[vcf-midatlantic] H89 for museum; gotek?
billdegnan at gmail.com
Sun May 16 20:18:23 UTC 2021
Alex Bodnar donated an H89 to Kennett Classic. If someone wants to drive
here and take it before someone else claims it, it's yours. It is in the
free pile right now because I don't have time to work on it. Between the
two you verybwell may have spare parts to make one working system. Come n
On Sun, May 16, 2021, 1:44 PM Herb Johnson via vcf-midatlantic <
vcf-midatlantic at lists.vcfed.org> wrote:
> The subject of the Museum's H89 and the May workshop continues. I'm not
> discussing the GoTek.
> In short summary, it works but there's some problems. It is not ready
> for Museum operation. I did not have time, to work on the companion
> external floppy drive, but I am aware of certain problems with it. I
> counted the H89's in the Warehouse, there are several which I did not
> examine closely. I will follow up in due course.
> Thanks to Jeff Saltzman, he provided assistance and tools some bootable
> diskettes from the H89 he successfully was able to operate. Thanks to
> CDL for their tools and workspace. Thanks to the VCFed staff for their
> assistance and borrowing the Radio Club's Variac, and conducting me to
> the Warehouse to assess the H89's there.
> By "works", I mean I could boot a HDOS 40 track hard-sectored diskette
> to the HDOS prompt. But
> 1) two characters on the keyboard, I and K and J, produce odd results.
> So it's hard to operate the H89 if you can't "type" I or J or K. The H89
> has a CPU/computer board and a seperate terminal board, they are
> connected by a serial link. so the problem is more likely on the
> "terminal" side.
> 2) The drive and controller are single-sided 40 track and hard sectored.
> So only HDOS and CP/M disks for the Heath H89 in that format can be
> used. The drive initially did not spin disks well because the hub mech
> was gummed up. I disassembled, cleaned, relubricated that mech.
> 3) There's tantalum caps on the CPU board of the system which are
> running just at rated voltage (20 volts). From my experience, they are
> at risk of shorting and catching fire. They could be replaced with
> higher voltage ratings, or possibly the DC voltage can be reduced, or
> the H89 can be run at reduced AC voltage (below 120VAC which is
> at-the-outlet at InfoAge). These are known issues with known solutions.
> (Readers: there's no need to go nuts about diagnosing these problems.
> They are known to any H89 owner who does repairs. I'm not stumped. I'm
> just sayin', these are the results of a day's work. )
> The H89 as displayed, has a companion disk drive in cabinet. The drive
> in it matches the drive described in the H89. It has at least the same
> gummy-spindle problem. I did not power it up or work on it Saturday, I
> won't be there Sunday.
> In the warehouse are about six H89's, condition undetermined. Rumor is,
> some were provided as with issues. I did not assess their operating
> condition, I just counted them, they are stored where they should be.
> I emailed some details to Jeff Brace today, and put paper notes on the
> units for the Museum staff. I'll publish details on my Web site in due
> course. I may be able to work further on these items, to be determined.
> Regards, Herb Johnson
> Herbert R. Johnson, New Jersey in the USA
> http://www.retrotechnology.com OR .net
> preserve, recover, restore 1970's computing
> email: hjohnson AT retrotechnology DOT com
> or try later herbjohnson AT comcast DOT net
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