[Coco] PT68K-4

[Dave Philipsen]

Thanks for that information.  I already had most of the documentation 
and firmware but hadn't seen the disk images before. Is there any 
information or documentation on the "imd" file format? What program is 
used to restore those images to disks?

Dave


On 9/20/2015 2:24 AM, Barry Nelson wrote:
> I found this information about MONK and the PT68K and the documentation at the links below…
>
> At Power On, MONK will beep the speaker and then look for a Terminal connected to COM1. If not found it will proceed to initialize for a PC keyboard and initialize the previoup selection made by the "X" command. If no selection exits it will try to find a display adaptor and initialize it. If for some reason you get a blank, screen enter "X" and the character "M" for MGA, "C" for CGA, "E" for EGA or "V" for VGA to tell MONK the type of Display you want. If a Terminal is found, it will try 19.2K baud rate, and then default to 9600. Monk will accept input from either the PC keyboard or the Terminal keyboard; however, programs using traps for I/O will use the selected I/O devices.
>
> Documentation
>
> http://bitsavers.trailing-edge.com/pdf/peripheralTechnology/PT68K4/
>
> Disk images
>
> http://bitsavers.trailing-edge.com/bits/PeripheralTechnology/
>
>
>   
> On Sep 20, 2015, at 1:18 AM, coco-request at maltedmedia.com wrote:
>
>> Date: Sat, 19 Sep 2015 23:30:20 -0500
>> From: Dave Philipsen <dave at davebiz.com>
>> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>> Subject: [Coco] PT68K-4
>> Message-ID: <55FE365C.8060808 at davebiz.com>
>> Content-Type: text/plain; charset=utf-8; format=flowed
>>
>> This is a fairly lengthy explanation/question about the PT68K-4 so if
>> you don't know what that is or you're not interested feel free to stop
>> here and go on to the next message.
>>
>> I have an old PT68K-4 motherboard that I bought somewhere around 25
>> years ago. At one time I had it up and running OSK V2.4 with a hard
>> drive, floppy, ET4000 VGA card, and a modem.  Well, along the way
>> everything but the motherboard and the original manual has disappeared.
>> It's been so long since I used this machine that I don't even remember
>> what the boot screen looked like.  So I found an old XT power supply, a
>> new HD floppy drive, a power LED, and a HALT LED and hooked them all
>> up.  The 'BIOS' EPROMs on this board are labeled 'MONK' which is the
>> monitor that was used for booting OSK. I believe 'HUMBUG' EPROMs were
>> used for other operating systems. The board has the full 4MB of memory
>> and I went ahead and 'wiggled' pretty much all of the chips of the
>> motherboard in their sockets including the RAM chips.  Right now I do
>> not have a VGA card but I'm waiting on receipt of an ISA bus ET4000 VGA
>> card from a gracious doner in Australia.
>>
>> When I turn on the power supply the POWER LED lights and the HALT LED
>> lights momentarily then goes out (which I'm pretty sure is normal).  I
>> also get a 'beep' out of the speaker which I believe is a very good
>> sign.  So I put a 'scope on the *CS line on the first DUART which
>> controls COM1 and COM2 and I see regular negative going strobe pulse
>> there indicating that the monitor is looking for input from a serial
>> port (presumably COM1).  Also, the schematic shows me that the 'beep' I
>> hear when I power up the motherboard comes from a single-bit output on
>> the DUART which to me means that the CPU is talking to the DUART.  I
>> also 'scoped the pin on the DUART where the recv/xmt clock comes in from
>> a can oscillator.  Rough calculations from my 'scope say the frequency
>> is about 3.7 MHz which is corrrect (oscillator is 3.6864 MHz).
>>
>> Here's the question:  Right after reset and the speaker beeps there is a
>> quick little burst of data that comes out of the TxD on the DUART.  I
>> can see the burst on my 'scope (it might be just one or two characters)
>> on the TxD pin of the DUART and I can see it on the TxD pin of the COM1
>> connector at RS232 levels.  When I hook this up to a COM port on my PC
>> with PuTTY running in serial port mode I get nothing intelligible coming
>> in to the serial port on the PC.  I've tried 200, 600, 1200, 2400, 9600,
>> 19200, and 38400 bps on PuTTY but I can't see anything other than some
>> garbage characters.  Can anyone tell what I should be seeing and what
>> the monitor program (MONK) expects to be seeing from me?
>>
>> Dave Philipsen
>>
>>
>>
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