"CF Card not present" -- can't format known-good card

Joel Burton

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Feb 28, 2022, 4:05:50 AM2/28/22

to LiNC80

Hi, all —

I have an SC504 CF adapter card (from the Kit from Steven Cousins, using his parts). It's on an otherwise-working Z50 computer made from his SC516 processor card and his 511 serial/timer card.

I bought a generic 512MB CF card, but I also have a 64MB card I got from the RC2014 project (which they installed CPM on for an RC2014 Classic).

I've tried to format both cards using the FORMAT program, but it always says:

"""
Compact Flash card format v0.4 by Stephen C Cousins

Compact flash card not present
"""

The "detect" and "power" LEDs are on; the "active" LED never seems to light.

Interestingly, when I start up SCM, it always says that the CF card is *not* detected using the DEVICES command. However, if I use the RESET command, it indicates that "CF Card @ 90 detected".

I'm not surprised if it may not work with the 512MB card I bought; I can see from other messages here that finding a working card is tricky. However, the 64MB from Spencer should work, no?

I do have a CF reader for my main computer and can try using "dd" to copy the CPM startup image directly to the card, as described at http://linc.no/products/linc80-sbc1/software-for-the-linc80/#imgtransfer (I tried that already using their CPM images, but I know this might not work w/Steven Cousins Z80 cards)

Is there a disk image for CPM I can try to put on the card from my Linux box? And does anyone have any advice on how to debug the failure to detect the card?

Thanks for any tips.

J.

Steve Cousins

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Mar 1, 2022, 7:08:09 PM3/1/22

to LiNC80

Hi Joel,

I'm finding the CF card detection used by the DEVICES command is marginal with some systems and CF cards. The detection is done immediately after reset and the result is remembered for the DEVICES command. The CF cards appear to take time to respond after a hardware reset and sometimes are not ready in time to be detected. Issuing a RESET command does not cause a hardware reset of the CF card so it responds without a delay. In any event, this detection is only used for the DEVICES command.

Software such as the format utility includes its own card-present test.

The format utility needs to match the address of the CF card. I'm wondering if you are using a version that does not match. Until the release of the SC500 series, all the utilities assume the CF card is at address 0x10. The SC500 series follows the Z50Bus guidelines and thus the recommended address had to be changed from 0x10. Try the attached format utility that assumes the address is 0x90.

I think my documentation needs to be improved to better explain the addressing issue and make the correct utilities easy to find.

One suggestion, make sure the CPU card and the CF card are next to each other on the backplane. There are a number of issues related to connecting a CF card directly to the processor bus, making it rather critical where things are.

I hope the above gives you some clues but if you still have trouble please let me know.

Steve

SCMon_CF_Format_Z80_CFx90_code8000.hex

Steve Cousins

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Mar 2, 2022, 6:59:58 AM3/2/22

to LiNC80

In answer to the question about disk images, there aren't any specifically for the Z50Bus, as far as I know.

However, any CP/M image designed for Grant Searle's implementation of the CP/M BIOS should be usable with a little work. That means images for the RC2014, LiNC80 SBC1, and others can be useful. All you need to do, I think, is to write the image to a CF card, fit the card to the Z50Bus system, then write the compatible version of the CP/M OS to the CF card using PutSysPlus via SCM. This will overwrite the OS installed as part of the image but shouldn't overwrite any of the files.

The CP/M OS written with PutSysPlus is the only part that should be hardware-specific. The rest of the files should remain unchanged by PutSysPlus. Any pure CP/M programs and data should be compatible with the Z50Bus range.

Another place to get images is Karl's website. There are some at the bottom of this page.

I think the only reason the standard RC2014 Compact Flash based software and utilities don't work on the SC500 series is the change in recommended address of the Compact Flash card to best match the Z50Bus guidelines for device addresses. This is proving painful as there are quite a few programs that directly access the CF card. I'm still working on porting them all. Once all the code is ported it will no longer be a significant issue. I do keep wondering if the address change is worth it but the work will soon be complete!