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KAYPRO and KayFreHD as a hard disk module

Hi JB

Sorry for the delay answering this. I did the work with Frank on the FreHD Kaypro integration. We did original work with the Kayplus ROM but found that it was not always reliable. I am running a FreHD with my Kaypro 4/83 (so using a Z80 shim rather than expansion interface connector) and it works fine.

Rather than persevere with the Kayplus ROM, get the Advent version and give that a try.

Another point to note is that the Kaypro hard disk drivers expect the first drive to be drive 1. This means on the FreHD they need to be called HARD4-1 (not HARD4-0).

I can send you a copy of the VHDUTL for the Kaypro (I wrote it) if you PM me your contact details.
 
Thank you jaquinn very much for taking the time to answer me :)

This is what I thought, reading your remarks, here and on other forums / lists, Kayplus is the most interesting ROM but ultimately the least reliable to work with the FreHD.

OK, I changed the name of the disk image to HARD4-1, and, oh surprise it works a lot better.

Yes, for the VHDUTL thank you it's really super nice :) I want it, I give you my email in MP.

Thank you for your help.
 
I would also like to take my 4/84 Plus 88 in this direction with ROM enhancement and FreHD. Any different considerations given the Plus 88 upgrade in place?

I haven't budged the Z80 daughterboard loose but I suspect I may need to at some point.

IMG_2169.jpg
 
You will need a replacement ROM that supports a hard disk drive. The two that have been used on 4/84 machines are the Kayplus (from http://www.microcodeconsulting.com/z80/kayplus.htm) and Advent 84.

The Kayplus web site says that "Advent and Co-Power 88 RAM card support are supported" but I don't have either a 4/84 or a Plus 88 board to know what that really means.

Your machine does have the 40 pin expansion connector so you can attach the FreHD - 4/84 type adapter that Frank S posted about earlier in the thread.

I would be interested to hear how you get on.
 
Formulator, I can't see any details in you photo, but if your 4/84 has the Kaypro standard "universal" ROM 81-478 then you already have hard drive support. If not, you could also use 81-478 as another replacement/upgrade ROM.
 
jaquinn said:
You will need a replacement ROM that supports a hard disk drive. The two that have been used on 4/84 machines are the Kayplus (from http://www.microcodeconsulting.com/z80/kayplus.htm) and Advent 84.

The Kayplus web site says that "Advent and Co-Power 88 RAM card support are supported" but I don't have either a 4/84 or a Plus 88 board to know what that really means.

Your machine does have the 40 pin expansion connector so you can attach the FreHD - 4/84 type adapter that Frank S posted about earlier in the thread.

I would be interested to hear how you get on.
Click to expand...

I didn't think anyone had the FreHD working reliably with the KayPlus ROM.
 
Alphasite said:
I didn't think anyone had the FreHD working reliably with the KayPlus ROM.
Click to expand...

It has been a while so I went back through the email to work out why we jumped from Kayplus to Advent.

The issue was not that it didn't work with the FreHD as a hard disk drive...... the problem was that tools like M80 and L80 did not work with the Kayplus ROM (at least in our experience). This was the case if run off the FreHD or from diskette.

I also had some feedback that existing from MBASIC did not perform a warm boot and any subsequent command would fail.

Given that Advent was available and did work with M80 and L80 we changed to that as the default.

There may be an answer to the Kayplus issues but we didn't chase it. Perhaps someone else wants to.
 
So I am getting to this thread late I realize. I just bought 3 of the Kaypro FreHD adapters of geneb's Design from OSH park. And I contacted Ian Mavrik and ordered a couple FreHD adapters from him as a build your own kit. I reached out to geneb about what components are needed to populate the kaypro adapter board but its been a long time and he doesnt have the info anymore.
Can someone please let me know the component list needed to populate Geneb's OSH park kaypro adapter board? https://www.oshpark.com/shared_projects/8UOxQcmf

Also as Jaquinn just posted, I was curious about which ROM to Use and I guess the answer is still the Advent ROM

Edit: I have two Kaypro 4/84's I would like to install these into.
 
VERAULT said:
So I am getting to this thread late I realize. I just bought 3 of the Kaypro FreHD adapters of geneb's Design from OSH park. And I contacted Ian Mavrik and ordered a couple FreHD adapters from him as a build your own kit. I reached out to geneb about what components are needed to populate the kaypro adapter board but its been a long time and he doesnt have the info anymore.
Can someone please let me know the component list needed to populate Geneb's OSH park kaypro adapter board? https://www.oshpark.com/shared_projects/8UOxQcmf

Also as Jaquinn just posted, I was curious about which ROM to Use and I guess the answer is still the Advent ROM

Edit: I have two Kaypro 4/84's I would like to install these into.
Click to expand...

I would recommend the Advent ROM. It works well from my experience.

Regarding components for Frank's design.... U1 and U2 are both 74LS00 from my email communications with him. C1 and C2 will be 0.1uf ceramic caps. From memory, R1 is a pullup resistor so 4K7 works well.
 
Well this past weekend I got my Kaypro 10 working with FreHD. Many thanks to jaquinn and TRS-Ian for sending some files I was missing. Once I had everything, it all went pretty smoothly. Now I just need to finish loading the software. Well that and build another FreHD since I used the one that had been on my TRS-80.
 
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Frank - Greetings from Texas USA. I could use two of these boards. I have two Kaypro 10 computers which I want to modify with the KayFreD modification. Please let me know regarding availability and cost.

Kind Regards,

Larry Green
 
So I am still getting all the components together to build my frehd and adapter modules. I do have a question, can someone recommend a good male/female power connector on ebay or wherever to use that would make disconnecting easy?
see image:IMG_20180704_122246595.jpg
 
On mine, I just soldered a short cable with a female floppy disk connector. On the next one I build, I may go with breakable pin header like the use with arduino's. Then make a cable for whatever my needs from there.
 
I used a floppy power cable Y-adapter. I cut off one of the connectors and soldered the +5 and ground to the adapter board. I use the other connector for the FreHD.
 
This is great news! I have a broken Kaypro 10 that doesn't have a HD nor a controller card. Perhaps I'll have the motivation to repair it now :)
 
I decided to try to get the Kayplus ROM working on my 10/83 with the SWP CO-POWER II board. I burned a 2764 EPROM and installed it in the 10/83 with the mods noted in the Kayplus manual. The Kaypro starts up and I can boot from floppy.

I had errors when I tried to format HD 1. I copied hard4-1 to hard4-0 and then tried again and it could see both drives and allowed me to format and verify both.

What I'm running into now is when I boot from floppy I can't access the hard drives. If I do a "DIR B:" the FreHD LED flashes but I get a BDOS error. I get a BDOS error and the FreHD LED doesn't flash.

Any ideas what I might be doing wrong?

I had the FreHD working just fine with the original 10/83 ROM. If I can't get this working then I'll try the TurboROM but I liked the idea of the RAMdisk in the SWP board working automatically with the Kayplus ROM.
 
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