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8 bit IDE (XTA) Replacement Project

I too am working on getting an 1110HD working. So far no luck.
The pic above confirms what I've found by probing the CP2024 drive. The DMA pins are oddball from IDE.
On starting the computer, the LED on the Pico flickers showing it's seeing activity.
This goes on for a few minutes and then the computer prints:

hard disk initialization failure has been noted...
Strike the F1 key to continue

It appears the Tandy BIOS is not getting the proper response and after some number of retries errors out.
The CP2024 uses the Cirrus CL-SH260 controller IC. Perhaps it's not register compatible with other XTA drives? I have the datasheet.
I've tried disconnecting the even numbered data and signal pins just in case. No luck there either.
Is there a way to have the XTA2SD log activity? It might help figure this out.
 
I too am working on getting an 1110HD working. So far no luck.
The pic above confirms what I've found by probing the CP2024 drive. The DMA pins are oddball from IDE.
On starting the computer, the LED on the Pico flickers showing it's seeing activity.
This goes on for a few minutes and then the computer prints:

hard disk initialization failure has been noted...
Strike the F1 key to continue

It appears the Tandy BIOS is not getting the proper response and after some number of retries errors out.
The CP2024 uses the Cirrus CL-SH260 controller IC. Perhaps it's not register compatible with other XTA drives? I have the datasheet.
I've tried disconnecting the even numbered data and signal pins just in case. No luck there either.
Is there a way to have the XTA2SD log activity? It might help figure this out.

Yes, you can use e.g. a logic analyzer, I use the Saleae logic 16 type, it is great. But it is very difficult to extract only the relevant bus signals. So I have developed a very special one with 32 signals and does only trigger and store datas if relevant bus signals changed. It does store 50000 events and does copy these datas on the SD-Card. These events are then copied to an excel sheet, where it can easily be investigated.

This is the Teensy Logger Board

1705163781715.png


and this is an example of a XTA2SD card booting

1705163847280.png


I have a few boards available.
 
I'm just scratching my head wondering how many people have never used an HP 16xx series logic analyzer
and are busy building their own.
32 channel analyzers were the absolute bottom of the line of HP's timing/state analysis products
 
A logic analyzer would only tell me what I can already get from the datasheet, register accesses. What I don't know is if those are the same as the ones in other drives like the ST325X in some Tandy 1000 models.
Does anyone know what controller IC the ST325X uses? Probably the same as the ST351A/X, which also has AT/XT capability like the Conner.
 
I've got an IBM Thinkpad 700C PS/2 which has a dead ESDI hard drive. But it's 2.5" with a 44 pin 'IDE style' connector.... Anyone have any suggestions as to how to make this fit!? Or of anyone knows of a 2.5" variant....?

Thanks!
 
Hi CallingElvis, I'm interested in an xta2sd card to install in a Zenith eaZy PC. I found this thread while searching for a solution to replace it's dead western digital HD since the motherboard doesn't have any isa or standard expansion ports
Anyhow, thank you for the project
Massimo
 
I've got an IBM Thinkpad 700C PS/2 which has a dead ESDI hard drive. But it's 2.5" with a 44 pin 'IDE style' connector.... Anyone have any suggestions as to how to make this fit!? Or of anyone knows of a 2.5" variant....?

Thanks!
@tubetimeus has a prototype replacement running.


 
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Hi CallingElvis, I'm interested in an xta2sd card to install in a Zenith eaZy PC. I found this thread while searching for a solution to replace it's dead western digital HD since the motherboard doesn't have any isa or standard expansion ports
Anyhow, thank you for the project
Massimo
Please check which HDD drive is installed. I have no information of the HDD bus of the Zenith eaZy PC. Just have to check if the XTA2SD will work.
 
it's a western digital model WD93020-XE2-10 and it's connected with a 40 pin ide cable.
 

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@CallinElvis - If you get one of these going for a Tandy 1000 RLXB or Tandy 1000 TL/2, I'd be more than happy to test them and/or help with materials cost, testing, etc. Please let me know. Those are the two systems I have that currently use those XTA drives.
 
I'm just scratching my head wondering how many people have never used an HP 16xx series logic analyzer
and are busy building their own.
32 channel analyzers were the absolute bottom of the line of HP's timing/state analysis products
I'm curious as well but don't want to hijack this thread. From 1980, when I was hired to do the 6809 ICE, until I retired a couple years ago, I had about seven different types of jobs but my cube never strayed more then 50 feet:) The 1610 and 1615 were the first LAs I used.
 
Lol. Even today, 30 years after the 1660 series was introduced, the best/fastest logic analyzers are only beginning to approach the 1663's HW performance. Then again, they are aboiut 100x cheaper. Of course, SW and ease of setup is a very different story. I actually haven't looked around much, but with a moderate amount of driver effort it's probably feasible to connect some of today's FPGA based LA SW to the 1663 and get the best of both worlds.

Before I retired I was very active in JEDEC, helping to define the DDR5 specification and Keysight's LA, scope, and EDA tool support for DDR5. For the past few years Keysight has been the last man standing in the high end LA business. The latest version (N4164A) is a sixth-generation HW and SW descendent of the 16500 and was instrumental in getting DDR5 and controller silicon out the door. It's still a huge market (I can't disclose exactly, but think in terms of tens of millions of dollars just for analyzers).
 
It was around 1977 or so that the rep from Electro Rents dropped by with a 1615 logic analyzer to try out. I was blown away by how simple it was to use (we already had the Tek 7D01 plugin for our scope). Still have fond memories of the thing. There were several LA manufacturers then--I think we also had a Biomation unit.

Then came the 80s and simulation was big. I recall Zentec(?) being one offering very expensive units.

Now it's all licensed cores and VHDL...
 
Is the XTA2SD available as a purchasable product/kit right now? Are there schematics/code available? If not, what would it take to get one? (I'm not afraid of a bit of soldering if needed... ) I have a couple of Tandy 1110hd machines that I'm planning on making a project of getting at least one working machine out of. I know that combination hasn't worked yet to date, but the idea looks promising.

I'm also wondering if emulating a 20mb disk exactly has been tried on that hardware combination. I came across a thread suggesting that might be a hard requirement on the 1110hd.
 
I have a very few plug and play PS2XT2SD cards included SD-Card for IBM PS/2 PS/1 to give away for 75 € plus shipping.

This card adapted a HDD and has the same function, any of the HDD type of the IBM BIOS can be chosen. Maximum is type 09 with 112 MB.

The image is stored in a file system on the SD-Card, data exchange has to be done with floppy or XT-IDE card.


View attachment 1246115
Is this still available? I need this to replace a PS/1 2011 HD..... In fact I need 2 .... the second one is to replace a HD from a Zenith Eazy PC that uses a hd 20 MB Winchester (XTA)
 
So, I was able to get an XTA2SD to function on a Tandy 1110HD with a big caveat. I couldn't get it working without patching the BIOS. Thankfully, both 1110HDs that I have use a socketed ROM of the AM27c256 variety (32k). Jameco had a few available still when I looked. I spent a few days digging around in the ROM with Ghidra trying to figure out what was going on. (I plan to do a more detailed write up on this soon.) There are three int 13h calls in the bios during the hdd process startup functions ah=10h, 09h, 11h called in that order. I haven't figured out exactly what those commands are sending to the drive but they all fail. Disabling (replacing the INT 13h call with CLC, NOP) them let's the XTA2SD just work, I was actually started when the machine booted out of the blue on me. That said, this approach is not for the faint of heart, requires expertise patching and burning a ROM, and likely has negative side effects I haven't discovered just yet. I would not recommend it except as a last resort.

Sha sum of the extracted ROM:
Code:
jules@metal tandy % shasum ./1110hd_bios/raw/bios.bin
2d55c362b6916d65be903ba4063095062f2bfaca  ./1110hd_bios/raw/bios.bin


Diff:
--- ./orig.hex    2024-05-28 01:54:01
+++ ./tandy/bios-works-patched-all-three.hex    2024-05-29 11:07:14
@@ -1282,9 +1282,9 @@
 00005010: 24fe c706 6c00 0000 bb9f 043d 3412 7503  $...l......=4.u.
 00005020: bb5a 00e4 21eb 0024 fee6 21eb 005a 33c9  .Z..!..$..!..Z3.
 00005030: 80ca 8080 fa80 7403 b90a 0080 ca80 b410  ......t.........
-00005040: cd13 730b 391e 6c00 7203 eb5b 90e2 ecb4  ..s.9.l.r..[....
-00005050: 09cd 1372 52c6 0644 0001 c606 4500 00b4  ...rR..D....E...
-00005060: 11cd 1373 00fe 0675 00fe c2f6 c201 7505  ...s...u......u.
+00005040: f890 730b 391e 6c00 7203 eb5b 90e2 ecb4  ..s.9.l.r..[....
+00005050: 09f8 9072 52c6 0644 0001 c606 4500 00b4  ...rR..D....E...
+00005060: 11f8 9073 00fe 0675 00fe c2f6 c201 7505  ...s...u......u.
 00005070: 8006 7700 04fe 0e75 00e4 21eb 000c 20e6  ..w....u..!... .
 00005080: 21eb 00c6 0677 0000 8a0e 7500 ba23 03b0  !....w....u..#..
 00005090: 0081 e1ff 00ee eb00 7405 83c2 04e2 f6ba  ........t.......


To make that a bit more clear:

Screenshot 2024-05-29 at 10.48.57 PM.png
Left hand side is the original right hand side is the patched version.

There are probably negative implications to this approach, so I can't exactly recommend it. But, it proves that there shouldn't be a hardware reason the card wouldn't work in the Tandy 1110HD. (Note: The adapter cable for this is also a pain and and a half to build, the XTA2SD and the main board use a different pitch connector so I had to use the smaller pitch ribbon cable, split it conductor by conductor on one end and attach it to the larger connecter one by one. It worked, but you'll need a steady hand, or an adapter board of some kind.)
 
So according to Wikipedia, Int 13h, function 10h is "is the drive ready?", 09h is "Initialize disk controller" and 11h is "Recalibrate drive".

Is this a situation where the XTA2SD simply doesn't support these calls because it doesn't need to?
 
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