Hello all.
I'd like to tell my update on the SIMH blinkenlight console project(s).
A year ago (or so), Vince and I developed the 6809 Core and I/O Boards.
To refresh your memory about this project: the 6809 Core Board runs an
application that communicates with a modified PDP-11 version of SIMH.
You connect the I/O Board to switches and LEDs that represent a PDP-11
console, in my project example an 11/40 console. This console is the
part that you had to do yourself, you could/can take a real console,
but as I said earlier, that's (perhaps) a waste of a good machine.
For this project, see www.pdp-11.nl/homebrew/startframe.html
I have a new application that takes the first project one step further.
The 6809 now simulates the PDP8 instruction set, and the I/O Board
simulates a complete pdp8/e console. See this project results on :
www.pdp-11.nl/homebrew/pdp8/pdp8startpage.html
Especially the second "project" is nice (IMHO).
I can run SpaceWar in OS/8 on the 6809 !
During the workz I added an IDE hard disk interface to the I/O Board!
The pdp8/e simulation boots DMS or OS/8 from the CompactFlash card.
As the performance is not *that* good (...), I upgraded the Core Board
to run twice as fast.
You can do that upgrade too, if you have installed the 6809, 6850, and
6821 in sockets. Replace these 3 chips with their "B" version, and
replace the 4 MHz clock with an 8 MHz version. That's all!
The RAM chip(s) and the EPROM that was delivered in the kit are fast
enough to support this upgrade.
The initial load of the pdp8 software is not "user friendly".
I am thinking about a Floppy Expansion Board (FEB) that connects to the
Core Board through the PIA socket. The 68(B)21 is installed on the FEB.
The FEB has all parts to connect 2 or 3 floppy disk drives, which can be
8", 5.25", 3.5" or 3". I will test the 3.5" version, but expect the other
drives sizes to operate corretly too. The controller will be the 1793.
I intend to write the floppy disk drivers in the monitor, so you can use
the floppy disk also in the 6809 environment. From my hobby 20+ years ago
I have a self-written DOS, not compatible with FAT-12. Sorry, the PC was
just 1 or 2 years old when I wrote that DOS. However, "my DOS" has all
the commands you'd expect.
I can make the FEB just for myself, but if there is more interest on this
follow-up project, I will document this work-in-progress better than I'd
do just for myself ...
An other thing I am thinking about, is a new design of the Core Board to
get a better performance for the pdp8/e simulation. I am looking into the
possibility what speed improvements this sim would get if I rewrote the
6809 pdp8/e code into 68000. The new Core Board will of course have an
68000 (or cost reducing) 68008 clocked at 10 MHz.
Any comment is welcome, but I will ignore proposals for CPLD, Atmel, etc.
enjoy the pdp8/e simulation webpage!
- Henk, PA8PDP. what's in a callsign :-)
Hi everyone!
I have an old Portable PC that I put a 2MB memory card in, along with an EGA
card, sound card, and some other stuff. I'm doing my best to max it out.
Anyway, I'm having some trouble with hard disks. I have two hard disk
controllers: a Seagate ST02 SCSI/Floppy controller, and a Juko Labs D16-X
IDE controller. Now both of these cards work okay, except they recognize
some strange sizes for the disks. The only disk that seems to show up
correctly is a Quantum LP105S...the others I tried, all bigger than a gig,
are either not recognized, or recognized with the wrong size. This is also
the case with the IDE controller - everything is recognized at 10MB. I
purchased an LBA PRO card for my machine hoping to overcome the large disk
size problem, but all it does is freeze the machine...however, if I remove
the 8088 and replace it with a NEC V20, I get the banner for the hard disk
drive card, and THEN the machine freezes.
So my questions are:
1. Does anyone know a good solution for putting a large drive in an XT,
while still leaving it an XT?
2. Should I leave the V20 in? I've heard it has compatibility issues with
some programs, but I'm not solid on my information.
Regards,
Julian
>From: "Vintage Computer Festival" <vcf at siconic.com>
>
>On Wed, 31 Aug 2005, Brad Parker wrote:
>
>> Another punch card question.
>>
>> Of those who've read cards recently, was moisture a problem? i.e. did
>> the cards ever swell due to moisture and then jam, or was this not a
>> problem? just curious.
>
>Never had a problem with this. Most of the problems I have are cards that
>have not been stored appropriately and have bent or otherwise deformed
>over time. It's a bitch having to bend them back flat (a process of
>bending with my hands, over my knee, and in some cases when they just
>won't cooperate, whacking them repeatedly over the edge of a table).
>
Hi
You should use a steam iron.
Dwight
Hi -- Somebody's got to want a TU81 half-inch tape drive from DEC?
Its in Alabama and currently no bids, start price $9.99.
http://cgi.ebay.co.uk/Mainframe-Tape-Backup-Digital-TA81-Unix-TU9QAA-DEC-NT…
For me it's too far, too heavy and I've got no room, no
half-inch tapes, and no PDP-11 to plug it into. Other
than that, I'd have it in a minute.
Regards,
Jonathan.
> >>Gooijen, Henk wrote:
> >>
> >>>Hi all,
> >>>I am looking into the possibility to add a floppy disk interface
> >>>to the 6809 Core Board. 20 years ago, so this is OT :-) , I built
> >>>a floppy disk interface for my 6800 system using the 1793.
> >>>I have ordered some 1793 from BG Micro, but checking the data
> >>>sheet of the 1793, I noticed taht the FDC requires +12 on pin #40.
> >>>I know the MB8877 is pin-compatible with the 1793, but does *not*
> >>>need the +12V.
> >>>I failed to locate a seller for the 8877, but I do not know "all"
> >>>major part sellers in the US. JameCo, BG Micro and DigiKey do not
> >>>have this part ... somebody knows a good stock of the 8877 ?
> >>>I can use the 1793, +12V is "ugly", but the voltage is present as
> >>>the +12V is needed for the floppy drive itself!
> >>>
> >>> thanks,
> >>>- Henk, PA8PDP.
> >>>
> >>>
> >>>
> >>>
> >>Has it really be the 1793? Or might not be a 2797 design (2797 is
> >>also available from BG micro) from www.swtpc.com/mholley
> >>(New design for SS30 FDC) is more appropriate for "new
> developments",
> >>given that it doesn't need that really ugly external data separator
> >>logic which always prevented me from building FDC boards (a usable
> >>separator chip is more difficult to find than the FDC chip, and the
> >>alternatives with a TTL-monoflop grave is not even more attractive).
> >>
> >>Actually, what is your real problem? You already have 12V for the
> >>floppy drive, so what prevents you from feeding it into pin #40 of
> >>the 1793? +12V on an otherwise +5V board is not more ugly than a
> >>+25V source on an eprommer board, or +12/-5V for 2708/4116 memory
> >>boards.
> >>
> >>Holger
> >>
> >>
> >
> >Thanks for the reply Holger.
> >Your remark about the +12 for the FDC // +25 for an EPROM programmer
> >is correct. I know of the existence of the 2797, but have totally
> >none experience with it what-so-ever. The link that you gave is nice
> >but I am not sure I can *copy* the design ... Further, I have
> >several 1793
> >
> >
> Hi Henk,
>
> What appears to make the design on that page a bit difficult is the
> presence of the CPLD, but this is not really required, unless you
> need full SS30 compatibility, and at the price of losing some
> flexibility in setting modes; the 2797 datasheet shows a really simple
> application circuit.
>
> >here, so that is cheap for me. I would need to buy the 2797 and ship
> >it to The Netherlands (sources here are not as good as in the US).
> >
> >
> The 2797 is available from www.bgmicro.com, and they have no problems
> to sell to Europe; I have ordered several times from them already, and
> I guess if it works for Germany, it will also work for the Netherlands
> surely it is not useful for a single 2793, but they might have more
> attractive gadgets for the electronics enthusiast to reach a minimum
> order limit (had never problems WRT).
>
> >The data separator I use with the 1793 is more stable, and built with
> >a VCO (LS629, LS393 and LS153). I will look into the 2797 a bit more,
> >but I guess I'll go with the 1793. I saw in the diagram of the 2797
> >that it has also 2 trimpots for the adjustment ... Not sure yet ...
> >
> >
> They are for precompensation, and the datasheet explains how
> to set them
> - one better has an oscilloscope for it, but
> I guess this won't be better for a 1793 either.
>
> Regards
> Holger
Yes, in my case you are better of with an 'scope too :-)
But I will try to find a way to get the adjustment OK without a scope.
Hmmm, that is -not- a promise ...!
(I got three 1793's from BG Micro yesterday in the mail)
greetz,
- Henk.
> Gooijen, Henk wrote:
>
> >Hi all,
> >I am looking into the possibility to add a floppy disk interface
> >to the 6809 Core Board. 20 years ago, so this is OT :-) , I built
> >a floppy disk interface for my 6800 system using the 1793.
> >I have ordered some 1793 from BG Micro, but checking the data
> >sheet of the 1793, I noticed taht the FDC requires +12 on pin #40.
> >I know the MB8877 is pin-compatible with the 1793, but does *not*
> >need the +12V.
> >I failed to locate a seller for the 8877, but I do not know "all"
> >major part sellers in the US. JameCo, BG Micro and DigiKey do not
> >have this part ... somebody knows a good stock of the 8877 ?
> >I can use the 1793, +12V is "ugly", but the voltage is present as
> >the +12V is needed for the floppy drive itself!
> >
> > thanks,
> >- Henk, PA8PDP.
> >
> >
> Has it really be the 1793? Or might not be a 2797 design (2797 is
> also available from BG micro) from www.swtpc.com/mholley
> (New design for SS30 FDC) is more appropriate for "new developments",
> given that it doesn't need that really ugly external data separator
> logic which always prevented me from building FDC boards (a usable
> separator chip is more difficult to find than the FDC chip, and the
> alternatives with a TTL-monoflop grave is not even more attractive).
>
> Actually, what is your real problem? You already have 12V for the
> floppy drive, so what prevents you from feeding it into pin #40 of
> the 1793? +12V on an otherwise +5V board is not more ugly than a
> +25V source on an eprommer board, or +12/-5V for 2708/4116 memory
> boards.
>
> Holger
Thanks for the reply Holger.
Your remark about the +12 for the FDC // +25 for an EPROM programmer
is correct. I know of the existence of the 2797, but have totally none
experience with it what-so-ever. The link that you gave is nice, but
I am not sure I can *copy* the design ... Further, I have several 1793
here, so that is cheap for me. I would need to buy the 2797 and ship
it to The Netherlands (sources here are not as good as in the US).
The data separator I use with the 1793 is more stable, and built with
a VCO (LS629, LS393 and LS153).
I will look into the 2797 a bit more, but I guess I'll go with the 1793.
I saw in the diagram of the 2797 that it has also 2 trimpots for the
adjustment ... Not sure yet ...
thanks,
- Henk, PA8PDP.
> -----Original Message-----
> From: cctalk-bounces at classiccmp.org
> [mailto:cctalk-bounces at classiccmp.org]On Behalf Of Dwight K. Elvey
> Sent: dinsdag 30 augustus 2005 19:47
> To: cctalk at classiccmp.org
> Subject: RE: searching for replacement for 1793 FDC
>
>
> >From: "Gooijen, Henk" <GOOI at oce.nl>
> >
> >> Gooijen, Henk wrote:
> >>
> >> >Hi all,
> >> >I am looking into the possibility to add a floppy disk interface
> >> >to the 6809 Core Board. 20 years ago, so this is OT :-) , I built
> >> >a floppy disk interface for my 6800 system using the 1793.
> >> >I have ordered some 1793 from BG Micro, but checking the data
> >> >sheet of the 1793, I noticed taht the FDC requires +12 on pin #40.
> >> >I know the MB8877 is pin-compatible with the 1793, but does *not*
> >> >need the +12V.
> >> >I failed to locate a seller for the 8877, but I do not know "all"
> >> >major part sellers in the US. JameCo, BG Micro and DigiKey do not
> >> >have this part ... somebody knows a good stock of the 8877 ?
> >> >I can use the 1793, +12V is "ugly", but the voltage is present as
> >> >the +12V is needed for the floppy drive itself!
> >> >
> >> > thanks,
> >> >- Henk, PA8PDP.
> >> >
> >> >
> >> Has it really be the 1793? Or might not be a 2797 design (2797 is
> >> also available from BG micro) from www.swtpc.com/mholley
> >> (New design for SS30 FDC) is more appropriate for "new
> developments",
> >> given that it doesn't need that really ugly external data
> separator
> >> logic which always prevented me from building FDC boards (a usable
> >> separator chip is more difficult to find than the FDC chip, and the
> >> alternatives with a TTL-monoflop grave is not even more
> attractive).
> >>
> >> Actually, what is your real problem? You already have 12V for the
> >> floppy drive, so what prevents you from feeding it into pin #40 of
> >> the 1793? +12V on an otherwise +5V board is not more ugly than a
> >> +25V source on an eprommer board, or +12/-5V for 2708/4116 memory
> >> boards.
> >>
> >> Holger
> >
> >Thanks for the reply Holger.
> >Your remark about the +12 for the FDC // +25 for an EPROM programmer
> >is correct. I know of the existence of the 2797, but have
> totally none
> >experience with it what-so-ever. The link that you gave is nice, but
> >I am not sure I can *copy* the design ... Further, I have
> several 1793
> >here, so that is cheap for me. I would need to buy the 2797 and ship
> >it to The Netherlands (sources here are not as good as in the US).
> >The data separator I use with the 1793 is more stable, and built with
> >a VCO (LS629, LS393 and LS153).
> >I will look into the 2797 a bit more, but I guess I'll go
> with the 1793.
> >I saw in the diagram of the 2797 that it has also 2 trimpots for the
> >adjustment ... Not sure yet ...
> >
> > thanks,
> >- Henk, PA8PDP.
> >
> >
>
> Hi
> The 2791/93 are a more flexable choice than the 2795/97.
> >From my understanding of the spec sheet, the 2791/93 can
> do both 5.25 and 8 inch without changing external parts.
> The 2795/97 requires different clock frequencies to do
> this.
> You give up the side select but as was mentioned before,
> I suspect that one could double up the direction bit
> to also do side select or just have a port to do that.
> Dwight
Thanks for pointing that out Dwight! I overlooked that!
Only the 2791/93 has an *internal* clock divider circuit needed when
you control either 5.25" or 8" drives.
For the 2795/97 this means additional external circuitry.
I have in my design an octal latch to control some things, so density
can be controlled with one bit from the latch.
All in all, I will make my design with the (available) 1793. I only
have *one* trimpot adjustment, the 279x has *two*.
I will take the +12 from the power supply. The 7660 is a good suggestion,
but increases the chip count by one, unnecessary.
Ok, one wire added instead :-)
BTW, my design should work with 8", 5.25", and 3" proven years ago, so I
expect that 3.5" will work too ... time to heat up the soldering iron!
thanks,
- Henk, PA8PDP.
Hi all
I didn't see anyone answer Kelly's question, and
since I remembered to bring my Super Serial Card
manual in today... OK, this is the "Apple ][
Super Serial Card" which I hope is the same as
an "Apple Super Serial ][" card...
The "Cable Socket" is a 10 pin right angle looks
like 0.1" pitch connector.
The schematic seems to indicate
Pin Name Goes to
1 FRMGND R7 100R to GND
2 TxD Pin 6 on jumper block
3 RxD Pin 12 on jumper block
4 RTS Pin 4 on jumper block
5 CTS Pin 2 on jumper block
6 DSR Pin 10 on jumper block
7 SCTS Pin 8 on switch 2
8 SGLGND GND
9 DTR Pin 8 on jumper block
10 DCD Pins 14 and 16 on jumper block
HTH
W
