IDE-SD adapter question

[Richard Cini]

Off hand, I wonder if the 486 doesn’t support logical block addressing in the BIOS (or its not enabled). Modern machines (and those of a Windows 95 vintage) do not use CHS addressing (cylinder, head, sector) any longer.

SD cards usually don’t return Sector errors because of the dynamic remapping the firmware does.

Rich

Get Outlook for iOS<https://aka.ms/o0ukef>
________________________________
From: cctech <cctech-bounces at classiccmp.org> on behalf of W2HX via cctech <cctech at classiccmp.org>
Sent: Friday, June 26, 2020 5:39:57 PM
To: cctech at classiccmp.org <cctech at classiccmp.org>
Subject: IDE-SD adapter question

Hi all,

Thanks for previous help on this project. I am working on an old 486 computer and I have replaced a 40 pin IDE hard drive with this SD adapter...
https://www.amazon.com/gp/product/B07G29TZPS/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

In general it seems to mostly be working. I can see a directory listing of several thousands files located on a 2GB SD card from yesteryear. The SD card was new when I installed it (has been in my possession for years).

However, I do get errors "sector not found" and if I A)bort I get INT 24 error.  I am trying to get windows 95 installed and this is certainly preventing that.

In the BIOS settings I have the hard drive set as "USER" and these parameters:
CY:[1024] HD:[16] ST:[63] LZ:[1024] WP:[0]
These were the parameters in use while I was still using the actual hard drive.

Question 1: Now that I am using an SD card instead of an IDE drive, what, if anything, should I be doing with these BIOS parameters?
Question 2: The BIOS has an option to format the hard drive. Should I format the SD card using this facility?

I did not explicitly put a filesystem on that SD card. I placed it in a windows 7 machine, it was recognized, and I began copying files to it. I then place the SD card into the 486 machine where I saw the sector not found errors.

Any advice how to proceed?
Thanks
Eugene