Boot retro PC using XTIDE (Part 1): What is XTIDE?

This video is just an explanation, what XT-IDE is and how it can help to boot old PCs using modern hard drives or even compact flash cards.
Part 2: • Boot retro PC using XT...
Music by Model Povedeniya
modelp.bandcamp.com/

[@JorgeCarvalho_web_dev]

Hi! Very nice introduction for the XT-IDE concept, starting to explain the basis for the BIOS in the NIC. Keep going!!! Waiting for the next part :) I had those problems with some old machines, now moving to a modern solution: VIA C3, compatible soket 370 Motherboard, some jumpers to set 66/100FSB outside the case and SETMUL :)

[@alpine7840]

This makes so simple!

[@camjohnson2004]

The reason the old motherboards can't read certain compact flash drives that are over 2GB is the fact that Compact flash cards use UDMA which older computers didn't support. Old 186, 286, 386 and sole 486 boards only support PIO or Programmed I/O mode. UMDA was added in the Pentium Era to increase HDD speeds beyond 33MB/s the UDMA mode for most older Compact Flash cards was UDMA4 or 100MB/s UDMA 6 is the current version which allows for 200MB/s on the larger Compact Flash cards. Since Compact Flash is not a HDD it only supports the UDMA mode and does not support PIO modes for slower speeds.

[@necro_ware]

That is not quite right, it is not necessarily because of UDMA. Most of the CF cards actually even support PIO mode. The problem starts with drives > 504MB because of LBA translation, which old BIOSes didn't support and this is what Universal XT-IDE BIOS fixes. But if you have UDMA only CF card, this would be a problem indeed, however I didn't see such cards yet. In fact if a card is not working, it is usually due to aggressive pull-down resistors on the databus inside of the CF card. This can be a problem on boards, which don't have additional bus drivers on the data bus.

[@Beus38]

@@necro_wareThank you both for the explanation. I have always wondered why the my 386 does not even start when I plug the CF to IDE adapter with SD to CF adapter card into the 1992 ISA ATA controller, while the integrated ATA controller on my 486 board from 1995 works flawlessly with it. So, it seems, might really be the pull-downs that take the whole bus down and prevent the machine from even working properly. So I am curious - are there some CF or SD adapters that DO work with these older controller cards and boards? Or rather - are there any specific requirements that the adapter/card must fulfill to work with them?

[@channelkerr]

Ugh Conner drives 🤮. My old Toshibas are "locked" to that brand of drives! Good overview and I don't think I've seen a 286 mobo with integrated IDE controller before!

[@jimbox114]

Thank you for video. I am looking at doing something like this with an old Pentium board that I have. Also kinda jealous you have a 286 board lol.

[@necro_ware]

You are welcome! I actually own multiple 286 mainboards :) But why do you think to use it with a pentium PC? Usually they don't have problems with more modern IDE devices.

[@QueenLISA_Cutee]

please make one video cfast industrial card to usb how to transfer bootable iso image

[@simaobola]

I loved the explanation. Thank you for the infotraining. I got one doubt: my retro system is EUROPC I, from SCHNEIDER, it only has 512 kb ram... would this project work in it anyway?

[@Beus38]

I assume it should. The x86 CPUs expect the first executable byte at FFFF:0000 which translates to real-mode address FFFF0 which is 16 bytes below 1 MB mark. It is the memory mapping IC on the boart that directs the calls to those addresses to BIOS ROM instead of RAM, so even if your computer does not have that much ram, the address is still valid and being directed to the ROM chip instead. The same happens for VGA BIOS ROM, video RAM itself, and it should also happen for any other controller ROM present in the system. The jumpers on the card tell the MMU on the board what address space it should route to that particular ROM chip.

[@erocdraHXAM]

Hi, XT-IDE looks interesting. i have a acer 1100/16 (386 from 1986) and he have a prehistoric Bios ther you can set type 1-47 (but 47 is not user defined) and type 60-83. I want to use a ESDI Harddisk on this System but it is much larger than the most Bios Harddrive settings (they doesnt show their value, i used checkit to get the value of cyl/head/sect. of the type 1-83) the largest disk type is Cyl1023/H15/35Sec my HP 97548E have 1457/16/57, my question: do you think it is Posible to boot with this disk settings with a xt-ide bios?

[@necro_ware]

With XTIDE you can even put 8GB into a 286, so, yes, it should be possible :)

[@baghdadiabdellatif1581]

I have a question plz My motherboard have PCI slot and ISA slot i have PCI network card can i put the extension bios on the PCI network card bios?

[@GamePlayShare]

I was always wondering if its possible to use any card with BIOS like those year2K cards instead NIC card.

[@necro_ware]

Yes, it is possible to use almost any ROM card.

[@GamePlayShare]

@@necro_ware Those year2K cards are easy to make. Could be an easy solution.

[@agentkruger]

👍👍👀👀✔✔

[@PiotrK2022]

@ Necroware Meh I prefer old noisy HDD because it souds so retro and nostalgic and I can't imagine Pentium or whatever old PC without it as well as without a flickering CRT...

[@necro_ware]

Whatever you like more, but I think at least it's good to know the options, don't you think?

[@PiotrK2022]

@@necro_ware Yes , I agree with u. I have no issues with that. I just share with my opition - that's all.

[@GamePlayShare]

Sometimes its not possible.

[@rel4325]

Hi,where did you buy CF-Adapter? i look everwhere to find like yours but no luck

[@necro_ware]

aliexpress, ebay, amazon - just search for "ide cf adapter"

[@rel4325]

@@necro_ware yea i try but all was diff of yours

[@mmg5205]

> ?t=365, BIOS rom scan address granularity dos info claims that BIOS rom scan should use 2K granularity, i never check the 2K value, but it looks true, for example whole XT system BIOS has only 8K size, not 16K (the tiny "XT system BIOS" does not support IDE or any other HDDs). XT/AT can not have different 2K/16K rom scan granularity, otherwise XT add-on cards will not work on AT.

[@orcunkokcu744]

You must be German 🤔 Since You really know how to explain such things 👀

[@necro_ware]

Well, not really, however I am livinig in Germany :) Anyway, I take it as a compliment, thank you very much!

[@OpenGL4ever]

Well, the solution might work, but on the other side CF cards are already getting obsolete. Personally, I would prefer another solution with e.g. M.2 SATA/PCI, but I haven't found an ISA controller for such old mainboards yet. For M.2 PCI, the controller would essentially have to emulate a PCI bus and then connect to ISA.

[@necro_ware]

You can buy sd to cf card adapter and you are good to go. Or simply sd to ide directly.

[@OpenGL4ever]

@@necro_ware I know. But SD cards usually have no wear leveling.

[@Beus38]

@@OpenGL4ever Wear leveling will anyway only work in OSes that support the SSD's TRIM function which is Win7 and later. Without it, any SSD is basically just reduced to the same flash memory. I heard there is a community-made driver for XP that adds support for that, and even a utility for DOS, but so far haven't dug deeper as I don't use SSDs in those computers.

[@Beus38]

@@OpenGL4ever Anyway, in a usual usage scenario, I expect that such an SD card will last longer than you need, I guess the amounts of writes to the same place will not be that high. I myself am using SD to CF adapters with SD cards in them but only started using them quite recently so cannot tell any long-term results. However, you can always take a SATA SSD (or a mSATA/M.2 SATA disk with an adapter to 2.5" SATA format) and connect it to IDE through any of these IDE to SATA adapters which are in abundance and for nearly nothing on ali/amzn.

[@OpenGL4ever]

@@Beus38 I know, but the trick is, to put the SSD in a modern machine once in a while. Or as you said, use special tools for this job.