I am looking for any working or not cfw-40s.
If you have any or any contacts please let me know?
Thanks
Randy Ferrell
I use it daily for enbedded programming.
Hi,
I've got a PDP-8E which I've almost got working.
Can anyone here help me figure out this remaining problem?
As I examine memory, the address lights count up to 01111, then
go back to 00000, instead of 10000. I can manually enter an address
higher than 1111, but the 10000 and 100000 bits don't stick -- they
go low, as soon as I hit the examine switch to step to the next
memory location.
I can manually load an address 1000000 or 10000000, and hit examine to
see 1000001, 1000010, 1000011, etc..., but once I reach 1001111, it's
back to 1000000.
It was recommended to me that it might be the carry between E52 and E37,
or the E38 input multiplexer for bit 7 (on M8300), so last night I
socketed and replaced all three of those ICs, but I still see the same
symptoms.
I have extender boards, so can access M8300 during operation. I
measured the carry line between E52 and E37 go low when I reach 1111, but
the light for line 10000 doesn't light on the front panel on the next
address, and I see the data from memory location 0000, 0001, etc.
repeated, displayed as I continue to step through memory locations,
as described above.
Of course, if someone has a spare M8300 they would be willing to sell me,
that's another option.
Mark
--
Mark G. Thomas (Mark at Misty.com)
voice: 215-591-3695
http://mail-cleaner.com/
Al,
this is really cool! Basically the complete system documentation. Would there
be a chance that somebody put a dump of the Zeus system at this place?
Thanks!,
Matt
>>used it, and I locked the heads afterwards...). But no source code, or
> >even full shcemaitcs (YET!).
>
>are the documents in
>http://bitsavers.org/pdf/zilog/s8000 useful
>used it, and I locked the heads afterwards...). But no source code, or
>even full shcemaitcs (YET!).
are the documents in
http://bitsavers.org/pdf/zilog/s8000 useful?
Hi Mark,
I have a spare board here in Austria, but its not tested. If you
want to have it for test your system, let me know. We will find some
smart deal for the shipping costs, I am shure.
With best regards
Gerhard
> Date: Thu, 8 May 2008 17:07:25 -0700 (PDT)
> From: William Maddox
> >From what I can see of it, the doors look a lot like the doors on the
> Calcomp disk drives used by DEC for the RX01. If you send me a better
> picture of it, or check the labelling on the drives, I might be able to
> verify this. There is a fellow in town who quite likely has a scrap
> drive -- I've seen a lot of the later RX02s that have been scrapped for
> motors and heads in his shop.
I've still got the docs for the IMSAI floppy box somewhere and can
check to make sure, but I believe the drives are Calcomp 103.
Miserable things, compared to the Shugart units.
Cheers,
Chuck
>>> Gaaah, it's coming back to haunt me! The NJ Computer Museum has a Zilog System 8000 model 21
Just to clarify, Jeff means the MARCH user group's museum, where we host VCF East, etc. ... we've never called ourselves the "NJ Computer Museum".
But, he's correct about the Zeus! It was donated by an individual member a couple of years ago.
-----Original Message-----
From: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] On Behalf Of Jeff Jonas
Sent: Wednesday, May 07, 2008 4:23 PM
To: cctech
Subject: Re: Minimal CP-M SBC design
I'm slow to enter the discussion because I'm still
busy sorting my z80 parts and single board systems
instead of enjoying them :-(
I'm of 2 minds regarding the Z80:
The "classic" vs. the "embedded" mind-set.
The embedded solution:
I have a Zilog 50 MHz eZ80 development board with more built-in features
that I may ever use: ethernet, InfraRed,
a LOT of flash and static RAM.
My frustration is the lack of support and community activity
despite some high profile contests using the board.
A clever fellow made an expansion board that adds
2 compact flash slots so it runs CP/M really fast!
That appeals to me since it allows it to run stand-alone
even for editing, storing and compiling applications.
And there's still the programming/debugging pod
for using a host system to debug the system
should it require external assistance.
Back to the original query:
the Zilog ez80 board may be appealing because
- it's fast (50MHz) and has a lot built in:
MMU, RAM, flash ROM, serial and ethernet ports.
- allows much more powerful tools on the host system
for source control, compilers, debugging via the pod.
- others are using it too
The classic side:
My first "at home" computer was a Servo-8 single board computer
(6 MHz Z80B, 64k ram, 2 serial ports, parallel port, SASI port).
I chose that over the 4 MHz Z80A Ampro Littleboard.
It cost about $500 (with CP/M and schematics)
so I was really hesitant to interface it to my own things
until I had some experience with cheaper Z80 systems
(particularly since all the parts were soldered in!)
Long long ago I breadboarded a 4 MHz z80a with 10K static RAM
(intending to use battery backup).
I originally intended to use a front panel of
LEDs and toggle switches (inspired by the Altair).
I gave that up while wiring up all the switches,
and instead used a Timex Sinclair 1000 as the front panel
(hey, a keyboard and display!) to the dual-port static RAM.
(the Timex is a complete Z80 system with just 4 chips:
z80 CPU, ROM, RAM and Programmable Logic Array for the rest).
I still want to use discrete Z80 chips because
- I have a logic analyzer to watch it run
(I've disassembled some embedded z80 terminals using it)
- I like the way the Z80 family chips interface so directly,
even for vectored interrupt mode.
- I still want to explore "clever" tricks for memory management such as
. using the "M" line to differentiate instruction from data reads
. implementing true "cycle stealing"
(access to memory not currently active by the CPU).
I salvaged many z80 based devices (terminals, modems, terminal servers)
and pondered reverse engineering them to reprogram for my own uses.
Perhaps I'm too impatient but it seemed easier to just
start from scratch, or buy a single board system and work from there.
I suspect I'll finally get brave enough to just interface
the additional Z80 chips to the Servo-8 Z80B SBC
since I like that more than the ez80 (so far).
Jeffrey Jonas
e-mail: jeffj at panix.com
-----REPLY-----
Jeff,
I am building a Z80 SBC as mentioned previously. If you want to add the
Z80 peripherals to a Z80 based SBC, have you considered just building an
ECB peripheral card?
My Z80 SBC design is based on the ECB bus and supports its optional use.
Maybe the best approach is to build of my SBCs and the ECB backplane and
you design the peripheral card to go along with it.
The Z80 SBC now only supports IO accesses on the ECB. I may extend the
design in the next version to allow full memory accesses across the ECB
for the next SBC design but so far I don't see much use in it since the
SBC already includes 1MB EPROM and 512K SRAM. The ECB pin out is the
same but the control logic of the SBC would have to change.
In addition, the Z80 SBC supports a IEI/IEO lines on the ECB including a
2200 ohm pull up resistor. The Z80 SBC supports the Z80 open drain /INT
line directly to the ECB coupled with a 2N2222 TO-18 transistor to drive
it. So far the only device attached to the Z80 /INT line is the 16550
UART. None of the current software uses the /INT line yet since I
implemented everything in polling mode only.
Maybe this is an opportunity to collaborate? A Z80 PIO/DART board
probably wouldn't be too difficult to implement on ECB. Check my
website if you are interested. I am using KiCad for EDA which is free
software.
Please let me know if interested. Thanks!
Andrew Lynch
Here's a representative lot:
<http://cgi.govliquidation.com/auction/view?id=1686038&convertTo=USD>
They have descriptions like "General Dynamics signal processor adapter
assembly" and they all look like circuit boards with a regular grid
and an arrangements of pins placed into the grids. The grids are
divided into areas and sometimes color coded. Does anyone have any
familiarity with them? There are a ton of these on govliq right now.
It seems to be some kind of test harness.
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://www.xmission.com/~legalize/book/download/index.html>
Legalize Adulthood! <http://blogs.xmission.com/legalize/>
> I picked up what I believe is a console from an Autonetics model D-37 Minuteman I missile guidance computer.
D-37 is a DTL computer for the Minuteman II.
There is some info and a picture on Wikipedia now
about it.
