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8-Bit IDE Controller

Today I got in my snail mailbox the naked XTIDE PCB I bought from lynchaj.

It's beautiful, man!

Now, it's time to practice my soldering skills on some "collateral damage" boards...
 
glad to see this round of cards is starting to hit their targets.
Good luck with the builds and let us know if you do anything interesting with them: PATA->SATA converters perhaps, or rigging one up in a non IBM or oddball clone. There is an "XTIDE tech support" thread on this forum just in case you run into troubles, and the main wiki page has build instructions.
 
I got to mine today, and slapped it together. I had a junker 40GB pata drive laying around to test with and it sees it as an 8gb.
I made a 1GB partition and marked it active, but it failed at 4% into the format.
I'll bring in my compact flash drive tomorrow, (I forgot it) and try again. (It's only 512meg).

Thanks to everyone involved in this project!

Later,
dabone
 
Just so there's no confusion, 8G is the expected behavior. (that's a DOS limitation, not the card, but c'mon, you don't really need more than 8G anyway!)
You could probably set up multiple partitions and try formatting different sections until you get one that works. By junker I'm assuming that you think the drive is not exactly reliable, so the failed format might also be expected?
 
Probably a bad drive, I didn't have much time to test. I haven't been to work all week till today so I had a few things I needed to catch up on.

And I know 8gb is the limit, but I also wonder if it suffers to problem of corrupting drives because of the mapping. I'll check out the tech support thread to read up on the subject. The drive I tried was a Western Digital WD400JB and yes it was just laying around in all my junk on my bench.

My goal is a cf solution, I purchased the backplane ide/cf adaptor for this purpose.
You know, power off, yank the card, and load up new stuff on a modern pc.

Maybe this weekend I'll be able to sit down and play, my multi i/o with clock also came in today and I didn't even get around to opening it.
(Kinda sad to open it, it's still got the original shrinkwrap.)

Later,
dabone
 
Ok, today I tried a sandisk 512meg cf card and adapter, and after reading the support thread I decided to change my 40 pin cable to an 80 pin. The card would see the card in the bios but when I tried to fdisk, it reported error reading fixed disk. Then when I did a warm reboot (Ctrl-alt-del or the reset button) the card would not show up in the bios. It required a power cycle to be seen by the bios again. (The bios was reporting the correct info for the card).

So I was bummed, and decided to try another hard drive, but got the same error. Then I stepped back and worked on something else for awhile and remembered, I changed the cable!. I put the 40 pin cable back on and now everything is working great. Fdisk, format, and now booting off the cf. The transfer rate according to coretest is 158k a sec which is about 100k slower than the hardcard I have. (But seek times are great!).

Thanks again. Great card at a really cheap price. Now where did I stick my old copy of dosmenu??


Later,
dabone
 
Quick question, guys. (my apologies if this has been asked and answered, but there are 123 pages of postings here).

Why are the unused positions of RP1 and RP2 grounded? It would seem to be a waste of power and accomplish nothing? Why not leave them open (handy for wired patches)?

I know it's a nit, but I'm starting to solder mine up and this one made me scratch my head...
 
Hi Chuck! Those are a left over artifact from earlier design that should have been removed. They are harmless but waste power as you noted. You can cut the traces if you want or leave it as is. If/when there is another version of the XT-IDE, I'll clean that up.

Thanks and have a nice day!

Andrew Lynch
 
Hi Andrew,

I thought it might have been an oversight. It's a bad habit I have--as I solder, I mentally work out how a PCB works and sometimes things grab your attention. A bad habit I picked up...
 
Hi again, Andrew,

If you do decide to work on another version, a minor convenience might be to add a 4-pin header to the board to provide +12 and +5 for disk drive power on the board. I suspect that a fair number of people are using an IDE-to-CF adapter and a header for power might be appreciated.
 
Hi again, Andrew,

If you do decide to work on another version, a minor convenience might be to add a 4-pin header to the board to provide +12 and +5 for disk drive power on the board. I suspect that a fair number of people are using an IDE-to-CF adapter and a header for power might be appreciated.

Or, perhaps, in an IBM PS/2 Model 30 that has no power plug for a drive... ;)
__
Trevor
 
I was just wondering about throughput and looked at http://wiki.vintage-computer.com/index.php/XTIDE_TestResults where I found a figure of 85 Kilobytes per second which converts to 0.68 Mega bits per second unless I'm mistaken?

However even an old Future Domain TMC 850 8 bit SCSI card will give you around 5 Megabits per second whilst the ISA bus theoretical bandwidth is around 9.6 Mega bits per second!

I'm assuming 85KBs can't be right?
 
I was just wondering about throughput and looked at http://wiki.vintage-computer.com/index.php/XTIDE_TestResults where I found a figure of 85 Kilobytes per second which converts to 0.68 Mega bits per second unless I'm mistaken?

However even an old Future Domain TMC 850 8 bit SCSI card will give you around 5 Megabits per second whilst the ISA bus theoretical bandwidth is around 9.6 Mega bits per second!

I'm assuming 85KBs can't be right?

It's not the bus speed that's the issue. While the ISA bus can do megabytes per second, the 8088 can't possibly work that fast. Under 4.77MHz, one byte takes 4 clock cycles of 210nS (a little less than 1uS) to complete, and in addition it will take from 2 to over 100 cycles to execute the instruction. The 8088 is able to buffer 4 bytes while an instruction executes.

An instruction can be from one to six bytes long, and this is the real bottleneck of the 8088; It spends most of the time fetching instructions, especially during loops or branches. This is the reason why todays computers has at least three levels of cache.

In the 8088's case, it can move memory with the rate of about 350KB/s under optimal coding. The old version of the XT-IDE needed quite a lot of instructions to fetch a word, like shifting of register/etc., and that's why you only get 85KB/s. With the mod, one word can be fetched using only two instructions. After some calculations on saved cycles, I have concluded that the modded design should be able to reach 247KB/s transfer rate (with minor modification of the BIOS), which is about a x2.9 increase in speed.

This is about 37.7 cycles per word on average, where the two instructions fetching the word takes 30 of these. The old routine used 109.4 cycles per word on average.
 
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I am trying to restore my Tandy 1000 TL in a similar method to the process shown here but the TL is a bit more flexible a machine than the HX. Currently my TL HAS a hard drive in it, but it is an ancient 21 MB MFM RLL hard drive that is failing. I have two such drives. I want to replacwe that hard drive with a 512 CF Card, but I need an XT IDE hard disk card made for the TL. Would anyone be willing to assist me?
 
found this by accident

found this by accident

A few years back (2003, I think), a friend wanted to make an IDE controller for a PC. His dream was to make something like a SUPER PCjr. He was using either a Tandy 1000A or SX to do his testing, so as not to risk his PCjr. I got interested because my favorite PC has always been the Tandy 1000TX. I hoped if something turned up I could use it in my TX, also. He had some kind of rig in his Tandy that allowed him to use an IDE, but it only gave him around half of the rated capacity. As I recall, he had a 830mb hard drive that gave him about 400mb with his adapter.

Not too bad, I thought... much better than the 42mb I'd "shoehorned" into my TX! Just over a month later, John was dead. His family junked everything he'd worked on in an effort to assuage their grief.

Running across this thread brought my previous hopes back into focus. Unfortunately, my eyesight is no longer very good. I now run my TX with an 8-bit vga adapter card, and the biggest monitor I could find. I would dearly love to buy 2 or 3 of these XT class IDE cards (I've always believe in having spares of critical parts). They would have to be completely finished (soldered, flashed, etc) as I'd have trouble doing anything more than just installing it.

Sounds to me as though this would make a nearly perfect "hardcard" using a 2 1/2 inch IDE drive. I think the reduction in power consumption would help the longevity of any Tandy 1000-class machine.

thanks
Mike H
 
XTIDE cards work very, very well in all sorts of tandy machines, and give you approximately 8.4G of hard disk space, depending on what DOS version you are using.
There's not actually enough software written for this class of machine to fill up that much hard disk space, believe me, I tried.

we are sold out at the moment, but are working on the next generation of the card. send me a PM and i can get you into the queue for when the cards are available again.

We are also working on an actual PCjr version of the card, and that thread is here:
http://www.brutman.com/forums/viewtopic.php?f=1&t=180
 
Was there even 8GB of software made for XT-class PCs?

I have a few smallish (by today's standards) 2 1/2 and 3 1/2 hard drives. My thought was to limit myself to sub-512mb and hope XTree could deal with 4 128mb partitions.

I wonder just how many of my old floppies are still readable? Fortunately, there are several storage sites online for older XT-class software.

I suppose I'll have to start looking for one of the old keyboard adapters, but I haven't even seen one in 18 years, or so...

Thanks to everyone who's responded.
Mike H
 
Hello, i have installed XT IDE on my AMSTRAD 1512 for two years now and works fine. I have posted again here. I used a 2.2GB Hard drive. Now i want to install a Sound Blaster Pro card. But i have an address conflict issue. During installation it lets me choose between 220h and 200h. In what base address should i set XTIDE in order to work?
 
Hello, i have installed XT IDE on my AMSTRAD 1512 for two years now and works fine. I have posted again here. I used a 2.2GB Hard drive. Now i want to install a Sound Blaster Pro card. But i have an address conflict issue. During installation it lets me choose between 220h and 200h. In what base address should i set XTIDE in order to work?
Do you have the Blaster installation/configuration software? If so, it will offer you choices. Also, if you have access to MS's 'MSD'EXE' it will show you where your IRQ's, etc. are.
 
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