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8-Bit IDE Controller

gerrydoire said:
I just used an IDE<>CF Connector, and used it like it was a regular hard drive.

I think you have to use Type1 cards only, I haven't tested more than 2 cards yet.

With a 2gig 80x card, it would read and write to the card, but refused to boot from it.

I have a few more type1 size cards comming in the mail to try out.

I think if you can have two 512meg cards on a PC or XT you have more space than you will ever really need.
Click to expand...

I have an ide ADP50L adapter, my type one CF 512 MB card type one do not work very stable. My 2 GB type II CF work like a charm on my PC XTRA, with reduced size.

However i have discovered that CF card do not generally like the main DOS OS FILES and MBR to be written more then once without a lowlevel format.

JT
 
lynchaj said:
Excuse Me? How much hardware, software, money, or time have you personally put into this project?

You are in no position to demand anything.

Andrew Lynch
Click to expand...

I'm the Ayatollah of Rock n' Rollah, that's why!!

:yesmaster:
 
No, actually you are just contributing to the nosie problem around here.

Time for a time out ...
 
BIOS successes today.

Multiple HDDs work now. Tested a few differently sized drives and both drives ID in POST and are able to fdisk, format and copy files as expected.

...and...drumroll please...

Enhanced INT 13 support is now working! I just got finished formatting a 250G* hard drive and it booted fine, and after copying a bunch of files over to it from drive D:, I then moved it onto my modern test system and it booted there too.

the format took close to an hour and half to complete, and that's on my 486-33 machine. I can't imagine what it's going to be like on a 4.77MHz box. I think it's a very, very good thing that you can prep a hard drive on a modern machine and then move it over to the XT.

I've stubbed out eINT13 verify command for now, but the basic routines of presence check, get drive params, read and write all work as they should. I should probably copy a bunch of files over to the drive on another machine and try to read back something that is way out on the drive just to make sure, but so far everything is working perfectly.

Next up, CD-ROM identification and CF support. CD-ROM will require an entire drive to be written, so CF will likely get my attention first.


-----------
* some notes:
1) In order to use eINT13 support, you need an O/S that uses it. I used win98SE DOS to fdisk and format the drive. DOS 6.22 will only see 8.4G, and will only allow partitions to be 2G in size. I do not know if win98SE DOS will work on an 8088 processor.

2) win98 DOS has some display bugs. My 250G drive showed in FDISK and format as only having 65533MB available. After formatting, I have ~130,405.59MB free. (I have some files on it, so I'm not sure of the exact size at the moment) Anyway, these appear to be cosmetic bugs only.

3) the reason a 250G drive is only ~130G is because we've only got 24Bit addressing available in LBA mode. It would require 48Bit LBA to break that barrier. It's possible to add support for that in the BIOS, and I likely will do it just for kicks, but it won't be done til a rainy day. 137G is enough for an 8088 machine!

Gerry, these notes are the kinds of things that should go into the PDF documentation for this card when it's ready for production. I'd like to put up a wiki somewhere for it too. I think these types of questions are going to come up often.
 
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From a command prompt W98/SE FDISK and FORMAT do indeed report drive sizes >64GB incorrectly (64GB less than actual); a replacement for FDISK is available from Microsoft:
http://support.microsoft.com/?kbid=263044

Format is initially incorrect, but the final size is correct; AFAIK there is no fix from MS:
http://support.microsoft.com/?kbid=263045

BTW, although I don't think I'll have any use for this project, I nevertheless take my hat off and kudos to you guys for making it a reality!
Great stuff!

mike
 
@hargle
sounds like to good to be true ... but is true.

this room is on fire now, hargle

two thumbs up!!
 
Today I found the n8vem project on "hackaday" which led me to discover the XT-IDE files there.

And that led me to this project here on this forum.

I think its really cool what you have done with the extended bios rom for this interface.

When I created the XT IDE interface I was using a 386 as a host for development (way back in 1997) with the target of an embedded 80c188 microprocessor board.

This board had its own task switching kernel so doing anything in DOS wasn't in the cards.

With a 10mhz XT I was able to read at about 20k-bytes per second, if memory serves.

(wire wrap proto card)

Anyway, cool that you guys are using this thing.

BTW, xtide.c compiles with Turbo C 2.01 which can be had for free here:

http://altd.embarcadero.com/download/museum/tc201.zip
 
Terry Yager said:
Scott Christensen...hmmmn, why does that name seem familiar?

--T
Click to expand...

Hi Terry! There is a Ward Christensen of XMODEM fame. He is/was pretty famous in the CP/M and vintage computer community.

Scott, are you related to Ward Christensen?

Thanks and have a nice day!

Andrew Lynch
 
Scott, do you still have an XT/PC? I'd very much like to send you a complimentary board of this design when we're finished with it.

The entire project will be open source: schematics, layout, BIOS, drivers, and even the BIOS flash update program. I'm not quite ready to unleash this BIOS onto the world source-wise just yet, due to some cleanup and further debugging that we're doing. There's also no revision control yet.

We need a wiki and some other webspace to host such source+binaries.

I have some spaces that I could use, but they aren't exactly vintage-computer related domain name wise, so maybe I might be able to convince one of the folks here to do a little subdomain hosting for it. Anyone?
 
I spent most of the weekend trying to locate my CF to IDE adapter. Couldn't locate it at all. I'll have to pop onto ebay or pick one up locally. User justjunk here has sent me a CF card for testing, so I have a couple of them that I can play with whenever I get an adapter.

I did get CD-ROM drives to ID during POST now. There's a ton of work to do there making a driver, but at least we can prove out that we can transfer a little bit of data off of ATAPI devices now too.

that's all from this corner of the world.
 
even though I seem to be talking to myself here lately, here's the latest status on the project:

1) Andrew sent me a wire-wrapped prototype board, so now each of us have our own test platform to work with. It's a work of art. The wire wrap stuff is really fascinating to look at, but it's functional too!

2) I got the BIOS flash program working, so now we have a software means of updating the BIOS in case of bugs or new features. It's by no means finished, but it is functional.

3) I'd been developing all of my code on a 486 test platform, but last night I dropped the card with my latest BIOS into an actual XT, and the machine signed on and detected the drive exactly like you'd expect it should. It didn't boot, but that's because I haven't been hooking INT 19 (oopsie!) that would enable booting. That should be a pretty easy fix to make though, and then I can give a full status report about performance and interoperability.

All in all, we are making really good progress in getting this card up and running.

I think the next step would be to do a very small run of PCBs (5 or 10) and get some components soldered down. Those cards will then become the next debug platforms and we will distribute some cards to a few others who might be willing to help out in debugging and regression testing to get the BIOS in shape.

If we don't find any major respin issues on the PCB, then it'll be production time! I don't know the ETA of any of these things.
 
hargle said:
even though I seem to be talking to myself here lately, here's the latest status on the project:

1) Andrew sent me a wire-wrapped prototype board, so now each of us have our own test platform to work with. It's a work of art. The wire wrap stuff is really fascinating to look at, but it's functional too!

2) I got the BIOS flash program working, so now we have a software means of updating the BIOS in case of bugs or new features. It's by no means finished, but it is functional.

3) I'd been developing all of my code on a 486 test platform, but last night I dropped the card with my latest BIOS into an actual XT, and the machine signed on and detected the drive exactly like you'd expect it should. It didn't boot, but that's because I haven't been hooking INT 19 (oopsie!) that would enable booting. That should be a pretty easy fix to make though, and then I can give a full status report about performance and interoperability.

All in all, we are making really good progress in getting this card up and running.

I think the next step would be to do a very small run of PCBs (5 or 10) and get some components soldered down. Those cards will then become the next debug platforms and we will distribute some cards to a few others who might be willing to help out in debugging and regression testing to get the BIOS in shape.

If we don't find any major respin issues on the PCB, then it'll be production time! I don't know the ETA of any of these things.
Click to expand...

Hi! Thanks! Good to hear the prototype is working. When you are ready, please post the BIOS updating utility and I'll use it on my prototype so we can get more testing. I've been busy on the workbench with the N8VEM 6809 host processor but if there is something specific I can do to help with the testing please let me know.

Your work on the BIOS update utility is critical since it minimizes remove and replace cycles on the prototype. Even with a ZIF, they are rather delicate and I prefer to leave them alone as much as possible.

Your idea of making a small production run of prototype PCBs is very good. I'd be glad to help make a limited run of PCBs using the same method I use for N8VEM. Let me know what you'd like to do.

Before we do a small prototype PCB run we need to settle on if we want a PCB respin. I have about 4 small issues which could be fixed (presumably) in a respin but that'll add another 3 weeks at least. I recommend extremely thorough testing of the two prototypes and shaking down the requirements one more time to get in all the PCB changes. PCB respins are time consuming so we have to be very selective as to if they are needed. Right now, I think the value of a respin is highly questionable but more testing may turn up something critical.

One of my 4 respin items is adding a bracket. Have you decided on whether you want a bracket? If so, which one? The PCB needs mounting holes if there is going to be a bracket and that affects the PCB layout. Would you send me a sample or at least a supplier part number so I can investigate what it'd do to the PCB layout?

Thanks and have a nice day!

Andrew Lynch
 
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