Re: CP/M 3 Boot from a Compact Flash - problems and need help.

Hi Thomas,

just reading through my notes as I haven't touched this in a couple of months which I will explain in the other thread when I get a chance.

I'm not sure at the moment why the displayed LBA value is incorrectly large but I have just fired up my system which does boot and it also shows the same incorrectly large value. But don't let this worry you as the moment, if I remember correctly the LBA value displayed on screen is pulled from memory locations that contain the CHS values. The actual LBA values sent to the drive should be correct. I will look at correcting this display error and upload a replacement archive.

But to press on, looking at your screen shot it would appear that the MYIDEROM has loaded the first 12 sectors into memory but has failed to launch CPMLDR.COM as there is no sign on header

A couple of tests to start off with (forward screen shots of HxD if you can)

1) pop your CF card into a card reader attached to your PC and launch HxD, Open the CF card (extras > removable disk)

take a look at the first byte of sector 0 (address 00000000) it should be hex value 31

2) pop your CF card back into your S100 system, launch MYIDEROM and hit the 'I' option once so that CPM SEC = 0001

then hit the 'R' option to read this sector into the buffer, this should load LBA sector 0 into the RAM buffer at 0100H

hit the esc key to drop back to your Z80 monitor and use your monitor to examine memory location 0100H

on the S100 Computers Z80 Monitor it is D0100,0200, memory location 0100H should also be 31H

these two tests should go some way to indicate that the CPMLDR.COM file data is located in the correct place on the CF card and LBA sector 0 loads correctly into the memory buffer using MYIDEROM routines.

IF the MYIDEROM code finds 31H at address 0100H then it will proceed to launch code from this address if it doesnt find 31H it should flag an error before exiting.

LOAD$DONE:
MVI E,REGstatus           ;Check the R/W status when done
CALL IDErd8D
BIT 0,D
JNZ CPMLoadErr          ;Z if no errors
LXI H,CPM$ADDRESS
MOV A,M
CPI 31H                          ;EXPECT TO HAVE 31H @80H IE. LD SP,80H
JZ CPM$ADDRESS       ;AS THE FIRST INSTRUCTION. IF OK JP to 100H in RAM
                                      ;Else fall through to error msg

regards

David Fry

On Wednesday, June 11, 2014 9:56:42 PM UTC+1, Thomas Owen wrote:

Hello David,
I had hoped you would see this post, and I thank you for the reply.   I used the version of MYIDEROM and all the files right out of your zip.

Regards,

Thomas

On Wednesday, June 11, 2014 4:27:30 PM UTC-4, David Fry wrote:

Hi Thomas,

If I understand you correctly you are using the ROM version of MYIDE to boot the system,

Did you use the version inside the zip archive I uploaded to my folder or are you using a version downloaded off of the S100 computers website ?

regards

David Fry

On Wednesday, June 11, 2014 8:35:13 PM UTC+1, Thomas Owen wrote:

Now that I have my IDE card passing all the preliminary tests, I am trying to install CP/M on the Compact Flash drive and get the system to boot.

System:

Compupro ZPU at 2 mhz.

IDE CF Card, version 2.0a

IMSAI SIO for console

Ram 17 with Eprom installed at ‘E000’

8 gb Kingston CF

Have read, and re-read all the articles I can on the site, and decided to use the method put together by David Fry found here.

http://s100computers.com/My%20System%20Pages/IDE%20Board/Z80%20CP_M%203.0%20build.pdf

Step 1 - I modified HLDRBIOS.ASM to support my Console device (IMSAI SIO)

Step 2 - I modified CHARIO3.ASM to support my Console device

Step 3 - Assembled and built the CPMLDR.COM

Step 4 - Copied it to the CF at Sector 0

Step 5 - Assembled and built the CPM3.SYS and copied it to the CF at sector 112

Step 6 - Moved sector 48 to sector 63 on the CF

I know the install is not complete, but at this point I wanted to see what a ‘Boot’ looked like from David’s MYIDEROM:

At boot I see displayed on the console and MYIDEROM reports this drive information:

Cyl:      3C82               Heads:            010                 Sectors: 0048

Then I choose ‘C’ for Boot CP/M and here is where I see a problem:

Notice the ‘LBA = 003C003C’.   Why is that value so high and incorrect?

Any suggestions to getting is completed?

Thanks in advance,

Thomas