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TexElec ISA IDE to SD Adapter on IBM 5150

ugadawg84

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Joined
Mar 21, 2023
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Has anyone been able to get this card operational on an IBM 5150 with any version of DOS other than 5.0?

My setup:
- IBM PC 5150 equipped with 2X 360K 5.25 floppy disks
- Total memory = 512K (256K on system board and 256K on IBM memory card adapter)
- IBM CGA card adapter
- ROM is correct for this adapter (1501476)

I have successfully formatted and installed DOS 3.1 on a 16Mb SD card via FDISK. However, when I
do a clean boot, the system hangs saying "Booting C>>C"

Thanks in advance.
 
Did you prepare the compact flash correctly?
1) fdisk for partition
2) fdisk/MBR
3) formats
 
Following this thread with interest, as I am still DEBATING purchasing the TexElec for my ndewly acquired Leading Edge Model D. Adrian Black had to flash a newer version of the Pheonix BIOS to get his working on a Model D (I don't have the ability to do that), so I am concerned RE: the XT-IDE BIOS
 
An update on this. I acquired a copy of MSDOS 5.0 and began the install procedure. 5.0 only recognized the 2 floppy drives and only gave floppy installation of 5.0 as an option. I then took the 16Mb SD card out of the 5150 and put it in my modern laptop. I blew away the previous DOS partition leaving the SD card without any partitions or OS. I put the card back in the 5150, restarted the MSDOS 5.0 intall procedure and the TexElec "hard drive" with SD card was recognized. The install process reformatted the SD properly and completed the installation. The system now boots from the 16Mb SD card in the TexElec without issue.

Also, the team at TexElec was very helpful with suggestions on getting this working. They strongly recommended, given it was a 5150, using a small size SD card.
 
The system now boots from the 16Mb SD card in the TexElec without issue.

Also, the team at TexElec was very helpful with suggestions on getting this working. They strongly recommended, given it was a 5150, using a small size SD card.

FWIW, I'm not really sure that's great advice. A 16Mb SD card is going to be old, very slow, and have worse wear leveling than a more modern card. There's nothing preventing you from using larger and more modern cards; Conventional MS/PC-DOS is limited to using only 8GB maximum of the card because of limits in the INT13 BIOS routines, but there's no harm in having unused space sitting after the partitions, and in fact it's beneficial when wear leveling is considered.

(I use a homemade functional equivalent of this card in my Tandy 1000s, and my favorite choice for SD cards is Samsung's "PRO Endurance" cards, which are rated for use in surveillance systems/dashcams/etc. A 32GB card is $9 and if Samsung is telling the truth about the wear life of these cards I could set up a DOS program to pound writes to the card constantly for over 20 years before I'd start even approaching the stated limits. And that doubles if I use a 64GB card.)

Re: slowness, I did test an ancient 32MB card in my system once, and according James Pearce's "disktest" benchmark that card was only capable of single-digit IOPS in the sector random read test. A more modern card does 57.
 
TexElec was just trying to take one step at a time by suggesting the small SD card to get a customer up and running and, for that, I'm very grateful to them.
 
It’s nice that they went to that effort I guess, but… I still think it’s not the greatest advice. The biggest issue people have with flash cards in these XTIDE devices (well, maybe the other biggest issue after CF compatibility woes, which I find these SD adapters usually solve) is XTIDE freaking out and acting badly because they get confused by MBR/partition table data left over on the card from its previous life.

New SD cards are usually pre formatted with FAT32 or VFAT which means, yeah, they might give XTIDE a headache. I think it might be better if the “very likely to be right” solution of doing a low-level blank of the card on a modern computer before using it was more widely prescribed as the first go-to.
 
Hi,
It is not XTIDE having a problem with ther existing MBR, but FDISK
It is described in the XTIDE Wiki to use an utility to blank the MBR, from the PC.
 
Well, to be technically correct (the best kind of correct) neither FDISK nor XTIDE has a problem with the MBR code. It's just that the CPU doesn't support it. So I guess you could say the CPU has a problem with it. 😉

I do agree that wiping the media, regardless of type, should be the first step when installing these things.
 
Well, to be technically correct (the best kind of correct) neither FDISK nor XTIDE has a problem with the MBR code. It's just that the CPU doesn't support it. So I guess you could say the CPU has a problem with it. 😉

I do agree that wiping the media, regardless of type, should be the first step when installing these things.
There is the second case, If we boot on a Floppy and FDISK Does not recognize, the MBR is not executed.
 
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