you have a terminal
>going spare (vt or hardcopy, either
>ist gut) then shout out and we can talk...
I don't have one spare, but people who
do might want you to pin down your
location a little ...
Antonio
I obtained a cheap (10 USD) Decitek papertape reader from Ebay. ( A tip for
those who believe that to be impossible : try .de instead of .com )
However it has a seemingly exploded IC on it : IC "I" below R5 and R4, has had
it top half blown off.....
Anybody with a similar reader could look up what kind of IC it was ?
And if anyone has the pinning for this reader handy...
I just saw that Decitek still exists. Do they react kindly to hobbyists ?
Jos Dreesen
some items sorta conspired to drive cpus to multiples of 8bits.
ASCII chars
width of data paths internal to MOS cpus early on.
byte wide memories, especially rom/prom/eprom
Personally I like either 18 ot 24 bits and have thought that
the PDP-8 with the right side (address portion) of the word
stretched to 18 bits or better yet 24 would be a nice machine.
24bits is majik as it's a multiple of 8.
PDP-8 addressing as 24bit 524288 word page, current and
also there is page 0 addressing! A field would be
16MB. EMA would not be needed.
Allison
-----Original Message-----
From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca>
To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org>
Date: Wednesday, April 10, 2002 11:21 AM
Subject: Re: TTL computing
>Richard Erlacher wrote:
>
>> 12-bit CPU's out there ??? Everybody knows that 12-bitters haven't
existed
>> since the '70's! After all, they stop existing on the day the last one
is
>> shipped. The device manufacturers stop considering a market as viable
once
>> the potential for 100K pieces per week per manufacturer is no longer
there.
>
>True about manufacturing, but I wish one had more choice with computer
>hardware/software for the PC user.I think DEC sold the PDP-8 until about
>1990. Since I can't find a 12/24 bit CPU that I like I am building my
>own. A 12/24 bit cpu chip could have came out around 1980 with the
>8086/6800. Part of the challenge in the cpu design I am doing in FPGA is
>to have it emulate (for the most part) a fictional 12/24 bit cpu in a 40
>pin dip.The last thing I added was a 8 bit refresh counter for dynamic
>memory and a single channel DMA for a floppy. Running at 4.9152 Mhz (
>800 ns memory access, 512Kb of ram ) I hope the Squash the XT market in
>1983!. :)
>
>--
>Ben Franchuk - Dawn * 12/24 bit cpu *
>www.jetnet.ab.ca/users/bfranchuk/index.html
>
> -----Original Message-----
> From: Ethan Dicks [mailto:erd_6502@yahoo.com]
> I do happen to have some twinax baluns from a former tenant of a
> shop that my former employer took over. They previous guys
> had an AS/400
> and terminals on peoples' desks. The best computer in the place was a
> 486 tower, in 2000! They were in the forklift business -
Wait -- if I understand you properly, they had an AS/400, but the best
computer was a 486?
I'm missing something here, and I'm certain to be near enlightenment
when I figure it out...
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'