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Re: [N8VEM-S100:2682] S100 IDE Version 02 - Silkscreen Error



Hi John,
 
Yes, mine behaves the same.
I have attached a picture below to illustrate my point.
In the picture I have crudely updated the blue designations to get the schematic to match the screen print designations on the PCB as you suggest but notice how the IDE control signals indicated by the black arrows now appear to go to the wrong ports, I'm no cad expert and correct me if I'm wrong but I would assume that /RESETA would be a 'net' label for that group of connections, wouldn't these also need renaming to correct the schematic ?
 
regards
 
David Fry
 

On Saturday, March 8, 2014 12:30:33 AM UTC, monahanz wrote:

Yes to load CPM the “A”  LED’s light up. On power up/reset D18 is on. Booting CPM D21 flashes as well.

From the front of the board,  the RHS CF card is used. You can in fact remove the LHS card.

I have MSDOS on my second/LHS CF card and am absolutely sure that is not accessed.

 

John

 

 

 

From: n8ve...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of David Fry
Sent: Friday, March 7, 2014 1:36 PM
To: n8ve...@googlegroups.com
Cc: mon...@vitasoft.org
Subject: Re: [N8VEM-S100:2682] S100 IDE Version 02 - Silkscreen Error

 

Hi John,

 

The only problem with updating the CF Card Slot text and LED text designations on the schematic is that the IDE control signals /IORDA  /IORDB  etc.. will then look like they go to the wrong CF slots.

 

Just to confirm, does your system initially boot from the CF slot directly above the DIL switches (P41) ?

because looking at the IDE control signals this is slot B, i mean it makes no difference to me if it boots from slot 'B' or 'A' I can always put a little sticker over the screen print to correct it. I'm just happy its now working and I can move onto the next step :-)

 

regards

 

David Fry
On Friday, March 7, 2014 9:02:24 PM UTC, monahanz wrote:

I see it now David. Looks like the blue comment text in the schematic was not updated when the silk-screen text on the board was changed. The two are not linked.

I don’t seem to be able to move the text in the .pdf file with my Acrobat Pro. Can you?

Andrew is so busy these days I don’t want to bother him with this. If you (or anybody else) cannot change the .pdf file I will just make a note on the web page.

John

 

From: n8ve...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of David Fry
Sent: Friday, March 7, 2014 10:58 AM
To: n8ve...@googlegroups.com
Cc: mon...@vitasoft.org
Subject: Re: [N8VEM-S100:2679] S100 IDE Version 02 - Silkscreen Error

 

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: n8ve...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of David Fry
Sent: Friday, March 7, 2014 7:21 AM
To: n8ve...@googlegroups.com
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

 

 

 

hope this give someone a heads up

 

regards

 

David Fry

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