Hey guys.. I bought this Homebrew Z80 machine from what I assume is the
early 80s (going by the chips). Pretty sure it's a Netronics keyboard but
wondering if any of you have seen a design like this one. I'm just curious
if it came from a magazine article or something as it goes beyond the
typical basic homebrew and even appears to have some ROMs. I'm not sure
what the TOS ROM is though.
I've put some pics of it here:
https://drive.google.com/drive/folders/0B4pq0-BHd2x6bjY3MTRZbGRCQmM?usp=shar
ing
Thoughts/opinions welcome.
Hi all!
Wishing you all a happy new year :)
I'm looking for a KIM-1 system and/or any other related hardware, the
earlier the better! If you have one you'd like to sell, please drop me a
line :)
-A
www.ebay.com/itm/302178528335
bought for the CHM collection.
This is the first one I've ever seen. I don't remember if the Morrow sons auctioned
one off when they were selling off George's shop.
It's essentially a MicroDecision III and MT-70 terminal according to the notes I scanned.
I have an IMSAI that I am restoring. The basics appear to be working
(front panel, CPU and RAM cards). I have a Processor Tech, 3P+S card
that is next on the list for testing. I have the manual, but the card
was not configured for RS-232...not sure what it was configured for
but it doesn't match anything in the manual. I plan to reconfigure it
for RS-232. I'm trying to locate boot loader code for that board to
allow serial uploading of files from a PC to the IMSAI? I have boot
loader code for a 2SIO board on an Altair that I restored awhile back,
and would like to find something similar for the 3P+S. I want to be
able to toggle in a boot loader routine and then initiate an upload
>from the PC to IMSAI -- something similar to this
https://www.youtube.com/watch?v=YwC1T9oLK1U&t=212s
(at 1:10s in) but with a 3P+S board on an IMSAI.
Also, a picture of your RS-232 configured card and wiring of the edge
connectors would be helpful to make sure I get things right. Any help
is appreciated.
Thanks, Win
wheagy at gmail.com?
Christian Corti had made available the German version of the LGP-30
Maintenance Manual, copied here:
http://ed-thelen.org/comp-hist/LGP-30MaintenanceManual-German.pdf
Ed Thelen had OCR?d and translated some of the pages, but I?m looking for a
copy of the complete English version if someone has it available. A search
of the CBI archives didn?t turn up anything, either.
If only paper copies exist, I would be glad to pay postage, scan, and send
back the manual if someone out there has it. Thanks- Cory
For what it's worth, xtrs (http://tim-mann.org/xtrs.html) emulates LD A,R
by putting an 8-bit random number in A. Of course that's cheesy and wrong
-- especially bit 7 being random instead of retaining a 0 from reset or the
last value written to it -- but at least it works OK with Ethan's
subroutine. The subroutine may loop a few times due to the value randomly
being negative or zero until it escapes the first time the value is
randomly positive.
xtrs sets the sign and zero flags according to the value, and does
something complicated with the other flags that I don't remember the reason
for -- but it might be correct; i think I got it from some reference on the
web last time I hacked on that instruction.
The pointer that someone posted to
http://www.worldofspectrum.org/faq/reference/z80reference.htm#RRegister may
inspire me to fix the emulation, though it looks like a bit of work to get
it exactly right...
On Thu, Dec 15, 2016 at 10:00 AM, <cctech-request at classiccmp.org> wrote:
> Message: 10
> Date: Wed, 14 Dec 2016 17:34:29 -0500
> From: Ethan Dicks <ethan.dicks at gmail.com>
> To: "General Discussion: On-Topic Posts" <cctech at classiccmp.org>
> Subject: Re: Z-80 code question about a loop that depends on the
> contents of the refresh register
> Message-ID:
> <CAALmimm07Bf=fjp70jzMKiV0m94aWxzggjeZuJg=ji
> LeLXT+gw at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> On Wed, Dec 14, 2016 at 4:26 PM, allison <ajp166 at verizon.net> wrote:
> >>> On 14/12/2016 09:19, Ethan Dicks wrote:
> >>>>
> >>>> So far, this loop hangs on all three emulators I've tried - simh's
> >>>> altairz80, simcpm010 for AmigaDOS, and EMUZ80 for Raspberry Pi. I'm
> >>>> guessing none of these environments emulate specific behavior of the
> >>>> Refresh register?
>
> > The first year of appearance for 64K DRAMS was mid to late 1980
> (expensive
> > and scarce) and mostly sampling to the big vendors. For regular users
> late 81
> > when the price started down.
>
> Right. I was a user of 8-bit micros in that exact era. My first
> hands-on experience as a user was the memory inside the Commodore 64.
> My first engineering experience was in 1984 on a product designed in
> 1983 (COMBOARD-II with 128K of 4164 chips and a 74S409 refresh
> controller).
>
> > There were three flavors, 8bit refresh, 7bit refresh, and
> > internal refresh came in a bit later by maybe mid 1982.
>
> I know there were different types but not those details. Thanks.
>
> > The Z80 could do 8bit refresh with hardware or software or the self
> refresh
> > (internal).
>
> I'm also a little fuzzy on this aspect of things because I was never a
> Z-80 user back in the day.
>
> Software Results considered a Z-80 COMBOARD very early on, but
> abandonded that approach because it would have likely required 2 hex
> Unibus modules and so opted to hold out a few months and go with a
> 68000 and SRAM design on a single hex card (my old boss still has an
> XC68000 with S/N 424 engraved on the lid).
>
> > Nominally the R register is a counter that increments from any value to
> 7bit
> > overflow.
>
> So I'm learning.
>
> > I believe most emulators actually do that.
>
> The first three emulators I tried (simcpm010, altairz80, and EMUZ80)
> on three different platforms (AmigaDOS, Linux, and ARM) do not. I now
> have a couple of names of DOS/Windows emulators that should. I will
> have to run them under Wine since I'm not a Windows user.
>
> It's funny because I would have tried this on simcpm010 25 years ago
> (it was on the Amiga disk I just extracted all these files from) and
> it would have failed then just as it fails today, and then, I had *no*
> idea why. I've learned a lot since then because it only took me a few
> hours of digging to uncover why.
>
> > Check MyZ80 Simon Crans work (32bit
> > dos/ pre-7-winders only or in a 32bit sim/VM).
>
> I will look that up.
>
> > Either that or lookup and assemble Grant Searle's low chip count Z80
> system.
>
> The worry is not running on real hardware. Once I get some time to
> clean up my XOR or dig out a Kaypro, I will run it on real hardware.
> I want to find/fix an emulator for modern machines so that other
> people can just grab and go. Also, this is not _just_ a Z-80 program,
> it's a CP/M program, with CP/M BDOS calls to open/close/read/write
> files and read-from/write-to the console (F_OPEN, F_CLOSE, F_READ,
> F_WRITE, C_READSTR, C_WRITE).
>
> Right now, I'm leaning towards fixing altairz80 first since that runs
> on "everything". I may also work with the author of EMUZ80 so it
> works on bare-metal Raspberry Pi (EMUZ80 is a Pascal app that runs in
> the Lazarus bare-metal framework, so you need Windows to rebuild the
> app). I don't mind putting known-working Windows-based emulators on
> a list of "verified environments", but I'm not going to push this to
> the public without a Mac and a Linux answer. Telling the world that
> they have to build a real Z-80 CP/M machine to play a game isn't going
> to hit a large audience.
>
> Thanks,
>
> -ethan
>
<<I happen to have a Atlantic Research Inc, serial datascope. It
contains <<several boards [std bus z80, rom/ram card, CRT5027 based crt
controller Card] <<however no manual. Someday I'll track down at least a
schematic and fix <<the CRT. The boards say T-Bar on them so the
instrument may even be from <<another company with the ACI label. It
would be fun to get it operational. I repaired the CRT and foudn it
generally less than useful and repurposed the CRT, Power supply and case
for a Embedded ELF system... with disk. So now I have the three STD
boards and 4 slot backplane... THey do have T-BAR on them and I can do
one of two things with them strip them for the CPU, SIO, RAM, EPROM,
SMC5027E CRTC. As is without manuals or other useful info they are junk
to be reused. Ideally with far more detailed info like schematics make a
dedicated z80 system. So I post it again... Allison