Todd, The Shadow ROM Kill Jumper JP5 moves from 1-2 when using v1.2 firmware to 2-3 when using v2.3 firmware. Ignoring the funny similarities in the jumper/version numbers... keeping the jumper in 2-3 when using v1.2 should not allow you to run CP/M. Wait! it shouldn't allow you to run the monitor either... in that version, the boot loader copies the ROM contents to upper RAM, then it writes a jump instruction into lower (Write Only) RAM, that instruction is written just after the OUT instruction that will kill the ROM... Bottom line, if v1.2 works with jumper in 2-3, then there's some kind of short in those circuits. Pull out that jumper and try following each trace and ohm it out with adjacent traces. I haven't heard of anyone having problems with micro shorts from PCBCART, I'm using 12mil spacing, which is a lot. It might be a solder short ? Happy Hunting!
Regards, Josh > Date: Sun, 22 Feb 2015 21:28:32 -0600 > From: [email protected] > To: [email protected] > Subject: Re: [N8VEM-S100:6415] Re: IMSAI 8080A CPU board help. > > No, I did not move the kill jumper. Stayed at 2-3 all the time. > All components used to make this board were new, except for 8250's, > 8212's & the CPU. These were bought 'as' NOS. I have a CPU tester so > that's ok and have tried several. > > I could swap the 8212's but since it works on v1.2 it 'must' be ok > for v2.3 ? > > I got rid of my HP Agilent 16xx Logic Analyzer. I had all the pod's > and clips but the darn thing didn't have a "save". Got tired of setting > it up all the time cuz it would forget when you turned it off. > > > ----- Original Message ----- > From: "Crusty OMO" <[email protected]> > To: [email protected] > Sent: Sunday, February 22, 2015 8:46:54 PM GMT -06:00 US/Canada Central > Subject: RE: [N8VEM-S100:6414] Re: IMSAI 8080A CPU board help. > > > Todd, > > That is really really weird! I am going to assume you are moving the Shadow > ROM kill jumper right? And you have the 8212 chip for the output port > installed (IC-J5)? > > At this point, I would hook up the analyzer and watch the activity on the > bus... If you are in the neighborhood, you can drop by and we can swap chips > to see if there's something intermittent about one of them? > > Regards, > Josh > > > > > Date: Sun, 22 Feb 2015 12:40:59 -0800 > From: [email protected] > To: [email protected] > Subject: Re: [N8VEM-S100:6409] Re: IMSAI 8080A CPU board help. > > > Update ! > > With only the CPU board <no prop i/o> I am able to boot/load the monitor and > CP/M > using v1.2 firmware and related files. I'm not familiar with the monitor > syntax. Is this > a common monitor program ? I'd like to know how to use it.. Otherwise I can > load > CP/M and get the a> prompt. A "dir" command gives me one file MON-32K.COM. > > Also, as mention in another thread, I was having an issue using v2.3 and a > memory > error. I did the test Josh had recommended to Jeff to test the lower RAM chip > with the > command R 00 7F. It took a bit but ran and passed. I switched the two memory > chips > and they all passed. > > At this point I want to 'assume' my hardware is good, but my setup doesn't > like v2.3 yet. > > > > > > > > On Saturday, February 21, 2015 at 10:52:17 PM UTC-6, litterbox99 wrote: > > Josh, > > I'm now using a comm port on the CPU board (w/HyperTerm & WinXP) & (The > Console I/O) on the other. > > They echo/mirror each other for key press & screen, but it still won't > respond to anything but < R > > for the Ram test that fails @042A > > Todd > > > ----- Original Message ----- > Todd, The firmware outputs to both the 8250 UART port 0 on board (I/O 20h) > and to the Console I/O board at I/O 00h. > It will also accept any input from either console. If you connect them both, > then you'll see a duplicate. > I was thinking of writing a seek and employee routine that would send > messages to a range of I/O address and scan them all for a response ie, > "Press <CR> to continue", but the variations were endless and such > programming would take too much time. So I just hard coded support for the > CONSOLE IO to the routines that already work with the on board uart. > > Cheers, Josh > > -- > You received this message because you are subscribed to the Google Groups > "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] . > For more options, visit https://groups.google.com/d/optout . > > > -- > You received this message because you are subscribed to the Google Groups > "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] . > For more options, visit https://groups.google.com/d/optout . > > -- > You received this message because you are subscribed to the Google Groups > "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
