Older docs for H89 CF RTC board

[David Luna]

I picked up the 10/31/2023 version of the H89-CF-SERIAL-PARALLEL-RTC controller board at VCF East. I can only find the docs for the 2/15/2024 revision. Does anyone know where I can find the docs for the 10/31 revision? 

Thanks,

Dave

[Joseph Travis]

Hi Dave,

That was the first revision of the board of which there was only a handful built as it required some rework.  I'll gather up the necessary info and send it to you.  In the meantime, the instructions for the current revision will serve well.

Regards,
Joe

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[David Luna]

Thanks, Joe! Much appreciated. I've been using the current revision instructions so far and wasn't sure if the assembly notes, boot ROM, CF image were different.

[Joseph Travis]

Dave,

Below is a link to the H89-CF stuff on my google drive.  You'll want to download the 2 .zip files.  The first one has the documentation for assembly and operation of the board along with the CF Boot ROM image and CF images for a H17 only system and a H17/H37 system.  If you only have a H17, do not attempt to use the H17/H37 image as it will hang while searching for hardware that doesn't exist.

https://drive.google.com/drive/folders/1N52XWvszla3BXCXrYK88cLSyTkviYu01?usp=drive_link

The second file contains photos of the rework done to the board.  The first few photos are to change the bottom serial port from DCE (DB-25 female) to DTE (DB-25 male).  This change isn't necessary, it will work fine if you use the DCE cable.  The next photo(s) you'll see(with wires running lengthwise) is for the RTC (Real Time Clock).  If you don't plan on using a RTC (as it isn't really necessary), you don't have to do that rework.  The last photo(s) are the corrections to the parallel printer port and was easier to implement using a DB-25 breakout board.

If you choose not to implement the RTC and the parallel printer port, you don't have to install the bottom 8255 or other components associated with them.

BTW - If your H89 is using the 444-62 monitor ROM in U518, you'll need to use a 2716 EPROM for the H89-CF Boot ROM and a minor wiring change (on the CPU board) -or- upgrade to the 444-142 monitor ROM and 444-83 (memory decoder) ROM at U516.  That upgrade is only necessary if you are / plan to use the Z89-37 soft sector controller board.

Feel free to reach out with any other questions that you may have.  Good luck!

Regards,

Joe

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[Joseph Travis]

Dave,

Something else I forgot to pass along, the board edge connectors you will need are available from newark.com and they are SAMTEC P/N:

BCS-125-L-S-HE 

BCS-110-L-S-HE

BR,

Joe

[Joseph Travis]

Hey Dave,

Can you look at your H89-CF board and tell me if Q1 (2N3904) is located near the battery or near U3 (TL7757)?

If it is near the battery, your board is Rev 1.0.  If near U3, it is Rev 1.1.

Thanks,

Joe

[David Luna]

The board is labeled as Rev 1.1 and I have Q1 near U3.

I'm waiting on two ICs, but I have everything else put together. I'm hoping I'll be able to test next weekend thanks to your help, Joe.

[Joseph Travis]

Okay, in that case you do have the latest version and don't have to worry about any of the rework previously mentioned.  I apologize for the confusion.  Follow the assembly directions given and feel free to contact me if you have any questions.

BR,
Joe

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[Geo Monroe]

I finally was able to boot my H8 with HDOS 3.0 I was unable to find any hard sector diskettes so I created a board using a Microchip PIC to make a soft sector diskette look like a hard sector diskette. I was able to use the h89trans utility to send over a hdos 3.0 bootable image and have it written to a diskette using h89ldr .

--

[Glenn Roberts]

Great! Did you look at the VSG or HSFE hard-sector emulators at all or just start from scratch? Curious how your solution compares. Congratulations. Nice work.

Sent from my iPad

On Apr 22, 2025, at 6:15 PM, Geo Monroe <george...@gmail.com> wrote:



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<IMG_3062.jpg>

[Geo Monroe]

I checked and it seems there were no longer available or hard to get

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[Geo Monroe]

I wanted something that would work with my H17 unmodified.

[Geo Monroe]

I will look at the gotek

[glenn.f...@gmail.com]

You say “my H17 unmodified” but not clear if you mean the drives or the controller, or both. Since you mention Gotek I presume you mean the controller board.

 

To my knowledge there is still no firmware for a Gotek that allows WRITE capability using the H17 controller board, only READ. My understanding is that a R/O capability for H17 format is built into the HxC firmware for Gotek. https://hxc2001.com/index.html This may just be a “small matter of software” but to my knowledge nobody has taken that on.

 

As far as I know the Virtual Sector Generators are still available at https://deramp.com/vsg.html. I have no firsthand experience using these with the Siemens drives but speed fluctuation can be an issue with the device.

 

As far as I know nobody is currently stocking the PCboards for the original Hard Sector Floppy Emulator (HSFE) by Chris Elmquist (hsfe.pdf), however Norberto has built HSFE capability into his H17 controller board H8 H17 VDIP1 FSB and a few others.

 

The other option that some have taken is to punch index holes into soft-sectored floppy disks for use with the stock H17 drive and controller. There are a number of members on the list who have these punches and can speak to the results and/or possibly punch some disks for others.

 

If you’re willing to make an investment of time/$ it can be very worthwhile to upgrade (i.e. replace) your controller board to a soft-sectored (H37) controller.  H8-H37-H67-DISK-Controller. You can still use your H17 drives, though they’re likely the original single-sided and thus limited to 160K in soft-sectored use. Installing an old “PC” (e.g. 360K) drive would double that and you can go further with either a 96TPI drive or 3.5” floppy drive to get to double it again (about 700K per disk.) The Goteks also work flawlessly with the soft sectored controller board.

 

Blank PCBs are available for the above-mentioned “Norberto” boards from Todd Goodman and instructions are on Norberto’s website.

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[Geo Monroe]

The board I made connects the H17 Drive cable to the H7 Controller connector. I saw designs where they modified the H17 Controller board. I also looked to see if I could find a H37 or H47 controller for the H8

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[Geo Monroe]

My H8 is one of the originals The H8-H37 I was unable to locate 

[Geo Monroe]

I looked at the blank cards but some of the cards required PALs and other custom parts that I was unable to obtain

[norberto.collado koyado.com]

New H8-H37 here: https://koyado.com/heathkit/New-H8-Website/h8-h37-h67-disk-controller.html GALS file available to burn.

New H8-H47 here: https://koyado.com/heathkit/New-H8-Website/h8-h47-sdc-disk-interface.html I will need to load latest Gerber/GAL files. I will fix that tomorrow.

 

Norberto

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[Geo Monroe]

It looks like for the H17 the gotek is read only 

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[norberto.collado koyado.com]

Correct!

 

From: se...@googlegroups.com <se...@googlegroups.com> On Behalf Of Geo Monroe
Sent: Wednesday, April 23, 2025 6:52 AM
To: se...@googlegroups.com
Subject: Re: [sebhc] Older docs for H89 CF RTC board

 

It looks like for the H17 the gotek is read only 

 

[norberto.collado koyado.com]

H47 files updated. Still need to work on the BOM…. https://koyado.com/heathkit/New-H8-Website/h8-h47-sdc-disk-interface.html

 

Norby

.

[Mark Garlanger]

Has anyone in the group imaged the ROM chip on the master drive of the H47?

Mark

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[David Luna]

Hi Joe, 

Thanks again for all of your help. I finally built and installed the H89-CF card, but the system hangs after I enter Go 20000 at the H: prompt.

I flashed the H89-H17 CF.imgc image, but I don't have an H17 or H37 card. I only have the CDR Systems FDC 880H floppy controller. Is it possible that it's halting because of the missing H17? Is there a way around that, or do I need to get one?

Thanks,

Dave

[Glenn Roberts]

Did you burn an EPROM with the boot code and verify that it is there at 020.000?

Sent from my iPad

On May 29, 2025, at 8:55 PM, David Luna <lunab...@gmail.com> wrote:

Hi Joe, 

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[David Luna]

Yes, I burned the EPROM and verified the write with the software on my PC. Is there a further check I can run at the H prompt?

I also applied the jumper mentioned in the docs. 

Thanks,

Dave

[Joseph Travis]

Hey Dave,

Unfortunately, it's not going to work with the CDR FDC880.  The CDR controller required removal of the H17 boot ROM as it was replaced by their CDR8390 ROM, which happens to occupy the same socket as the CF boot ROM -and- there's no work around to make it compatible.

The easiest way to use the H89-CF board in your system would be to remove the CDR controller and its 3 ROMs and restore the CPU board back to the Heathkit ROMs and H17 (or H17 & Z37) controller(s).

I can get you the Heathkit ROMs and H17 controller if you need them.

Regards,

Joe

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[norberto.collado koyado.com]

Take out the H89 CF/RTC board and then type Go 020.000.

 

You should get the following message on the screen:

 

 

From: se...@googlegroups.com <se...@googlegroups.com> On Behalf Of David Luna
Sent: Thursday, May 29, 2025 7:20 PM
To: SEBHC <se...@googlegroups.com>
Subject: Re: [sebhc] Older docs for H89 CF RTC board

 

Yes, I burned the EPROM and verified the write with the software on my PC. Is there a further check I can run at the H prompt?

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