holidays and stuff
Alexandre Souza - Listas pu1bzz.listas at gmail.com
<mailto:cctalk%40classiccmp.org?Subject=Re%3A%20holidays%20and%20stuff&In-Re
ply-To=%3C8ACC14CA48B347038CC2D8CFB528832B%40portajara%3E>
Sat Dec 25 11:52:54 CST 2010
[snip]
> Pics! MSX stuff isn't terribly common here, in my experience.
Well, these are not THE 2.0 I got today, but all photos are mine, with
my old MSXes:
http://msxpro.com/acvs2.0.htmlhttp://msxpro.com/kitddx.htmlhttp://msxpro.com/kitddx2-2p_as.html
And lots of MSX things (most did by me, or by Luciano Sturaro, the owner
of the site):
http://msxpro.com/projetos.html
Of course, there is always my site, with lots of photos:
http://tabalabs.com.br
Want more? :oD
-----REPLY-----
Hi Alexandre,
We are working on an N8VEM home computer design which will be BIOS
compatible with MSX-1. The hardware is somewhat compatible but we are
making some changes due to parts obsolescence, etc. For example replacing
the parallel matrix keyboard with a PS/2 keyboard port, adding IDE, SD, and
floppy controller, etc. One of the builders has demonstrated the MSX CBIOS
using the N8VEM SBC and SCG (sprite color graphics and sound board). That
will be the basis for the new home computer except it will be based on the
Z8S180, 1MB SRAM, 512K Flash ROM, TMS9918 VDP, AY-3-8910, and various IO
ports. The MSX CBIOS is in the MSX BIOS folder.
If you are interested in working on a homebrew MSX computer please stop by
the N8VEM project. There is a folder on the N8VEM wiki called "home
computer" with the schematics and PCB layout. The prototype PCB is in trace
route optimization right now and once some of the other projects clear out I
am planning on a small run of prototype PCBs for initial build and test.
Probably in a couple of months or so.
Thanks and have happy holidays!
Andrew Lynch
C64/C128 CP/M Cartridge Interest?
Jim Brain brain at jbrain.com
<mailto:cctalk%40classiccmp.org?Subject=Re%3A%20C64/C128%20CP/M%20Cartridge%
20Interest%3F&In-Reply-To=%3C4D157503.4070909%40jbrain.com%3E>
Fri Dec 24 22:37:23 CST 2010
[snip]
>
> N8VEM is a good candidate...
A couple of reasons:
* N8VEM, while a great solution, is enormous. There are many closet
C128 CP/M users, and they'd never go for such a huge addition to
their setup. A cartridge form factor, easy decision. Others
would scoff at relegating their C128 as a dumb terminal to another
machine (for instance, they could easily do the same thing by
running a CP/M emu on their PC and connecting the C128 to the PC
via a null modem cable). It's perception.
* There is more to a C128 CP/M cartridge than just using the C128 as
a dumb terminal. Some C128 CP/M apps might take advantage of the
functions in the C128 itself, like the 40 column screen and such.
Thus, memory mirroring and such would be useful. I didn't bring
it up initially, because A) not sure if apps did that. B) I just
wanted to start small, and thought that interfacing the Z80 to the
CBM bus would be a good start
* I theorized that a tiny CP/M board might be of use where N8VEM was
too big or too expansive.
* I so want to start learning Verilog. I thought, if I got a
basic environment going, I could then take a look at virtualizing
the pieces to an FPGA connected to the C128/C64. But, since I
know little of Z80 and CP/M (having used it long ago), I thought
going to FPGAs from nothing was too large a leap.
* The next step after that is an accelerated CP/M. This plays in
with my hope to obtain the rights to the SuperCPU for the
C64/C128. It lacked accelerated Z80/CP/M compatibility, which I
thought I could add, though maybe not.
I'm gathering from the results that there might not be the interest I
had theorized, which is fine. But, I thought I'd at least ask.
Jim
[snip]
-----REPLY-----
Hi Jim,
I gather the form factor you have in mind is the classic C64 game cartridge?
The CP/M cartridge I recall from the 1980's was much larger than a game
cartridge so that's were I was coming from. I've never heard a Eurocard
board (160x100mm) described as "enormous" but clearly you are thinking about
a much smaller board than I was.
I suppose such a cartridge is possible but it would require a few very dense
parts. Probably a CPLD at a minimum probably a FGPA with fine pitch SMT
connections. At least to me, you would need a four chip minimum a Z80,
SRAM, Flash ROM, and glue logic. Maybe less if you can blow a Z80 core into
an FPGA which is possible I believe. All in SMT QFP packaging to get the
density to fit multiple chips into a 2"x3" PCB. It sounds more like a
commercial product than a hobbyist project to me though.
Actually, the C64 ECB bridge approach idea is not using the C64/C128 as only
dumb terminal. It would be 3 or so general purpose IO ports. Then the
C64/C128 could serve IO to the Z80 when it is running. The Z80 sends an IO
request to the C64 which passes status and data back. The 6510 would run an
IO server program and the Z80 would be its client. Assuming an interrupt
driven design the IO processor (6510) could serve the Z80 IO as a
"background" task to a limited extent.
This is how the N8VEM SBC with the 6809/6802/6502 host processor works. The
6809 runs independently but passes its IO requests to the Z80 which serves
terminal IO, disk IO, parallel port, video or whatever. It fully utilitizes
the Z80 and 6809 as a dual independent processors with their own RAM/ROM.
However the 6809 host processor can be optionally upgraded to include its
own unique IO set for more independence or as stand alone mode.
I am not familiar with the SuperCPU but based on quick web search it appears
to be roughly Eurocard sized. Good luck with your project.
Thanks and have a nice day!
Andrew Lynch
PS, we had a builder recently who crafted his own N8VEM SBC using a CPLD
design. Basically it was all the large IC s (CPU, RAM, ROM, UART, PPI) and
one large CPLD. It seemed to work well enough too. I was considering doing
something similar on the N8VEM home computer project since it is limited to
60 square inches. However, we seemed to have resolved the PCB layout issues
using regular PTH DIP/PLCC 2 layer PCB construction.
Subject:
Re: Using a Variac to revive power supplies
From:
Tobias Russell <toby at pdp11.co.uk>
Date:
Thu, 23 Dec 2010 19:06:04 +0000
To:
"General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Ok, I suspected as much.
So for a linear supply such as the 8/E's is a Variac a valid way to go or
should I reform the capacitors individually as I've done previously?
All the best,
Toby
------------------------------------------------------------------------
Toby, I've found that removing every single electrolytic and reforming
to full
(or 10% over) capacity provides the best results. The Variac method --
while
better than nothing -- doesn't limit your current... plus doesn't reform
all caps
to full capacity, nor tell you anything about their condition and leakage.
1. Remove cap.
2. Check ESR. If ok then..
3. Reform with resistor and variable power supply while monitoring
current...
raise input voltage slowly to keep max current to no more than 1ma.
Let current settle down every so often to check for leakage rates
at various voltages... One method I use is halves... start out at 50%
rated voltage, let settle, then 75%, settle, then 87%, 95, 100....
Checking leakage at each stage like this gives you an idea of
cap condition.. so you can decide whether to replace or not.
4. Check ESR again.
5. Check capacity.
6. If capacity is within 10% of spec, ESR is what it should be, and your
leakage rates are acceptable, then you're good to reinstall.
Otherwise,
replace!
- John Singleton
I had to pass up a gig because my buttset ran down its batteries. That's
not much of a problem except that I found out that the Harris TS22 series
has an irritating little problem of locking up if both the 9V and 3V
batteries are both dead. Does anyone here know how to get a TS22L
unlocked without sending it out for repair?
--
David Griffith
dgriffi at cs.csubak.edu
I've recently acquired a Variac (220V 10A) and was wondering what the
collectives views are on using them to revive long dormant power supplies.
Previously I have removed the electrolytics and reformed them with a bench
power supply setup, slowly ramping up the voltage (as per
http://www.vcomp.co.uk/tech_tips/reform_caps/reform_caps.htm). Am I right in
thinking I can use the Variac to effectively reform the capacitors in
circuit?
I'm currently rebuilding one of my PDP-8/E's which has a linear PSU which I
believe is ok, but will it also work with later DEC switchmode PSUs?
All the best,
Toby
HP 10276A LSI-11 Logic Analyzer Probe Interface
I just picked up an HP 10276A LSI-11 logic analyzer problem interface
off of eBay. It was listed simply as a 10269C but it looked like the
attached card was a Q-Bus card so I bought it and it turned out to be
an HP 10276A.
I can't find any information about the 10276A on the net. Any chance
anyone on this list has a manual for the 10276A?
I posted some photos of the 10276A card here:
http://sites.google.com/site/glensvintagecomputerinfo/
If I can get this card to work with my logic analyzer it might be
useful to help debug why I cannot successfully install 2.11 BSD from a
tape drive attached to a CMD CQD-200 while the installation works fine
with a CMD CQD-220. Probably some sort of compatibility issue in the
2.11 BSD TMSCP driver.
-Glen
KANSAS CITY, MO -- December 17, 2010 -- Bob Bishop, co-founder of Apple's R&D lab, will be the keynote speaker at KansasFest 2011. Bob is part of the early history of the Apple computer and has developed numerous commercial software titles, worked side-by-side with Apple co-founder Steve Wozniak, written a book on assembly language programming, and published articles in most Apple II magazines. Bob has lived what most of us only dream about, and he has the stories to prove it.
In 1976, Dr. Bishop knocked on Steve Jobs' door and ended up owning an Apple I. Soon, he bought one of the first Apple II computers. A few months later, the first graphical Apple II games, like Rocket Pilot and Star Wars, came from Bob's keyboard before Apple had even finished the documentation. Later, Bob brought speech to the personal computer with Apple-Talker and Apple-Listener. In 1978, Bob and Steve Wozniak founded Apple's research and development division. His program Apple-Vision was included on DOS 3.3 master disks, demonstrating the audio and video capabilities of the Apple II. Even after retiring in 1981, he continued using, programming, and writing about the entire Apple II line.
The stories do not end with the Apple II. Bob has hosted a radio show using the "Mr. Logic" personality, written essays, founded a comic book club, designed a computer programming language, and written online riddles. Alas, Bob has not yet founded the fanciful "Subroutine Shack" stores "for supplying software components." Today, he lives in California, still "plays with computers," and laments that his Web site is forever under construction.
KansasFest 2011, the 22nd annual Apple II conference, is set for July 19th through July 24th at Rockhurst University in Kansas City, Missouri. KansasFest was originally hosted by Resource Central and has been brought to you by the KFest Committee since 1995. Any and all Apple II users, fans, and friends are invited to attend this year's event. Registration details will be announced on the KansasFest Web site in early 2011. For photos, schedules, and presentations from past year's events, please visit the event's official Web site at http://www.kansasfest.org/.
CONTACT:
KansasFest 2011
http://www.kansasfest.org/http://twitter.com/kansasfest/