telemonster
Member
Hello all!
I've owned an IMSAI 8080 for a number of years now -- but I have never quite figured out how to use it / get it working.
My system has 6 x 8K boards in it, that seem to be addressed properly.
There is a Northstar Floppy controller which I'm ignoring for now, it's hard sectored disks. I did buy some widget that is supposed to emulate the hard sectoring but haven't assembled or touched it yet.
There is a video output board. Processor Technology VDM-1. I have tried it with and without it
There is a serial IO card that also includes a monitor ROM. It also has a cassette interface as well.
I have hooked a terminal up to it, and from the manual for the serial IO card it says to execute at C800. I have done this, and the lights on the front panel start to run. Code is executing.
But I never see any serial output on the terminal. I'm supposed to get a prompt.
I've replaced the line driver chips after the UART, but no difference. I've watched serial output with an oscope and I don't think anything comes out of the serial port.
I walked thru examining the first bytes of the monitor ROM versus the program listing in it's manual and it looked good, so I am able to see that.
Any thoughts as to what next? I pulled out the card that has the composite video output. I hooked up a monitor to it in the past and don't remember seeing a prompt there. The system came complete to me, but no floppy disks.
Any pointers appreciated. I'm a S-100 newbie, and it's been kind of a long journey piecing together how this is supposed to work.
I've owned an IMSAI 8080 for a number of years now -- but I have never quite figured out how to use it / get it working.
My system has 6 x 8K boards in it, that seem to be addressed properly.
There is a Northstar Floppy controller which I'm ignoring for now, it's hard sectored disks. I did buy some widget that is supposed to emulate the hard sectoring but haven't assembled or touched it yet.
There is a video output board. Processor Technology VDM-1. I have tried it with and without it
There is a serial IO card that also includes a monitor ROM. It also has a cassette interface as well.
I have hooked a terminal up to it, and from the manual for the serial IO card it says to execute at C800. I have done this, and the lights on the front panel start to run. Code is executing.
But I never see any serial output on the terminal. I'm supposed to get a prompt.
I've replaced the line driver chips after the UART, but no difference. I've watched serial output with an oscope and I don't think anything comes out of the serial port.
I walked thru examining the first bytes of the monitor ROM versus the program listing in it's manual and it looked good, so I am able to see that.
Any thoughts as to what next? I pulled out the card that has the composite video output. I hooked up a monitor to it in the past and don't remember seeing a prompt there. The system came complete to me, but no floppy disks.
Any pointers appreciated. I'm a S-100 newbie, and it's been kind of a long journey piecing together how this is supposed to work.