Norberto’s H8 Computer

 
 
 

This Web page is about my original H8 Heath computer which I bought in 1978. The original H8 Heath Computer was unstable due to the fact that all the backplane connectors were tin plated which caused bad connections. To improve this issue, I upgraded the backplane by using gold plated connectors. At such time I decided to also buy the T-H90 backplane from Trionyx due to its features. Later I decided to upgrade the Heathkit 8080A board with the Z80 board from Trionyx to be able to run the Z80-H at 10 MHz.  As time passed, I decided to design my own 256K memory board to be able to use the bank switching software from Trionyx. Then I designed the Super-Buffer board to be able to control the CPU speed, to control the 256K memory board, to be able to update the OS time clock and to be able to buffer the printer output into 512K of memory. Initially I was using a TTY-33 teletype printer on my H8 Heath Computer without any issues. I did try in using the H-9 terminal but the MTBF (Mean Time Between Failures) was so LOW. Finally when the H19 terminal was available, I did buy the one with the green screen.

In 1986 I decided to put into storage my complete H8 Computer system and it was until 2006 that I decided to take it out from storage. I was concern about the H8 Heath Computer on not responding, but on power-on it worked fine; I was excited to see it working. The next step was to power-on the H19 terminal and it also worked fine. Then I decided to power-on my 10MB hard drive connected to the Xebec controller, but it failed to work. The Xebec controller was still functioning, but the hard drive didn’t make it due to exposure to humidity changes since 1986.

The next step was to get new or restore floppy drives to read my floppy media which has been in storage since 1986. After acquiring several floppy drives from eBay, I was happy to at least be able to read about 98% of the floppy media. My main target was to recover the hard drive utilities to be able to add a new Winchester hard drive to the Xebec controller. I was lucky to recover all the   CP/M utilities sold by Quikdata, but failed to recover the HDOS utilities as well. Hopefully one of these days I will be able to find in eBay the Quikstor HDOS utilities. Afterwards I joined the SEBHC.ORG group which inspired me to design a new H8-Z67 controller and the H8/H89-Z67-IDE storage board. Also I’m working on the H89-Z67 controller design. This is done to enable the entire Heath Computer hobbyist that are still preserving the Heath computer history and to be able to boot from the IDE hard drives which are available at this time.

As this writing (dated 11/28/2010) the H8 Heath Computer and the H19 are still working as the day I bought them. The H8 is also booting CP/M and now HDOS from my CF cards.

Date and Time: April 26, 2016 10:32 PM

 

These pictures represents all the long hours I did spend on the design of the H8-Z67 and the H8/H89-Z67-IDE Storage Controller to be able to boot CP/M from two IDE drives or from two CF cards as shown.

Norberto’s H8 Restoration Project