>
>Subject: SC/MP 8073 addressing query
> From: Doug Jackson <doug at stillhq.com>
> Date: Wed, 21 Jan 2009 09:26:13 +1100
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>Hi list,
>
>I have an interesting question regarding the INS8073 (National
>Semiconductor SC/MP 3 with BASIC in ROM).
>
>Finally, somebody gave me a round tuit, and I have started work on a
>simple 8073 system.
>
>Eventually, it will have 8K of ROM, 8K of RAM, an 8255, and a switch /
>LED interface. Currently on the board, I have the 6264 RAM tied to the
>8073, with no address decoding (ie the CS* on the RAM is tied to A15 on
>the CPU). Sadly, as a simple test, this does not operate as I would
>expect. I would have expected that the RAM would have been selected
>anywhere in the lower 32K or the memory map, and I would have a simple
>system that would spit out a console prompt. But no luck.
>
>Now the question.... The internal ROM is located in the lowest 4K or
>the memory map. When the CPU is fetching data from the lower 4K, does
>it assert the NRDS line, and sample the external bus? My belief is that
>it does not, as the trivial application note that I have seen simply
>ties a couple of 2114 to the processor, and uses A10 as the chip select.
>
I built one years ago and pull it out frm time to time.
No, it's less than 4K and yes you do get NRDS.
Also you need pull up resistors on selected lines to set baus rate and
boot on rom.
I'd use 2116(2kb) or 2164s(8kB) as they are 8bits wide and really save
on parts and power over 2114. One 2164 placed at at 1000h makes for a
tiny sysem.
Finally NIBLE when it starts does a memory check for (Ep)rom at 8000h.
There are some addresses that are tested for information that have to
be respected.
If no one comes up with the circuit that National had for the demo board
they sold I can scan my copy, it's pretty poor but may help. The manual
is just too thick for me to scan or copy.
Allison
>Any ideas?
>
>Doug
>
>
>
>--
>Doug Jackson, I-RAP, MAIPM, MIEEE
>
>Principal Information Security Consultant
>EWA-AUSTRALIA
>PO Box 6308 O'Connor ACT 2602
>Level 1, 214 Northbourne Ave, Braddon ACT 2612
>
>Tel: +61 (0)2 6230 6833
>Fax: +61 (0)2 6230 5833
>Mob: +61 (0)414 986 878
>
>http://www.ewa-australia.com
>
>
>============================================
>
>IMPORTANT: This email remains the property of Electronic Warfare
>Associates - Australia. If you have received this email in error,
>you are requested to contact doug.jackson at ewa-australia.com or Ph
>+61 2 62306833 and delete the email. This message is not to be
>copied or distributed to other parties without the express permission
>of the author. Any personal information in this email must be handled
>in accordance with the Privacy Act 1988 (Cth).
>
>============================================
I need disk 12 (of 27) of Lotus smartsuite 3 (Win 3.1 era), part # R03380. The contents are something like lotus012.dsk (single file). The funny thing is that this disk cannot be read at all in the drive, wonder what caused that.
The vax unix nerds on the list might find this mildly interesting:
I hacked a copy of simh vax780 to look like a vax 11/730. I made a
modified version of the standalone netbsd "boot" program which does nfs
loads from a deuna (it will do copy's too, which is handy at times)
With that I finished debugging netbsd 2.0.3 on the 730. I've gotten it
to boot to a shell prompt on a simh 11/730 with 4mb of memory using an
nfs root. woo hoo!
So, next I'll make a disk image and put my unibus scsi card in my real
730 and debug that. With any luck it will just work.
Once it's going on real hardware I'll get it going on the latest netbsd
(4.0?) and get a patch back to the netbsd/vax maintainer.
[for those who care, I use a linux program which simulates the tu58 to
boot my 730. I made a boot tape image with putr which contains the
netbsd boot program (as well as the other files needed to load
microcode, etc). I plan to spend some time and make a linux program
which will put together valid tu58 tape images, just to make my life
easier, since putr requires DOS.]
I have to give the netbsd folks a lot of credit. Their posix build
system is very handy. But note that releases before 2.0.3 will *NOT*
build on a posix machine - they require native netbsd to build cleanly.
I've always had a soft spot for the 730; maybe because the 780 was
just too damn big! :-)
-brad
Digging though my SGI stuff and found these. Got rid of my PI 4D/35 a long
time ago. I have 16x8Mb ram sticks that should max out one of these
machines. If interested email me with offer.
After years of looking at an HP LJ4L I got at the Uni surplus that
someone had removed the fuser from, I found a nearly-unused 4L at the
nearby thrift store yesterday. It printed the test page without a
burp, but was on the shelf without a price. I found someone to get it
priced and walked out a happy customer $6 later.
The only thing it's missing is a right-angle IEC power cord to fit
behind the access door, but it works well enough with a straight-in
cable.
-ethan
I've got an overabundance of consoles, some boxed, some not. I've also got
speech synth carts and even an expansion box (fairly rare and I imagine what
most people would be interested in). Make it worth my while to ship to you
and its yours. Otherwise some of this will probably end up in the garbage.
The best s-100 memory cards will use static memory cards ... the chips will
be 2102's (for very old 4k and 8k cards), 4044's, 2114's, 2147's or a few
others for 16K and 32k cards or 6116's for 64k cards (some of these chips
had other numbers for what were, essentially, the same chip). The best
cards are the Godbout / CompuPro cards, which I believe were all static, but
quite a few other static memory cards were good also.
There are SOME good dynamic cards, I've had excellent success with Cromemco
16KZs, and with the SD Sales Expandoram cards. The problem is that it's
hard to know which dynamic cards are good vs. which ones are bad (and the
bad are very bad indeed), and there can be a lot of compatibility problems
with front panels and DMA. So I prefer to avoid them, but a few of them are
ok.
> -----Original Message-----
> From: cctalk-bounces at classiccmp.org
> [mailto:cctalk-bounces at classiccmp.org]On Behalf Of Josh Dersch
> Sent: Tuesday, January 27, 2009 1:46 AM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Recommendations for IMSAI-compatible RAM cards?
>
>
> Hey all --
>
> Acquired an IMSAI 8080 in half-assembled condition (but the price was
> right). I believe that (after doing some thorough cleaning, debugging,
> and replacing of old cabling) that I've got the front panel and CPU
> functioning correctly. However, the IMSAI came without any RAM cards so
> I'm unable to go any further at the moment.
>
> I have one S-100 RAM card but I have no documentation on it and it's
> missing a couple of ICs (and what they're supposed to be, I don't
> know). It's a PSS RAM65. My internet searches for info confirm that
> the card does indeed exist, but I can find no technical information.
>
> From my research, my understanding is that S-100 RAM cards are fickle
> and compatibility with front-panel machines can be an issue. Does
> anyone have any recommendations for what to look out for as I begin my
> search? Anyone have any decent RAM cards they'd be willing to part with?
>
I've been contacted by someone offering a PC Jr. Please contact
original author directly. He's planning to recycle it tomorrow if
there's no interest.
Eric
---------- Forwarded message ----------
From: Alex Khajehtoorian <alex.khajehtoorian at gmail.com>
Subject: IBM PC Jr.
To: korpela at ssl.berkeley.edu
Dr. Korpela,
This might seem a little random, but i recently installed BOINC
software for SETI at home and while reading up on the project and team i
noticed that you enjoy to restore vintage computers.
I'm not sure how vintage you consider an IBM PC Jr, but i have one
that is in excellent condition. I have contacted museums and schools
and no one has a need for it. I'd rather not recycle it because it is
like new.
If you'd like, its all yours.
http://www.computercloset.org/IBMPCjr.htm that's not mine, but an
example
Feel free to ask colleagues. I live in San Jose and you can have it anytime.
Regards,
Alex Khajehtoorian
Finally got off my rear end and updated the Little Orphan Tomy Tutor site,
focusing on the TMS 9995-based Tomy Tutor home computer. I've added more
information on the marketing promise (including the "TI Adapter") thanks to
a full video capture of the Demonstration Cartridge, started uploading scans
of the official User Club newsletters, uploaded the printer interface (allowing
you to connect any standard parallel-port printer to the Tomy Tutor) schematic
and redid most of the photography, along with a reorganized cartridge list,
updated trade list and other ticky stuff.
Hope you enjoy it,
http://www.floodgap.com/retrobits/tomy/
--
------------------------------------ personal: http://www.cameronkaiser.com/ --
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com
-- Smile if you like this tag line. -------------------------------------------
