Help Getting XT-IDE and HD Floppy Controller Working on Vendex 888-XT

[chjmartin2]

Hi,

I have a Vendex 888-XT and would really like to be able to use an XT-IDE in it and access high density floppy drives. Let me tell you a little about this XT Class machine. It is an odd system to say the least. The "motherboard" really consists of a backplane, and two full length ISA cards. One card has the CGA card on it and system memory and the other card has the 8088, ROM. The backplane has a floppy disk controller connector, and a serial and parallel port.

When I install the XT-IDE, it does recognize the boot rom and shows the details, but it will not recognize any compact flash drive, even ones that I know for sure work because I plug them into a different XT class machine and they boot perfectly and easily.

I am using a Gotek with Flashfloppy on it and I can use it fine with the machine with the built in floppy controller at 360k/720k. I plug it into the on-board floppy controller and I am off to the races. There is NO dip switch setting to disable the on-board floppy controller. When I install the high def controller (It is a combo serial port/floppy controller based on Serjey's design) it again recognizes the ROM and I can get into the set up. Here is where it gets weird, if I plug in the on-board floppy, when it tries to boot it tries to load from BOTH the on-board and from the ISA card floppy controller. Enabling the secondary floppy controller doesn't help, although I am not sure I have the right cable for that.

So, I have fiddled with settings, etc. and I can't use the XT-IDE utility to program the card on this computer but like I said, it does recognize the boot rom. I have fiddled with all of the settings on the gotek and what I can change on the HD floppy controller and nothing works. They BOTH work just fine in a second XT that I have.

In desperation I got out my eprom writer and erased the EPROM and wrote out the Generic Turbo XT BIOS, which, did speed up the boot but didn't make either peripheral work.

So, any ideas on what to try next? Is it possible that there is simply no way to make this work? I guess I could just live with the Gotek in 720k mode, but man that feels like giving up. Ideas?

Chris

 

[chjmartin2]

Anybody have any experience with these? https://www.drem.info/

I figured if I can get an old RLL/MFM drive working on the machine than I could get one of these. I have an old hard-drive and I am going to try it. Not sure how reliable/working it is, but will give it a whirl.

 

[hmb]

Anybody have any experience with these? https://www.drem.info/

Yes, I have several of these DREM hard drive emulators. A DREM will (once configured) emulate virtually any MFM hard drive make and model with a standard ST506 interface. It is relatively expensive, therefore I wouldn't suggest buying one until you are certain you can get a standard PC MFM hard drive card (connected to an old but real MFM drive) working in your 888-XT. If you get that working, you can replace the real MFM drive with a DREM.

 

[modem7]

Let me tell you a little about this XT Class machine ...

And the photos at [here] help me too.

When I install the XT-IDE, it does recognize the boot rom and shows the details, but it will not recognize any compact flash drive, even ones that I know for sure work because I plug them into a different XT class machine and they boot perfectly and easily.

You have a known working XT-IDE/adapter/CF combination. So as not to introduce variables, you move the entire known working combination to the Vendex (which if required, includes attaching a power cable to the adapter). The XTIDE Universal BIOS (XUB) within the boot ROM presents on-screen, but to the right of 'Master at 300h:' is either nothing or gibberish. All of that together, screams 'conflict of I/O ports' (see [here]) at me.

So, I have fiddled with settings, etc. ...

Does "fiddled with settings, etc." include changing the I/O port range used by XT-IDE card (jumpers/switches, plus reconfiguration of XUB to reflect the new I/O port range) ?

.. and I can't use the XT-IDE utility to program the card on this computer ...

Provide detail.

 

[modem7]

I am using a Gotek with Flashfloppy on it and I can use it fine with the machine with the built in floppy controller at 360k/720k. I plug it into the on-board floppy controller and I am off to the races. There is NO dip switch setting to disable the on-board floppy controller. When I install the high def controller (It is a combo serial port/floppy controller based on Serjey's design) it again recognizes the ROM and I can get into the set up. Here is where it gets weird, if I plug in the on-board floppy, when it tries to boot it tries to load from BOTH the on-board and from the ISA card floppy controller.

If the ISA card floppy controller ('high def controller') and the Vendex's on-board floppy controller are using the same range of I/O ports (i.e. which is a conflict of I/O ports), then both controllers are going to respond to commands from the BIOS.

 

[modem7]

When I install the high def controller (It is a combo serial port/floppy controller based on Serjey's design) ...

Looking online, that will be the 'ISA Floppy Disk and Serial Controller' card detailed on the web page at [here].

Enabling the secondary floppy controller doesn't help, ...

That is expected.

Background:

* The code in the BIOS expansion ROM of Sergey's 'ISA Floppy Disk and Serial Controller' is the same as that used for the XT-FDC card.
* SECONDARY CONTROLLER - SOFTWARE SUPPORT: That code has optional support for 'secondary floppy disk controller'.
* SECONDARY CONTROLLER - HARDWARE SUPPORT: The XT-FDC card has switches/jumpers to control whether the card is a primary or secondary floppy controller.

Issue:

HARDWARE SUPPORT: Sergey's 'ISA Floppy Disk and Serial Controller' lacks switches/jumpers to make it a secondary floppy controller.

Is it possible that there is simply no way to make this work? I guess I could just live with the Gotek in 720k mode, but man that feels like giving up. Ideas?

An XT-FDC card may work. Note my use of "may". For example, is the secondary range of I/O addresses going to conflict with something in your Vendex ?

I have no experience with floppy controllers configured as secondary, but there are members here who do have.

I see at [here] a reference to a possible issue in sharing the IRQ (interrupt) and DMA channels between primary and secondary floppy controllers.

 

[chjmartin2]

And the photos at [here] help me too.


You have a known working XT-IDE/adapter/CF combination. So as not to introduce variables, you move the entire known working combination to the Vendex (which if required, includes attaching a power cable to the adapter). The XTIDE Universal BIOS (XUB) within the boot ROM presents on-screen, but to the right of 'Master at 300h:' is either nothing or gibberish. All of that together, screams 'conflict of I/O ports' (see [here]) at me.


Does "fiddled with settings, etc." include changing the I/O port range used by XT-IDE card (jumpers/switches, plus reconfiguration of XUB to reflect the new I/O port range) ?


Provide detail.

So this did it, what i didn't try was changing the I/O port range and moving from 300/308 to 320/328 solved my issue and now it boots! I really didn't think that the I/O port could be it so shame on me for not trying that sooner. So, now one problem solved. I have no idea what is on the system that is using 300 but something is. I had gotten an old MFM hard drive running so I knew a hard drive could boot. Thanks for asking specific to the I/O. I couldn't get the config program to work on the machine so I did it off-line and burned the ROM and that updated and worked great!

 

[chjmartin2]

Yes, I have several of these DREM hard drive emulators. A DREM will (once configured) emulate virtually any MFM hard drive make and model with a standard ST506 interface. It is relatively expensive, therefore I wouldn't suggest buying one until you are certain you can get a standard PC MFM hard drive card (connected to an old but real MFM drive) working in your 888-XT. If you get that working, you can replace the real MFM drive with a DREM.

So I did just that and got my ST11R working along with a Seagate HD. The HD is clearly on its way out, but it booted. Anyway, I was able to get the XT-IDE working by changing the I/O address. But I still think this looks like a cool device.

 

[dhau]

Did you try different addresses for the XT IDE bios? Like c000, c800, d000, d800?

Also, if you boot from a floppy with something like checkit, what do you see in memory map?

I think you should try some generic Phoenix XT bios and see if this fixes your issues. If it does, you can dig more into the original bios to figure out what is wrong.

 

[modem7]

Did you try different addresses for the XT IDE bios? Like c000, c800, d000, d800?
Also, if you boot from a floppy with something like checkit, what do you see in memory map?

No need. The XT-IDE problem was resolved. See post #7.

I think you should try some generic Phoenix XT bios and see if this fixes your issues. If it does, you can dig more into the original bios to figure out what is wrong.

Regarding the floppy part of this thread, the OP's desire is for the use of HD floppies/diskettes.
According to the OP, the built-in floppy controller hardware does not support HD operation, and that controller cannot be disabled.
That points to a couple of possibilities:
* The addition of a 'secondary' type floppy controller to the computer, one that supports HD operation, together with suitable software/firmware.
* A parallel port connected 3.5" disk drive, together with its matching driver.