Hi John, Yes, referring to the picture at the bottom of your web page when I boot my system the LED labeled 'A' lights up (4th from left) but looking at the part number on the pcb this LED is D18, when you then check the schematic you find that D18 is in fact 'CF-B' select so the IDE drive control signal steering logic U18+U19 sends the IDE control signals to socket P41 which is labelled on the schematic as 'CF card B'. P41 is the socket directly above the DIL switches. Looking at the screenprint labelling on the version 02 prototype it seems to tie in with the schematics which I tend to work from. I guess it's not as simple as just updating the schematics as this would mess up the net lists would it not ?. regards David Fry
On Friday, March 7, 2014 6:13:51 PM UTC, monahanz wrote: > Thanks for the info David. > > It’s been a while since I did that board, (2011). The two things I > learned way back then with those CF cards was that the length of time of > the reset pulse was very important as was the height of the read/write > pulse. Buried somewhere in the IEEE specks, the latter was 4 volts! > > > > The confusion on the web page pictures arose because one is a picture of > the prototype, the bottom one is the final “production” board. > > > > On my systems here (3), in all cases when I boot up CPM for example, > always the “A” LEDs light up. Only when I go to a second drive does the > “B” LED light up. Is that not what you see using the picture at the bottom > of the web page. > > > > If not, I suspect the 4K ROM based version software has the bit selection > for the drives the other way around. That’s an older version. I would use > the later diagnostic version. > > > > John > > > > > > *From:* [email protected] <javascript:> [mailto: > [email protected] <javascript:>] *On Behalf Of *David Fry > *Sent:* Friday, March 7, 2014 7:21 AM > *To:* [email protected] <javascript:> > *Subject:* [N8VEM-S100:2674] S100 IDE Version 02 - Silkscreen Error > > > > Hi all, > > > > Following on from my recent 'New build' post I have spend several hours > over the last few days trying to get my S100 IDE Version 02 card to work. > > > > Initial power up looked good with all the led's initialising under the Z80 > monitor, I compiled a copy of John's MYIDE.ASM (Rom Version) to reside at > memory address 8000H and programmed the resulting hex file into one of my > 28C256 EEPROM's, carefully opened up a 16Kb memory window at 8000H on my > RAM/ROM board and dropped the chip into the 8bit socket then powered the > system up and ran the code at 8000H, after a brief delay it seemed to > recognise a CF card but the description header and CHS info was all > scrambled. I tried out a couple of functions (read a sector/write a sector > etc...) but something was amiss, data was not being retained by the CF > card, I tried attaching a hard disk to the cable instead (in fact 4 > different hard drives) and none of them were detected !!!!. > > > > So I rechecked my work, all the IC's were correct with maybe the exception > that I used 74LS03's in positions U19 and U19 so I attached my oscilloscope > to the /IOWRA and /IORDA and confirmed what John Monahan had mentioned in > his web page write up that these signal levels were only hitting 3.4v on my > board, > > So I ordered up a pair of 74S03 IC's and fitted them whilst at the same > time I replaced RR1 with a 330ohm part to increase the drive current on > these signal lines. > > Re-scoping the /IOWRA and /IORDA signal lines now confirmed that they were > fine and hitting 5v levels but this did not solve my problem. > > > > To cut a long story short and after much head scratching I noticed that on > Johns web page for this board he has two pictures of the S100 IDE Version > 02 board at the bottom of the page. On one of the boards the leds (from > left to right) go A B A B ..... and on the picture below the leds go B A B > A..... my board goes B A B A. > > This was the clue... > > Referring to the schematic and confirming operation on my board, on power > up U16A D-type flip flop Q output will go low making D18 (CF-B select) > illuminate, this same Q output state determines which IDE control signals > are active via U18/U19, of course with my board being silkscreened wrong it > was indicating CF-A was active and as such I had my IDE cable plugged into > the wrong socket all along :-)))) > > Changing the cable over to connector P41 everything now works fine both CF > cards and hard drives Hoorahhhh... > > > > This was a great learning experience for me to learn how the MYIDE > software interacts with the hardware, during my investigations I did write > up some notes on testing the board hardware by outputting values to the > various I/O ports which may be of use to someone in the future, > > > > S100 IDE Board Version 02 board build.doc > > > > http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder¶m=David%20Fry > > > > > > hope this give someone a heads up > > > > regards > > > > David Fry > > -- > 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] <javascript:>. > 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.
