H89-Z37 done!

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

just finished building and calibrating my second H89-Z37 board (Norberto’s “new and improved” soft-sectored controller for the H-89). It’s working great. With a GoTek or even 3.5” floppy drive you can reliably store 640K on a single disk or image. It’s also highly versatile in configuring the drives. It can also interface to 8” drives. For a description of the drive jumper system see the documentation on the equivalent H8 board here (starting on P. 7):

https://koyado.com/heathkit/New-H8-Website/download/h37_67_v_1_1_jumper_definitions.pdf

 

 

Though this board is a 10-year-old design, it’s still a great performer. The floppy controller chip is the only part that’s a little challenging to find.  Todd recently posted a note to this group that a new batch of these blank PCBs are now available for assembly. I for one am a happy customer 😊

 

• Glenn

 

[Joseph Travis]

Very nice!  I imagine you could tap the STEP signal from the LED in order to create a sound effect for the GoTek drive if desired.

Joe

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[norberto.collado koyado.com]

Nicely done!  I put my heart on such controller design as the original Heath H37 was hard to find and parts became obsolete. Running the Z80 CPU at 8MHz, you can run this floppy controller at 2MHz to support High floppy densities (HD disks). 

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

You’re referring to 5-1/4” (1.2M) drives here, right?  those “look like” 8” drives from an electrical interface perspective?

 

• Glenn

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[norberto.collado koyado.com]

I did test with the 1.44M floppy and it worked fine. How ever the data transfer is still 256bytes per sector, so you do not get the 1.44M storage capacity. Perhaps with CPM-3 this is doable.

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Subject: RE: [sebhc] H89-Z37 done!

 

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