> Rob Jarratt 25 Nov 2023 8:47 a.m.
> Of course the worry is, why? There could be a fault on the board.
> I am hesitant just to replace the fuse and try it...
An older CRT terminal is probably a bit too much current draw for this, but
you can prob use it in a setup to test parts...
A very handy gadget you can make very easily, which I use all the time when
testing small devices in "unknown operational state" is a simple current
limiter. (following discussion based on North America power, numbers may be
different if you are in a different part of the world).
The "smallest" typical line circuit is 15A which is more than enough to
cause
damage to small devices experiencing excessive power draw through a fault
(often indicated by a blown fuse).
The "limiter" relies on the fact that an incandescent light bulb will
draw/pass
a fair bit of current when it is cold, and much less when it's warm. (this
is
because they are designed to "turn on" fast)
In my case, I have three light sockets wired in parallel, all in series with
the hot side of a receptacle. This lets me change from a single 25w bulb
(very
little current possible) up to 3 100w bulbs (a good part of amp before it
seriously limits). For example, 100w bulbs draw .833ish (100/120) when
operating fully lit - x3 = 2.5A max current - this would only happen if the
device under test was "shorted", presenting 0 series resistance and would
therefore effectively have 0 volts across it.
In practice, you could prob. draw 1/2 amp (160ish ma per bulb) without
warming
them "too much" to seriously drop a lot of voltage. Much more than that and
the
bulbs will light up rather than hearing "popping" sounds from the device
under
test :-)
-- Btw, I've given most of my CRT terminals away - For VT100's I use my
"PC100"
program - It provides very good VT100 emulation using an old DOS (or DosBox)
PC - it remains "text" mode, so it turns "smooth scroll" into "slow scroll"
and
large fonts into "double spaced" fonts - but in all other respects nothing
I've
used it on has been able to tell it's not an actual VT100!
(I'm sure there are better/graphical VT100 emulations "out there")
Dave
--
----------------------------------------------------------------------------------
Search "Dave's Old Computers" see "my personal" at bottom!
Hello list,
there is a PDP 11/23 Plus with two RL02 drives available near Stuttgart, Germany.
The configuration corresponds to the one shown here:
http://www.cosam.org/computers/dec/pdp11-23/cabinet.html
Contact me off-list if you are interested.
Cheers,
Pierre
-----------------------------------------------------------------------------
http://www.digitalheritage.de
Not a COMPUTER but I have a Pro-log M900 EPROM burner that has a second source INS4004 on the board. This isn't my M900 (my INS4004 is white/gold), but here is a view of the board/chip: http://www.wolfgangrobel.de/programmer/img_m900/m900_06.jpg
-W
Date: Wed, 22 Nov 2023 09:36:19 -0500
From: Paul Koning <paulkoning(a)comcast.net>
Subject: [cctalk] Re: Intel 4004(sp?)
To: ED SHARPE <couryhouse(a)aol.com>, "cctalk(a)classiccmp.org"
<cctalk(a)classiccmp.org>
Message-ID: <7ECB8A1C-DB41-45E7-9416-F71AD3289C94(a)comcast.net>
Content-Type: text/plain; charset=us-ascii
> On Nov 22, 2023, at 3:51 AM, ED SHARPE via cctalk <cctalk(a)classiccmp.org> wrote:
>
> Was there ever a COMPUTER using a 4004 that you cud really do something or did tat finally arrive with the 8008 as in the skelby shelby sp? 8008 i now there was an Intel INTELIC 4 (?sp) could n that use 4004 or one of the later 4000 numbered proc. We have an intelec 8 and 8 inch floppy drives here at smecc musem .... always wanted a 4!Ed
Don't know about commercial products. But a classmate of mine got Honors in Independent Study for a project where he built a useable general purpose computer out of a 4004, plus a boatload of other stuff. It filled a wire-wrap panel board about 8 x 10 inches. He wrote some software for it as well, and took it to a summer internship at one of the National Labs (in the Midwest -- Argonne?) where as I understand it they liked it enough to ask him for a copy of the system. He graduated in 1975, so the work was done in the year or so leading up to that.
One complication was the terminal I/O (Teletype 33); originally he had a bit-banging interface for that, which isn't easy on a 4004. At some point he finagled a UART chip out of one of the DEC field service engineers, I think that was one of the first single chip UARTs, used in the earlier DEC PDP-11 terminal adapters.
paul
what about that intel 3000 bit slice thing is it almost a microprocessor yes no and why? Ed#
In a message dated 11/21/2023 3:34:03 PM US Mountain Standard Time, c.murray.mccullough(a)gmail.com writes:
There are 5 other possibilities for the honour:e or noe and why?
No. 2:
Texas Instruments applied for a “computing systems CPU” in 1971 and awarded a patent in 1973. The question though is: did TI have a functioning processor based on the TMS1000. Not sure if they did!
No. 3:
“In 1969 Four-Phase Systems built the 24-bit AL1, which used multiple chips segmented into 8-bit hunks, not unlike a bit-slice processor. In a patent dispute a quarter century later proof was presented that one could implement a complete 8-bit microprocessor using just one of these chips. The battle was settled out of court, which did not settle the issue of the first micro.”
No. 4:
Is this the first microprocessor?
Here is a source:
https://historydraft.com/story/microprocessor/pico-electronics-and-general-…
No. 5:
"In 1969 Four-Phase Systems built the 24-bit AL1, which used multiple chips segmented into 8-bit hunks, not unlike a bit-slice processor. In a patent dispute a quarter century later proof was presented that one could implement a complete 8-bit microprocessor using just one of these chips. The battle was settled out of court, which did not settle the issue of the first micro."
It seems the answer depends on what is a microprocessor...I suppose when it comes down to capitalism patents count more than anything else!
Happy computing,
Murray 🙂
On Tue, Nov 21, 2023 at 5:00 PM ED SHARPE via cctalk <cctalk(a)classiccmp.org> wrote:
I had heard something about a f14 chip pehS being first but not avail. To general public???Ed#
Sent from AOL on Android
On Tue, Nov 21, 2023 at 2:41 PM, Joshua Rice via cctalk<cctalk(a)classiccmp.org> wrote:
On 21/11/2023 09:03, ED SHARPE via cctalk wrote:
> So what are the other contenders and what do they bring to table
The 4004 was definitely the first commercially available single-chip CPU
on the market, but if you include multi-chip LSI designs, the lines get
blurry.
I just pushed two additions to https://github.com/pkoning2/decstuff :
In "patches" a new patch for the DEUNA driver. This fixes a problem seen when doing user (as opposed to DECnet) I/O, as well as two errors that show up when using units beyond the first.
Directory "ntp" is new. This is a simple NTP protocol client for RSTS, which will synchronize the system clock with an NTP server on the LAN. It includes handling of timezone rules, so the right thing will happen at daylight savings time (summer time) boundaries. The clock is maintained to the full RSTS resolution -- typically 1/50th or 1/60th second, but can be as low as 10 ms if the KW-11/P clock is used.
paul
I'm working on some code where it would be handy to map the top of the I/O page along with the bottom of physical memory. An obvious hack is to point the APR to the I/O page address needed, then set the length so that the address modulo 2^22 also covers the low memory range.
It seems from the architecture manual that this would work, and SIMH seems to do this (since it adds VA and PAR then masks with a 22 bit mask). Would this work on real hardware?
paul
